JP2015067994A - Construction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent overturn of a machine body and reduce degree of fatigue of an operator with a simple and inexpensive configuration.SOLUTION: A controller (70) correction-controls to reduce a discharge rate of a hydraulic pump (1)according to an attitude of a machine body (12) on the basis of an output from a gyro sensor (8) so that the machine body (12) is made less likely to fall over. Thus, motion of a hydraulic cylinder (41) for driving a boom (25) becomes lower than usual, operation by an operator is easy, the fall of the machine body (12) can be suppressed, and the degree of fatigue of the operator can be reduced.

Description

  The present invention relates to a construction machine such as a hydraulic excavator or a crane.

  Conventionally, there is a construction machine described in JP-A-7-180192 (Patent Document 1).

  This conventional construction machine calculates the static overturning moment and the dynamic overturning moment by the calculation means from the outputs of the tilt angle sensor of the airframe, the rotation angle sensor of the turning body, the boom rotation angle sensor and the arm rotation angle sensor, Furthermore, the sum of the static overturning moment and the dynamic overturning moment is obtained, and when the overturning condition is satisfied, the proportional solenoid valve is controlled to reduce the oil to the hydraulic motor that drives the rotating body. The revolving body is decelerated to prevent falling.

JP 7-180192 A

  However, in the conventional construction machine described above, when the overturning condition is satisfied on the slope, only the speed of the turning body is reduced. Therefore, even if the speed of the turning body is reduced, the turning may occur depending on the operation of the boom. There was a problem that there was. Specifically, for example, when performing a boom operation on an inclined ground, or when performing an operation to lift the boom, the balance may be lost due to the inclination angle or reaction of the boom operation, and the aircraft may fall down. Beyond the ground, the operator must be careful with each operation.

  For this reason, the conventional construction machine has a problem that the operator has to control the position and speed of the boom with great care, resulting in high fatigue.

  In the conventional construction machine described above, the static fall moment and the dynamic fall moment are calculated from the outputs of the machine tilt angle sensor, the turning body rotation angle sensor, the boom rotation angle sensor, and the arm rotation angle sensor, and are proportional. Since the solenoid valve has to be controlled, there is a problem that the control and structure are complicated and the manufacturing cost is increased.

  Accordingly, an object of the present invention is to provide a construction machine that can suppress the overturn of the airframe and can reduce an operator's fatigue degree with a simple and inexpensive configuration.

In order to solve the above problems, the construction machine of this invention is
A traveling device;
The aircraft provided in the traveling device;
A boom provided on the aircraft,
A gyro sensor for detecting the attitude of the aircraft,
A hydraulic pump;
An actuator for driving at least the boom;
A control valve for controlling oil supplied from the hydraulic pump to the actuator;
A remote control for outputting operation signals for the hydraulic pump and the control valve;
Based on the operation signal and the output from the gyro sensor, a controller for correcting and controlling the discharge amount of the hydraulic pump so as to prevent the airframe from falling over according to the attitude of the airframe. It is characterized by that.

  According to the above configuration, the controller performs correction control based on the output from the gyro sensor so as to reduce the discharge amount of the hydraulic pump in accordance with the attitude of the aircraft so that the aircraft does not easily fall over. To do.

  As described above, the discharge amount of the hydraulic pump is reduced based on the output from the gyro sensor according to the attitude of the airframe so that the airframe is unlikely to fall down, so at least oil is supplied from the hydraulic pump. The operation of the actuator including the actuator for driving the boom is slower than usual, so that the operation of the operator is facilitated, the fall of the construction machine can be suppressed easily and inexpensively, and the fatigue level of the operator is reduced. be able to.

  In addition, since the discharge amount of the hydraulic pump is controlled according to the attitude of the aircraft in this way, it is possible to ensure the same operability as usual even in various aircraft attitudes, and the work attitude and work state Deterioration of operability due to the combination can be suppressed. For example, by lowering the gain of the change in pump discharge amount relative to the operation amount, the movement of the actuator during operation can be slowed down, so the aircraft should move more safely even when operating normally. Thus, the operator's fatigue level can be suppressed.

