JP5615732B2 - Excavator - Google Patents

Description

  The present invention relates to an excavator having a working element driven by an actuator.

  As an example of an excavator, an excavator that excavates earth and sand with a bucket is known. In a general shovel, the bucket is attached to the tip of a rotatable arm, and the arm is attached to the tip of a rotatable boom. In order to move the bucket to a desired position, the upper turning body to which the boom is attached is turned, and the boom and the arm are turned.

  When the position of the bucket is moved by rotating the boom, inertial force due to the weight of the boom, the arm, and the bucket acts on the boom. For example, when lifting the boom to the maximum height, after accelerating the pivoting motion of the boom within the pivoting range of the boom, decelerate the boom when approaching the end of the pivoting range (for example, the maximum boom height). Stop. Such a pivoting movement of the boom is performed by the operator operating the operation lever of the driver's seat.

  For example, the operator of the shovel gradually loosens the operation lever operation and gradually decelerates the boom as it approaches the end of the movable range of the boom (for example, the maximum height of the boom), and the boom reaches the maximum height position. It is possible to stop smoothly at that point. However, depending on the operator (for example, an operator who is unfamiliar with the operation), when the boom starts to decelerate by the operation lever, the boom reaches the end of the movable range (for example, the maximum height of the boom). However, there may still be a large moment of inertia. In this case, when the boom reaches the end of the movable range of the boom (for example, the maximum height of the boom), the boom automatically stops, so that the boom suddenly stops with a large moment of inertia remaining. It will be stopped. In such a state, not only the boom itself vibrates in the vicinity of the stop position due to the inertia moment of the boom, but also the entire shovel vibrates with the vibration of the boom, so that the operator feels uncomfortable or uncomfortable. .

  Even when the boom is stopped within the movable range, not at the end of the movable range of the boom (for example, the maximum height of the boom), the lever operation (lever operation for stopping the boom) by the operator is abrupt. In such a case, the boom vibrates at the stop position of the boom, thereby causing the entire excavator to vibrate, causing the operator to feel uncomfortable or uncomfortable.

  The above situation also occurs in the excavator turning mechanism. That is, the excavator turning mechanism turns the upper turning body, and even when the operation lever is suddenly returned when the upper turning body is turned to approach the turning stop position, the upper portion having a large moment of inertia The revolving body is suddenly stopped, and the upper revolving body vibrates in the vicinity of the stop position of the upper revolving body, and the entire excavator also vibrates with this, giving the operator a sense of incongruity and discomfort.

  Therefore, the moment of inertia is detected while the swinging body is turning, and the flow rate of hydraulic fluid supplied to the turning hydraulic motor is limited so that the moment of inertia does not exceed a certain value, which makes the operator feel uncomfortable or uncomfortable. The technique which suppresses is proposed (for example, refer patent document 1).

Japanese Patent Laid-Open No. 11-37108

  In the technique described in Patent Document 1 described above, the operator's uncomfortable feeling is suppressed by limiting the moment of inertia of the swivel body so that the actual operation follows the operation amount of the operation lever. When the operator suddenly returns the operation lever to the stop position, it is not possible to suppress the vibration of the revolving body or the entire shovel as described above. Moreover, when the movable range is defined like a boom, the case where it stops suddenly automatically in the edge part of a movable range is not considered.

  Accordingly, the present invention has been made in view of the above-described problems, and even when an operator attempts to stop the work element suddenly by operating the operation lever, the work element is controlled to stop smoothly. The purpose is to suppress the occurrence of vibrations and eliminate the discomfort and discomfort to the operator.

According to one embodiment of the present invention, an operation lever operated by an operator to control the operation of the work element, an actuator that drives the work element, and an operation of the actuator is detected and a detection signal is output. A detector and a control device for controlling the drive of the actuator;
The control device creates an inertial load calculation unit that calculates an inertial load acting on the actuator based on a detection signal from the detector, and generates a stop pattern of a lever operation amount based on the inertial load, And the lever operation amount obtained from the operation of the operation lever, and if the lever operation amount is larger than the stop pattern, the lever operation amount obtained from the operation of the operation lever is replaced with the stop pattern. And a control unit that controls the inertial energy of the working element to be reduced.

