JP4966081B2 - Hydraulic fluid control device for work equipment - Google Patents

Description

  The present invention relates to a hydraulic oil amount control device that can avoid an insufficient hydraulic oil amount in a working machine driven by a plurality of hydraulic cylinders such as a crane truck.

  For example, a working machine driven by a plurality of hydraulic cylinders such as a crane truck includes a hydraulic oil tank that stores hydraulic oil supplied to the hydraulic cylinders (see, for example, Patent Document 1 and Patent Document 2). .

  By the way, in a working machine in which a working device is mounted on a vehicle such as a crane truck, the weight of the working device is increased due to the increase in size or the number of functions of the working device while the vehicle weight is legally restricted. There is a tendency. For this reason, in working machines, as one means for satisfying these conflicting requirements, the amount of hydraulic oil stored in the hydraulic oil tank is determined as the amount of hydraulic oil required when all hydraulic actuators including a plurality of hydraulic cylinders are driven simultaneously. Set a lower amount to reduce the vehicle weight by the reduced hydraulic oil weight, or divert the reduced hydraulic oil weight to increase the size or multi-function of the work equipment, within the legal vehicle weight range. Realization of larger size or more functions.

  However, when the amount of hydraulic oil stored in the hydraulic oil tank is limited in this way, naturally, depending on the operating status of each hydraulic actuator, a situation where the hydraulic oil amount becomes insufficient may occur. For example, in a hydraulic cylinder, the amount of hydraulic oil used is maximized in the fully extended state. Therefore, when several hydraulic cylinders are close to the fully extended state, another hydraulic cylinder increases the amount of hydraulic oil used. When it is operated to the side (that is, the extension side), it is conceivable that the hydraulic oil is insufficient in amount.

  However, an effective technique for avoiding the occurrence of such a shortage of hydraulic oil has not yet been proposed, and thus there has been a problem in terms of ensuring operational reliability of the work machine.

  Incidentally, in Patent Document 2, in order to avoid idling of the hydraulic pump and seizure due to leakage of hydraulic oil during operation of the working device, the total amount of oil used in the hydraulic cylinder and residual oil amount in the hydraulic oil tank is A technique has been proposed in which it is judged that the hydraulic oil is insufficient and a warning is issued when the oil quantity falls below a predetermined oil quantity (that is, the minimum oil quantity that does not cause idling or seizure of the hydraulic pump). This is a countermeasure for the shortage of hydraulic oil due to the leakage of hydraulic oil, and cannot be an effective means for avoiding the shortage of hydraulic cylinder amount of hydraulic oil that may occur depending on the operation state of the hydraulic actuator.

  Patent Document 3 proposes a technique related to an expansion / contraction mechanism that expands and contracts an expansion / contraction boom step by step with a single hydraulic cylinder. The operation of the telescopic mechanism will be briefly described with reference to FIG.

  FIG. 2A shows the fully contracted state of the telescopic boom 3. Here, the telescopic boom 3 is configured by inserting an intermediate boom 3B and a top boom 3C into the base boom 3A so as to be telescopic.

  A single boom telescopic cylinder 7 is fitted into the telescopic boom 3. The boom telescopic cylinder 7 connects the end of the rod 7B to the base end of the base boom 3A by a fulcrum pin 11, while the rod side end of the cylinder tube 7A connects to the base boom 3C by the connecting pin 12. It is connected to the base end. In this case, the connecting pin 12 can be selectively connected to the base end portion of the top boom 3C and the base end portion of the intermediate boom 3B (see FIG. 4D).

  When the telescopic boom 3 is fully extended from the fully contracted state, first, the boom telescopic cylinder 7 is extended. Then, by the extension of the boom telescopic cylinder 7, only the top boom 3C is extended while the intermediate boom 3B remains, as shown in FIG. Here, the distal end portion of the intermediate boom 3B and the proximal end portion of the top boom 3C are connected and fixed by a fixing pin (not shown), and both are integrated.

  Thereafter, the connecting pin 12 is removed from the base end portion of the top boom 3C, and the boom telescopic cylinder 7 is fully contracted (see FIG. 3C).

  Next, the connecting pin 12 is connected to the base end of the intermediate boom 3B, and the boom telescopic cylinder 7 is extended again. Then, as shown in FIG. 4D, the extension of the boom telescopic cylinder 7 extends the intermediate boom 3B together with the top boom 3C, so that the telescopic boom 3 is fully extended.

  Here, the base end portion of the intermediate boom 3B and the tip end portion of the base boom 3A are connected and fixed by a fixing pin (not shown), and both are integrated. Accordingly, the base boom 3A, the intermediate boom 3B, and the top boom 3C of the telescopic boom 3 are integrated in a fully extended state.

  Thereafter, when the connecting pin 12 is removed from the base end of the intermediate boom 3B and the boom telescopic cylinder 7 is fully contracted, the telescopic boom 3 is fully extended as shown in FIG. The boom telescopic cylinder 7 is positioned on the base boom 3A side in the fully contracted state. In this case, in consideration of the reduction operation of the telescopic boom 3, the connection state between the base end portion of the intermediate boom 3B and the boom telescopic cylinder 7 by the connecting pin 12 may be maintained. Thus, the extension operation of the telescopic boom 3 is completed.

