JP6689772B2 - Excavator - Google Patents

Description

  The present invention relates to excavators.

  BACKGROUND ART Conventionally, there is known a shovel that delays the movement of an end attachment by reducing the horsepower of a hydraulic pump when a boom angle is equal to or greater than a predetermined value (see, for example, Patent Document 1).

International Publication No. 2012/121252

  However, the above-mentioned shovel does not disclose control of the horsepower of the hydraulic pump when the shovel is impacted by excavation work or the like.

  By the way, when the shovel receives an impact due to excavation work or the like, vibration occurs in the upper swing body and the attachment, and it is difficult to perform desired excavation work. Therefore, the operator may temporarily suspend the excavation work until the vibration of the upper swing body and the attachment is subsided. At this time, the shovel continues to consume fuel, and thus consumes extra fuel.

  Therefore, in view of the above problems, it is an object to provide a shovel that can suppress unnecessary fuel consumption.

  According to the excavator according to one aspect of the present invention, the lower traveling body, the upper revolving body rotatably mounted on the lower traveling body, and the hydraulic fluid that is attached to the upper revolving body and is discharged by the hydraulic pump are driven. An attachment, an acceleration sensor attached to at least one of the upper swing body and the attachment, and a detection value of the acceleration sensor is larger than a predetermined value, a control device for reducing the horsepower of the hydraulic pump, Equipped with.

  According to the embodiment of the present invention, unnecessary fuel consumption can be suppressed.

A side view showing an example of a shovel according to an embodiment of the present invention. Block diagram showing a configuration example of a drive system of the shovel of FIG. The figure which shows an example of a structure of the machine guidance apparatus of the shovel of FIG. Flowchart showing an example of the flow of horsepower control processing Time chart of an example of horsepower control processing Flowchart showing another example of the flow of horsepower control processing Time chart of another example of horsepower control processing The flowchart which shows another example of the flow of horsepower control processing. Time chart of yet another example of horsepower control processing

  Hereinafter, embodiments for carrying out the invention will be described with reference to the drawings. In each drawing, the same components may be denoted by the same reference numerals and duplicate description may be omitted.

  FIG. 1 is a side view illustrating a shovel PS according to an embodiment of the present invention.

  As shown in FIG. 1, an upper swing body 3 is rotatably mounted on a lower traveling body 1 of the shovel PS via a swing mechanism 2. A boom 4 is attached to the upper swing body 3. An arm 5 is attached to the tip of the boom 4. A bucket 6 is attached to the tip of the arm 5 as an end attachment (work site) by an arm top pin P1 and a bucket link pin P2. As the end attachment, a slope bucket, a dredging bucket, a breaker or the like may be attached. As described above, the attachment mainly includes different members such as the boom 4, the arm 5, the end attachment, the bucket link mechanism, the boom cylinder 7, and the arm cylinder 8.

  The boom 4, the arm 5, and the bucket 6 form an excavation attachment as an example of the attachment, and are hydraulically driven by the boom cylinder 7, the arm cylinder 8, and the bucket cylinder 9, respectively. A boom angle sensor S1, an arm angle sensor S2, and a bucket angle sensor S3 are attached to the boom 4, the arm 5, and the bucket 6, respectively. The excavation attachment may be provided with a bucket tilt mechanism.

  The boom angle sensor S1 detects the rotation angle of the boom 4. The boom angle sensor S1 is, for example, an acceleration sensor that detects an inclination with respect to a horizontal plane and detects a rotation angle of the boom 4 with respect to the upper swing body 3. Further, the boom angle sensor S1 detects the magnitude and frequency of the shock received by the boom 4.

  The arm angle sensor S2 detects the rotation angle of the arm 5. The arm angle sensor S2 is an acceleration sensor that detects, for example, an inclination with respect to a horizontal plane to detect a rotation angle of the arm 5 with respect to the boom 4. In addition, the arm angle sensor S2 detects the magnitude and frequency of the impact received by the arm 5.