In the excavator described above, the working element includes a bucket, an arm to which the bucket is attached, and a boom to which the arm is attached, and the detector includes a boom angle detector and an arm angle detector. The inertia load calculation unit calculates the inertia load based on a boom angle detection signal output from the boom angle detector and an arm angle detection signal output from the arm angle detector, and performs the control. Preferably, the unit controls the driving of the boom along the stop pattern so that the inertial energy of the work element is reduced. In addition, the allowable energy calculation unit that calculates the allowable energy based on the operation amount of the operation lever is compared with the inertial load and the allowable energy to determine whether the inertial load is greater than the allowable energy. further comprising a determination unit, wherein, when the inertial load is smaller than the allowable energy also have good as to control the boom based on the operation amount of the operating lever. Alternatively, a lever operation amount change rate calculation unit that calculates a change rate of the lever operation amount based on the operation of the operation lever, and the control unit, when the change rate of the lever operation amount is greater than a threshold value The boom may be controlled based on the operation amount of the operation lever.

Further, in the excavator described above, the working element includes a revolving body that is driven by a revolving mechanism and to which the boom is attached, the detector includes a revolving angle detector, and the inertial load calculation unit includes the revolving unit based on the rotation angle detection signal outputted from the angle detector calculates the inertial load, wherein, when the lever operation amount obtained from the operation of the operation lever is greater than the stop pattern, the working It is good also as controlling the turning drive of the said turning body so that the inertial energy of an element may become small. In addition, a lever operation amount change rate calculating unit that calculates a change rate of the lever operation amount based on the operation of the operation lever, and the control unit, when the change rate of the lever operation amount is larger than a threshold value The turning drive of the revolving structure may be controlled based on the operation amount of the operation lever.

  According to the present invention, even if a lever operation that causes the work element to stop suddenly is performed by the operator, the work element is controlled so as to stop smoothly regardless of the lever operation by the operator, thereby generating vibration. It is possible to suppress the discomfort and discomfort to the operator.

It is a side view of the hydraulic excavator which is an example of an excavator. It is a schematic side view of the hydraulic excavator during excavation of earth and sand. It is a figure for demonstrating permissible inertial energy. It is a block diagram of a system for correcting a lever operation amount when stopping a boom at an upper limit position or a lower limit position. It is a functional block diagram for demonstrating in detail the system of FIG. It is a figure for demonstrating the lever operation amount for preventing the vibration in the upper limit or lower limit position of a boom, (a) shows the displacement of a boom cylinder, (b) shows the change of inertia energy, (c). Indicates the amount of lever operation. It is a block diagram of the system for correct | amending the lever operation amount at the time of stopping a boom in the middle of a movable range. It is a figure which shows the relationship between inertia energy and target stop time ts. It is a functional block diagram for demonstrating in detail the system of FIG. It is a figure for demonstrating the relationship between real stop time and estimated stop time. It is a flowchart of the drive control which prevents the vibration of a boom at the time of stopping a boom in the middle of a movable range. It is a figure which shows the change of a boom cylinder position, inertia energy, and lever operation amount at the time of stopping a boom in the middle of a movable range. It is a block diagram of an example of composition which generates pilot pressure with a correction operation signal, and performs drive control of boom raising or boom lowering. FIG. 11 is a block diagram of another example of a configuration in which pilot pressure is generated by a correction operation signal and drive control for raising or lowering a boom is performed.

  Next, embodiments will be described with reference to the drawings.

  First, a hydraulic excavator will be described as an example of an excavator to which the present invention is applicable. FIG. 1 is a side view of a hydraulic excavator as an example of an excavator. FIG. 2 is a schematic side view of a hydraulic excavator during excavation of earth and sand. An upper swing body 3 is mounted on the lower traveling body 1 of the hydraulic excavator via a swing mechanism 2. A boom 4 extends from the upper swing body 3, and an arm 5 is connected to the tip of the boom 4. Further, the bucket 6 is connected to the tip of the arm 5. The boom 4, the arm 5, and the bucket 6 are hydraulically driven by a boom cylinder 7, an arm cylinder 8, and a bucket cylinder 9, respectively. The upper swing body 3 is mounted with a cabin 10 as a cab and an engine (not shown) as a power source. Further, the upper swing body 3 is provided with a controller 30 (see FIG. 2) which is a control device for controlling the operation of the working element of the hydraulic excavator. The controller 30 controls the operation of each work element based on an instruction from an operator (operator), an operation signal from an operation lever, and detection information from sensors provided in each part of the hydraulic excavator. The controller 30 is an electronic control device, and includes a CPU for performing computations, a ROM, a RAM, and the like as storage devices (memory).

  The boom 4 is supported so as to be able to turn up and down with respect to the upper turning body 3, and a boom angle sensor S1 (see FIG. 2) is attached to the turning support portion (joint). The boom angle sensor S1 can detect the boom angle θ1, which is the tilt angle of the boom 4 from the horizontal direction.

