JP6722627B2 - Hydraulic excavator - Google Patents

Description

The present invention, a working machine is attached to a revolving structure provided on a traveling body, various attachments including a material handling machine are selectively attached to the working machine according to work, and the working machine and a cab are provided. The present invention relates to a hydraulic excavator having an interference prevention control function for preventing the interference of the vehicle.

For hydraulic excavators, various types of attachments can be attached to the tip of the arm depending on the purpose, such as excavating and loading earth and sand with a bucket, dismantling and removing work using a breaker or lifting magnet, for example. it can. In this hydraulic excavator, it is necessary to shift the work implement to a specified traveling posture when performing a traveling operation. By driving the boom cylinder, the arm cylinder, and the bucket cylinder by operating the lever to shift the working machine to the traveling posture, the hydraulic excavator can travel stably. On the other hand, a hydraulic excavator equipped with a function that detects the strokes of the boom cylinder, the arm cylinder, and the bucket cylinder, and determines that the work implement has moved to the running posture when the detected values match a preset value is known. (See Patent Document 1). It is configured so that the monitor can confirm whether the stroke detection value of the boom cylinder, etc. matches the corresponding setting value. While confirming the stroke detection value on the monitor, the boom cylinder, etc. is driven to drive the work machine. Can be shifted to a running posture.

On the other hand, there are also known hydraulic excavators that employ interference prevention control that prevents the bucket from interfering with the cab when the standard bucket set for each boom, arm, and model is operated toward the cab. (See Patent Document 2, etc.). The interference prevention control is a well-known control technique that stops the work machine before the bucket enters the entry prohibition area set in front of the operator's cab based on the detection signal of the stroke sensor (or angle sensor) of each cylinder. is there.

JP, 2009-97303, A

JP-A-7-109750

As an attachment of a hydraulic excavator, there are various material handling machines such as lifting magnets that grip and transport materials such as waste materials and forest resources. These material handling machines are generally large compared to buckets, which are standard attachments used mainly for excavation and loading operations.

It is conceivable that the hydraulic excavator of Patent Document 1 employs the interference prevention control as in Patent Document 2 and the interference prevention control functions according to the attached attachment. However, in the hydraulic excavator of Patent Document 1, the traveling posture of the working machine is specified assuming that the bucket is mounted. Therefore, when the material handling machine larger than the bucket is mounted, the transition to the traveling posture is completed. The interference prevention control may be activated. In this case, it is difficult to detect the running posture.

In addition, in the hydraulic excavator of Patent Document 1, the operation of shifting the working machine to the running posture must be performed while observing the detection value of the stroke sensor. Therefore, in order to confirm the value detected by the stroke sensor on the monitor, the operation of the working machine must be interrupted frequently, and there is room for improvement in terms of smoothing the work of moving the working machine to the running posture. It was

An object of the present invention is to provide a hydraulic excavator that can smoothly shift a working machine to a running posture according to the type of attachment even in a model that employs interference prevention control.

In order to achieve the above-mentioned object, the present invention includes a traveling body, a revolving structure having a driver's cab that is rotatably provided on an upper portion of the traveling structure, and a working machine provided in a front portion of the revolving structure, The work machine includes a boom, an arm, an attachment, a boom cylinder, an arm cylinder, an attachment cylinder, a boom angle, a boom sensor for detecting the boom angle, an arm sensor for detecting the arm angle, and an attachment sensor for detecting the attachment angle. In a hydraulic excavator, the storage unit that stores each setting angle of the boom, arm, and attachment when traveling, the interference prevention control unit that prevents interference between the working machine and the cab, and the traveling attitude of the working machine A function for enabling the function of the running attitude calculation unit as well as the function of the interference prevention control unit by inputting a command signal from a running attitude calculation unit for calculating and a running mode switch provided in the cab A switching unit, and the control device further operates the boom cylinder when a difference between the boom setting angle stored in the storage unit and the boom angle detected by the boom sensor is equal to or less than a setting value. A boom stop command unit for stopping and an arm stop command for stopping the operation of the arm cylinder when the difference between the arm set angle stored in the storage unit and the arm angle detected by the arm sensor is a set value or less. Unit, and an attachment stop command unit that stops the operation of the attachment cylinder when the difference between the set angle of the attachment stored in the storage unit and the attachment angle detected by the attachment sensor is a set value or less. It is characterized by having a device.

