JP3555733B2 - Hydraulic excavator boost control method and apparatus - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a hydraulic shovel pressure increasing control method and apparatus for temporarily increasing hydraulic oil flowing into a hydraulic actuator mounted on a hydraulic shovel.
[0002]
[Prior art]
Hereinafter, an example of a conventional shovel will be described with reference to FIG. Reference numeral 31 shown in FIG. 3 is a lower traveling body. The lower traveling body 31 is composed of a track frame 31b, an idler wheel 31c and a traveling motor 31d mounted on front and rear ends of the track frame 31b, and an idler wheel 31c. And a shoe 31e wound around a traveling motor 31d. An upper swing body 32 is mounted on the upper part of the lower traveling body 31 so as to be freely swingable. The upper swing body 32 includes a counter weight 32a mounted at a rear end and an operator cab 30 mounted at a front part. The operator cab 30 includes an operator seat (not shown) disposed behind the operator cab 30, a pair of operation levers (not shown) disposed on both front sides of the operator seat, and an operator seat (not shown) disposed in front of the operator seat. A pair of traveling levers are arranged. At the front of the operator's cab 30, an attachment 33 including a boom 34, an arm 35, and a bucket 36 is provided so that the attachment 33 can be freely raised and lowered with a boom foot pin (not shown) as a fulcrum. The boom 34 can be raised and lowered freely by a boom cylinder 34 a disposed between the front part of the upper swing body 32 and the boom 34. The arm 35 is rotatably mounted at the end of the boom 34. The arm 35 is rotatable by an arm cylinder 35a disposed between the back of the boom 34 and the end of the arm 35. Further, the bucket 36 is rotatably mounted at the tip of the arm 35. The bucket 36 is rotatable by a bucket cylinder 36a disposed between the bucket 36 and the back of the arm 35.
[0003]
The shovel driver sits on the operator seat and operates the traveling lever to supply hydraulic oil for a hydraulic pump mounted inside the upper swing body 32 to the traveling motor 31d to move the shovel. By operating the operation lever, the hydraulic oil of the hydraulic pump is supplied to a turning motor (not shown) to turn the upper revolving unit 32. In addition, by supplying the operating oil to the cylinders 34a, 35a, 36a, the attachment 33 is turned on. To perform operations such as excavation. When the above-mentioned hydraulic excavator performs an excavation operation, a large excavation force may be required depending on an operation state. In such a case, the relief pressure is temporarily increased to increase the excavation force.
[0004]
Conventional techniques for temporarily increasing the relief pressure include, for example, Japanese Patent Publication No. 4-77801, Japanese Patent Application Laid-Open No. Sho 62-224702, and Japanese Patent Application Laid-Open No. Hei 8-60704. In these publications, while the pressure switch is pressed (for a certain period of time after being pressed if the timer function is provided), the pressure switching valve is switched so that the pilot hydraulic oil discharged from the pilot pump is used for the pressure increase. The pressure is led to the pilot port of the relief valve via the switching valve, and the set pressure of the relief valve is temporarily increased.
[0005]
[Problems to be solved by the invention]
As described above, in the prior art, when a large excavation force is required during excavation work of a hydraulic excavator, the set pressure of the relief valve is temporarily increased by pressing a boost switch to obtain a large excavation force. ing. However, even in non-excavation work (for example, running and turning operations), if the pressurizing switch is pressed, the set pressure of the relief valve increases, and if the operator accidentally presses the pressurizing switch during running or turning, The running force and the turning force suddenly increase, and the crawler idles on a soft land or breaks a groove being formed. Further, there has been a problem that the number of times of boosting is unnecessarily increased and the useful life of the hydraulic actuator is shortened.
[0006]
The present invention has been made in view of such circumstances, and increases the set pressure of the relief valve only in the case of work requiring a large excavation force, thereby improving the safety of the boosting operation. It is an object of the present invention to provide a boost control method and a boost control device of a hydraulic shovel capable of improving the service life of an actuator.
[0007]
[Means for Solving the Problems]
According to the first aspect of the present invention, when a plurality of hydraulic actuators connected to a hydraulic pump are operated in accordance with the operation of a plurality of operation levers to perform an operation such as excavation, the operation is pressed when a large excavation force is required. A pressure increase control of a hydraulic shovel provided with a pressure increase switch, and by pressing the pressure increase switch to temporarily increase a set pressure of a relief valve connected to the hydraulic actuator, thereby increasing a maximum pressure of hydraulic oil flowing into the hydraulic actuator. In the method, a signal corresponding to the operation of each of the operation levers when the boost switch is pressed is detected, and the detected signal is separated into a digging signal and a non-digging signal, and the digging signal is included in the signal. And raising the set pressure of the relief valve temporarily only when it is determined that a non-digging signal is not included. It is a control method.