  The arm 5 is pivotably supported at the tip of the boom 4, and an arm angle sensor S <b> 2 (see FIG. 2) is attached to the pivot support portion (joint). The angle of the arm 5 relative to the boom 4 is detected by the arm angle sensor S2, and the arm angle θ2 that is the tilt angle of the arm 5 from the horizontal direction can be obtained from the detected angle of the arm 5 and the boom angle θ1.

  The bucket 6 is pivotably supported at the tip of the arm 5, and a bucket angle sensor (see FIG. 2) is attached to the pivot support portion (joint). The angle of the bucket 6 relative to the arm 5 is detected by the bucket angle sensor S3, and the bucket angle θ3 that is the inclination angle of the bucket 6 from the horizontal direction is detected from the detected bucket angle, boom angle θ1, and arm angle θ2. it can.

  The turning mechanism 2 for turning the upper turning body 3 is provided with a turning angle sensor S4. The turning angle sensor S4 can detect a turning angle that is an angle from a position where the upper turning body 3 faces the front.

  Further, the cabin 10 provided in the upper swing body 3 is provided with an operation lever device 20 provided with an operation lever 20a operated by an operator. The operator can raise and lower the boom 4 or turn the upper swing body 3 by operating the operation lever 20a, for example.

  In the hydraulic excavator having the above-described configuration, there are, for example, a boom raising operation, a boom lowering operation, and a turning operation as a work process in which a large inertial force acts on the work element. In the boom raising operation and the boom lowering operation, the boom 4, the arm 5, the bucket 6, the earth and sand in the bucket 6 become an inertia load, and a large inertia force acts on the boom 4 when the boom 4 is rapidly stopped. The vertically movable range of the boom 4 is determined by the stroke of the boom cylinder 7 that drives the boom 4.

  If the boom moving range reaches the upper limit of the boom movable range when the boom 4 is raised, the boom cylinder 7 cannot extend any further, and the upward rotation of the boom 4 is rapidly decelerated. At this time, since a large moment of inertia acts on the portion supporting the boom 4, the bucket 6 cannot be stopped at the upper limit position and will return after being overrun, and the portion including the bucket 6, the arm 5, and the boom 4 will be returned. Vibration occurs. Along with this vibration, the hydraulic excavator itself also vibrates, which gives the operator in the driver's seat a sense of discomfort and discomfort.

  The same applies to the lowering operation of the boom 4. When the lowering speed of the boom 4 reaches the lower limit of the movable range of the boom while the lowering speed of the boom 4 is lowered, the boom cylinder 7 cannot be further contracted, so that the boom 4 is rotated downward. Is decelerated abruptly. At this time, since a large moment of inertia acts on the portion supporting the boom 4, the bucket 6 cannot stop at the lower limit position and overruns, and vibration occurs in the portion including the bucket 6, the arm 5, and the boom 4. . Along with this vibration, the hydraulic excavator itself also vibrates, which gives the operator in the driver's seat a sense of discomfort and discomfort.

  Such vibrations that make the operator feel uncomfortable also occur when the boom 4 is suddenly stopped at an intermediate position between the upper limit and the lower limit of the movable range.

  Also in the turning operation, if the turning of the upper turning body 3 is suddenly stopped, the upper turning body 3 stops while vibrating before and after the turning stop position, which gives an uncomfortable feeling to the operator.

  When the boom 4 is stopped at the upper limit and the lower limit of the movable range, the stop position of the boom 4 is known. Therefore, when the boom 4 is moving at a high speed even when the boom 4 is close to the stop position, From this, it is possible to suppress the rapid deceleration of the boom 4 by forcibly decelerating with a preset deceleration pattern.

  On the other hand, when stopping in the middle of the movable range of the boom 4 or when stopping the turning operation, it is not known where to stop, so it is predicted that the operator is going to stop from the lever operation, and the stop is predicted By forcibly decelerating with a preset deceleration pattern from the time of the above, rapid deceleration in the turning operation of the boom 4 and the turning operation of the upper-part turning body 3 can be suppressed.

  First, the deceleration control of the boom 4 when the boom 4 is stopped at the upper limit and the lower limit of the movable range will be described.

  FIG. 3 is a graph showing the allowable inertia energy Ea of the boom 4 with respect to the displacement of the boom cylinder 7. In FIG. 3, the position where the rod of the boom cylinder 7 is most extended or retracted is shown as the end position. The end position is a position where the boom cylinder 7 cannot extend any further (cannot be displaced further) or a position where the boom cylinder 7 cannot be retracted any more (cannot be displaced any more). It is a position in a state where the height or the minimum height is reached.

