JP2018071271A - Construction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To execute drive control of a bucket to an excavating side only under conditions in which there is a great possibility that sediment and the like are being stored when avoidance control of an arm is executed.SOLUTION: A hydraulic shovel 1 comprises a controller 32 that executes drive control of an arm 6 to a push side when a bucket 7 approaches a predetermined control start distance from a cab seat 17a while executing drive control of the bucket 7 to an excavating side, and sensors 12 to 15 that detect information for specifying a position of the bucket 7. The controller 32 specifies a position of the bucket 7 in approaching based on the information detected by the sensors 12 to 15 when the bucket 7 approaches the control start distance, and executes the drive control of the bucket 7 to the excavating side when the position of the bucket in approaching is rotated to the excavating side with respect to a predetermined basic position, while cancelling execution of the drive control of the bucket 7 to the excavating side when the position of the bucket in approaching matches with the basic position or when the position of the bucket in approaching is rotated to an opening side further than the basic position.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a construction machine including an airframe, a driver's seat provided on the airframe, and an attachment attached to the airframe so as to be displaceable.

  2. Description of the Related Art Conventionally, an attachment having a boom that is pivotably attached to an airframe, an arm that is pivotally attached to the boom, and a bucket that is pivotally attached to the arm is provided. Construction machinery is known.

  Further, a construction machine (e.g., a position sensor that detects the position of the bucket, a driver's seat provided in the fuselage, and a control unit that controls the drive of the attachment based on the position of the bucket detected by the position sensor) Patent Document 1) is also known.

  Specifically, the control means described in Patent Document 1 is such that when the bucket tries to enter the driver's seat beyond the restraint surface that is a predetermined distance away from the driver's seat, the tip of the arm moves away from the boom ( The drive of the arm is controlled so that the arm rotates to the arm pushing side (hereinafter, this control is referred to as arm avoidance control).

  However, as in Patent Document 1, when the arm is turned to the arm pushing side, the bucket attached to the tip of the arm is also turned in the opening direction. For example, when dirt or the like is stored in the bucket If arm avoidance control is executed while maintaining the bucket posture, earth and sand in the bucket will fall.

  Therefore, for example, when the bucket approaches a predetermined distance from the driver's seat, the arm avoidance control is executed and the bucket is driven so as to automatically rotate the bucket to the excavation side (side approaching the driver's seat). A construction machine that controls the machine is also known (for example, Patent Document 2).

Japanese Patent No. 3464111 Japanese Patent No. 4446042

  However, in the construction machine described in Patent Document 2, the bucket is rotated to the excavation side when the bucket approaches a predetermined distance from the driver's seat without considering the attitude of the bucket.

  Therefore, even when the bucket is in an open state where it is clear that earth and sand are not stored, drive control to the excavation side of the bucket is performed wastefully.

  In addition, operating the bucket to the excavation side in a situation where it is clear that no dirt or the like is stored in the bucket as described above is against the operator's intention and is not suitable for the situation at the site. Probability is high.

  An object of the present invention is to provide a construction machine capable of executing drive control to the excavation side of a bucket only in a situation where there is a high possibility that earth and sand are stored when arm avoidance control is executed. There is.

  In order to solve the above-described problems, the present invention provides a construction machine, which includes a fuselage, a driver seat provided in the fuselage, a boom rotatably attached to the fuselage, and the boom. And an attachment having an arm pivotably attached to the arm, and a position detecting means for detecting information for identifying the position of the bucket relative to the body And when the bucket approaches a preset control start distance with respect to the driver seat based on the information detected by the position detection means, the arm is driven and controlled to the push side, and the bucket is moved to the excavation side. And a controller for controlling the driving of the bucket, and a posture detecting means for detecting information for specifying the posture of the bucket. The approaching posture of the bucket is specified based on the information detected by the posture detection means when the vehicle approaches the control start distance, and the approaching posture is set to the excavation side with respect to a preset basic posture. When the bucket is rotating, drive control to the excavation side of the bucket is performed, while when the approaching posture coincides with the basic posture or when the bucket is rotated more open than the basic posture Provided is a construction machine that prohibits execution of drive control to the excavation side of a bucket.

  According to the present invention, when the bucket approaches the control start distance and the attitude of the bucket at this time (approaching attitude) rotates to the excavation side with respect to the basic attitude, the excavation side of the bucket Can be performed.

  Here, the “basic posture” is set in advance as a boundary posture between a posture in which earth and sand can be stored in the bucket and a posture in which it is difficult to store earth and sand in the bucket.

  Therefore, according to the present invention, it is possible to execute the operation of the bucket toward the excavation side when the bucket is in a posture that is highly likely to store earth and sand.

  On the other hand, even if the bucket is approaching the control start distance, the bucket posture at this time (the approaching posture) coincides with the basic posture or rotates to the opening side (the side far from the driver's seat) with respect to the basic posture. When the bucket is running, that is, when the bucket is in a posture that is unlikely to store earth and sand, the operation of the bucket toward the excavation side can be prohibited.

  Therefore, according to the present invention, when the arm avoidance control is executed, the drive control to the excavation side of the bucket can be executed only in a situation where there is a high possibility that earth and sand are stored.

  Here, the posture detecting means can adopt means capable of detecting information for specifying the shape of the bucket (for example, a distance sensor capable of detecting the distance to the bucket, etc.). The posture detection means is required to have high performance.

  Therefore, in the construction machine, the posture detection means can detect information for specifying the position of the rotation center of the bucket with respect to the arm and the position of the tip of the bucket, and the controller detects the posture detection Based on the information detected by the means, the approaching posture is excavated with respect to the basic posture when the tip of the bucket is located behind the rotation center in the front-rear direction with respect to the driver seat. While determining that the bucket is pivoting to the side, when the tip end of the bucket is located at the same position as the front-rear direction position of the pivot center or before the position, when approaching the basic posture It is preferable to determine that the posture is rotated to the open side.