In one embodiment,
The controller performs correction control based on the operation signal from the remote controller so that the discharge amount of the hydraulic pump decreases when the boom operates in a direction in which the airframe falls.

  According to the above embodiment, when the boom operates in the direction in which the airframe falls, the correction control is performed so that the discharge amount of the hydraulic pump is reduced, that is, in consideration of the operating direction of the boom. Since the discharge amount of the hydraulic pump is reduced and the speed of the actuator is lowered, the fall of the construction machine can be further suppressed, and the fatigue level of the operator can be further reduced.

In one embodiment,
The aircraft includes a swivel,
The actuator includes a hydraulic motor for turning the swivel,
The gyro sensor is provided on the swivel base.

  According to the above embodiment, since the gyro sensor is provided on the swivel base, the gyro sensor detects an inclination of the swivel base with respect to the horizontal plane, and the orientation of the swivel base, that is, the plane of the boom. The direction in viewing can be detected.

  Therefore, the controller reduces the discharge amount of the hydraulic pump according to the tilt of the swivel and the direction of the boom in a plan view represented by the operation signal from the gyro sensor, and an actuator and a hydraulic pressure that drive the boom It is possible to reduce the speed of the motor. Therefore, the fall of the construction machine can be further suppressed, and the operator's fatigue can be further reduced.

In one embodiment,
The controller corrects to reduce the discharge amount of the hydraulic pump based on the tilt angle of the swivel and the output of the gyro sensor indicating the direction of the boom in plan view so that the airframe is unlikely to fall down. Control.

  According to the above embodiment, the hydraulic motor and the boom for turning the swivel base by reducing the discharge amount of the hydraulic pump in consideration of the tilt angle of the swivel base and the orientation of the boom in plan view. Since the speeds of both the driving actuator and the actuator are reduced, it is possible to further suppress the fall of the construction machine and to further reduce the operator's fatigue.

One embodiment is:
A boom rotation angle sensor for detecting the rotation angle of the boom,
Based on the tilt angle of the swivel and the output of the gyro sensor representing the direction of the boom in plan view, the discharge amount of the hydraulic pump that has been corrected and controlled is determined based on the rotation angle of the boom. Further correction is performed with a correction coefficient determined for the above.

  According to the embodiment, the discharge amount of the hydraulic pump that is determined (corrected and controlled) based on the output of the gyro sensor that represents the tilt angle of the swivel base and the direction of the boom in plan view, Further correction is made with a correction coefficient determined for the risk of airframe condition based on the rotation angle of the boom, so that the discharge amount of the hydraulic pump can be reduced more appropriately, and the speed of the actuator can be reduced more appropriately. The operator's fatigue level can be further reduced.

In one embodiment,
The control valve includes a meter-in passage, a meter-out passage, and a bleed-off passage.

  According to the embodiment, the control valve includes a meter-in passage, a meter-out passage, and a bleed-off passage having respective opening characteristics, and the operability and feeling of operation are improved. On the basis of the output, the controller reduces the discharge amount of the hydraulic pump according to the attitude of the machine body, so that the operator's fatigue can be further reduced.

In one embodiment,
The remote control is a remote control valve.

  According to the embodiment, since the remote controller is a remote control valve, it is possible to control a pilot pressure that is a hydraulic signal according to an operation amount or to output an operation signal that is an electric signal according to the operation amount. it can.

  However, the remote control valve may generate only a hydraulic signal.

  According to the present invention, based on the output from the gyro sensor, the discharge amount of the hydraulic pump is reduced according to the attitude of the aircraft so that the aircraft does not easily fall down. The operation becomes slower than usual, and the operation of the operator is safe and easy, the fall of the construction machine can be suppressed easily and inexpensively, and the fatigue level of the operator can be reduced.