  The allowable inertia energy indicated by the solid line in FIG. 3 is stopped when the boom 4 is decelerated from the state of rotating at the maximum speed and stopped at the upper limit position and the lower limit position (corresponding to the end position of the boom cylinder). The inertial energy has such a magnitude that no vibration is generated in the boom 4 at the position, or the operator does not feel uncomfortable or uncomfortable even if the vibration is generated. The end position of the boom cylinder 7 is known in advance, and if the displacement speed of the boom cylinder 7 (that is, the rotation speed of the boom 4) is known, it is set in advance how much to start decelerating and how to decelerate. Can be kept.

  The allowable inertia energy indicated by the solid line in FIG. 3 is equal to the inertia energy Ea0 of the boom 4 when the boom 4 is driven at the maximum speed while the cylinder displacement is small. As the cylinder displacement increases, it approaches the end position, so if it is driven at the maximum speed beyond that, it cannot stop smoothly at the end position.

  The inertial energy indicated by the dotted line in FIG. 3 is an example of the inertial energy of the boom 4 when the boom cylinder 7 is driven by the operation signal from the operation lever actually operated by the operator. If the actual inertial energy does not exceed the allowable inertial energy, the boom 4 can be smoothly stopped at the upper limit position or the lower limit position (end position).

Therefore, the inertia energy when driving in accordance with an operation signal from the operation lever is actually output, determines whether or not exceeded the allowable inertia energy, if it exceeds a position exceeding so as not to rapid deceleration (i.e., st From 1), deceleration is started so as to follow the allowable inertial energy.

  Here, a system configuration for performing the above-described control will be described. FIG. 4 is a schematic block diagram of a system for correcting an operation signal representing a lever operation amount.

  In FIG. 4, first, the motion detection value of each work element 40 of the hydraulic excavator is input to the inertial load calculation unit 42 of the controller 30. The inertial load calculation unit 42 calculates the inertial energy of the work element 40 based on the input motion detection value of the work element 40 and supplies the calculated inertial energy to the determination unit 44 of the controller 30. On the other hand, the allowable energy calculation unit 46 of the controller 30 calculates the allowable inertia energy of the boom 4 based on the operation signal indicating the lever operation amount of the operator, and supplies the determined allowable energy to the determination unit 44.

  The determination unit 44 compares the inertial energy supplied from the inertial load calculation unit 42 with the allowable inertial energy supplied from the allowable energy calculation unit 46, and determines which is larger. When the inertial energy supplied from the inertial load calculation unit 42 is larger than the allowable inertial energy, the determination unit 44 may generate vibration when stopped at the upper or lower limit position of the boom 4 because the inertial energy is too large. The determination result is supplied to the control unit 48 of the controller 30.

  Based on the determination result from the determination unit 44, the control unit 48 smoothly decelerates the boom 4 and stops at the upper limit or lower limit position (corresponding to the end position of the boom cylinder 7) (hereinafter referred to as an operation signal change pattern). (Referred to as a stop pattern), and the stop pattern is supplied to the switching unit 50 of the controller 30 as an operation signal.

  The switching unit 50 is also supplied with an operation signal generated when the operator actually operates the operation lever. Normally, the switching unit 50 outputs the operation signal generated by the actual lever operation to the work element 40 as it is, but when the operation signal is supplied from the control unit 48, the operation signal is not replaced by the actual lever operation. In addition, an operation signal from the control unit 48 is output to the work element 40.

  The above configuration will be described in more detail with reference to FIG. In the case of a hydraulic excavator, the working element 40 includes the boom 4, the arm 5, the bucket 6, and the turning mechanism 2 of the upper turning body 3. The operation detection value of the boom 4 is a boom angle detected by the boom angle sensor S1, the operation detection value of the arm 5 is an arm angle detected by the arm angle sensor S2, and the operation detection value of the bucket 6 is detected by the bucket angle sensor S3. The bucket angle to be detected. Moreover, the operation detection value of the turning mechanism 2 of the upper turning body 3 is a turning angle detected by the turning angle sensor S4.