  According to this aspect, since the posture detecting means capable of detecting information for specifying the two positions of the position of the rotation center and the position of the tip of the bucket may be employed, the shape of the bucket is specified. Compared with the case where the posture detecting means is employed, the function required for the posture detecting means can be simplified, and the cost of the construction machine can be reduced.

  Specifically, for example, the posture detection means includes a boom sensor that can detect the angle of the boom with respect to the airframe, an arm sensor that can detect the angle of the arm with respect to the boom, a bucket sensor that can detect the angle of the bucket with respect to the arm, It can be set as the structure which has these.

  And according to the said aspect, based on the positional relationship in the front-back direction of the rotation center specified by the attitude | position detection means and the front-end | tip part of a bucket, the bucket is rotating to the excavation side with respect to a basic attitude, or it opens. It can be determined whether it is rotating to the side.

  The “front-rear direction with respect to the driver's seat” is a direction when the front of the operator seated on the driver's seat is the front.

  In the construction machine, the controller stores in advance a reference plane extending in the left-right direction and the up-down direction orthogonal to the front-rear direction in front of the driver seat in the front-rear direction, and the tip of the bucket and the rotation When at least one of the centers reaches the reference plane, it is determined that the bucket has approached the control start distance, and when the tip of the bucket reaches the reference plane before the rotation center, the basic While determining that the approaching posture is rotated to the excavation side with respect to the posture, the basic posture when the tip of the bucket reaches the reference plane at the same time as or later than the rotation center On the other hand, it can be determined that the approaching posture rotates to the open side.

  Therefore, different criteria are used for determining whether the bucket has approached the control start distance and for determining whether the bucket is rotating to the excavation side or to the opening side with respect to the basic posture. Compared with the case, the control by the controller can be simplified.

  In the construction machine, the controller specifies a current posture of the bucket based on information detected by the posture detection means during drive control of the arm to the push side, and the current posture and the approach posture It is preferable to perform drive control to the excavation side of the bucket so as to fill the deviation.

  According to this aspect, the posture of the bucket can be reliably brought close to the approaching posture based on the current posture of the bucket specified during the drive control to the pushing side of the arm.

  Here, even when the bucket is being operated by the operator, when the bucket approaches the control start distance and the approaching posture rotates to the excavation side with respect to the basic posture, the bucket is forcibly moved to the excavation side. It is also possible to control the drive. However, in this case, there is a high possibility that the operator is operating the bucket suitable for the situation in the field, and it is important to respect such operation.

  Therefore, the construction machine further includes bucket operating means for operating the bucket, and a bucket operation detector for detecting whether or not the bucket operating means is operated, and the controller is configured so that the approaching attitude is the basic attitude. The bucket rotates to the excavation side, and when the bucket operation detector detects that the operation of the bucket operation means is not performed, the bucket performs drive control to the excavation side, When the approaching posture rotates to the excavation side with respect to the basic posture and the bucket operation detector determines that the operation of the bucket operation means is being performed, the bucket is driven to the excavation side. It is preferable to prohibit the control.

  According to this aspect, when the operation of the bucket operation means is being performed, that is, when the operation of the bucket is being performed by the operator, drive control of the bucket to the excavation side is prohibited. Thereby, operation of an operator's bucket can be respected.

  On the other hand, since the drive control to the pushing side of the arm is performed, it is possible to effectively suppress the bucket from approaching the driver's seat while respecting the bucket operation of the operator.

  According to the present invention, when the arm avoidance control is executed, the drive control to the excavation side of the bucket can be executed only in a situation where there is a high possibility that earth and sand are stored.

1 is a side view showing an overall configuration of a hydraulic excavator according to an embodiment of the present invention. It is a top view which expands and shows the offset boom of FIG. It is a circuit diagram of the hydraulic circuit provided in the hydraulic excavator of FIG. It is a block diagram which shows the electric constitution provided in the hydraulic shovel of FIG. It is a flowchart which shows the process performed by the controller of FIG. It is a flowchart which shows the content of the avoidance process of FIG.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. The following embodiments are examples embodying the present invention, and are not of a nature that limits the technical scope of the present invention.

  FIG. 1 is a side view showing a hydraulic excavator 1 as an example of a construction machine according to an embodiment of the present invention.

  Referring to FIG. 1, a hydraulic excavator 1 includes a lower traveling body 2 having a crawler 2 a, an upper revolving body 3 that is turnably provided on the lower traveling body 2, and an attachment 4 that is attached to the upper revolving body 3. And. The lower traveling body 2 and the upper swing body 3 constitute an example of the airframe.

  The upper swing body 3 includes an upper frame 16 that is pivotably attached to the lower traveling body 2, and a cab 17 provided on the upper frame 16. The cab 17 includes a driver's seat 17a and a wall portion (reference numeral omitted) that surrounds the driver's seat 17a and covers the driver's seat 17a from above. In the following description, the front / rear, left / right, and up / down directions viewed from the operator seated on the driver's seat 17a are used. Specifically, the front-rear direction is a direction when the front of the operator seated on the driver's seat 17a is the front. The left-right direction is a direction orthogonal to the front-rear direction on a horizontal plane. The vertical direction is a direction orthogonal to the front-rear direction and the left-right direction.

  The attachment 4 has a boom 5 having a base end portion that is pivotally mounted about a boom foot pin J 1 extending in the left-right direction with respect to the upper swing body 3, and extends in the left-right direction with respect to the distal end portion of the boom 5. An arm 6 having a base end portion rotatably attached around the arm pin J4; a bucket 7 attached rotatably around a bucket pin J5 extending in the left-right direction with respect to the distal end portion of the arm 6; Have

  Referring to FIGS. 1 and 2, the boom 5 is rotatable with respect to the rear boom 5a and a rear boom 5a having a base end portion rotatably supported with respect to the upper swing body 3 by a boom foot pin J1. A pair of offset booms 5b each having a base end part attached to the upper part, and an upper part rotatably attached to the tip part of the offset boom 5b and attached to the arm 6 by the arm pin J4 And a boom 5c.