[0008]
According to this, when a large excavation force is required during the excavation work of the hydraulic excavator, the set pressure of the relief valve can be temporarily increased by depressing the boost switch to obtain a large excavation force. Also, in the case of non-digging work or a combined work of digging work and non-digging work, even if the boost switch is pressed, the set pressure of the relief valve does not increase, so that the operator may perform an unexpected movement. And the safety of the boost operation is improved. Furthermore, the useful life of the actuator is not shortened due to the unnecessary increase in the number of times of boosting.
[0009]
According to a second aspect of the present invention, in the method of controlling a pressure of a hydraulic shovel according to the first aspect, the non-digging signal includes a traveling and turning signal.
[0010]
In this case, even when the operator erroneously performs an operation that requires boosting during running or turning, the running force or turning force suddenly increases, and the crawler idles on a soft ground, There is no movement that the operator cannot expect, such as breaking the groove.
[0011]
According to a third aspect of the present invention, when a plurality of hydraulic actuators connected to a hydraulic pump are operated in accordance with the operation of a plurality of operation levers to perform work such as excavation, the hydraulic press is pressed when a large excavation force is required. A pressure increase control of a hydraulic shovel provided with a pressure increase switch, and by pressing the pressure increase switch to temporarily increase a set pressure of a relief valve connected to the hydraulic actuator, thereby increasing a maximum pressure of hydraulic oil flowing into the hydraulic actuator. In the device, signal detection means for detecting a signal corresponding to the operation of each of the operation levers, and signal separation means for separating the signal detected by the signal detection means into an excavation signal and a non-excavation signal, Only when it is determined that the signal when the boost switch is pressed includes the excavation signal and does not include the non-digging signal, the relief And it is characterized in that it comprises a relief valve control means for temporarily increasing the set pressure of the.
[0012]
According to this configuration, when a large excavation force is required during the excavation work of the hydraulic excavator, the set pressure of the relief valve can be temporarily increased by pressing the boost switch to obtain the large excavation force. . Also, in the case of non-digging work or a combined work of digging work and non-digging work, even if the boost switch is pressed, the set pressure of the relief valve does not increase, so that the operator may perform an unexpected movement. And the safety of the boost operation is improved. Furthermore, the useful life of the actuator is not shortened due to the unnecessary increase in the number of times of boosting.
[0013]
A fourth aspect of the present invention is the hydraulic shovel booster control device according to the third aspect, wherein the non-digging signal includes a traveling and turning signal.
[0014]
According to this, even when the operator erroneously performs an operation that requires a pressure increase during traveling or turning, the traveling force or the turning force suddenly increases, and the crawler idles on a soft ground, or during formation. This prevents the operator from performing unexpected movements such as breaking the groove.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail based on the boost control device shown in FIG. Note that components having the same configuration as the prior art are denoted by the same reference numerals.
[0016]
In FIG. 1, reference numerals 31 dL and 31 dR denote left and right traveling motors mounted on the lower traveling body 31. The left and right traveling motors 31dL, 31dR and the traveling pilot switching valves 2L, 2R are respectively connected by pipes, and control is performed by switching the traveling pilot switching valves 2L, 2R. Reference numeral 1 denotes a swing motor mounted on the upper swing body 30. The turning motor 1 and the turning pilot switching valve 3 are connected by a pipeline, and control is performed by switching the turning pilot switching valve 3. Reference numerals 34a, 35a, and 36a denote boom cylinders, arm cylinders, and bucket cylinders mounted on the attachment 33, respectively. The cylinders 34a, 35a, 36a, the boom pilot switching valve 4, the arm pilot switching valve 5, and the bucket pilot switching valve 6 are respectively connected by pipes, and the pilot switching valves 4, 5, 6 are switched. Perform control.
[0017]
Note that the actuator of the hydraulic shovel in this embodiment corresponds to a traveling motor, a swing motor, a boom cylinder, an arm cylinder, and a bucket cylinder, but is not limited thereto.
[0018]
Next, reference numerals 7 and 8 denote first and second pumps (hydraulic pumps) for discharging hydraulic oil, respectively, reference numeral 9 denotes an oil tank, and reference numeral 10L denotes a hydraulic oil line 11L and an oil tank 9 of the first pump 7. Reference numeral 10R denotes a relief valve provided between the hydraulic oil line 11R of the second pump 8 and the oil tank 9. Reference numerals 12 and 12 'denote springs that regulate the left and right relief valves 10L and 10R to a normal relief set pressure. Reference numerals 13 and 13' denote pilot pressures when the normal relief set pressure is set to be increased. Is a pilot port to be introduced.