The inertia load calculation unit 42 calculates the operation speed of the boom cylinder 7 from the change in the boom angle, calculates the operation speed of the arm cylinder 8 from the change in the arm angle, and calculates the operation speed of the bucket cylinder 9 from the change in the bucket angle. Is obtained by calculation. In addition, the inertial load calculation unit 42 calculates the turning speed of the upper swing body 3 from the change in the turning angle. For example, when the boom raising operation is performed, the inertial load calculation unit 42 determines the inertial force acting on the boom 4 from the weight of the bucket 6, the arm 5, the boom 4, and the operation speed of the boom cylinder 7 ( That is, inertia energy) is obtained by calculation. For the arm 5 and the bucket 6 as well, the inertial force is similarly calculated. Alternatively, when performing a turning operation, an inertial force (that is, inertia energy) acting on the upper swing body 3 is obtained by calculation from the weight of the upper swing body 3 and the swing speed of the upper swing body 3. The inertia energy obtained by the inertia load calculation unit 42 as described above is supplied to the determination unit 44. Here, it is not always necessary to use the operation speed of the bucket cylinder in calculating the inertia energy. In addition, the inertial energy of the turning motion may be calculated by calculation using only the turning speed.

  On the other hand, the allowable energy calculation unit 46 calculates the allowable inertia energy from the operation amount of the operation lever. For example, in the case of the pivoting operation of the boom 4, the allowable inertia energy is inertia energy set so as to change as indicated by a solid line in FIG. 3 in the process in which the tip of the boom 4 rotates to the upper limit or lower limit position. By adjusting the rotation speed so that the inertial energy until the boom 4 stops does not exceed the allowable inertial energy, the boom 4 can be stopped at the upper limit or lower limit position while smoothly decelerating. That is, by adjusting the rotation speed so that the inertial energy of the boom 4 does not exceed the allowable energy, the boom 4 smoothly stops at the upper limit or lower limit position. Thereby, the impact at the time of a stop is suppressed, the vibration at the time of a stop is suppressed, and the discomfort and discomfort to an operator can be reduced. In other words, the allowable energy is the upper limit value of the inertia energy for slowing down moderately to the extent that the operator does not feel uncomfortable or uncomfortable.

  In the determination unit 44, it is determined whether or not the inertial energy obtained by the inertial load calculation unit 42 exceeds the allowable inertial energy. If the inertial energy does not exceed the allowable inertial energy, it is determined that the boom 4 is operated at a rotation speed at which the inertial energy can be smoothly stopped, and the actual operation of the operator is left without adjusting the lever operation amount. On the other hand, when it is determined that the inertial energy exceeds the allowable inertial energy, the determination unit 44 instructs the control unit 48 to correct the lever operation amount.

  The control unit 48 that is instructed to correct the lever operation amount generates a pattern of lever operation amount that can control the boom 4 so that the actual inertia energy of the boom 4 changes along the allowable inertia energy ( (Refer FIG.6 (c)). Then, the control unit 48 compares the lever operation amount with the generated pattern. If the lever operation amount is larger than the stop pattern, the control unit 48 supplies a correction operation signal corresponding to the created pattern to the switching unit 50. When the correction operation signal is supplied from the control unit 48, the switching unit 50 receives the correction operation signal from the control unit 48 instead of the operation signal generated and supplied by the actual lever operation. In this case, the boom 4) is supplied to a control mechanism. On the other hand, if the lever operation amount is equal to or less than the stop pattern, the actual operation by the operator is left without adjusting the lever operation amount.

  FIGS. 6A and 6B are diagrams for explaining the lever operation amount for preventing vibration at the upper limit or lower limit position of the boom 4. FIG. 6A shows the displacement of the boom cylinder, and FIG. 6B shows the change of inertia energy. , (C) shows the lever operation amount.

  As shown in FIG. 6B, when the actual inertia energy obtained by the inertia load calculation unit 42 exceeds the allowable inertia energy at time ts1, the relationship between the preset inertia energy and the target stop time ts (FIG. 8), the control unit 48 generates a lever operation amount correction pattern as shown by the solid line in FIG. 6C, and generates an operation signal corresponding to the correction pattern. When the lever operation amount is compared with the generated pattern and the lever operation amount is larger than the stop pattern, the boom 4 is controlled by this correction operation signal, and the inertia energy of the boom 4 is shown by a solid line in FIG. Thus, the allowable inertia energy (indicated by a one-dot chain line) changes. Therefore, the boom cylinder displacement stops at the cylinder end position with almost no vibration as shown by the solid line in FIG.

  6 (a), 6 (b), and 6 (c), the dotted line indicates the case where the boom 4 is driven in accordance with the actual operation of the operating lever, and it vibrates by overshooting from the boom cylinder end. However, it is shown that it converges to the boom cylinder end, and correspondingly, the inertial energy also becomes zero while vibrating.

  On the other hand, the solid lines in FIGS. 6 (a), 6 (b), and 6 (c) are lines indicating the case where the boom 4 is driven by the operation signal generated by the lever operation amount correction pattern, and the boom cylinder is hardly vibrated. You can see that it stops at the end.