It is a front view of the construction machine of 1st Embodiment of this invention. It is a block diagram of the principal part of the said 1st Embodiment. It is a circuit diagram of the principal part of the said 1st Embodiment. It is a flowchart explaining operation | movement of the controller of the said 1st Embodiment. It is a graph which shows correction | amendment control of the discharge amount of the hydraulic pump of the said 1st Embodiment. It is a schematic front view explaining operation | movement of the construction machine of the said 1st Embodiment. It is a schematic plan view explaining operation | movement of the construction machine of the said 1st Embodiment. It is a flowchart explaining operation | movement of the controller of the construction machine of 2nd Embodiment of this invention. It is a graph explaining correction | amendment control of the discharge amount of the hydraulic pump of the said 2nd Embodiment.

  Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

(First embodiment)
As shown in FIG. 1, the hydraulic excavator as an example of the construction machine of the first embodiment includes a traveling device 11 and a machine body 12 provided in the traveling device 11, and the machine body 12 is attached to the traveling device 11. A supported lower portion 21 and an upper turntable 23 provided on the lower portion 21 through a turning mechanism 22 so as to be turnable are provided. A cab 24 is provided on one front side of the swivel base 23, and a boom 25 is provided in the center of the front of the swivel base 23 so as to be able to be lifted and lowered. An arm 26 is rotatably provided at the tip of the boom 25, and a bucket 27 is rotatably provided at the tip of the arm 26.

  The boom 25 is lifted by a boom hydraulic cylinder 41, the arm 26 is rotated by an arm hydraulic cylinder 42, and the bucket 27 is rotated by a bucket hydraulic cylinder 43. The hydraulic cylinders 41, 42, and 43 are examples of actuators.

  Above the turntable 23, the hydraulic motor 2 for turning the turntable 23 via the turn mechanism 22, a turn angle sensor 45 for detecting the turn angle of the turntable 23, and the attitude of the turntable 23. And a gyro sensor 8 for detecting the above.

  Further, the rotation angle of the boom 25 is detected by the boom rotation angle sensor 51, the rotation angle of the arm 26 is detected by the arm rotation angle sensor 52, and the rotation angle of the bucket 27 is detected by the bucket rotation angle sensor 53. I have to.

  The swivel base 23, boom 25, arm 26, bucket 27, hydraulic motor 2, boom hydraulic cylinder 41, arm hydraulic cylinder 42, bucket hydraulic cylinder 43, and the like constitute a working machine 40.

  FIG. 2 is a block diagram of a main part of the construction machine according to the first embodiment. As shown in FIG. 2, the supply direction and supply amount of hydraulic fluid from the hydraulic pump 1 to the hydraulic motor 2 for the swivel base are controlled by a control valve 3, which is an operation remote control valve as an example of a remote control. The pilot pressure from 5 is controlled.

  Further, as shown in FIG. 2, a control valve (not shown) is connected to a hydraulic cylinder 41 as an actuator for driving the boom 25 (see FIG. 1), as shown in FIG. Control the oil. Although not shown, the control valve is provided for each actuator such as the hydraulic cylinder 42 for the arm and the hydraulic cylinder 43 for the bucket.

  The control valve 3 is a spool valve, and has a bleed-off passage 31, a meter-in passage 32, and a meter-out passage 33 as schematically shown in FIG. The opening area (opening characteristics) with respect to the operation amount of the bleed-off passage 31, the meter-in passage 32, and the meter-out passage 33 is indicated by a solid line in each graph of FIG. 3 by a groove-like passage (not shown) machined in the spool valve. As such, it is predetermined. By using the control valve 3 having such opening characteristics, operability and operational feeling are improved.

  As shown in FIG. 2, the gyro sensor 8 includes the body attitude information, that is, the inclination angle of the body 12 with respect to the horizontal plane (inclination angle with respect to the horizontal plane of the swivel base 23) and the orientation of the swivel base 23, that is, the work machine. A signal representing the direction of 40 in plan view (the direction of plan view of the boom 25) is output to the controller 70. The controller 70 is based on an operation signal (a pressure or an angle signal corresponding to an operation lever angle) received from an operation remote control valve 5 as an example of a remote controller, and the body posture information which is an output of the gyro sensor 8. A discharge amount command signal is created and output to the hydraulic pump 1.