  The base end portion of the offset boom 5b is attached to the rear boom 5a so as to be rotatable about an offset pin J2 orthogonal to the boom foot pin J1. The tip end of the offset boom 5b is attached to the upper boom 5c so as to be rotatable about an offset pin J3 parallel to the offset pin J2. The two offset booms 5b are arranged in parallel to each other, the two offset pins J2 are arranged in the left-right direction, and the two offset pins J3 are arranged in the left-right direction.

  Accordingly, as shown by a two-dot chain line in FIG. 2, both the offset booms 5b rotate to the right or left about the offset pin J2, so that the upper boom 5c is maintained in the rear boom while the posture of the upper boom 5c is maintained. Offset to the right or left with respect to 5a. When the upper boom 5c is offset, the positions of the upper frame 5c and the arms 6 and buckets 7 connected thereto are changed in the front-rear direction.

  Further, the attachment 4 pushes the arm 6 against the boom 5, the boom hoisting cylinder 8 that raises and lowers the rear boom 5 a relative to the upper swing body 3, the offset cylinder 9 that rotates the offset boom 5 b right or left. An arm cylinder 10 that rotates in the (forward direction) and pulling direction (backward direction), and a bucket cylinder 11 that rotates the bucket 7 in the opening direction (forward direction) and excavating direction (backward direction) with respect to the arm 6; It has.

  The end of the offset cylinder 9 on the head side is attached to the base end of one offset boom 5b so as to be rotatable about a pin J6 parallel to the offset pin J2, and the end of the offset cylinder 9 on the rod side Is attached to the tip of the other offset boom 5b so as to be rotatable about a pin J7 parallel to the pin J6.

  Further, the attachment 4 includes a boom angle sensor 12 (see FIG. 4) that detects the angle of the boom 5 with respect to the upper swing body 3 (upper frame 16), and an offset angle sensor 13 that detects the offset angle of the offset boom 5b with respect to the rear boom 5a. (See FIG. 4), an arm angle sensor 14 that detects an angle of the arm 6 with respect to the boom 5, and a bucket angle sensor 15 that detects an angle of the bucket 7 with respect to the arm 6. As these sensors 12-15, a rotary encoder is employable, for example.

  When the work is performed using the attachment 4 configured as described above, the bucket 7 approaches the driver's seat 17a when the boom 5 is rotated in the upward direction while the arm 6 is rotated in the pulling direction to some extent.

  In order to suppress the operation of the bucket 7 at a position away from the driver's seat 17a to some extent, the excavator 1 moves the arm 6 when the bucket 7 approaches a preset control start distance with respect to the driver's seat 17a. The bucket 7 is driven to the excavation side as needed while being driven to the push side.

  Specifically, the hydraulic excavator 1 includes a hydraulic circuit 18 shown in FIG. 3 for driving the arm cylinder 10 and the bucket cylinder 11, and a controller 32 shown in FIG. 4 for controlling the driving of the hydraulic circuit 18. .

  First, the hydraulic circuit 18 will be described with reference to FIG.

  The hydraulic circuit 18 includes a main pump 19 that supplies hydraulic oil to the arm cylinder 10 and the bucket cylinder 11, an arm control valve 20 that controls supply and discharge of hydraulic oil to and from the arm cylinder 10, and hydraulic oil to the bucket cylinder 11. And a bucket control valve 21 for controlling the supply and discharge of.

  The arm control valve 20 has a neutral position (center position in the figure) for stopping the supply and discharge of hydraulic oil to and from the arm cylinder 10 and an arm pulling position for driving the arm 6 in the pulling direction (extending the arm cylinder 10). It is possible to switch between (right position in the figure) and an arm pushing position (left position in the figure) for driving the arm 6 in the pushing direction (reducing the arm cylinder 10). The arm control valve 20 has a pull-side pilot port and a push-side pilot port. When the pilot pressure is supplied to the pull-side pilot port, the arm control valve 20 is switched to the arm pulling position, and the pilot-side pilot port has a pilot pressure. Is switched to the arm pushing position, and is urged to the neutral position in a state where pilot pressure is not supplied to both pilot ports.

  The bucket control valve 21 has a neutral position (a central position in the figure) for stopping supply and discharge of hydraulic oil to and from the bucket cylinder 11 and a bucket opening position for driving the bucket 7 in the opening direction (reducing the bucket cylinder 11). It is possible to switch between (a right position in the figure) and a bucket excavation position (a left position in the figure) for driving the bucket 7 in the excavating direction (reducing the bucket cylinder 11). The bucket control valve 21 has an open side pilot port and an excavation side pilot port. When the pilot pressure is supplied to the open side pilot port, the bucket control valve 21 is switched to the bucket open position, and the pilot pressure is supplied to the excavation side pilot port. Is switched to the bucket excavation position, and is urged to the neutral position in a state where pilot pressure is not supplied to both pilot ports.

  The hydraulic circuit 18 includes a pilot pump 22 for supplying pilot pressure to the control valves 20, 21, arm operating means 23 for adjusting the pilot pressure for the arm control valve 20, and a bucket control valve. Bucket operating means 27 for adjusting the pilot pressure with respect to 21.

  The arm operation means 23 includes an operation lever (reference numeral omitted) and a remote control valve (reference numeral omitted) that outputs a pilot pressure corresponding to the operation amount of the operation lever.

  An arm pulling proportional valve 24 is provided between the arm operating means 23 and the pulling pilot port of the arm control valve 20. The arm pulling proportional valve 24 is urged to a position (right position in the figure) where the arm operating means 23 and the pulling pilot port are connected in a state where no command is input from the controller 32, and according to the command from the controller 32. Thus, the position is switched to the position (left position in the figure) for connecting the pulling pilot port and the tank. The arm pulling proportional valve 24 can adjust the opening according to the magnitude of the command value (current value) from the controller 32.