In the hydraulic excavator according to the present invention, the function of the interference prevention control is stopped by turning on the traveling mode switch prior to traveling work. As a result, the work implement can be moved to a traveling posture corresponding to the type of attachment without the interference prevention control becoming an obstacle. At that time, the operator does not need to operate while confirming the angle of the boom or the like forming the working machine on the monitor or the like, and may appropriately operate the lever device in the image of bringing the working machine closer to the traveling posture. In the process of this operation, the boom, arm, and attachment will stop in sequence from the one that matches the angle of the running posture, so you can easily shift the work implement to the running posture without operating it while checking the monitor in particular. You can Therefore, it is possible to smoothly shift the working machine to an accurate traveling posture in accordance with the type of attachment while mounting the interference prevention control.

A side view showing appearance of a hydraulic excavator concerning one embodiment of the present invention. FIG. 1 is an enlarged view of the tip of a working machine provided in the hydraulic excavator shown in FIG. The side view showing the inside of the operator's cab provided in the hydraulic excavator shown in FIG. 1 together with the external structure. A schematic diagram showing a functional block of a control device together with a hydraulic circuit of a hydraulic drive device provided in the hydraulic excavator shown in FIG. 1. A conceptual diagram of a control device provided in the hydraulic excavator shown in FIG. The side view showing the running posture of the hydraulic excavator shown in FIG. The flowchart showing the procedure of the boom stop control in the traveling mode by the control device provided in the hydraulic excavator shown in FIG. The flowchart showing the procedure of the arm stop control in the traveling mode by the control device provided in the hydraulic excavator shown in FIG. The flowchart showing the procedure of the attachment stop control in the traveling mode by the control device provided in the hydraulic excavator shown in FIG.

Embodiments of the present invention will be described below with reference to the drawings.

-Hydraulic excavator-
FIG. 1 is a side view showing an appearance of a hydraulic excavator according to an embodiment of the present invention. In this figure, a hydraulic excavator equipped with a grapple, which is a kind of material handling machine, is used as the attachment 23 at the tip of the working machine. As the attachment 23, a material handling machine for gripping an object such as the grapple or the lifting magnet (FIG. 2) and various attachments including a bucket which is a standard attachment are selectively used according to the application. Many attachments other than the bucket, including the material handling machine, have a larger operating range, in other words, a larger maximum turning radius than the bucket. The material handling machine is also called an object handling machine. An example of an attachment that can be mounted on a work machine for a hydraulic excavator is disclosed in Japanese Patent Laid-Open No. 2017-048574. The front side (left side in FIG. 1) and the rear side (right side in FIG. 1) of the operator sitting in the driver's seat are the front and the rear of the swing body of the hydraulic excavator.

The hydraulic excavator shown in the figure includes a vehicle body 10 and a working machine (front working machine) 20. The vehicle body 10 includes a traveling body 11 and a swing body 12.

In the present embodiment, the traveling body 11 is a crawler type having left and right crawlers 13 having endless track tracks, and travels by driving the left and right crawlers 13 by the left and right traveling drive devices 18, respectively. The traveling drive device 18 includes a hydraulic motor and a speed reducer.

The revolving structure 12 is rotatably provided on the traveling structure 11 via a revolving device (not shown). An operator's cab (cab) 14 on which an operator rides is provided at a front portion of the revolving structure 12 (on the left side of the front portion in the present embodiment). A power chamber 15 accommodating a prime mover 41 (FIG. 4), a hydraulic drive device, and the like is mounted on the rear side of the operator's cab 14 of the revolving structure 12, and a counterweight 16 for adjusting the longitudinal balance of the vehicle is mounted on the rearmost part. Has been done. The prime mover 41 is an engine (internal combustion engine) or an electric motor. A revolving motor (not shown) is included in the revolving device that connects the revolving structure 12 to the traveling structure 11. The revolving motor drives the revolving structure 12 with respect to the traveling structure 11 to revolve. Although the swing motor in this embodiment is a hydraulic motor, an electric motor may be used, or both a hydraulic motor and an electric motor may be used. The operator's cab 14 is a movable type which is connected to a revolving frame 17 which is a base frame of the revolving structure 12 via a link and whose height and inclination angle can be changed by a hydraulic cylinder (not shown). The configuration of the movable cab and the like are described in detail in JP 2013-014914 A and the like.

The work machine 20 is provided on the front part of the revolving structure 12 (on the right side of the cab 14 in the present embodiment). The work machine 20 is a multi-joint work device including a boom 21, an arm 22, an attachment 23, a boom cylinder 24, an arm cylinder 25, an attachment cylinder 26, and sensors 27 to 29.