[0019]
The hydraulic oil sucked up from the oil tank 9 by the first pump 7 passes through the traveling pilot switching valve 2L, the arm pilot switching valve 5, the turning pilot switching valve 3, and the traveling motor 31dL, the arm cylinder 35a, The turning motor 1 is driven. Then, it reaches the relief valve 10L through the operating pressure pipeline 11L. Here, if the operating oil is equal to or higher than the set pressure of the relief valve 10L, the oil is relieved to the oil tank 9. Hydraulic oil sucked up from the oil tank 9 by the second pump 8 passes through the traveling pilot switching valve 2R, the boom pilot switching valve 4, the bucket pilot switching valve 6, and travels through the traveling motor 31dR, the boom cylinder. 34a and the bucket cylinder 36a are driven. Then, it reaches the relief valve 10R through the hydraulic oil pipeline 11R. Here, if the operating oil is equal to or higher than the set pressure of the relief valve 10R, the oil is relieved to the oil tank 9.
[0020]
In FIG. 1, reference numerals 14L and 14R are hydraulic remote control valves controlled by operation of a pair of operation levers 32cL and 32cR. More specifically, reference numeral 15 is a pilot valve for turning left of the hydraulic remote control valve 14L, reference numeral 15 'is a pilot valve for turning right, reference numeral 16 is a pilot valve for pulling an arm, and reference numeral 16' is a pilot valve for pushing an arm. Reference numeral 17 denotes a pilot valve for releasing the bucket of the hydraulic remote control valve 14R, reference numeral 17 ′ denotes a pilot valve for excavating the bucket, reference numeral 18 denotes a pilot valve for lowering the boom, and reference numeral 18 ′ denotes a pilot valve for raising the boom.
[0021]
Reference numerals 19L and 19R are remote control valves for traveling controlled by operation of a pair of traveling levers 32dL and 32dR. More specifically, reference numeral 20F is a forward pilot valve of the traveling remote control valve 19L, reference numeral 20R is a reverse pilot valve, reference numeral 20'R is a forward pilot valve of the traveling remote control valve 19R, and reference numeral 20'R is reverse. It is a pilot valve.
[0022]
The hydraulic remote control valves 14L and 14R and the traveling remote control valves 19L and 19R are connected to the pilot pump 21 which is a hydraulic pressure source that discharges pilot pressure, via respective pipes.
[0023]
Next, the operation of the hydraulic remote control valves 14L and 14R and the traveling remote control valves 19L and 19R will be described. By operating the operation lever 32cL, the pilot valve 15 for turning left, the pilot valve 15 'for turning right, the pilot valve 16 for pulling the arm, and the pilot valve 16' for pushing the arm are controlled, respectively, so that the pilot pressure is reduced. Via the road ho-ho, ha-he, ri-ri, and nu-nu, it reaches the turning pilot switching valve 3 and the arm pilot switching valve 5, and performs switching control. By operating the operation lever 32cR, the bucket discharge pilot valve 17, the bucket excavation pilot valve 17 ', the boom lowering pilot valve 18, and the boom raising pilot valve 18' are controlled, respectively, so that the pilot pressure is increased. The control is performed by way of a pipeline pilot valve, a bucket pilot switching valve 6, and a boom pilot switching valve 4 via pipes o, ru, teach, and toe. Further, by operating the traveling levers 32dL and 32dR, the forward pilot valve 20F, the reverse pilot valve 20R, the forward pilot valve 20'R, and the reverse pilot valve 20'R are respectively controlled, and the pilot pressure is reduced. The traveling pilot switching valves 2L and 2R are connected via pipelines ye, roro, haha, and ni to perform switching control.
[0024]
Further, a signal detecting means for detecting each pilot pressure derived from each of the remote control valves 15 to 20'R is provided. Specifically, the travel remote control valves 19L and 19R are provided with a travel pressure sensor 22a, the boom lowering pilot valve 18 is provided with a boom lowering pressure sensor 22b, and the boom raising pilot valve 18 'is provided with a boom raising pressure. The bucket discharge pilot valve 17 is provided with a bucket discharge pressure sensor 22d, the bucket excavation pilot valve 17 'is provided with a bucket excavation pressure sensor 22e, and the arm pull pilot valve 16 is provided with an arm pull. A pressure sensor 22f is provided, an arm pushing pressure sensor 22g is provided on the arm pushing pilot valve 16 ', and a turning pressure sensor 22h is provided on the turning pilot valves 15, 15'. The pressure sensors 22a to 22h, which are the signal detection means described above, input a pressure signal to the controller 23 when each of them detects a pilot pressure.