  When such a telescopic mechanism is provided, only one boom telescopic cylinder 7 is provided, and when the telescopic boom 3 is fully extended, the boom telescopic cylinder 7 is fully contracted (that is, the amount of hydraulic oil used is reduced). For example, as shown in the configuration in which the telescopic boom 3 is expanded and contracted by a plurality of boom telescopic cylinders, each boom telescopic cylinder is fully extended (that is, hydraulic oil is used). Compared to the case where the amount of hydraulic oil is maintained, the amount of hydraulic oil used is small, which is advantageous in terms of reducing the amount of hydraulic oil stored in the hydraulic oil tank.

  However, even if this expansion / contraction mechanism technique is applied as it is as a technique for avoiding the shortage of hydraulic oil that may occur depending on the operation state of the hydraulic actuator, a useful effect cannot be obtained.

Japanese Utility Model Publication No.59-64891 Japanese Patent Laid-Open No. 4-238921 JP2003-2583A.

  Therefore, the present invention is based on the premise that the residual oil amount of the hydraulic oil may be reduced to near the lower limit value depending on the operating condition of the hydraulic cylinder, and if the residual oil amount is further restricted from being close to the lower limit value, From the standpoint that it is possible to avoid the occurrence of a shortage of oil, in a situation where there is a concern about the shortage of hydraulic oil, the operation of the hydraulic cylinder is controlled in a direction that further reduces the hydraulic oil. It was made for the purpose of avoiding the occurrence of a shortage of oil in advance and thus improving the operational reliability of the work machine.

  In the present invention, the following configuration is adopted as a specific means for solving such a problem.

  In the first invention of the present application, in a hydraulic oil amount control device for a working machine driven by a plurality of hydraulic cylinders, a residual oil amount acquisition means for acquiring a residual oil amount in a hydraulic oil tank; Compared with the lower limit value of the set residual oil amount, operation restriction signal output means for outputting an operation restriction signal when the residual oil amount falls below the lower limit value of the residual oil amount, and the residual oil when receiving the operation restriction signal Drive control means for outputting a drive control signal to the cylinder drive means for restricting the drive of the hydraulic cylinder in the direction in which the amount decreases is provided.

  According to a second invention of the present application, in the working oil amount control device for a working machine according to the first invention, the remaining oil amount acquisition means is configured to use a total oil amount used in each hydraulic cylinder and a working oil tank. The remaining oil amount is obtained by calculation based on the total amount of oil stored in the tank.

  In the third invention of the present application, in the working oil amount control device for a working machine according to the first invention, the residual oil amount acquisition means is configured to directly detect the residual oil amount in the hydraulic oil tank. It is a feature.

  According to a fourth invention of the present application, in the working oil amount control device for a working machine according to the third invention, the oil temperature of the working oil in the working oil tank is reflected in the detection of the residual oil amount. Yes.

  According to a fifth invention of the present application, in the hydraulic oil amount control device for a working machine according to the first, second, third, or fourth invention, one of the hydraulic cylinders is sequentially provided at a plurality of front end sides in a base boom. A telescopic drive hydraulic cylinder inserted into a telescopic boom formed by inserting the booms in a telescopic manner, the rod end of the telescopic drive hydraulic cylinder being pivotally supported by the base boom base end, The rod side end of the cylinder tube can be connected / released with the base end of the target boom, and the booms adjacent to the telescopic boom can be fixed / released. If the plurality of front-end booms are provided with a telescopic mechanism configured to be telescopically driven step by step with respect to the base boom, the telescopic drive is received when the operation restriction signal is received. It is characterized in that to reduce operating a use hydraulic cylinders.

  According to a sixth invention of the present application, in the hydraulic oil amount control device for a working machine according to the fifth invention, the hydraulic oil length control means for the telescopic drive hydraulic cylinder is provided, and when the operation restriction signal is received, It is determined whether or not the length of the drive hydraulic cylinder is equal to or less than a predetermined length set in advance, and when the length is not less than the predetermined length, the contraction operation of the telescopic drive hydraulic cylinder is executed.

  In the present invention, the following effects can be obtained.

  (A) According to the working oil amount control device for a working machine according to the first invention of the present application, the remaining amount of working oil in the working oil tank obtained by the remaining oil amount obtaining means, and a preset remaining oil When the amount of residual oil is reduced below the lower limit of the residual oil amount, an operation restriction signal is output from the operation restriction signal output means, and when this operation restriction signal is received, the drive control means Since the drive control signal is output and the hydraulic cylinder drive in the direction in which the residual oil amount decreases is regulated, the residual oil amount is further reduced in the state where the residual oil amount is lower than the lower limit value. Insufficient oil amount can be prevented in advance and reliably, and as a result, operational reliability of the work implement is ensured.

  (B) According to the working oil amount control device for a work machine according to the second invention of the present application, the residual oil amount acquisition means is stored in the total oil amount used in each hydraulic cylinder and the working oil tank. Since it is configured to acquire the residual oil amount by calculation based on the total oil amount of the tank to be obtained, the residual oil amount that changes momentarily with the operation of the work machine can be acquired continuously, Insufficient amount of hydraulic oil can be avoided more reliably, and the effects described in (a) above can be further ensured.

  (C) According to the working oil amount control device for a work machine according to the third invention of the present application, the residual oil amount acquisition means is configured to directly detect the residual oil amount in the hydraulic oil tank. The configuration and the control system of the oil amount acquisition means become simpler, and the effects described in (a) can be obtained at a lower cost.