  On the other hand, a shuttle valve 26 is provided between the arm operating means 23 and the push side pilot port of the arm control valve 20. The shuttle valve 26 is connected to the arm push proportional valve 25 so that the higher pilot pressure of the pilot pressure from the arm operating means 23 and the pilot pressure from the arm push proportional valve 25 is supplied to the push pilot port. ing. The arm push proportional valve 25 is connected to the pilot pump 22 at a position upstream of the arm operating means 23, and is urged to a position where the shuttle valve 26 is connected to the tank in a state where a command from the controller 32 is not inputted. In response to a command from the controller 32, the position is switched to a position where the shuttle valve 26 and the pilot pump 22 are connected. The arm push proportional valve 25 can adjust the opening degree according to the magnitude of the command value (current value) from the controller 32.

  The bucket operation means 27 has an operation lever (reference numeral omitted) and a remote control valve (reference numeral omitted) that outputs a pilot pressure corresponding to the operation amount of the operation lever.

  A shuttle valve 29 is provided between the bucket operating means 27 and the excavation side pilot port of the bucket control valve 21. A bucket excavation proportional valve 28 is connected to the shuttle valve 29 so that the higher pilot pressure of the pilot pressure from the bucket operating means 27 and the pilot pressure from the bucket excavation proportional valve 28 is supplied to the excavation side pilot port. ing. The bucket excavation proportional valve 28 is connected to the pilot pump 22 at a position upstream of the bucket operation means 27, and is urged to a position where the shuttle valve 29 is connected to the tank in a state where a command from the controller 32 is not input. In response to a command from the controller 32, the position is switched to a position where the shuttle valve 29 and the pilot pump 22 are connected. The bucket excavation proportional valve 28 can adjust the opening degree according to the magnitude of the command value (current value) from the controller 32.

  Pressure sensors 30 and 31 are provided between the bucket operating means 27 and both pilot ports, respectively. The pressure sensor 30 detects the pilot pressure supplied from the bucket operating means 27 to the excavation side pilot port, and the pressure sensor 31 detects the pilot pressure supplied from the bucket operating means 27 to the opening side pilot port.

  Referring to FIGS. 1, 2, and 4, the controller 32 controls the drive of the arm 6 to the push side and the bucket 7 when the bucket 7 approaches a preset control start distance with respect to the driver seat 17 a. Is driven to the excavation side. The “control start distance” in the present embodiment is the control start surface C1 in which at least one of the rotation center of the bucket 7 with respect to the arm 6 (the center of the bucket pin J5) and the tip of the bucket 7 is set outside the driver seat 17a. It is the distance of the bucket 7 when reaching the reference plane extending along the vertical direction and the horizontal direction. The control start surface C1 includes the reference surface extending in the vertical direction and the left-right direction in front of the driver seat 17a, the top surface extending in the front-rear direction and the left-right direction above the driver seat 17a, and the reference surface and the top surface. And a round surface for connecting the two via a round portion.

  On the other hand, the controller 32 stops the drive control to the push side of the arm 6 and the drive control to the excavation side of the bucket 7 when the bucket 7 moves away from the driver's seat 17a by a preset control stop distance. The “control stop distance” in the present embodiment is the control stop surface C2 in which at least one of the rotation center of the bucket 7 with respect to the arm 6 (center of the bucket pin J5) and the tip of the bucket 7 is set outside the driver's seat 17a. Is the distance of the bucket 7 when it is located outside the reference plane extending along the vertical direction and the horizontal direction (the side away from the driver's seat 17a). The control stop surface C2 is a surface set in parallel to the control start surface C1 outside the control start surface C1 (side away from the driver's seat 17a). Specifically, the control stop surface C2 includes the reference surface extending in the vertical direction and the left-right direction in front of the driver seat 17a, the top surface extending in the front-rear direction and the left-right direction above the driver seat 17a, and a reference surface. A round surface for connecting the surface and the top surface via the round portion. By setting the control stop surface C2 outside the control start surface C1 in this way, the bucket 7 can be reliably moved further outside than the control start surface C1.

  Specifically, the controller 32 includes a position calculation unit 33 that calculates the position of the bucket 7, and drive control on the push side of the arm 6 and the excavation side of the bucket 7 based on the position of the bucket 7 calculated by the position calculation unit 33. And an automatic control unit 34 that automatically executes the drive control.

  The position calculation unit 33 includes a length from the center of the boom foot pin J1 to the center of the offset pin J2, a length from the center of the offset pin J2 to the center of the offset pin J3, and from the center of the offset pin J3 to the center of the arm pin J4. , The length from the center of the arm pin J4 to the center of the bucket pin J5, and the length information from the center of the bucket pin J5 to the tip of the bucket 7 are stored in advance. Further, the position calculation unit 33 acquires angle information detected by the sensors 12 to 15 and uses the angle information and the length information, and the rotation center position of the bucket 7 (the center position of the bucket pin J5) and the bucket. The position in the front-rear direction of the front end portion of 7 is calculated. That is, in this embodiment, the boom angle sensor 12, the offset angle sensor 13, the arm angle sensor 14, and the bucket angle sensor 15 are positions that detect information for specifying the position of the bucket 7 with respect to the upper swing body 3 (airframe). It corresponds to detection means.

  Further, the position calculation unit 33 calculates the angle of the bucket 7 with respect to the upper swing body 3 (airframe) using the angle information and the length information. That is, in the present embodiment, the boom angle sensor 12, the offset angle sensor 13, the arm angle sensor 14, and the bucket angle sensor 15 correspond to posture detection means that detects information for specifying the posture of the bucket 7.