[0025]
The input state of the boost switch 26 is input to the controller 23 every moment.
[0026]
The controller 23 uses the pressure signal detected by the signal detecting means as a digging pressure signal (here, pressure signals from the boom lowering sensor 22b, the bucket digging sensor 22e, and the arm pulling sensor 22f) and a non-digging pressure. A signal (a pressure signal other than the excavation pressure signal) is provided, and the pressure signal separated by the signal separation means is only the excavation pressure signal, and the boost switch 26 is pressed. In this case, the relief valve control means issues a switching command to the boosting switching valves 24L, 24R provided between the pilot pump 21 and the pipelines of the respective relief valves 10L, 10R. Further, the switching of the pressure switching valves 24L, 24R causes the pilot pressure discharged from the pilot pump 21 to act on the pilot ports 13, 13 'provided in the relief valves 10L, 10R, respectively. The set pressure of each of the relief valves 10L and 10R is increased.
[0027]
Here, the sensors 22a to 22h are provided as signal detecting means for detecting the respective pilot pressures derived from the remote control valves 15 to 20'R. However, this signal detecting means is used as a traveling pressure which does not require a large excavation amount. It is also possible to increase the set pressure of each of the relief valves 10L and 10R only when the sensor 22a or the turning pressure sensor 22h is attached to only the pressure switch 26 and the sensors 22a and 22h do not detect a signal. Good.
[0028]
Next, as an example, a boost control method of a hydraulic shovel equipped with the boost controller according to the above embodiment will be described.
[0029]
During the operation of the hydraulic excavator, the operation levers 32cL and 32cR and the traveling levers 32dL and 32dR are operated. Thus, the traveling pressure sensor 22a, the boom lowering sensor 22b, the boom raising sensor 22c, the bucket discharging sensor 22d, the bucket excavating sensor 22e, the arm pulling sensor 22f, the arm pushing sensor 22g, and the turning pressure sensor. The pressure signals detected at 22h are input to the controller 23 moment by moment. When the shovel driver presses the boost switch 26, a boost signal is input to the controller 26. The controller 26 uses the pressure signals detected by the sensors 22a to 22h as excavation pressure signals (here, pressure signals from the boom lowering sensor 22b, the bucket excavation sensor 22e, and the arm pulling sensor 22f). It is separated into a digging pressure signal (a pressure signal other than the digging pressure signal), and only when the digging pressure signal is detected and the signal of the boosting switch 26 is detected, the switching of the boosting switching valves 24L and 24R is performed. Outputs the instruction to be performed. As a result, the relief set pressure of the relief valves 10L and 10R is temporarily increased to increase the maximum pressure of the hydraulic oil flowing into the hydraulic actuator.
[0030]
FIG. 2 is a flowchart illustrating one embodiment of a method for controlling the pressure of a hydraulic shovel according to the present invention.
[0031]
In FIG. 2, in step S1, it is determined whether or not the boost switch 26 has been pressed by an operator's operation, and if so, the process proceeds to step S2. On the other hand, if it is not pressed, the process returns to S1.
[0032]
In step S2, pressure signals from the pressure sensors 22a to 22h that detect pilot pressures derived by operating the operation levers 32cL and 32cR and the travel levers 32dL and 32dR are detected. If no pressure signal is detected, the process returns to step S1. Conversely, when a pressure signal is detected, the process proceeds to step S3.
[0033]
In step S3, the pressure signal detected in step S2 is a digging pressure signal (here, pressure signals from the boom lowering sensor 22b, the bucket digging sensor 22e, and the arm pulling sensor 22f) and a non-digging pressure signal ( Excluding the excavation pressure signal).
[0034]
In step S4, it is determined from the pressure signals separated in step S3 whether or not the excavation pressure signal is included. If the signal includes the excavation pressure signal, the process proceeds to step S5. Conversely, when the signal does not include the excavation pressure signal, the process returns to step S1.
[0035]
In step S5, it is determined, from among those including the excavation pressure signal of step S4, those that include the non-excavation pressure signal and those that do not. If the signal includes the non-digging pressure signal, the process returns to step S1. Conversely, when the non-digging pressure signal is not included (only the digging pressure signal), the process proceeds to step S6.
[0036]
In step S6, the relief set pressures of the relief valves 10L and 10R are temporarily increased, and the maximum pressure of the hydraulic fluid flowing into the hydraulic actuator corresponding to the excavation pressure signal detected in step S5 is increased. Return.