  The bucket angle sensor S3 detects the rotation angle of the bucket 6. The bucket angle sensor S3 is an acceleration sensor that detects, for example, an inclination with respect to a horizontal plane and detects a rotation angle of the bucket 6 with respect to the arm 5. Further, the bucket angle sensor S3 detects the magnitude and frequency of the shock received by the bucket 6. The bucket angle sensor S3 is attached to the bucket link mechanism in FIG.

  When the excavation attachment includes a bucket tilt mechanism, the bucket angle sensor S3 additionally detects the rotation angle of the bucket 6 around the tilt axis. The boom angle sensor S1, the arm angle sensor S2, and the bucket angle sensor S3 are potentiometers that use variable resistors, stroke sensors that detect the stroke amount of the corresponding hydraulic cylinders, rotary encoders that detect the rotation angle around the connection, etc. May be

  The upper swing body 3 is mounted with a power source such as the engine 11 and a vehicle body inclination sensor S4 and is covered with a cover 3a. The vehicle body inclination sensor S4 detects the inclination angle of the upper swing body 3. The vehicle body tilt sensor S4 is, for example, an acceleration sensor that detects a tilt with respect to a horizontal plane to detect a tilt angle of the upper swing body 3. Further, the vehicle body inclination sensor S4 detects the magnitude and frequency of the impact received by the upper swing body 3.

  An imaging device 80 is provided above the cover 3a of the upper swing body 3. The imaging device 80 includes a camera 80L for imaging the left side, a camera 80R for imaging the right side, and a camera 80B for imaging the rear side from the upper swing body 3 toward the cabin 10. The cameras 80L, 80R, and 80B are digital cameras having an image pickup device such as a CCD or a CMOS, and send captured images to the display device 40 provided in the cabin 10.

  The upper swing body 3 is provided with a cabin 10 as a driver's cab. At the top of the cabin 10, a GPS device (GNSS receiver) G1 and a transmission device T1 are provided. The GPS device G1 detects the position of the shovel PS by the GPS function and supplies the position data to the machine guidance device 50 in the controller 30. The transmitter T1 transmits information to the outside of the shovel PS. Further, in the cabin 10, a controller 30, a display device 40, an audio output device 43, an input device 45, and a storage device 47 are provided.

  The controller 30 functions as a main control unit that controls the driving of the shovel PS. The controller 30 is composed of a computer including a CPU, a RAM, a ROM and the like.

  The controller 30 also functions as a machine guidance device 50 that guides the operation of the shovel PS (machine guidance function). The machine guidance device 50 notifies the operator of work information such as the distance between the target surface, which is the surface of the target landform set by the operator, and the work site of the attachment. The distance between the target surface and the work site of the attachment is, for example, the distance between the tip (toe) of the bucket 6 serving as the end attachment, the back surface of the bucket 6, the tip of the breaker serving as the end attachment, and the target surface. The machine guidance device 50 notifies the operator of work information via the display device 40, the voice output device 43, etc., and guides the operation of the shovel PS.

  In the embodiment of the present invention, the machine guidance device 50 is incorporated in the controller 30, but the machine guidance device 50 and the controller 30 may be provided separately. In this case, the machine guidance device 50, like the controller 30, is configured by an arithmetic processing device including a CPU and an internal memory. Various functions of the machine guidance device 50 are realized by the CPU executing the programs stored in the internal memory.

  The display device 40 displays an image including various work information according to a command from the machine guidance device 50 included in the controller 30. The display device 40 is, for example, a vehicle-mounted liquid crystal display connected to the machine guidance device 50.

  The voice output device 43 outputs various voice information in response to a voice output command from the machine guidance device 50 included in the controller 30. The voice output device 43 includes an in-vehicle speaker connected to the machine guidance device 50, for example. Further, the audio output device 43 may include an alarm device such as a buzzer.