  Then, the position calculation unit 33 outputs the rotation center position of the bucket 7, the position of the tip of the bucket 7, and the position of the bucket 7 with respect to the upper swing body 3 to the automatic control unit 34.

  The automatic control unit 34 compares the positional relationship between the rotation center position of the bucket 7 and the tip position of the bucket 7 with the control start surface C1 and the control stop surface C2, and according to a command from the comparison unit 35. A storage unit 36 that stores the angle of the bucket 7 with respect to the upper swing body 3 and a command determination unit that determines command values (current values) for the proportional valves 24, 25, and 28 in accordance with commands from the comparison unit 35 and the storage unit 36. 37.

  The comparison unit 35 is configured such that at least one of the position of the rotation center of the bucket 7 and the position of the tip of the bucket 7 reaches the reference plane (surface extending along the vertical direction and the horizontal direction) of the control start surface C1 (hereinafter referred to as “the control center 35”). When the bucket 7 is close to the control start distance), the control unit 37 outputs to the command determination unit 37 that the drive control to the pushing side of the arm 6 is executed. On the other hand, in the comparison unit 35, at least one of the position of the rotation center of the bucket 7 and the position of the tip of the bucket 7 is located outside the reference plane (surface extending in the vertical and horizontal directions) of the control stop surface C2. When this is done (hereinafter referred to as when the bucket 7 has moved away to the control stop distance), a message indicating that the drive control on the push side of the arm 6 is to be stopped is output to the command determination unit 37.

  Moreover, the comparison part 35 specifies the attitude | position at the time of the approach of the bucket 7 based on the information detected by the sensors 12-15 when the bucket 7 approached the control start distance as described above, and a preset basic angle On the other hand, it is determined whether or not the approaching posture is rotating toward the excavation side. Specifically, the comparison unit 35 acquires the position of the rotation center of the bucket 7 and the position of the tip of the bucket 7 (the posture when the bucket 7 approaches) from the position calculation unit 33, and the tip of the bucket 7 starts control. It is determined whether or not the reference surface of the surface C1 has reached before the rotation center of the bucket 7. Here, the “basic angle” is set in advance as a boundary posture between a posture in which earth and sand can be stored in the bucket 7 and a posture in which it is difficult to store earth and sand in the bucket 7. Specifically, as shown by the solid line in FIG. 1, the “basic angle” is such that the tip of the bucket 7 and the rotation center of the bucket 7 are arranged at the same position in the front-rear direction (aligned in the vertical direction). N) The posture of the bucket 7 (basic posture) is set. The posture in which the bucket 7 is rotated to the excavation side with respect to this basic posture, that is, the position of the rotation center of the tip of the bucket 7 with respect to the reference surface of the control start surface C1 as indicated by a two-dot chain line in FIG. In the posture reached earlier than that, there is a high possibility that earth and sand are stored in the bucket 7. On the other hand, when the bucket 7 is in a posture that matches the basic posture or when the bucket 7 is in a posture rotated to the open side from the basic posture, that is, the tip of the bucket 7 is in the same position as the rotation center in the front-rear direction. Or a posture in front of the rotation center with respect to the reference surface of the control start surface C1 is unlikely to store earth and sand in the bucket 7.

  And the comparison part 35 will perform the drive control to the excavation side of the bucket 7 when the front-end | tip part of the bucket 7 arrives ahead of the rotation center of the bucket 7 with respect to the reference plane of the control start surface C1. The data is output to the storage unit 36. On the other hand, the comparison unit 35 is provided on the reference surface of the control start surface C1 when the tip of the bucket 7 reaches the reference surface of the control start surface C1 simultaneously with the rotation center of the bucket 7 or after the rotation center of the bucket 7. When it reaches, a command for prohibiting execution of drive control to the excavation side of the bucket 7 is output to the storage unit 36.

  The storage unit 36 receives the command of the execution of drive control from the comparison unit 35 to the excavation side of the bucket 7, and the bucket 7 is moved relative to the upper swing body 3 when the bucket 7 approaches the control start distance. The angle (the angle in the proximity posture) is stored as the target angle.

  In addition, the storage unit 36 receives an instruction to execute drive control from the comparison unit 35 to the excavation side of the bucket 7, and the bucket 7 is not operated based on the pilot pressure detected by the pressure sensors 30 and 31. When it is determined as an operation, the target angle is output to the command determination unit 37. On the other hand, even when a command for executing drive control to the excavation side of the bucket 7 is input from the comparison unit 35, the bucket 7 is operated based on the pilot pressure detected by the pressure sensors 30 and 31. When it is determined that the bucket 7 is driven, the drive control of the bucket 7 to the excavation side is prohibited. Thus, the pressure sensors 30 and 31 in the present embodiment constitute an example of a bucket operation detector that detects whether or not the bucket operation means 27 is operated.

  The command determination unit 37 determines a command value (current value) for the arm push proportional valve 25 when a command to execute drive control to the push side of the arm 6 is input from the comparison unit 35. Specifically, the command determining unit 37 stores in advance a command characteristic map shown in step T1 of FIG. This command characteristic map shows the relationship between the rotation center of the bucket 7 and the tip of the bucket 7 that is close to the reference surface of the control start surface C1 with respect to the driver seat 17a and the command value for the arm push proportional valve 25. ing. Further, in the command characteristic map, the reference symbol X1 indicates the position of the reference surface of the control start surface C1, and the reference symbol X2 indicates the position of the reference surface of the control stop surface C2. It means that the bucket 7 approaches the driver's seat 17a as it goes. In this way, the command determination unit 37 determines a larger command value as the bucket 7 approaches the driver's seat 17a, that is, determines a larger pilot pressure for the pilot port on the arm pushing side as the bucket 7 approaches the driver's seat 17a.