  By this discharge amount command signal, the discharge amount of the hydraulic pump 1 is corrected and controlled as indicated by a broken line in the horizontal graph of the hydraulic pump 1 in FIG. In this graph, the solid line represents the discharge amount of the hydraulic pump 1 with respect to the normal operation amount in which the discharge amount of the hydraulic pump 1 is not corrected. The hydraulic pump 1 is a variable displacement hydraulic pump, but a fixed displacement hydraulic pump may be used to control the rotation speed and control the discharge amount.

  This correction control is performed in the procedure of steps S1 to S5 shown in FIG. As shown in FIG. 4, first, the controller 70 takes in the output (airframe posture information) of the gyro sensor 8 (step S1), and determines whether or not the swivel base 23 is inclined more than a predetermined value. (Step S2). If not, the determination in step S2 is repeated, and if yes, the process proceeds to step S3.

  In step S <b> 3, based on the body posture information from the gyro sensor 8, it is determined whether or not the direction of the boom 25 in plan view is upward in the tilt direction of the swivel base 23. If NO is determined in step S3, the process returns to step S2. If YES is determined in step S3, the process proceeds to step S4.

  In step S4, it is determined by the operation signal from the operation remote control valve 5 whether or not the direction in which the boom 25 is rotated is downward in the tilt direction of the swivel base 23. If not, the process returns to step S2. Proceed to step S5.

  In step S5, the discharge amount of the hydraulic pump 1 is corrected and controlled according to the operation amount in a pattern indicated by a broken line with respect to the discharge amount of the hydraulic pump 1 at the normal time indicated by the solid line in FIG. The pattern shown by the broken line in FIG. 5 reduces the increase rate of the discharge amount of the hydraulic pump 1 relative to the operation amount, slows the speed change, limits the upper limit of the discharge amount, and suppresses the maximum speed. 12 is prevented from suddenly becoming a dangerous posture. In FIG. 5, a plurality of broken lines use the tilt angle of the swivel base 23 as a parameter, and the larger the tilt angle, the lower the broken line, and the smaller the discharge amount. The broken line pattern may be stored in advance in a memory (not shown), and the hydraulic pump 1 may be controlled by reading out the discharge amount of the hydraulic pump 1 from the memory in accordance with the operation amount and the tilt angle of the swivel base. Alternatively, the discharge amount of the hydraulic pump 1 may be controlled by an arithmetic expression stored in advance representing the broken line.

  In the hydraulic excavator having the above-described configuration, it is assumed that the hydraulic excavator is now positioned on the slope 100 inclined more than a predetermined value as shown in FIG. Then, it is assumed that the boom 25 is rotated by the operation remote controller valve 5 as shown by an arrow X in FIG.

  At this time, because of the lifting operation of the boom 25 in the tilted posture of the fuselage 12, the center of gravity of the fuselage 12 retreats and the possibility of the fuselage 12 to fall increases. However, correction control is performed as follows. The overturning of the body 12 is suppressed, and the operator's feeling of fatigue is reduced.

  The controller 70 determines that the swivel base 23 is tilted more than a predetermined value based on the body posture information from the gyro sensor 8 (step S2 in FIG. 4), and further from the gyro sensor 8. Is determined that the direction of the boom 25 is upward in the tilt direction of the swivel base 23 in plan view (step S3).

  Next, based on an operation signal from the operation remote control valve 5, it is determined that the direction X in which the boom 25 is rotated is downward in the tilt direction of the swivel base 23 (step S5), and is indicated by a broken line in FIG. In the pattern, correction control is performed so that the discharge amount of the hydraulic pump 1 with respect to the operation amount is reduced as compared with the normal time (step S4). The correction control indicated by the broken line in FIG. 5 uses the tilt angle of the swivel base 23 as a parameter, and the greater the tilt angle, the greater the reduction in the discharge amount.