  The input device 45 is a device for an operator of the shovel PS to input various information to the controller 30 including the machine guidance device 50. The input device 45 includes, for example, a membrane switch provided on the surface of the display device 40. Further, the input device 45 may be configured to include a touch panel and the like.

  The storage device 47 is a device for storing various types of information. The storage device 47 is a non-volatile storage medium such as a semiconductor memory. The storage device 47 stores various information output by the controller 30 including the machine guidance device 50.

  FIG. 2 is a block diagram showing a configuration example of a drive system of the shovel PS of FIG. 1, in which a mechanical power system, a high-pressure hydraulic line, a pilot line, and an electric drive / control system are respectively indicated by a double line, a solid line, a broken line, And a dotted line.

  The drive system of the shovel mainly includes the engine 11, the main pump 12, the regulator 13, the pilot pump 14, the control valve 15, the operating device 16, the pressure sensor 17, the pressure sensor 18, the controller 30, and the engine control unit (ECU) 74. Composed of.

  The engine 11 is controlled by the ECU 74. The engine 11 is a power source of the shovel, and is, for example, an engine that operates to maintain a predetermined rotation speed, and an output shaft of the engine 11 is connected to input shafts of the main pump 12 and the pilot pump 14.

  The main pump 12 is a device for supplying hydraulic oil to the control valve 15 via a high-pressure hydraulic line, and is, for example, a swash plate type variable displacement hydraulic pump.

  The regulator 13 is a device for controlling the discharge flow rate of the main pump 12. The regulator 13 controls the discharge flow rate of the main pump 12 by adjusting the swash plate tilt angle of the main pump 12 according to, for example, the discharge pressure of the main pump 12 or a control signal from the controller 30.

  The pilot pump 14 is a device for supplying hydraulic oil to various hydraulic control devices via a pilot line, and is, for example, a fixed displacement hydraulic pump.

  The control valve 15 is a hydraulic control device that controls the hydraulic system of the shovel PS. The control valve 15 receives, for example, one or more of the boom cylinder 7, the arm cylinder 8, the bucket cylinder 9, the left and right traveling hydraulic motors 20L and 20R, and the turning hydraulic motor 21 from the main pump 12. Oil is selectively supplied. In the following, the boom cylinder 7, the arm cylinder 8, the bucket cylinder 9, the left and right traveling hydraulic motors 20L and 20R, and the turning hydraulic motor 21 will be collectively referred to as "hydraulic actuators".

  The operating device 16 is a device used by an operator to operate the hydraulic actuator. The operating device 16 supplies the hydraulic oil received from the pilot pump 14 to the pilot port of the flow control valve corresponding to each hydraulic actuator via the pilot line. The pressure (pilot pressure) of the hydraulic oil supplied to each of the pilot ports is the pressure corresponding to the operation direction and the operation amount of the operation lever or the operation pedal (not shown) of the operation device 16 corresponding to each hydraulic actuator. To be done.

  The pressure sensor 17 is a sensor for detecting the operation content of the operator using the operation device 16. The pressure sensor 17 detects, for example, the operating direction and the operating amount of the operating lever or the operating pedal of the operating device 16 corresponding to each hydraulic actuator in the form of pressure, and outputs the detected value to the controller 30. The operation content of the operation device 16 may be detected using a sensor other than the pressure sensor.

  The pressure sensor 18 detects the discharge pressure of the main pump 12 and outputs the detected value to the controller 30.

  The controller 30 controls the operation of the entire shovel PS including the ECU 74. The controller 30 is a control device for controlling the operating speed of the hydraulic actuator, and is composed of, for example, a computer including a CPU, a RAM, a ROM and the like. Further, the controller 30 reads out the programs corresponding to the impact determination unit 301, the horsepower control unit 302, and the motion control unit 303 from the ROM and expands the programs in the RAM, and causes the CPU to execute the corresponding processes.