The boom 21 is connected to the frame of the revolving structure 12 by a pin (not shown) extending left and right. The boom cylinder 24 connects the boom 21 and the swing structure 12. As the boom cylinder 24 expands and contracts, the boom 21 rotates up and down with respect to the revolving structure 12. The arm 22 is connected to the tip of the boom 21 by a pin (not shown) extending left and right. The arm cylinder 25 connects the arm 22 and the boom 21. The arm cylinders 25 are provided on the left and right side surfaces of the work machine 20 (two in total), and both ends of the work machine 20 on the left and right side surfaces are opposite to the boom 21 and the arm 22 side surface, respectively. It is rotatably connected. The arm 22 rotates with respect to the boom 21 as the arm cylinder 25 expands and contracts. The attachment 23 is connected to the tip of the arm 22 by a pin (not shown) extending in the left-right direction. The base end of the attachment cylinder 26 is connected to the arm 22, and the tip end thereof is connected to the attachment 23 and the arm 22 via a link. The attachment 23 rotates with respect to the arm 22 as the attachment cylinder 26 expands and contracts. The boom cylinder 24, the arm cylinder 25, and the attachment cylinder 26 are hydraulic cylinders that drive the work machine 20. In this specification, when a plurality of boom cylinders 24, arm cylinders 25, and attachment cylinders 26 are mentioned, they may be collectively referred to as “hydraulic cylinders” such as hydraulic cylinders 24 to 26.

The sensor 27 is a boom sensor (boom sensor) that detects the boom angle θA and outputs the boom angle θA to the control device 60 (FIG. 4 ), and is, for example, an angle sensor provided at the rotation fulcrum of the boom 21. In the present embodiment, the boom angle θA is a line L1 passing through the support points P1 and P2 of the boom 21 and the arm 22 and a vertical line L0 (a line perpendicular to the ground plane of the traveling body 11) as viewed from the left and right in this embodiment. It is assumed that the angle is formed by and. The support point P1 is a rotation fulcrum of the boom 21 with respect to the revolving structure 12, and the support point P2 is a rotation fulcrum of the arm 22 with respect to the boom 21. The boom angle θA may be directly detected by the sensor 27, or may be calculated by the control device 60 from a detection signal of the sensor 27.

The sensor 28 is a sensor for the arm (arm sensor) that detects the arm angle θB and outputs it to the control device 60, and is, for example, an angle sensor provided at the rotation fulcrum of the arm 22. In the present embodiment, the arm angle θB is an angle formed by a line L2 passing through the support points P2 and P3 of the arm 22 and the attachment 23 when viewed from the left and right and the line L1. The support point P3 is a rotation fulcrum of the attachment 23 with respect to the arm 22. The arm angle θB may be directly detected by the sensor 28, or may be calculated by the control device 60 from a detection signal of the sensor 28.

The sensor 29 is a sensor for attachment (attachment sensor) that detects the attachment angle θC and outputs it to the control device 60, and is configured, for example, as illustrated in FIG. 2. FIG. 2 shows a state in which a lifting magnet is attached as the attachment 23. The sensor 29 of the present embodiment is installed on a side surface (left side surface in this example) of the arm 22 away from the tip of the arm 22. This sensor 29 is connected to a link connecting the attachment cylinder 26 to the arm 22 and the attachment 23 via a lever 29a and a rod 29b, and detects the angle of the link as an attachment angle θC. In this embodiment, the attachment angle θC is an angle formed by a line L3 passing through the two support points P3 and P4 of the attachment 23 and the above line L2 when viewed from the left and right. The support point P4 is a fulcrum of connection between the attachment 23 and the link. The attachment angle θC may be directly detected by the sensor 29, or may be calculated by the control device 60 from a detection signal of the sensor 29. An element denoted by reference numeral 29c is a signal line (sensor harness) that connects the sensor 29 and the control device 60, and a detection signal of the sensor 29 is input to the control device 60 via the signal line 29c.