  In addition, the command determination unit 37 determines a command for prohibiting the pull-side operation of the arm 6 when a command to execute drive control to the push side of the arm 6 is input from the comparison unit 35. Specifically, the command determination unit 37 determines a command value for switching the arm pulling proportional valve 24 so as to connect the arm pulling side pilot port to the tank.

  Further, the command determination unit 37 includes the target angle of the bucket 7 stored in the storage unit 36 and the current angle (current posture) of the bucket 7 calculated by the position calculation unit 33 during the drive control of the arm 6 to the pushing side. The command value for the bucket excavation proportional valve 28 is determined so as to fill the deviation. Note that the command determination unit 37 applies the power to the bucket excavation proportional valve 28 only when the current angle of the bucket 7 is smaller than the target angle, that is, when the bucket 7 is rotated to the open side from the posture of the target angle. Determine the command value.

  Hereinafter, processing executed by the controller 32 will be described with reference to FIGS. 1, 3, 5, and 6.

  When the processing is started, first, values related to positions used in the subsequent processing are calculated (steps S1 to S3). Specifically, in step S1, the angle of the bucket 7 with respect to the upper swing body 3 (airframe) is calculated based on the angles detected by the sensors 12-15. In step S2, the angle detected by the sensors 12-14, the distance from the boom foot pin J1 to the offset pin J2, the distance from the offset pin J2 to the offset pin J3, the distance from the offset pin J3 to the arm pin J4, and the arm pin J4 The position in the front-rear direction of the rotation center (bucket pin) of the bucket 7 is calculated based on the distance from the bucket pin J5. In step S3, the angle detected by sensors 12-15, the distance from boom foot pin J1 to offset pin J2, the distance from offset pin J2 to offset pin J3, the distance from offset pin J3 to arm pin J4, and from arm pin J4 Based on the distance to the bucket pin J5 and the distance from the bucket pin J5 to the tip of the bucket 7, the position in the front-rear direction of the tip of the bucket 7 is calculated.

  Next, it is determined whether or not a control flag indicating whether or not the drive control to the push side of the arm 6 is being executed is OFF (whether or not the control is being executed) (step). S4).

  If it is determined that the control flag is OFF (YES in step S4), whether or not at least one of the rotation center of the bucket 7 and the tip of the bucket 7 has reached the control start surface C1 (bucket 7). Whether or not the control start distance has been approached) is determined (step S5).

  If it is determined that the bucket 7 has approached the control start distance (YES in step S5), the control flag is set to ON (step S6), while it is determined that the bucket 7 has not approached the control start distance. (NO in step S5), the control flag is set to OFF (step S8).

  On the other hand, if it is determined in step S4 that the control flag is ON (NO in step S4), at least one of the rotation center of the bucket 7 and the tip of the bucket 7 is outside the reference surface of the control stop surface C2 (operation). It is determined whether or not it is on the side away from the seat 17a (whether the bucket 7 approaching the control start distance has moved away to the control stop distance) (step S7).

  Here, when it is determined that at least one of the rotation center of the bucket 7 and the tip end portion of the bucket 7 is on or inside the control stop surface C2 (NO in step S7), the bucket approaches the control start distance. Since 7 is not far from the control stop distance, the control flag is set to ON (step S6).

  On the other hand, if it is determined that the bucket 7 that has approached the control start distance has moved away to the control stop distance (YES in step S7), the control flag is set to OFF (step S8).

  When the setting of the control flag is completed in step S6 and step S8, it is determined whether or not the control flag is ON (step S9). If it is determined that the control flag is ON, an avoidance process T shown in FIG. 6 is performed. Executed.

  When the avoidance process T is executed, first, a command value for the arm push proportional valve 25 (hereinafter referred to as an arm push command value) and a command value for the arm pull proportional valve 25 (hereinafter referred to as an arm pull command value) are determined. (Step T1).

  Specifically, in step T1, the arm push command value is determined based on the command characteristic map shown in FIG. 6 and the position of the rotation center of the bucket 7 and the position of the tip of the bucket 7 calculated in steps S2 and S3. decide. In step T1, an arm pull command value for switching the arm pull proportional valve 25 is determined. In step T 1, the arm push command value is output to the arm push proportional valve 25 and the arm pull command value is outputted to the arm pull proportional valve 24.

  Next, it is determined whether or not an angle storage flag indicating that the angle of the bucket 7 when approaching the control start distance (approach at the time of approach) is stored as a target angle is ON (step T2).

  Here, if it is determined that the angle storage flag is OFF (NO in step T2), it is determined whether or not drive control to the excavation side of the bucket 7 is to be executed in subsequent steps T3 and T4. Determined.

  Specifically, in Step T3, the tip of the bucket 7 has reached the position of the rotation center of the bucket 7 with respect to the reference plane (a plane extending along the vertical direction and the horizontal direction) of the control start surface C1. It is determined whether or not. If YES is determined here, that is, if it is determined that the tip of the bucket 7 is located behind the rotation center of the bucket 7, it is estimated that there is a high possibility that dirt or the like is stored in the bucket 7. Step T4 is then executed.

  In Step T4, it is determined whether or not the bucket operating means 27 is operated by the operator, that is, whether or not the operator is operating the bucket 7 according to the work situation.

  If “YES” is determined here, the operator does not want a special action by the bucket 7, so the angle storage flag is set to ON (step T5), and the bucket 7 approaches the control start distance. The angle of the bucket 7 is stored as a target angle (step T6).

  On the other hand, if it is determined NO in step T3, it is estimated that there is a low possibility that dirt and the like are stored in the bucket 7, and if it is determined NO in step T4, the operator's operation should be given priority. In these cases, the angle storage flag is set to OFF (step S10), the target angle is deleted (step S11), and drive control of the bucket 7 to the excavation side is prohibited.