  Specifically, the controller 30 receives a detection value output from at least one of the boom angle sensor S1, the arm angle sensor S2, the bucket angle sensor S3, and the vehicle body tilt sensor S4. Then, the controller 30 executes the processing by the impact determination unit 301, the horsepower control unit 302, and the motion control unit 303 based on these detection values. After that, the controller 30 appropriately outputs a control signal corresponding to the processing result of each of the impact determination unit 301, the horsepower control unit 302, and the operation control unit 303 to the ECU 74, the regulator 13, or the operation device 16.

  The impact determination unit 301 determines whether or not the shovel PS has been impacted based on the detection signal of at least one of the boom angle sensor S1, the arm angle sensor S2, the bucket angle sensor S3, and the vehicle body tilt sensor S4. To judge.

  Specifically, the impact determination unit 301 has a magnitude of impact detected by at least one of the boom angle sensor S1, the arm angle sensor S2, the bucket angle sensor S3, and the vehicle body tilt sensor S4 that is larger than the first threshold value. In this case, it is determined that the shovel PS is in a shocked state. On the other hand, when the magnitude of the impact detected by at least one of the boom angle sensor S1, the arm angle sensor S2, the bucket angle sensor S3, and the vehicle body tilt sensor S4 is less than or equal to the first threshold value, the impact determination unit 301 determines whether the shovel It is determined that the PS has not been impacted. The first threshold value is set according to the magnitude of the shock to be detected and the like.

  In addition, the impact determination unit 301, when the frequency of the impact detected by at least one of the boom angle sensor S1, the arm angle sensor S2, the bucket angle sensor S3, and the vehicle body tilt sensor S4 is larger than the second threshold, the shovel PS. Is judged to have been shocked. On the other hand, when the frequency of the shock detected by at least one of the boom angle sensor S1, the arm angle sensor S2, the bucket angle sensor S3, and the vehicle body tilt sensor S4 is equal to or lower than the second threshold, the shock determination unit 301 shovels PS. Is determined not to be impacted. The second threshold value is set according to the magnitude of the shock to be detected and the like.

  Further, the impact determination unit 301 detects that the magnitude of the impact detected by the first acceleration sensor is larger than the first threshold, and the frequency of the impact detected by the first acceleration sensor and the second acceleration sensor. When the frequency of the impact is substantially the same, it is determined that the shovel PS is in the impacted state. The first acceleration sensor is at least one of a boom angle sensor S1, an arm angle sensor S2, a bucket angle sensor S3, and a vehicle body tilt sensor S4. The second acceleration sensor is a sensor different from the first acceleration sensor among at least one of the boom angle sensor S1, the arm angle sensor S2, the bucket angle sensor S3, and the vehicle body tilt sensor S4.

  The horsepower control unit 302 outputs a control signal to the ECU 74 or the regulator 13 to change the horsepower of the main pump 12 based on the determination result of the impact determination unit 301. Specifically, when the impact determination unit 301 determines that the shovel PS is in an impacted state, the horsepower control unit 302 controls the ECU 74 to reduce the rotation speed of the engine 11, thereby The horsepower of the pump 12 is reduced. The rotation speed of the engine 11 is detected by the rotation speed sensor 11a. The rotation speed of the engine 11 detected by the rotation speed sensor 11a is output to the ECU 74. Further, the horsepower control unit 302 may reduce the horsepower of the main pump 12 by adjusting the regulator 13 and reducing the discharge flow rate of the main pump 12. Then, since the horsepower of the main pump 12 is reduced, the amount of hydraulic oil supplied to the hydraulic actuator is reduced. Thereby, unnecessary fuel consumption can be suppressed and energy efficiency can be improved.