  As shown by the broken line in FIG. 5, by controlling the discharge amount of the hydraulic pump 1, the increase gain of the discharge amount with respect to the operation amount is reduced, and the speed change of the actuators such as the boom 25 and the swivel base 23 is blunted. Further, the upper limit of the discharge amount can be limited to suppress the maximum speed of the boom 25, the swivel base 23, and the like, so that the airframe 12 can be prevented from suddenly becoming a dangerous posture, and the overturn of the airframe 12 can be suppressed. .

  Moreover, since the speed change of actuators, such as the boom 25 and the turntable 23, becomes dull, an operator does not need to be excessively cautious and can reduce an operator's fatigue degree.

  In addition, it is possible to suppress deterioration in operability due to a combination of work postures and work states. For example, by reducing the discharge amount of the hydraulic pump 1, the movement of the actuator during operation can be slowed down, so that the airframe 12 can be made to move more safely even when performing a normal operation. Thus, the operator's fatigue level can be suppressed.

  Further, since the correction is made so as to reduce the discharge amount of the hydraulic pump 1 while maintaining the opening characteristic of the control valve 3, the operability and operational feeling for the operator are not impaired.

(Second Embodiment)
The hydraulic excavator as an example of the construction machine of the second embodiment is only for further correcting the discharge amount pattern of the hydraulic pump 1 at the time of correction shown in FIG. 5 by the output of the boom rotation angle sensor 51 shown in FIG. However, it is different from the hydraulic excavator of the first embodiment.

  Therefore, since the hardware of the second embodiment is the same as that of the first embodiment, FIGS. 1 to 3 and FIG. 5 and the description thereof are cited, and only different configurations will be described below.

  The flowchart shown in FIG. 8 of the second embodiment is different from the flowchart shown in FIG. 4 of the first embodiment only in that step S6 is added. The description of the embodiment is omitted with reference to only the step S6.

  In step S6 of FIG. 8, the controller 70 sets the corrected discharge amount shown in FIG. 9A of the hydraulic pump 1 determined by the tilt angle of the swivel base 23 and the orientation of the boom 25 obtained in step S5. The correction discharge amount of the hydraulic pump 1 is corrected by multiplying the correction coefficient according to the risk level of the airframe state shown in 9 (B), and the discharge amount of the hydraulic pump 1 is controlled to the corrected correction discharge amount.

  Here, the danger level of the airframe state is defined as the rotation angle detected by the boom rotation angle sensor 51 corresponding to the height of the boom 25 because the danger level of the airframe 12 increases as the boom 25 rises higher. ing. However, in addition to the output of the boom rotation angle sensor 51, the risk of the aircraft state is determined using the output of the arm rotation angle sensor 52, or using the outputs of the arm rotation angle sensor 52 and the bucket rotation angle sensor 53, You may define by the height of the working machine 40. FIG. However, since the rotation angle of the boom 25 is the main factor of the risk level of the fuselage state, the second embodiment defines the rotation angle of the boom 25.

  And the graph which shows the relationship between the danger level of a body state and a correction coefficient as shown to (B) of FIG. 9 is memorize | stored beforehand in the memory which is not shown in figure. Then, the corrected output value, that is, the corrected discharge amount corrected by the inclination angle of the swing body 23 and the direction of the boom 25 shown in FIG. 9A, and the correction coefficient shown in FIG. The corrected discharge amount after correction of the hydraulic pump 1 is calculated by multiplication. During the operation of the boom 25, the correction coefficient is successively changed in accordance with the rotation angle of the boom 25, so that the corrected discharge amount after the correction of the hydraulic pump 1 is sequentially changed.

  As described above, the controller 70 sequentially corrects the corrected discharge amount corrected by the tilt angle of the revolving structure 23 and the direction of the boom 25 by the correction coefficient that changes in accordance with the rotation angle of the boom 25. Since the discharge amount of the hydraulic pump 1 is controlled to the corrected discharge amount, the discharge amount of the hydraulic pump 1 is more appropriately reduced, and the speeds of actuators such as the boom 25 and the hydraulic motor 2 are more appropriately reduced. Thus, it is possible to more reliably suppress the overturn of the airframe and to further reduce the fatigue level of the operator.