  (D) According to the hydraulic fluid amount control device for a working machine according to the fourth aspect of the present invention, the following specific effects can be obtained in addition to the effects described in (c) above. In other words, in the present invention, since the oil temperature of the hydraulic oil in the hydraulic oil tank is reflected in the detection of the residual oil amount, the oil amount of the hydraulic oil changes in accordance with the volume expansion based on the oil temperature. Therefore, the remaining oil amount can be detected with higher accuracy.

  (E) According to the working oil amount control device for a work machine according to the fifth invention of the present application, in the working oil amount control device for a work machine according to the first, second, third, or fourth invention, One of the hydraulic cylinders is a telescopic drive hydraulic cylinder inserted into a telescopic boom formed by sequentially inserting a plurality of front end side booms into the base boom, and the telescopic drive hydraulic cylinder is a rod thereof. While the end portion is pivotally supported by the base boom base end portion, the rod side end portion of the cylinder tube can be connected to and released from the base end portion of the target boom, and adjacent booms of the telescopic booms can be connected to each other. It is possible to fix and release, and with a telescopic mechanism configured such that the plurality of front end side booms are telescopically driven with respect to the base boom by expansion and contraction of the telescopic drive hydraulic cylinder. When the operation restriction signal is received, the expansion / contraction driving hydraulic cylinder is contracted, so that, for example, the expansion / contraction driving hydraulic cylinder is held in a fully extended state by the contraction of the expansion / contraction driving hydraulic cylinder. Compared to the case of the configuration described above, the amount of residual oil increases by the amount of oil corresponding to the volume difference between the expansion side oil chamber and the reduction side oil chamber of the telescopic drive hydraulic cylinder, and it is suppressed that the oil amount becomes insufficient. Therefore, the effect described in (a), (b), (c) or (d) is further promoted.

  (F) According to the working oil amount control device for a working machine according to the sixth invention of the present application, in the working oil amount control device for the working machine according to the fifth invention, the length detection of the extension drive hydraulic cylinder is performed. When the operation restriction signal is received, it is determined whether or not the length of the expansion / contraction drive hydraulic cylinder is equal to or less than a predetermined length set in advance. Since the hydraulic cylinder is configured to perform the reduction operation, as the expansion / contraction drive hydraulic cylinder is reduced, the residual oil amount is increased by the reduction amount, and the plurality of oils in the direction in which the residual oil amount decreases. The hydraulic cylinder drive restriction is released, and the plurality of hydraulic cylinders can be driven.

  Hereinafter, the present invention will be specifically described based on preferred embodiments.

  FIG. 1 shows a crane vehicle Z as a working machine equipped with a hydraulic oil amount control device according to the present invention. This crane vehicle Z is configured by connecting a base end portion of a telescopic boom 3 to a swivel 2 mounted on the vehicle 1 so that it can be raised and lowered, and a jib 4 connected to the tip of the telescopic boom 3 so that it can be raised and lowered. Is done.

  The telescopic boom 3 is located on the base end side of the telescopic boom 3 and a base boom 3A whose base end is connected to the swivel base 2 side, and an intermediate part that is telescopically inserted into the base boom 3A. A boom 3B and a top boom 3C that is telescopically inserted into the intermediate boom 3B are configured to be raised and lowered by expansion and contraction of a boom raising and lowering cylinder 5 disposed between the base boom 3A and the swivel base 2. The Further, the telescopic boom 3 is telescopically operated by a telescopic mechanism (see FIG. 1) in which the top boom 3C and the intermediate boom 3B are expanded and contracted step by step with respect to the base boom 3A using a single hydraulic cylinder. 8). For this reason, a single boom telescopic cylinder 7 having a rod end connected to the base end portion of the base boom 3A is disposed in the base boom 3A. Further, the rod side end of the cylinder tube of the boom telescopic cylinder 7 can be selectively connected to and released from the base end of the intermediate boom 3B and the base end of the top boom 3C. Further, the distal end portion of the base boom 3A and the proximal end portion of the intermediate boom 3B, the distal end portion of the intermediate boom 3B, and the proximal end portion of the top boom 3C can be selectively connected / released, respectively. Such a configuration is as described above.

  Needless to say, it is also possible to employ a conventional general expansion / contraction mechanism, that is, a configuration in which each boom is expanded and contracted by the cooperation of a plurality of hydraulic cylinders and wire ropes.

  The jib 4 has a multistage expansion / contraction configuration, and is driven up and down by a jib hoisting cylinder 6 disposed between the top end of the top boom 3C. Further, the jib 4 includes a conventionally known expansion / contraction mechanism, that is, a plurality of built-in jib expansion / contraction cylinders 8 (only the proximal end hydraulic cylinder is shown in FIG. 1 for convenience of drawing) and each An expansion / contraction mechanism composed of a wire rope hung between the jibs of the stage is provided, and is extended / contracted by the cooperation of the expansion / contraction operation of each hydraulic cylinder and the tension operation of each wire rope.

  In addition to the hydraulic cylinders 5 to 8, a hydraulic oil tank 9 that stores hydraulic oil supplied to hydraulic actuators such as a hydraulic hydraulic motor for rotation and a hydraulic cylinder for the outrigger 10 is stored at the rear of the swivel base 2. Is provided.