  The operation control unit 303 outputs a control signal to the operation device 16 so as to change the position of the bucket 6 based on the determination result of the impact determination unit 301. Specifically, when the shock determination unit 301 determines that the shovel PS is in a shocked state, the operation control unit 303 adjusts the operation direction and the operation amount of the operation lever or the operation pedal of the operation device 16. By doing so, for example, the bucket 6 is moved in a direction of separating from the target surface (target position). Then, by separating the bucket 6 from the target position, it is possible to prevent unintended excavation. In addition, when the shock determination unit 301 determines that the shovel PS is in a shocked state, the operation control unit 303 adjusts the operation direction and the operation amount of the operation lever or the operation pedal of the operation device 16. , Suppress hunting, for example.

  Further, an operation valve capable of controlling the pressure (pilot pressure) of the hydraulic oil supplied to the pilot port of the flow control valve corresponding to each hydraulic actuator may be provided between the operation device 16 and the control valve 15. . In this case, the operation control unit 303 may output a control signal to the operation valve so as to change the position of the bucket 6 or suppress hunting based on the determination result of the impact determination unit 301. Good.

  When the impact determination unit 301 determines that the shovel PS is in the impacted state, the storage unit 304 stores the impacted position.

  Next, the machine guidance device 50 will be described. FIG. 3 is a diagram showing an example of the configuration of the machine guidance device for the shovel shown in FIG.

  The machine guidance device 50 receives various signals and data supplied to the controller 30 from the boom angle sensor S1, the arm angle sensor S2, the bucket angle sensor S3, the vehicle body tilt sensor S4, the GPS device G1, the input device 45, and the like. .

  The machine guidance device 50 calculates the actual operating position of the attachment such as the bucket 6 based on the received signal and data. Then, the machine guidance device 50 compares the actual operating position of the attachment with the target surface, and calculates the distance between the bucket 6 and the target surface, for example. The machine guidance device 50 also calculates the distance from the central axis of rotation of the shovel PS to the toe of the bucket 6, the inclination angle of the target surface, and the like, and sends these to the display device 40 as work information.

  When the machine guidance device 50 and the controller 30 are separately provided, the machine guidance device 50 and the controller 30 are communicably connected to each other through the CAN.

  The machine guidance device 50 includes a height calculation unit 503, a comparison unit 504, a display control unit 505, and a guidance data output unit 506.

  The height calculation unit 503 calculates the height of the tip (toe) of the bucket 6 from the angles of the boom 4, the arm 5, and the bucket 6, which are obtained from the detection signals of the boom angle sensor S1, the arm angle sensor S2, and the bucket angle sensor S3. Calculate the

  The comparison unit 504 compares the height of the tip (toe) of the bucket 6 calculated by the height calculation unit 503 with the position of the target surface indicated in the guidance data output from the guidance data output unit 506. Further, the comparison unit 504 calculates the inclination angle of the target surface with respect to the shovel PS. Various data obtained by the height calculation unit 503 and the comparison unit 504 are stored in the storage device 47.

  The display control unit 505 transmits the height of the bucket 6, the inclination angle of the target surface, and the like obtained by the comparison unit 504 to the display device 40 as work information. The display device 40 displays the work information sent from the display control unit 505 on the screen together with the captured image sent from the imaging device 80. Further, the display control unit 505 can issue an alarm to the operator via the voice output device 43 when the bucket 6 is at a position lower than the target surface.

  Next, an example of processing in which the controller 30 controls horsepower (hereinafter referred to as “horsepower control processing”) will be described. FIG. 4 is a flowchart showing an example of the flow of horsepower control processing. The controller 30 repeatedly executes the horsepower control process in a predetermined cycle.

  First, the impact determination unit 301 determines whether the magnitude of the impact detected by at least one of the boom angle sensor S1, the arm angle sensor S2, the bucket angle sensor S3, and the vehicle body tilt sensor S4 is larger than the first threshold value. It is determined (step ST11).