[0037]
Here, the excavation pressure signal is a pressure signal from the boom lowering sensor 22b, the bucket excavation sensor 22e, and the arm pulling sensor 22f, but the excavation pressure signal can be switched according to the work content. For example, when the work is performed with the bucket 36 in the opposite direction to the normal mounting direction, the pressure signals of the arm pushing sensor 22g and the bucket discharging pressure sensor 22d can be used as the excavation pressure signal.
[0038]
Furthermore, although a pressure sensor is used here to detect a pressure signal, a pressure switch or the like may be used.
[0039]
Furthermore, here, the signal due to the operation of the operation lever is detected by pressure, but the invention is not limited to this. A limit switch or a proximity switch may be connected to the operation lever, and the operation may be detected as an electric signal. Needless to say.
[0040]
Also, here, the setting is made such that a large excavation force is obtained while the boost switch is pressed. However, even if the setting is made such that a large excavation force is obtained for a certain period of time after the press of the boost switch (timer function). Good. Further, when it is determined that a large digging force is required by detecting the operation state of the operation lever, a setting may be made so that a large digging force is obtained.
[0041]
【The invention's effect】
According to the present invention, when a large excavation force is required during excavation work of a hydraulic excavator, a large excavation force can be obtained by temporarily increasing a set pressure of a relief valve by pressing a boost switch. . Also, in the case of non-digging work or a combined work of digging work and non-digging work, the set pressure of the relief valve does not increase even if the boost switch is pressed, so that the operator may make unexpected movements. And the safety of the boost operation is improved. Furthermore, the useful life of the actuator is not shortened due to the unnecessary increase in the number of times of boosting.
[0042]
Therefore, even when the operator erroneously performs an operation that requires an increase in pressure during traveling or turning, the traveling force or the turning force suddenly increases, and the crawler idles on a soft ground, or a groove being formed. The operator does not make any unexpected movements, such as breaking down.
[Brief description of the drawings]
FIG. 1 is an electric / hydraulic circuit diagram showing an embodiment of a booster control device for a hydraulic shovel according to the present invention.
FIG. 2 is a flowchart illustrating an embodiment of a method for controlling a pressure increase of a hydraulic shovel according to the present invention.
FIG. 3 is a side view of a conventional hydraulic excavator.
[Explanation of symbols]
Reference Signs List 1 swing motor 7, 8 hydraulic pump 10L, 10R relief valve 22a traveling pressure sensor 22b boom lowering pressure sensor 22c boom raising pressure sensor 22d bucket discharging pressure sensor 22e bucket excavating pressure sensor 22f arm pulling pressure sensor 22g arm Pushing pressure sensor 22h Turning pressure sensor 26 Step-up switch 31dL, 31dR Traveling motor 32cL, 32cR Operating lever 32dL, 32cR Traveling lever 34a Boom cylinder 35a Arm cylinder 36a Bucket cylinder

Claims (4)

When performing a work such as excavation by operating a plurality of hydraulic actuators connected to a hydraulic pump in accordance with the operation of a plurality of operation levers, a boost switch is provided which is pressed down when a large excavation force is required . In a boost control method for a hydraulic shovel in which the set pressure of a relief valve connected to the hydraulic actuator is temporarily increased by being pressed to increase the maximum pressure of hydraulic oil flowing into the hydraulic actuator, the boost switch is pressed. A signal corresponding to the operation of each of the operation levers at the time of the operation, and separates the detected signal into an excavation signal and a non-excavation signal. A pressure increase control method for a hydraulic shovel , wherein the set pressure of the relief valve is temporarily increased only when it is determined that : 2. The method according to claim 1, wherein the non-digging signal includes a traveling and turning signal. When performing a work such as excavation by operating a plurality of hydraulic actuators connected to a hydraulic pump in accordance with the operation of a plurality of operation levers, a boost switch is provided which is pressed down when a large excavation force is required . In a booster control device for a hydraulic shovel, which temporarily increases a set pressure of a relief valve connected to the hydraulic actuator by pressing to increase the maximum pressure of hydraulic oil flowing into the hydraulic actuator, the operation of each of the operation levers Signal detection means for detecting a signal corresponding to the signal, and signal separation means for separating the signal detected by the signal detection means into an excavation signal and a non-excavation signal, when the boost switch is pressed signal drilling signal is included in, and only when it is determined that the non-excavation signal is not included, temporarily increase the set pressure of the relief valve Hydraulic excavator boost control apparatus characterized by comprising a relief valve control means for causing. The boost control device for a hydraulic shovel according to claim 3, wherein the non-digging signal includes a traveling and turning signal.

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