  By the way, in this crane vehicle Z, from the viewpoint of suppressing the vehicle weight, the hydraulic oil tank 9 does not store a sufficient amount of oil to drive all the hydraulic actuators simultaneously. When all of these hydraulic actuators are driven simultaneously, there is a possibility that a shortage of oil will occur. When driven under a condition where the amount of residual oil in the hydraulic oil tank 9 is reduced, the hydraulic actuator that may cause a shortage of the oil amount includes the boom hoisting cylinder 5, the jib hoisting cylinder 6, the boom expansion and contraction. Among the hydraulic actuators other than the cylinder 7 and the jib telescopic cylinder 8, since the amount of oil used for the turning hydraulic motor is constant in any driving state, the jack hydraulic cylinder and the slide of the outrigger 10 are also provided. Since the hydraulic cylinder for use has a small amount of oil itself, there is little possibility of causing an oil shortage by driving.

  Therefore, in consideration of the amount of oil used by each of the hydraulic actuators, in this crane vehicle Z, the hydraulic oil tank is provided for each of the boom hoisting cylinder 5, the jib hoisting cylinder 6, the boom telescopic cylinder 7, and the jib telescopic cylinder 8. In the state in which the residual oil amount 9 is reduced below a certain level, the driving in the direction in which the residual oil amount decreases is regulated, thereby preventing the occurrence of an insufficient oil amount in advance. Hereinafter, the oil amount control of the hydraulic oil will be specifically described.

  First, the control concept of the hydraulic oil amount control device according to the present invention will be described.

  The first control concept relates to a specific method for avoiding a shortage of the hydraulic oil amount associated with the driving of the hydraulic actuator, and the residual oil in the hydraulic oil tank 9 when the shortage of the oil amount is avoided. The remaining oil amount is compared with a preset lower limit value of the remaining oil amount.If the remaining oil amount falls below the lower limit of the remaining oil amount, the hydraulic oil is deficient as the hydraulic actuator is driven. In this case, the operation of the hydraulic actuator is prohibited in a direction that leads to a further decrease in the residual oil amount.

  Here, the above-mentioned “residual oil amount lower limit value” can be arbitrarily set according to the working conditions of the work implement, and as described above, “the minimum oil amount that does not cause idling or seizure of the hydraulic pump. In addition, for example, the jib 4 may be further driven in the fully extended state of the telescopic boom 3 that uses the largest amount of oil, that is, in the state where the boom telescopic cylinder 7 is fully extended. It is also possible to set the minimum oil amount as possible.

  Further, when the lower limit value of the residual oil amount is set to the minimum oil amount that can drive the jib 4, the jib 4 can be driven even if the jib 4 can be driven. Since the residual oil amount decreases with the driving, if this falls below the lower limit value of the residual oil amount, there may occur a situation where the driving of the jib 4 cannot be continued. It is conceivable to change and set the oil amount lower limit value to a value that is lower than the initial set value, whereby the driving of the jib 4 can be continued.

  And under this 1st control thought, the following two methods are adopted as a residual oil quantity acquisition method. One of them detects the current amount of oil used in the hydraulic actuator, and calculates and obtains the amount of residual oil by calculation based on the amount of oil used and the total amount of tank oil initially stored in the hydraulic oil tank 9. (Hereinafter referred to as “first residual oil amount acquisition method”). The other is a method in which the residual oil amount is directly detected by a detector, and in that case, the residual oil amount is acquired in consideration of the volume change of the residual oil amount due to the oil temperature (hereinafter referred to as “second residual oil”). "Oil quantity acquisition method").

  The second control concept is to control only hydraulic actuators that are likely to cause a shortage of hydraulic oil, that is, the boom hoisting cylinder 5, the jib hoisting cylinder 6, the boom telescopic cylinder 7, and the jib telescopic cylinder 8 to be controlled. Hydraulic motors and the like are excluded from control measures, thereby avoiding a shortage of oil with simple and inexpensive control. Therefore, in the embodiment described later, the slide cylinder of the outrigger 10 is not controlled, but it is of course possible to include it in the controlled object depending on the structure of the slide cylinder (this will be described later).

  The third control idea is an idea related to the extension mechanism of the extension boom 3. That is, as the expansion / contraction mechanism of the hydraulic cylinder, a conventional general expansion / contraction mechanism (hereinafter referred to as a “first expansion / contraction mechanism”) that expands and contracts each boom using an individual hydraulic cylinder, and the description has been given with reference to FIG. As described above, there is an expansion / contraction mechanism (hereinafter referred to as “second expansion / contraction mechanism”) that expands and contracts each boom step by step with a single hydraulic cylinder. In the former, in the boom extended state, each hydraulic cylinder also maintains the extended state, and a large amount of hydraulic oil is used. On the other hand, in the latter, since the hydraulic cylinder can be reduced and held in the boom extended state, the amount of oil used in the hydraulic cylinder is small, and the amount of residual oil in the hydraulic oil tank 9 increases accordingly. Will do. The third control concept is to reflect such a difference in the expansion / contraction mechanism of the telescopic boom 3 in the avoidance control for the insufficient oil amount.

  Here, even if an increase in the residual oil amount can be expected as the hydraulic cylinder is reduced, for example, when the residual oil amount lower limit value is set to an oil amount that can drive the jib 4 as described above. Since there is no point in reducing the hydraulic cylinder when the amount of oil increased with the reduction of the hydraulic cylinder is an oil amount that cannot drive the jib 4, in the first and third embodiments below, the hydraulic cylinder Is set in advance as a "predetermined length", and when the current length of the hydraulic cylinder is less than a predetermined length, the hydraulic cylinder is not reduced. ing. Note that the “predetermined length” that serves as a reference for the reduction operation of the hydraulic cylinder is set based on the relationship with the “residual oil amount lower limit value”. In order to ensure that the lower limit value of the remaining oil amount is set to a higher oil amount side in order to ensure the above, the “predetermined length” may be set shorter. In some cases, the “predetermined length” may be set to “all It can also be set to “compressed state”.