  In the first and second embodiments, the correction of the discharge amount of the hydraulic pump 1 with respect to the operation amount is indicated by a broken line in FIG. 5, but this correction is not limited to a broken line, You may make it correct | amend along the curved curve.

  In the first and second embodiments, the operation remote control valve 5 that outputs a pilot hydraulic pressure signal and an electrical signal is used as the remote control. However, a remote control that outputs only an electrical signal may be used.

  In the first and second embodiments, the control valve 3 is a single valve having the meter-in passage 32, the meter-out passage 33, and the bleed-off passage 31, but each control valve has a meter-in passage, It may be a composite valve composed of a plurality of valves corresponding to the meter-out passage and the bleed-off passage. The control valve may be a control valve having a meter-in passage and a meter-out passage and having no bleed-off passage.

  In the first and second embodiments, the construction machine is a hydraulic excavator. However, the present invention is not limited to the hydraulic excavator but can be applied to a construction machine such as a crane. For example, it may be a construction machine that has a boom and an arm and does not have a swivel, such as a truck crane.

  Of course, the constituent elements described in the first and second embodiments and modifications may be combined as appropriate, and may be selected, replaced, or deleted as appropriate.

DESCRIPTION OF SYMBOLS 1 Hydraulic pump 2 Hydraulic motor 3 Control valve 5 Operation remote control valve 70 Controller 8 Gyro sensor 11 Traveling device 12 Airframe 23 Turntable 25 Boom 26 Arm 27 Bucket 31 Bleed-off passage 32 Meter-in passage 33 Meter-out passage 41, 42, 43 Hydraulic pressure Cylinder 40 Working machine 51 Boom rotation angle sensor 52 Arm rotation angle sensor 53 Bucket rotation angle sensor

Claims (7)

A traveling device (11);
An airframe (12) provided in the traveling device (11);
A boom (25) provided on the airframe (12);
A gyro sensor (8) for detecting the attitude of the airframe (12);
A hydraulic pump (1);
An actuator (2, 41) for driving at least the boom (25);
A control valve (3) for controlling oil supplied from the hydraulic pump (1) to the actuator (2, 41);
A remote control (5) for outputting an operation amount signal for the hydraulic pump (1) and the control valve (3);
Based on the operation amount signal and the output from the gyro sensor (8), the hydraulic pump (1) discharges so that the airframe (12) is unlikely to fall down according to the attitude of the airframe (12). A construction machine comprising a controller (70) that performs correction control so as to reduce the amount. The construction machine according to claim 1,
Based on the operation amount signal from the remote controller (5), the controller (70) moves the hydraulic pump (1) when the boom (25) operates in the direction in which the body (12) falls. The construction machine is characterized in that correction control is performed so as to reduce the discharge amount. The construction machine according to claim 2,
The airframe (12) includes a swivel (23),
The actuator (2, 41) includes a hydraulic motor (2) for turning the turntable (23),
The construction machine, wherein the gyro sensor (8) is provided on the swivel base (23). The construction machine according to claim 3,
The controller (70) causes the airframe (12) to fall over based on the output of the gyro sensor (8) indicating the tilt angle of the swivel base (23) and the orientation of the boom (25) in plan view. A construction machine that performs correction control so as to reduce the discharge amount of the hydraulic pump (1) so as to be difficult. The construction machine according to claim 4,
A boom rotation angle sensor (51) for detecting the rotation angle of the boom (25);
Based on the output of the gyro sensor (8) indicating the tilt angle of the swivel base (23) and the direction of the boom (25) in plan view, the discharge amount of the hydraulic pump (1) subjected to correction control is determined. A construction machine characterized by further correcting with a correction coefficient determined for the risk of airframe condition based on the rotation angle of the boom (25). In the construction machine according to any one of claims 1 to 5,
The control valve (3) includes a meter-in passage (32), a meter-out passage (33), and a bleed-off passage (31). The construction machine according to any one of claims 1 to 6,
The construction machine characterized in that the remote control (5) is a remote control valve (5).

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