  When it is determined in step ST11 that the magnitude of the impact is larger than the first threshold value, the horsepower control unit 302 reduces the horsepower of the main pump 12 (step ST12). Specifically, the horsepower control unit 302 controls the ECU 74 to reduce the rotational speed of the engine 11, thereby reducing the horsepower of the main pump 12. Alternatively, the horsepower control unit 302 adjusts the regulator 13 to reduce the discharge flow rate of the main pump 12, thereby reducing the horsepower of the main pump 12. Then, the process ends.

  On the other hand, when it is determined in step ST11 that the magnitude of the impact is less than or equal to the first threshold value, the process ends without reducing the horsepower of the main pump 12.

  FIG. 5 is a time chart of an example of horsepower control processing. FIG. 5A shows the relationship between time t (horizontal axis) and the acceleration (vertical axis) detected by the arm angle sensor S2. b) shows the relationship between time t (horizontal axis) and pump horsepower (vertical axis). Further, in FIG. 5A, the solid line shows the time change of the acceleration when the horsepower control process is performed, and the broken line shows the time change of the acceleration when the horsepower control process is not performed.

  As shown in FIGS. 5A and 5B, in the impact determination unit 301, at time t1, the acceleration, which is the magnitude of the impact, becomes larger than the first threshold value Gth1, and the shovel PS is impacted. It is determined to be in the state. After that, the horsepower control unit 302 reduces the horsepower of the main pump 12 from the horsepower W1 during normal work to a predetermined horsepower W2 during horsepower reduction. Then, since the horsepower of the main pump 12 is reduced, the amount of hydraulic oil supplied to the hydraulic actuator is reduced. Thereby, unnecessary fuel consumption can be suppressed and energy efficiency can be improved. Further, since the horsepower of the main pump 12 is reduced, as shown in FIG. 5A, the amount of change in acceleration is reduced and the sway is reduced as compared with the case where the horsepower of the main pump 12 is not reduced. To be done.

  Next, another example of the horsepower control process will be described. FIG. 6 is a flowchart showing another example of the flow of horsepower control processing. The controller 30 repeatedly executes the horsepower control process in a predetermined cycle.

  First, the impact determination unit 301 determines whether the impact frequency detected by at least one of the boom angle sensor S1, the arm angle sensor S2, the bucket angle sensor S3, and the vehicle body tilt sensor S4 is higher than the second threshold value. Is determined (step ST21).

  When it is determined in step ST21 that the impact frequency is higher than the second threshold value, the horsepower control unit 302 reduces the horsepower of the main pump 12 (step ST22). Specifically, the horsepower control unit 302 controls the ECU 74 to reduce the rotational speed of the engine 11, thereby reducing the horsepower of the main pump 12. Alternatively, the horsepower control unit 302 adjusts the regulator 13 to reduce the discharge flow rate of the main pump 12, thereby reducing the horsepower of the main pump 12. Then, the process ends.

  On the other hand, if it is determined in step ST21 that the impact frequency is equal to or lower than the second threshold value, the process ends without reducing the horsepower of the main pump 12.

  FIG. 7 is a time chart of another example of the horsepower control process, and FIG. 7A shows a relationship between time t (horizontal axis) and acceleration (vertical axis) detected by the arm angle sensor S2. 7 (b) shows the relationship between time t (horizontal axis) and pump horsepower (vertical axis).

  As shown in FIGS. 7A and 7B, the impact determination unit 301 determines that at time t2, the frequency of the impact becomes larger than the second threshold and the shovel PS is in the impacted state. To do. After that, the horsepower control unit 302 reduces the horsepower of the main pump 12 from the horsepower W1 during normal work to a predetermined horsepower W2 during horsepower reduction. Then, since the horsepower of the main pump 12 is reduced, the amount of hydraulic oil supplied to the hydraulic actuator is reduced. Thereby, unnecessary fuel consumption can be suppressed and energy efficiency can be improved. The impact frequency may be a frequency at a predetermined time Δt starting from time t1 when the acceleration, which is the magnitude of the impact, becomes larger than the first threshold value Gth1.