  Based on the above control ideas, actual hydraulic oil amount control will be specifically described based on the first to fourth embodiments.

  Note that the first embodiment is directed to a method that employs a “first residual oil amount acquisition method” and that expands and contracts the telescopic boom 3 using a “second telescopic mechanism”.

  The second embodiment is intended for the one that adopts the “first residual oil amount acquisition method” and that expands and contracts the telescopic boom 3 by the “first telescopic mechanism”.

  The third embodiment is directed to a method that employs a “second residual oil amount acquisition method” and that expands and contracts the telescopic boom 3 using a “second telescopic mechanism”.

  The fourth embodiment is directed to a method that employs a “second residual oil amount acquisition method” and that expands and contracts the telescopic boom 3 using a “first telescopic mechanism”.

A: First Embodiment As described above, the hydraulic oil amount control device according to the first embodiment employs the “first residual oil amount acquisition method” and the telescopic boom 3 is moved to the “second The object is to be expanded and contracted by an “extension mechanism”, and FIG. 2 shows its control block.

  The control of the first embodiment includes a controller 30, and various input elements and output elements are attached to the controller 30.

  As input elements, a boom operation input detector 31 that detects an operation input of the telescopic boom 3 (an input related to the telescopic operation and the hoisting operation), and a jib operation that detects an operation input of the jib 4 (an input related to the telescopic operation and the hoisting operation). An input detector 32, a boom telescopic cylinder length detector 33 for detecting the length of the boom telescopic cylinder 7, and a boom for detecting the undulation angle of the telescopic boom 3 (that is, the length of the boom hoisting cylinder 5 indirectly). The undulation angle detector 34, the jib length detector 35 for detecting the length of the jib telescopic cylinder 8, and the jib length for detecting the undulation angle of the jib 4 (that is, the length of the jib undulation cylinder 6 indirectly). A detector 35 is provided.

  The jib telescopic cylinder 8 is conveniently grasped as an assembly of a plurality of hydraulic cylinders provided in the jib 4 as described above, and the jib length detector 35 is also a plurality of hydraulic cylinders. It is understood for convenience as a set of lengths.

  As output elements, a boom expansion / contraction cylinder drive means 41 configured by a control valve for controlling supply / discharge of hydraulic oil to / from the boom telescopic cylinder 7 and a control valve for controlling supply / discharge of hydraulic oil to / from the boom hoisting cylinder 5 are used. Boom hoisting cylinder driving means 42 constructed, jib telescopic cylinder driving means 43 composed of a control valve for controlling supply / discharge of hydraulic oil to / from the jib telescopic cylinder 8, and hydraulic oil supply / discharge to the jib hoisting cylinder 6 A jib hoisting cylinder driving means 44 composed of a control valve for controlling the oil pressure, and a display / alarm means 45 for displaying the possibility of oil shortage and issuing an alarm are provided.

  The controller 30 includes a used oil amount calculating means 21, a remaining oil amount calculating means 22, an operation restriction signal output means 23, a drive control means 24, a tank total oil amount memory 25, and a remaining oil amount lower limit value memory 26. Is provided.

  The used oil amount calculating means 21 includes the used oil amount of the boom telescopic cylinder 7 from the boom telescopic cylinder length detector 33, the used oil amount of the boom hoisting cylinder 5 from the boom hoisting angle detector 34, and In response to the amount of oil used in the jib telescopic cylinder 8 from the jib length detector 35 and the amount of oil used in the jib undulation cylinder 6 from the jib undulation angle detector 36, the total use is the sum of these oil amounts. The oil amount Qa is calculated and output to the residual oil amount calculating means 22 described below. The amount of oil used in the boom hoisting cylinder 5 is calculated based on the length of the boom hoisting cylinder 5 corresponding to the boom hoisting angle, and the amount of oil used in the jib hoisting cylinder 6 corresponds to the jib hoisting angle. Needless to say, it is calculated based on the length of the jib hoisting cylinder 6 to be operated.

  The residual oil amount calculating means 22 receives the total used oil amount Qa from the used oil amount calculating means 21 and the tank total oil amount Qt read from the tank total oil amount memory 25, and calculates the current hydraulic oil by calculation. The residual oil amount Qb in the tank 9 is calculated and output to the operation restriction signal output means 23 described below.

  The operation restriction signal output means 23 receives the residual oil quantity Qb from the residual oil quantity calculation means 22 and the residual oil quantity lower limit value Qm from the residual oil quantity lower limit value memory 26 and compares them, and the residual oil quantity When Qb is equal to or less than the remaining oil amount lower limit Qm, an operation restriction signal C is output to the drive control means 24 described below.

  The drive control means 24 is constantly supplied with an operation input related to the telescopic boom 3 from the boom operation input detector 31 and an operation input related to the jib 4 from the jib operation input detector 32. When the operation restriction signal C is received from the signal output means 23, the amount of oil used among the boom telescopic cylinder driving means 41, the boom hoisting cylinder driving means 42, the jib telescopic cylinder driving means 43, and the jib hoisting cylinder driving means 44 is A drive control signal is output to the hydraulic cylinder that is about to be operated in an increasing direction, and its operation is restricted, thereby preventing the occurrence of a shortage of hydraulic oil in advance.