  Next, the deceleration control of the boom 4 when the boom 4 is stopped in the middle of the movable range of the boom 4 will be described with reference to FIG.

  When the boom 4 is stopped in the middle of the movable range of the boom 4, the stop position of the boom is not known in advance, and the operator operates the operation lever so as to stop at an arbitrary position. Therefore, in this case, it is necessary to predict that the operator is about to stop the boom 4 and the position where the boom is to be stopped.

  Accordingly, in the boom 4 deceleration control system when the boom 4 is stopped in the middle of the movable range of the boom 4, the lever operation amount change rate calculation unit 52 is provided instead of the above-described allowable energy calculation unit 46 and is calculated. The lever operation amount change rate kr1 is transmitted to the determination unit 44.

  The determination unit 44 compares the lever operation amount change rate kr1 and the threshold value kr0 to determine which is longer. When the lever operation amount change rate kr1 is equal to or greater than the threshold value kr0 (here, kr1 and kr0 are both negative values), it is determined that the operation is not a stop operation, and the lever operation amount is not corrected and left to the operator's operation. On the other hand, when the lever operation amount change rate kr1 is smaller than the threshold value kr0, it is determined as a stop operation, and an instruction for comparing the stop pattern with the operation amount is sent to the control unit 48.

  Upon receiving an instruction to compare the stop pattern with the operation amount, the control unit 48 calculates the target stop time ts at that time based on the relationship between the preset inertia energy and the target stop time ts (see FIG. 8). . Here, the target stop time ts is a stop time necessary for smoothly stopping the boom 4 when the deceleration starts from the current speed of the boom 4 and stops. Then, the control unit 48 calculates a stop pattern that stops the boom 4 at the calculated target stop time ts, and compares the lever operation amount with the generated stop pattern. When the lever operation amount is smaller than the stop pattern, the control unit 48 supplies a correction operation signal corresponding to the stop pattern to the switching unit 50. When the correction operation signal is supplied from the control unit 48, the switching unit 50 receives the correction operation signal from the control unit 48 instead of the operation signal generated and supplied by the actual lever operation. In this case, the boom 4) is supplied to a control mechanism.

  The above configuration will be described in more detail with reference to FIG. The inertial load calculation unit 42 has the same function as the inertial load calculation unit 42 shown in FIG. Therefore, for example, when the boom raising operation is performed, the inertial load calculating unit 42 calculates the inertial force acting on the boom 4 from the weight of the bucket 6, the arm 5, the boom 4 and the operation speed of the boom cylinder 7 ( That is, inertia energy) is obtained by calculation.

  On the other hand, the control unit 44 obtains the target stop period ts as the time required to smoothly decelerate from the present time and stop the boom 4 from the inertial energy of the boom 4 supplied from the inertial load calculating unit 42. The target stop time ts is proportional to the inertia energy of the boom 4 and can be calculated using a relational expression between the inertia energy and the target stop time ts. Or the map which shows the relationship between inertial energy and target stop time ts may be prepared, and target stop time ts may be calculated | required from the value of inertial energy.

  When the operator operates the operation lever, the change rate kr of the lever operation amount changes as shown in FIG. The change rate kr of the lever operation amount can be obtained by differentiating the change of the lever operation amount shown in FIG. That is, the change rate kr of the lever operation amount corresponds to the speed at which the lever is operated. When the change rate kr of the lever operation amount is a positive value (plus), it can be determined that the vehicle is accelerating, and when it is negative (minus), the vehicle is decelerating. The change rate kr of the lever operation amount corresponds to the slope of the line indicating the lever operation amount pp in the graph of FIG.

  Therefore, when the change rate kr1 is smaller than the threshold kr0, the determination unit 44 determines that the operation is a stop operation.

  FIG. 11 is a flowchart of drive control for preventing vibration of the boom when stopping the boom in the middle of the movable range.

  Referring to FIG. 11, first, in step S <b> 1, the stop time calculation unit 52 determines whether the operation lever is operated. This determination is performed by determining whether or not the lever operation amount pp is larger than the threshold value pps (pp> pps). If the lever operation amount pp is less than or equal to the threshold value pps (pp ≦ pps), the determination in step S1 is repeated. If it is determined in step S1 that the lever operation amount pp is larger than the threshold value pps (pp> pps), the process proceeds to step S2.

  Subsequently, in step S2, the lever operation amount change rate calculation unit 52 determines whether the operator has operated the operation lever to start deceleration. This determination is performed by determining whether or not the change rate kr1 of the lever operation amount has become a value (negative value) smaller than the threshold value kr0, as shown in FIG. When the operator starts a deceleration operation, the change rate kr1 of the lever operation amount becomes a value (a negative value) smaller than the threshold value kr0.