  Next, still another example of the horsepower control process will be described. FIG. 8 is a flowchart showing yet another example of the flow of horsepower control processing. The controller 30 repeatedly executes the horsepower control process in a predetermined cycle.

  First, the impact determination unit 301 determines whether or not the magnitude of the impact detected by the first acceleration sensor is larger than the first threshold value (step ST31). The first acceleration sensor is at least one of a boom angle sensor S1, an arm angle sensor S2, a bucket angle sensor S3, and a vehicle body tilt sensor S4.

  When it is determined in step ST31 that the magnitude of the impact is larger than the first threshold value, the impact determination unit 301 determines that the frequency of the impact detected by the first acceleration sensor and the frequency of the impact detected by the second acceleration sensor are equal to each other. It is determined whether they are substantially the same (step ST32). The second acceleration sensor is a sensor different from the first acceleration sensor among at least one of the boom angle sensor S1, the arm angle sensor S2, the bucket angle sensor S3, and the vehicle body tilt sensor S4. On the other hand, if it is determined in step ST31 that the magnitude of the impact is less than or equal to the first threshold value, the process ends.

  When it is determined in step ST32 that the frequency of the shock detected by the first acceleration sensor and the frequency of the shock detected by the second acceleration sensor are substantially the same, the horsepower control unit 302 determines the horsepower of the main pump 12. It is reduced (step ST33). Specifically, the horsepower control unit 302 controls the ECU 74 to reduce the rotational speed of the engine 11, thereby reducing the horsepower of the main pump 12. Alternatively, the horsepower control unit 302 adjusts the regulator 13 to reduce the discharge flow rate of the main pump 12, thereby reducing the horsepower of the main pump 12. Then, the process ends.

  On the other hand, in step ST32, when it is determined that the frequency of the shock detected by the first acceleration sensor and the frequency of the shock detected by the second acceleration sensor are not substantially the same, the horsepower of the main pump 12 is not reduced. , The process ends.

  FIG. 9 is a time chart of still another example of the horsepower control processing. FIG. 9A shows the relationship between the time t (horizontal axis) and the acceleration (vertical axis) detected by the arm angle sensor S2. FIG. 9B shows the relationship between the time t (horizontal axis) and the acceleration (vertical axis) detected by the boom angle sensor S1. FIG. 9C shows the relationship between time t (horizontal axis) and pump horsepower (vertical axis). Further, in FIG. 9A, the solid line shows the time change of the acceleration when the shovel PS is impacted, and the broken line shows the time change of the acceleration during normal excavation when only the arm 5 of the shovel PS is operated. Shows.

  As shown in FIGS. 9A to 9C, in the impact determination unit 301, at time t3, the magnitude of the impact detected by the arm angle sensor S2 is larger than the first threshold value Gath1, and The impact frequency detected by the arm angle sensor S2 and the impact frequency detected by the boom angle sensor S1 become substantially the same, and it is determined that the shovel PS is in the impacted state. After that, the horsepower control unit 302 reduces the horsepower of the main pump 12 from the horsepower W1 during normal work to a predetermined horsepower W2 during horsepower reduction. Then, since the horsepower of the main pump 12 is reduced, the amount of hydraulic oil supplied to the hydraulic actuator is reduced. Thereby, unnecessary fuel consumption can be suppressed and energy efficiency can be improved.

  By the way, as shown by the broken line in FIG. 9A, during normal excavation when only the arm 5 of the shovel PS is operated, the magnitude of the impact detected by the arm angle sensor S2 is the first threshold value Gate1. May be larger than In this case, since the frequency of the shock detected by the arm angle sensor S2 and the frequency of the shock detected by the boom angle sensor S1 are different, the shock determination unit 301 determines that the shovel PS is in a shocked state. do not do. That is, false detection can be suppressed.