  In this embodiment, the boom telescopic cylinder length detector 33, the boom undulation angle detector 34, the jib length detector 35, the jib undulation angle detector 36, the used oil amount calculating means 21, and the remaining oil amount calculating means. 22 and the tank total oil amount memory 25 constitute “residual oil amount obtaining means 20” in the claims.

  Next, actual hydraulic oil amount control will be described based on the flowchart shown in FIG.

  After the start of control, first, in step S1, the boom length, boom undulation angle, jib length, jib undulation angle, boom operation input and jib operation input are read.

  Next, in step S2, the amount of oil used for each of the hydraulic cylinders 5 to 8 is obtained, and the total amount of oil used Qa is further obtained. In step S3, the current residual oil amount Qb is obtained from the total used oil amount Qa and the total tank oil amount Qt.

  Thereafter, in step S4, the residual oil amount Qb is compared with the residual oil amount lower limit value Qm read from the memory. Here, when “Qm <Qb” is satisfied, the remaining oil amount Qb has a margin and there is no fear that the oil amount will be insufficient, so this is allowed without prohibiting the operation of the hydraulic cylinder (step S5).

  On the other hand, when “Qm ≧ Qb”, that is, when the residual oil amount Qb decreases below the residual oil amount lower limit value Qm and the hydraulic cylinder operates in a direction in which the residual oil amount Qb decreases, the oil amount is insufficient. If there is a possibility of falling into the control, the control shifts to hydraulic cylinder operation prohibition control or residual oil amount recovery control.

  That is, in step S6, since the amount of remaining oil cannot be increased any more, the operation in the direction in which the amount of oil used in each of the hydraulic cylinders 5 to 8 increases, for example, the raising and lowering operation of the telescopic boom 3 is performed. The operation and the raising / lowering operation of the jib 4 are prohibited, and it is possible to prevent the oil amount from being insufficient due to the driving of the hydraulic cylinder.

  Further, in step S7, it is determined whether or not the boom telescopic cylinder 7 has been reduced to a predetermined length or less. Here, when it is determined that the boom telescopic cylinder 7 is contracted to a predetermined length or less, an increase in the remaining oil amount that is more effective (that is, the jib 4 can be operated) is increased. Since it cannot be expected, control is returned.

  On the other hand, if it is determined that the boom telescopic cylinder 7 has not been reduced to a predetermined length or less, the boom telescopic cylinder 7 is reduced until the boom telescopic cylinder 7 is reduced to a predetermined length or less. (Step S8), the effective residual oil amount is increased, and the control is returned when this amount is reduced below a predetermined level (step S7).

  By continuing such control, it is possible to prevent the oil amount from being insufficient due to the driving of each hydraulic cylinder, and to ensure the operational reliability of the crane vehicle Z. Is.

B: Second Embodiment As described above, the hydraulic oil amount control according to the second embodiment employs the “first residual oil amount acquisition method”, and the telescopic boom 3 is moved to the “first telescopic boom”. The control block diagram and the description thereof are based on the control block diagram and the description in the first embodiment, and here, based on the flowchart shown in FIG. The control of will be described.

  That is, after the start of control, first, in step S1, the boom length, boom undulation angle, jib length, jib undulation angle, boom operation input and jib operation input are read.

  Next, in step S2, the amount of oil used for each of the hydraulic cylinders 5 to 8 is obtained, and the total amount of oil used Qa is further obtained. In step S3, the current residual oil amount Qb is obtained from the total used oil amount Qa and the total tank oil amount Qt.

  Thereafter, in step S4, the residual oil amount Qb is compared with the residual oil amount lower limit value Qm read from the memory. Here, when “Qm <Qb” is satisfied, the remaining oil amount Qb has a margin and there is no fear that the oil amount will be insufficient, so this is allowed without prohibiting the operation of the hydraulic cylinder (step S5).

  On the other hand, when “Qm ≧ Qb”, that is, when the residual oil amount Qb decreases below the residual oil amount lower limit value Qm and the hydraulic cylinder operates in a direction in which the residual oil amount Qb decreases, the oil amount is insufficient. Therefore, the operation in the direction in which the amount of oil used in each of the hydraulic cylinders 5 to 8 increases is prohibited (step S6).

  By continuing such control, it is possible to prevent the oil amount from being insufficient due to the driving of each hydraulic cylinder, and to ensure the operational reliability of the crane vehicle Z. Is.

C: Third Embodiment As described above, the hydraulic oil amount control device according to the third embodiment employs the “second residual oil amount acquisition method” and the telescopic boom 3 is moved to the “second The object is to be expanded and contracted by an “extension mechanism”, and FIG. 5 shows its control block.

  In the control of the third embodiment, a controller 30 is provided, and various input elements and output elements are attached to the controller 30.

  As input elements, a boom operation input detector 31 that detects an operation input of the telescopic boom 3 (an input related to the telescopic operation and the hoisting operation), and a jib operation that detects an operation input of the jib 4 (an input related to the telescopic operation and the hoisting operation). An input detector 32, a tank oil temperature detector 37 for detecting the oil temperature of the hydraulic oil stored in the hydraulic oil tank 9, and a tank residual oil amount detector for directly detecting the residual oil amount in the hydraulic oil tank 9. 38 is provided.