  If it is determined in step S2 that the lever operation amount change rate kr1 is not a value (negative value) smaller than the threshold kr0, the process returns to step S1. On the other hand, if it is determined that the change rate kr1 of the lever operation amount is smaller than the threshold kr0 (a negative value), the lever operation amount change rate calculation unit 52 determines the target stop time ts based on the inertial energy in step S3. And a stop pattern that is an operation amount for stopping is calculated.

  Subsequently, in step S4, the control unit 48 compares the operation amount with the stop pattern, and determines whether or not the operation amount is smaller than the stop pattern. When the operation amount is equal to or greater than the stop pattern, it is determined that the deceleration operation is performed so as to smoothly stop the boom 4, and the process returns to step S1. On the other hand, when the operation amount is smaller than the stop pattern, it is determined that the lever operation of the operator is sudden and the boom 4 is suddenly stopped, and the process proceeds to step S5.

  In step S5, the control unit 48 generates a correction operation signal corresponding to the stop pattern set in step S3. And the control part 48 supplies the produced | generated correction operation signal to the switch part 50, and complete | finishes a process.

  Through the above processing, the correction operation signal is supplied from the switching unit 50 to the drive mechanism of the work element 40 (boom 4), and the work element 40 (boom 4) is driven by the correction operation signal. Therefore, when it is determined that the operation of the work element 40 (boom 4) by the operator is a sudden stop, a correction operation signal is supplied to the drive mechanism of the work element 40, so that the work element 40 can be operated regardless of the operation of the operator. It is controlled to stop smoothly.

  FIG. 12 is a diagram showing changes in the boom cylinder position, inertia energy, and lever operation amount when the boom is stopped in the middle of the movable range by the process shown in FIG.

  FIG. 12A shows the displacement of the boom cylinder 7. The solid line in FIG. 12A indicates the displacement of the boom cylinder 7 when the boom 4 is controlled by the correction operation signal and stopped. The dotted line in FIG. 12A shows the displacement of the boom cylinder 7 when the drive control is performed with the operation signal generated by the operator's lever operation without generating the correction operation signal, and the operator's operation is an abrupt operation. Therefore, it can be seen that vibration occurs in the displacement of the boom cylinder 7. On the other hand, the displacement of the boom cylinder 7 indicated by the solid line in FIG. 12A is controlled by the correction operation signal so as to stop at the target stop time ts, so that the stop cylinder can reach the stop position smoothly. Recognize.

  FIG. 12B shows a change in inertia energy and a change in target stop time ts. The target stop time ts increases as the inertial energy E increases as indicated by the alternate long and short dash line. The inertia energy of the boom 4 is attenuated while vibrating as indicated by a dotted line when suddenly stopped without correction, but changes smoothly as indicated by a solid line when controlled by a correction operation signal.

  FIG. 12C shows a change in the lever operation amount and a change in the change rate kr of the lever operation amount. The lever operation amount as operated by the operator suddenly becomes zero at time tr as shown by the dotted line. However, when it is determined that the rate of change kr1 is smaller than the threshold kr0 at time t1 and the operation amount is determined to be smaller than the stop pattern, a pattern that smoothly becomes zero at the target stop time ts as shown by the solid line. Control according to. For this reason, when the boom 4 is stopped, as shown by the solid line in FIG.

  Although the above description is about the case where the boom 4 is stopped in the middle of the movable range, the same control can be performed when the turning motion of the upper swing body 3 is stopped. In the above description, the boom 4 and the boom cylinder 7 may be replaced with the upper swing body 3 and the swing motor, respectively.

  Next, the drive control of the boom 4 by the correction operation signal will be described.

  FIG. 13 is a block diagram of a configuration in which pilot pressure is generated by a correction operation signal to perform boom up or boom down drive control. The operation signal (electric signal) generated by the operation signal generation unit 20b of the operation lever device 20 operated by the operator is supplied to the boom raising electromagnetic proportional valve 60 or the boom lowering electromagnetic proportional valve 62 via the switching unit 50. Is done.

  Pilot pressure is supplied from a pilot pressure pump 64 to the boom raising electromagnetic proportional valve 60 and the boom lowering electromagnetic proportional valve 62. The boom raising electromagnetic proportional valve 60 and the boom lowering electromagnetic proportional valve 62 adjust the pilot hydraulic pressure by the operation signal or the correction operation signal supplied from the switching unit 50 and supply the adjusted pilot hydraulic pressure to the control valve 66. The control valve 66 is a pilot pressure actuated valve, and controls to supply the hydraulic pressure supplied from the main pump to the boom cylinder 7 and other hydraulic loads based on the supplied pilot pressure.