  If YES in step T2, that is, if the target angle has already been set, it is determined in step T7 and step T8 whether or not the drive control of the bucket 7 to the excavation side should be continued. Is done. Specifically, Step T7 is the same processing as Step T3, and Step T8 is the same processing as Step T4. When NO is determined in these steps T7 and T9, processing for prohibiting drive control of the bucket 7 to the excavation side is executed (steps S10 and S11).

  Even when it is determined in step S9 described above that the control flag is OFF, processing for prohibiting drive control of the bucket 7 to the excavation side is executed (steps S10 and S11).

  On the other hand, after the target angle is stored (after step T6) and after step T8, the angle of the bucket 7 with respect to the upper swing body 3 at the current time is calculated by the position calculation unit 33, and the bucket 7 at the current time is calculated. It is determined whether or not the angle (hereinafter referred to as the current angle) is smaller than the angle (hereinafter referred to as the control start angle) of the bucket 7 when approaching the control start distance (step T9). ).

  Here, if it is determined that the current angle is smaller than the control start angle, drive control in the excavation direction of the bucket 7 is performed so as to fill an angle obtained by subtracting the current angle from the control start angle (deviation between both angles). It is executed (step T10).

  As described above, when the bucket 7 approaches the control start distance and the posture of the bucket 7 at this time (the approaching posture) rotates to the excavation side with respect to the basic posture (in steps T3 and T7). In the case of YES), the operation to the excavation side of the bucket 7 can be executed.

  Therefore, when the bucket 7 is in a posture that is highly likely to store earth and sand, the operation of the bucket 7 toward the excavation side can be executed.

  On the other hand, even if the bucket 7 is approaching the control start distance, the bucket 7 at this time (the approaching posture) matches the basic posture or is rotated to the opening side (the side far from the driver's seat) with respect to the basic posture. When moving (when NO in steps T3 and T7), that is, when the bucket is in a posture that is unlikely to store earth and sand, the operation of the bucket 7 toward the excavation side may be prohibited. it can.

  Therefore, when the avoidance process T of the arm 6 is executed, the drive control of the bucket 7 to the excavation side can be executed only in a situation where there is a high possibility that earth and sand are stored.

  Moreover, according to the said embodiment, there can exist the following effects.

  Posture detection means (boom angle sensor 12, offset angle sensor 13, arm angle sensor 14) capable of detecting information for specifying two positions: the position of the rotation center of the bucket 7 and the position of the tip of the bucket 7. Since the bucket angle sensor 15) may be employed, the function required for the posture detection means can be simplified as compared with the case where the posture detection means for specifying the shape of the bucket 7 is employed. The cost of the hydraulic excavator 1 can be reduced.

  And based on the positional relationship in the front-back direction of the rotation center specified by the posture detection means and the tip of the bucket 7, the bucket 7 is rotated to the excavation side or rotated to the open side with respect to the basic posture. Can be determined.

  Determination of whether or not the bucket 7 has approached the control start position using the reference surface on the control start surface C1, and determination of whether the bucket 7 is rotated to the excavation side or to the open side with respect to the basic posture It can be performed. Therefore, the control by the controller 32 can be simplified as compared with the case where separate criteria are used for these determinations.

  By performing feedback control so as to fill in the deviation between the current posture of the bucket 7 specified during the drive control of the arm 6 to the push side and the posture when the bucket 7 approaches the control start distance, Can be brought close to the approaching posture.

  When the operation of the bucket operating means 27 is being performed, that is, when the operation of the bucket 7 is being performed by the operator, drive control of the bucket 7 to the excavation side is prohibited. Thereby, an operation of the bucket 7 by the operator can be respected.

  On the other hand, since the drive control to the pushing side of the arm 6 is performed, it is possible to effectively suppress the bucket 7 from approaching the driver's seat while respecting the operation of the bucket 7 by the operator.

  In addition, this invention is not limited to the said embodiment, For example, the following aspects can also be employ | adopted.

  In the embodiment, whether or not the excavation side drive control of the bucket 7 is executed based on whether or not the tip of the bucket 7 has reached the reference surface of the control start surface C1 before the rotation center of the bucket 7. The determination condition is not limited to this.

  For example, a specific angle of the bucket 7 with respect to the upper swing body 3 (airframe) is stored in advance as an angle in the basic posture of the bucket 7, and the angle of the bucket 7 when the control start distance is approached is stored. Whether or not the excavation side drive control of the bucket 7 is to be executed may be determined based on whether or not the angle is on the excavation side rather than the angle.

  In the embodiment, the boom angle sensor 12, the offset angle sensor 13, the arm angle sensor 14, and the bucket angle sensor 15 are shared as the position detection means and the attitude detection means. However, the position detection means and the attitude detection means are different. It may be a configuration.

  The position detection means only needs to be able to detect information on the position of the bucket 7 with respect to the upper swing body 3 (airframe). For example, a distance sensor capable of detecting the distance to the detection object can be used.

  Although the boom angle sensor 12, the offset angle sensor 13, the arm angle sensor 14, and the bucket angle sensor 15 are illustrated as the posture detection means, the posture detection means is not limited to these. For example, an imaging device or a distance sensor for specifying the shape of the bucket 7 can be employed as the posture detection means.

  The example in which the control of the arm 6 and the bucket 7 is started when at least one of the rotation center of the bucket 7 and the tip of the bucket 7 reaches the reference surface of the control start surface C1 has been described. It is not limited to this. For example, the control may be started when both the rotation center of the bucket 7 and the tip of the bucket 7 are located inside the reference surface of the control start surface C1. When a distance sensor is employed as the position detection means, the control of the arm 6 and the bucket 7 may be started when the portion of the bucket 7 that is closest to the driver's seat 17a reaches the reference surface of the control start surface C1. .