  As output elements, a boom expansion / contraction cylinder drive means 41 configured by a control valve for controlling supply / discharge of hydraulic oil to / from the boom telescopic cylinder 7 and a control valve for controlling supply / discharge of hydraulic oil to / from the boom hoisting cylinder 5 are used. Boom hoisting cylinder driving means 42 constructed, jib telescopic cylinder driving means 43 composed of a control valve for controlling supply / discharge of hydraulic oil to / from the jib telescopic cylinder 8, and hydraulic oil supply / discharge to the jib hoisting cylinder 6 A jib hoisting cylinder driving means 44 composed of a control valve for controlling the oil pressure, and a display / alarm means 45 for displaying the possibility of oil shortage and issuing an alarm are provided.

  The controller 30 is provided with calculation means 27, operation restriction signal output means 23, drive control means 24, and residual oil amount lower limit value memory 26.

  The calculation means 27 receives the hydraulic oil temperature from the tank oil temperature detector 37 and the residual oil amount from the tank residual oil amount detector 38, and calculates an accurate residual oil amount Qb in consideration of the oil temperature. This is obtained and output to the operation restriction signal output means 23 described below.

  The operation restriction signal output means 23 receives the residual oil amount Qb from the calculating means 27 and the residual oil amount lower limit value Qm from the residual oil amount lower limit value memory 26 and compares them, and the residual oil amount Qb is When the oil amount lower limit value Qm is equal to or less than the oil amount lower limit value Qm, an operation restriction signal C is output to the drive control means 24 described below.

  The drive control means 24 is constantly supplied with an operation input related to the telescopic boom 3 from the boom operation input detector 31 and an operation input related to the jib 4 from the jib operation input detector 32. When the operation restriction signal C is received from the signal output means 23, the amount of oil used among the boom telescopic cylinder driving means 41, the boom hoisting cylinder driving means 42, the jib telescopic cylinder driving means 43, and the jib hoisting cylinder driving means 44 is A drive control signal is output to the hydraulic cylinder which is about to be operated in an increasing direction, and its operation is restricted, thereby preventing the occurrence of a shortage of hydraulic oil in advance.

  In this embodiment, the tank oil temperature detector 37, the tank residual oil amount detector 38, and the calculation means 27 constitute the "residual oil amount acquisition means 20" in the claims.

  Next, actual hydraulic oil amount control will be described based on the flowchart shown in FIG.

  After starting the control, first, in step S1, the boom operation input, the jib operation input, the hydraulic oil temperature, and the residual oil amount are read.

  Next, in step S2, an accurate residual oil amount Qb is obtained by considering the hydraulic oil temperature in the read residual oil amount.

  Thereafter, in step S3, the residual oil amount Qb is compared with the residual oil amount lower limit value Qm read from the memory. Here, when “Qm <Qb” is satisfied, the remaining oil amount Qb has a margin and there is no risk of the oil amount becoming insufficient, so that this is permitted without prohibiting the operation of the hydraulic cylinder (step S4).

  On the other hand, when “Qm ≧ Qb”, that is, when the residual oil amount Qb decreases below the residual oil amount lower limit value Qm and the hydraulic cylinder operates in a direction in which the residual oil amount Qb decreases, the oil amount is insufficient. If there is a possibility of falling into the control, the control shifts to hydraulic cylinder operation prohibition control or residual oil amount recovery control.

  That is, in step S5, since the amount of remaining oil cannot be increased any more, the operation in the direction in which the amount of oil used in each of the hydraulic cylinders 5 to 8 increases, for example, the raising and lowering operation of the telescopic boom 3 is performed. The operation and the raising / lowering operation of the jib 4 are prohibited, and it is possible to prevent the oil amount from being insufficient due to the driving of the hydraulic cylinder.

  Further, in step S6, it is determined whether or not the boom telescopic cylinder 7 has been reduced to a predetermined length or less. Here, when it is determined that the boom telescopic cylinder 7 is contracted to a predetermined length or less, an increase in the remaining oil amount that is more effective (that is, the jib 4 can be operated) is increased. Since it cannot be expected, control is returned.

  On the other hand, if it is determined that the boom telescopic cylinder 7 has not been reduced to a predetermined length or less, the boom telescopic cylinder 7 is reduced until the boom telescopic cylinder 7 is reduced to a predetermined length or less. (Step S7), the effective residual oil amount is increased, and the control is returned when the effective residual oil amount is reduced below a predetermined value (step S6).

  By continuing such control, it is possible to prevent the oil amount from being insufficient due to the driving of each hydraulic cylinder, and to ensure the operational reliability of the crane vehicle Z. Is.

D: Fourth Embodiment As described above, the hydraulic oil amount control according to the fourth embodiment employs the “second residual oil amount acquisition method” and the telescopic boom 3 is moved to the “first telescopic expansion / contraction”. The control block diagram and the explanation thereof are based on the control block diagram and the explanation in the third embodiment, and here, based on the flowchart shown in FIG. The control of will be described.

  After starting the control, first, in step S1, the boom operation input, the jib operation input, the hydraulic oil temperature, and the residual oil amount are read.

  Next, in step S2, an accurate residual oil amount Qb is obtained by considering the hydraulic oil temperature in the read residual oil amount.