  On the other hand, the correction operation signal generated in the control unit 48 as described above is also supplied to the switching unit 50. When the correction operation signal is not supplied, the switching unit 50 supplies the operation signal from the operation lever device 20 to the boom raising electromagnetic proportional valve 60 or the boom lowering electromagnetic proportional valve 62, but the correction operation signal is supplied. When this is done, a correction operation signal is supplied to the boom raising electromagnetic proportional valve 60 or the boom lowering electromagnetic proportional valve 62 instead of the operation signal from the operation lever device 20. Thus, a pilot pressure corresponding to the correction operation signal is generated by the boom raising electromagnetic proportional valve 60 or the boom lowering electromagnetic proportional valve 62, and the hydraulic pressure obtained by controlling the control valve 66 by this pilot pressure is supplied to the boom cylinder 7. Then, the boom 4 is driven and controlled.

  As shown in FIG. 14, by setting the control valve 66 as an electromagnetically operated valve, the operation signal or the correction operation signal from the switching unit 50 can be supplied to the control valve 66 as it is to control the hydraulic pressure supply. it can.

DESCRIPTION OF SYMBOLS 1 Lower traveling body 2 Turning mechanism 3 Upper revolving body 4 Boom 5 Arm 6 Bucket 7 Boom cylinder 8 Arm cylinder 9 Bucket cylinder 10 Cabin 20 Operation lever apparatus 20a Operation lever 30 Controller 40 Work element 42 Inertial load calculation part 44 Judgment part 46 Permissible Energy calculation section 48 Control section 50 Switching section 52 Stop position calculation section 60 Boom raising electromagnetic proportional valve 62 Boom lowering electromagnetic proportional valve 64 Pilot pressure pump 66 Control valve S1 Boom angle sensor S2 Arm angle sensor S3 Bucket angle sensor S4 Turning angle Sensor

Claims (6)

An operation lever operated by an operator to control the operation of the work element;
An actuator for driving the working element;
A detector that detects the operation of the actuator and outputs a detection signal;
A control device for controlling the drive of the actuator,
The controller is
An inertial load calculation unit for calculating an inertial load acting on the actuator based on a detection signal from the detector;
A stop pattern of lever operation amount is created based on the inertia load, the stop pattern is compared with the lever operation amount obtained from the operation of the operation lever, and when the lever operation amount is larger than the stop pattern An excavator comprising: a control unit that performs control so that inertial energy of the work element is reduced along the stop pattern instead of a lever operation amount obtained from operation of the operation lever . The excavator according to claim 1,
The working element includes a bucket, an arm to which the bucket is attached, and a boom to which the arm is attached,
The detector includes a boom angle detector and an arm angle detector,
The inertia load calculation unit calculates the inertia load based on a boom angle detection signal output from the boom angle detector and an arm angle detection signal output from the arm angle detector,
The said control part controls the drive of the said boom so that the inertial energy of the said working element may become small along the said stop pattern. The excavator characterized by the above-mentioned. The excavator according to claim 2, wherein
An allowable energy calculation unit for calculating allowable energy based on an operation amount of the operation lever;
A determination unit that compares the inertial load with the allowable energy and determines whether the inertial load is greater than the allowable energy; and
The said control part controls the said boom based on the operation amount of the said operation lever, when the said inertial load is smaller than the said allowable energy, The excavator characterized by the above-mentioned. The excavator according to claim 2 or 3,
A lever operation amount change rate calculating unit that calculates a change rate of the lever operation amount based on the operation of the operation lever;
The excavator characterized in that the control unit controls the boom based on an operation amount of the operation lever when a change rate of the lever operation amount is larger than a threshold value. The excavator according to claim 2 , wherein
The working element includes a revolving body that is driven by a revolving mechanism and to which the boom is attached,
The detector includes a turning angle detector;
The inertial load calculating unit calculates the inertial load based on a turning angle detection signal output from the turning angle detector;
Characterized in that said control unit, when the lever operation amount obtained from the operation of the operation lever is greater than the stop pattern, for controlling the rotation driving of the turning body so inertial energy decreases the working element And excavator. The excavator according to claim 5, wherein
A lever operation amount change rate calculating unit that calculates a change rate of the lever operation amount based on the operation of the operation lever;
The excavator characterized in that, when the rate of change of the lever operation amount is greater than a threshold value, the control unit controls the turning drive of the revolving structure based on the operation amount of the operation lever.

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