  Although the embodiments for carrying out the present invention have been described above, the above contents are not intended to limit the contents of the present invention, and various modifications and improvements can be made within the scope of the present invention.

  In the above embodiment, when the detected value of the acceleration sensor is larger than the predetermined value, the horsepower of the main pump 12 is reduced and the processing is ended. However, for example, the horsepower of the main pump 12 is reduced and the acceleration is increased. You may transmit the detection value of a sensor to the management apparatus installed in the remote place via a network. In this case, it is possible to simultaneously transmit a captured image when the detection value of the acceleration sensor exceeds a predetermined value. Further, by transmitting the values before and after the time when the value exceeds the predetermined value, it is possible to estimate the change in the posture of the shovel PS and the work content at that time.

1 Lower Traveling Body 2 Revolving Mechanism 3 Upper Revolving Body 4 Boom 5 Arm 6 Bucket 11 Engine 12 Main Pump 13 Regulator 30 Controller 301 Impact Judgment Section 302 Horsepower Control Section 303 Motion Control Section PS Shovel S1 Boom Angle Sensor S2 Arm Angle Sensor S3 Bucket Angle sensor S4 Body tilt sensor

Claims (8)

An undercarriage,
An upper revolving structure mounted on the lower traveling structure so as to be freely rotatable,
An attachment that is attached to the upper swing body and is driven by hydraulic fluid discharged by a hydraulic pump,
An acceleration sensor attached to at least one of the upper swing body and the attachment;
When the detection value of the acceleration sensor is larger than a predetermined value, a control device that reduces the horsepower of the hydraulic pump,
With
Shovel. The detection value of the acceleration sensor includes the magnitude of the shock received by the shovel,
The control device reduces the horsepower of the hydraulic pump when the magnitude of the impact is larger than a first threshold value,
The shovel according to claim 1. The detection value of the acceleration sensor includes the frequency of the shock received by the shovel,
The control device reduces the horsepower of the hydraulic pump when the frequency of the shock is greater than a second threshold value,
The shovel according to claim 1. The acceleration sensor includes a first acceleration sensor attached to the attachment, and a second acceleration sensor attached to the upper swing body or a member different from the attachment to which the acceleration sensor is attached,
The detection value of the first acceleration sensor includes the magnitude and frequency of impact received by the shovel,
The detection value of the second acceleration sensor includes the frequency of the shock received by the shovel,
The control device detects that the magnitude of the impact detected by the first acceleration sensor is larger than a first threshold, and the frequency of the impact detected by the first acceleration sensor and the second acceleration sensor. If the frequency of the impact is substantially the same, the horsepower of the hydraulic pump is reduced,
The shovel according to claim 1. The hydraulic pump is driven by an engine,
The control device reduces the horsepower of the hydraulic pump by reducing the rotational speed of the engine,
The shovel according to any one of claims 1 to 4. The hydraulic pump is a swash plate type variable displacement hydraulic pump,
The control device reduces horsepower of the hydraulic pump by adjusting a regulator,
The shovel according to any one of claims 1 to 4. A shovel equipped with a machine guidance function for informing the operator of the distance between the current position of the end attachment and the target position,
An undercarriage,
An upper revolving structure mounted on the lower traveling structure so as to be freely rotatable,
An attachment that is attached to the upper swing body and is driven by hydraulic fluid discharged by a hydraulic pump,
An acceleration sensor attached to at least one of the upper swing body and the attachment;
An impact determination unit that determines whether or not the shovel is in a state of being impacted, based on the detection value of the acceleration sensor,
When the impact determination unit determines that the shovel is in a state of being impacted, an operation control unit that moves the end attachment in a direction of separating from the target position,
With
Shovel. When the impact determination unit determines that the shovel is in a state of being impacted, the impact determination unit further includes a storage unit that stores the impacted position.
The shovel according to claim 7.

Images