  The example in which the control of the arm 6 and the bucket 7 is stopped when at least one of the rotation center of the bucket 7 and the tip of the bucket 7 is located outside the reference surface of the control stop surface C2 has been described. Is not limited to this. For example, the control of the arm 6 and the bucket 7 may be stopped when both the rotation center of the bucket 7 and the tip of the bucket 7 are located outside the reference surface of the control stop surface C2. Further, when a distance sensor is employed as the position detecting means, the control may be stopped when the portion of the bucket 7 farthest from the driver's seat 17a is located outside the reference surface of the control stop surface C2.

  In the embodiment, the example in which the drive control of the bucket 7 to the excavation side is performed so as to fill the deviation between the current posture and the approaching posture is described, but the drive control of the bucket 7 is not limited to this.

  Specifically, the controller 32 (storage unit 35) stores the target posture in advance as an posture capable of stably storing sediment and the like, and the controller 32 (command determination unit 37) stores the current posture and the target posture. It is also possible to execute drive control of the bucket 7 so as to fill the deviation (determine a command value for the bucket excavation proportional valve 28).

  For example, by causing the controller 32 to store the horizontal posture of the bucket 7 as shown by a two-dot chain line in FIG. 1 as a target posture, the bucket 7 is brought close to the horizontal posture during the drive control to the push side of the arm 6, and the like Can be stored stably. As described above, the basic posture is set as a boundary posture between a posture in which earth and sand can be stored in the bucket and a posture in which it is difficult to store earth and sand in the bucket 7. Therefore, if the target posture is a posture rotated 90 ° from the basic posture to the excavation side, earth and sand can be stored relatively stably.

  When the controller 32 stores the target posture in advance as described above, steps S10 and S11 in the flowchart shown in FIG. 5 can be omitted. Specifically, if YES is determined in step S9, the avoidance process T is executed, whereas if NO is determined in step S9, the process returns to step S1 without executing the avoidance process T. Furthermore, steps T2 to T6 can be omitted in the flowchart of FIG. Specifically, after execution of step T1, step T7 is executed. If it is determined as YES in step T7, step T8 is executed, and if it is determined YES in step T8, step T9 is executed. If NO is determined in steps T7 and T8, the process returns to step S1.

  When adjusting the control start condition and the control stop condition as described above, the distances from the driver's seat 17a of the control start surface C1 and the control stop surface C2 are changed as necessary.

  The construction machine is not limited to a hydraulic type, and may be a hybrid type or an electric type.

C1 Control start surface (surface including reference surface)
J5 Bucket pin (defining the rotation center for the bucket arm)
1 Hydraulic excavator (an example of construction machinery)
2 Lower traveling body (an example of the aircraft)
3 Upper revolving structure (an example of the aircraft)
4 Attachment 5 Boom 6 Arm 7 Bucket 12 Boom angle sensor (an example of position detection means and posture detection means)
13 Offset angle sensor (an example of position detecting means and posture detecting means)
14 Arm angle sensor (an example of position detecting means and posture detecting means)
15 Bucket angle sensor (an example of position detection means and posture detection means)
17a Driver's seat 27 Bucket operation means 30, 31 Pressure sensor (bucket operation detector)
32 controller

Claims (5)

A construction machine,
The aircraft,
A driver's seat provided on the aircraft,
An attachment having a boom rotatably attached to the airframe, an arm rotatably attached to the boom, and a bucket rotatably attached to the arm;
Position detecting means for detecting information for specifying the position of the bucket with respect to the airframe;
Based on the information detected by the position detecting means, when the bucket approaches the control start distance set in advance with respect to the driver's seat, the arm is driven to the push side and the bucket is driven to the excavation side. A controller to control;
Posture detecting means for detecting information for specifying the posture of the bucket,
The controller specifies an approaching posture of the bucket based on information detected by the posture detecting means when the bucket is close to the control start distance, and the approaching approach to a preset basic posture When the posture is rotated to the excavation side, drive control of the bucket to the excavation side is executed, while when the approaching posture coincides with the basic posture or to the opening side from the basic posture. A construction machine that prohibits execution of drive control to the excavation side of the bucket. The construction machine according to claim 1,
The posture detection means can detect information for specifying the position of the rotation center of the bucket with respect to the arm and the position of the tip of the bucket,
Based on the information detected by the posture detection means, the controller determines whether the tip of the bucket is positioned behind the center of rotation in the front-rear direction with respect to the driver seat. When the approaching posture is determined to be rotating toward the excavation side, the basic position is determined when the tip of the bucket is positioned at the same position as or in front of the position in the front-rear direction of the rotation center. A construction machine that determines that the approaching posture rotates to the open side with respect to the posture. A construction machine according to claim 2,
The controller stores in advance a reference plane extending in the left-right direction and the vertical direction perpendicular to the front-rear direction in front of the driver seat in the front-rear direction, and at least one of the tip end portion of the bucket and the rotation center is When the reference plane is reached, it is determined that the bucket has approached the control start distance, and when the tip of the bucket reaches the reference plane before the rotation center, the bucket is While it is determined that the approaching posture is turning to the excavation side, the approaching to the basic posture is achieved when the tip of the bucket reaches the reference plane at the same time as or after the turning center. A construction machine that determines that the time posture rotates to the open side. The construction machine according to any one of claims 1 to 3,
The controller specifies the current posture of the bucket based on information detected by the posture detection means during drive control of the arm to the pushing side, and fills a deviation between the current posture and the posture at the time of approach. A construction machine that performs drive control to the excavation side of the bucket. The construction machine according to any one of claims 1 to 4, further comprising: a bucket operation means for operating the bucket; and a bucket operation detector that detects whether or not the bucket operation means is operated,
The controller is configured to rotate the bucket when the approaching attitude rotates to the excavation side with respect to the basic attitude and the bucket operation detector detects that the bucket operation means is not operated. While performing drive control to the excavation side, it is determined that the approaching posture rotates to the excavation side with respect to the basic posture, and that the bucket operation means is operated by the bucket operation detector. A construction machine that prohibits drive control of the bucket toward the excavation side.

Images