  Thereafter, in step S3, the residual oil amount Qb is compared with the residual oil amount lower limit value Qm read from the memory. Here, when “Qm <Qb” is satisfied, the remaining oil amount Qb has a margin and there is no risk of the oil amount becoming insufficient, so that this is permitted without prohibiting the operation of the hydraulic cylinder (step S4).

  On the other hand, when “Qm ≧ Qb”, that is, when the residual oil amount Qb decreases below the residual oil amount lower limit value Qm and the hydraulic cylinder operates in a direction in which the residual oil amount Qb decreases, the oil amount is insufficient. Therefore, the operation in the direction in which the amount of oil used in each of the hydraulic cylinders 5 to 8 increases is prohibited (step S5).

  By continuing such control, it is possible to prevent the oil amount from being insufficient due to the driving of each hydraulic cylinder, and to ensure the operational reliability of the crane vehicle Z. Is.

E: Others In the above embodiments, the operation restriction targets are specified as the hydraulic cylinders of the boom hoisting cylinder 5, the jib hoisting cylinder 6, the boom telescopic cylinder 7 and the jib telescopic cylinder 8, but in other embodiments, For example, the slide beam of the outrigger 10 is configured to include the “second expansion / contraction mechanism”, and a slide hydraulic cylinder (not shown) that performs expansion / contraction drive of the slide beam is also operated in the hydraulic oil amount control of the present invention. It can also be included in the regulation.

1 is an overall view of a crane vehicle equipped with a hydraulic oil amount control device according to the present invention. It is a control block diagram of the hydraulic fluid amount control device according to the first embodiment of the present invention. It is a flowchart of the hydraulic fluid amount control apparatus which concerns on 1st Embodiment of this invention. It is a flowchart of the hydraulic fluid amount control apparatus which concerns on 2nd Embodiment of this invention. It is a control block diagram of the hydraulic fluid amount control apparatus which concerns on 3rd Embodiment of this invention. It is a flowchart of the hydraulic fluid amount control apparatus which concerns on 3rd Embodiment of this invention. It is a flowchart of the hydraulic fluid amount control apparatus which concerns on 4th Embodiment of this invention. It is explanatory drawing of expansion-contraction operation | movement of the expansion-contraction boom by a boom expansion-contraction cylinder.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ·· Vehicle 2 ·· Swivel 3 ·· Telescopic boom 4 ·· Jib 5 ·· Boom hoisting cylinder 6 · · Jib hoisting cylinder 7 · · Boom telescopic cylinder 8 · · Jib telescopic cylinder 9 · · Hydraulic oil tank 10 · Outrigger 11 26 ..Residual oil amount lower limit memory 27 ..Calculation means 30 ..Controller 31 ..Boom operation input detector 32 ..Jib operation input detector 33 ..Boom telescopic cylinder length detector 34. Detector 35 .. Jib length detector 36 .. Jib undulation angle detector 37 .. Tank oil temperature detector 38 .. Tank residual oil amount detector 41. Motion means 42 ... boom hoisting cylinder drive means 43 .. jib telescopic cylinder drive means 44 .. jib derricking cylinder driving unit 45 ... display and alarm means Z .. crane (working machine)

Claims (6)

A hydraulic fluid amount control device for a working machine driven by a plurality of hydraulic cylinders,
A residual oil amount acquisition means for acquiring the residual oil amount in the hydraulic oil tank;
An operation restriction signal output means for comparing the residual oil amount with a preset lower limit value of the residual oil amount and outputting an operation restriction signal when the residual oil amount falls below the lower limit of the residual oil amount;
A work machine comprising drive control means for outputting a drive control signal to the cylinder drive means for restricting drive of the hydraulic cylinder in a direction in which the residual oil amount decreases when receiving the operation restriction signal. Hydraulic oil amount control device. In claim 1,
The residual oil amount acquisition means is configured to acquire the residual oil amount by calculation based on the total amount of oil used in each hydraulic cylinder and the total amount of oil stored in the hydraulic oil tank. A working oil amount control device for a working machine. In claim 1,
The working oil amount control device for a working machine, wherein the residual oil amount obtaining means directly detects the remaining oil amount in the working oil tank. In claim 3,
A working oil amount control device for a working machine, wherein the oil temperature of the working oil in the working oil tank is reflected in the detection of the residual oil amount. In claim 1, 2, 3 or 4,
One of the hydraulic cylinders is a telescopic drive hydraulic cylinder inserted into a telescopic boom formed by sequentially inserting a plurality of distal end booms into the base boom so as to be telescopically extendable. While the rod end is pivotally supported by the base boom base end, the rod side end of the cylinder tube can be connected to and released from the base end of the target boom, and adjacent booms of the telescopic boom Is capable of being fixed / released, and is provided with an expansion / contraction mechanism configured such that the plurality of front end side booms are expanded and contracted step by step with respect to the base boom by expansion / contraction of the expansion / contraction drive hydraulic cylinder. A working oil amount control device for a working machine, wherein the hydraulic cylinder for expansion / contraction driving is contracted when receiving the operation restriction signal. In claim 5,
When the length detection means of the expansion / contraction driving hydraulic cylinder is provided and the operation restriction signal is received, it is determined whether or not the length of the expansion / contraction driving hydraulic cylinder is equal to or less than a predetermined length. An operating oil amount control device for a working machine, wherein when the length is not less than the length, the contraction operation of the expansion / contraction drive hydraulic cylinder is executed.

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