-Operating room-
FIG. 3 is a side view showing the inside of the cab 14 together with the external structure. The driver's cab 14 is supported by a front part in the upper part of the turning frame 17 (FIG. 1) and is offset to one side in the left-right direction (left side in this example) with respect to the turning center of the turning frame 17. However, the driver's cab 14 may be arranged on the right side of the machine body. The driver's cab 14 includes a driver's seat (not shown), lever devices 31 to 33, a console box 34, a gate lock lever (not shown), a driving mode switch 35, an attachment selection switch 36 (FIG. 4), etc. inside the body 14a. I have it. The body 14 a is an outer shell of the cab 14 surrounding the driver's seat, and is fixed to the revolving frame 17. As described above, in the hydraulic excavator of this example, the driver's cab 14 can be moved up and down via the links, and thus the body 14a is strictly fixed on the bed supported by the links. Attached to the swivel frame 17. When the cab 14 is non-movable, the body 14a is directly fixed to the revolving frame 17. As shown in FIG. 1, in this embodiment, a door is provided on the left side wall of the body 14a, and the operator opens and closes the door to get on and off the operator's cab 14. The driver's seat is a seat on which the operator sits, and is fixed on the floor plate in the body 14a. The floor plate is also fixed on the bed or the swing frame 17 similarly to the body 14a.

The lever devices 31 to 33 (FIG. 4) instruct the operation of the hydraulic cylinders 24 to 26, respectively, and are operated by two operation levers together with the lever device instructing the operation of the swing motor. In other words, these lever devices are apparently two cross-operated lever devices installed one on the left and one on the right of the driver's seat, and the two lever devices share one operating lever on the left side of the driver's seat, and others. The two lever devices share the one operating lever on the right side of the driver's seat. The operation lever is tilted forward and backward and left and right, and an operation in the front and back direction instructs the operation of the corresponding hydraulic actuator, and an operation in the left and right direction instructs the operation of another corresponding hydraulic actuator. Inside the driver's cab 14, for example, lever devices with pedals for traveling operation are also arranged side by side on the front side of the driver's seat. In the present embodiment, the lever device 31 is a boom lever device for boom operation that instructs the operation of the control valve 45 for the boom. The lever device 32 is an arm lever device for operating the arm that instructs the operation of the control valve 46 for the arm. The lever device 33 is an attachment lever device for operating an attachment for instructing the operation of the control valve 47 for the attachment. Corresponding control valves 45 to 47 are operated by operating the lever devices 31 to 33, the hydraulic cylinders 24 to 26 expand and contract, and the boom 21, the arm 22, and the attachment 23 rotate.

The gate lock lever is a lever-shaped gate that is installed on the entry/exit side (left side in this example) of the driver's seat so as to prevent the operator from getting off when lying down. The operator cannot get off the vehicle unless the gate lock lever is pulled up to open the entry/exit section for the driver's seat. A gate lock valve (not shown) is operated depending on the position of the gate lock lever, and the operation of the hydraulic cylinders 24 to 26 by the lever devices 31 to 33 is disabled when the entry/exit portion is opened.

The traveling mode switch 35 is a switch that is operated when shifting the work implement 20 to the traveling posture, and in the present embodiment, a case where the traveling mode switch 35 is installed in the console box 34 adjacent to the driver's seat is illustrated. When the traveling mode switch 35 is turned on, the interference prevention control function (described later) is invalidated and the traveling attitude calculation function (described later) is activated. On the contrary, when the traveling mode switch 35 is turned off, the interference prevention control function becomes effective and the traveling posture calculation function becomes ineffective. Further, the attachment selection switch 36 is an operating device that selects and inputs the type of the attached attachment 23, and various switches such as buttons displayed on the touch panel can be applied in addition to mechanical switches such as dials. .. The signals from the drive mode switch 35 and the attachment selection switch 36 are input to the control device 60 (FIG. 4).

-Hydraulic drive-
FIG. 4 is a schematic diagram showing a functional block of a control device together with a hydraulic circuit of a hydraulic drive device provided in the hydraulic excavator shown in FIG. The same components as those already described are denoted by the same reference numerals in the same drawing, and the description thereof will be omitted.

First, the hydraulic drive system will be described with reference to FIG. The hydraulic drive device is a device that drives the hydraulic cylinders 24 to 26 and is housed in the power chamber 15. This hydraulic drive device includes hydraulic pumps 42 to 44, control valves 45 to 47, a pilot pump 48, lever devices 31 to 33, and the like.

The hydraulic pumps 42 to 44 are variable displacement pumps that discharge hydraulic oil that drives the hydraulic cylinders 24 to 26 and the like, and are driven by the prime mover 41. The hydraulic oil discharged from the hydraulic pumps 42 to 44 flows through the discharge pipes 42a to 44a and is supplied to the hydraulic cylinders 24 to 26 via the control valves 45 to 47, respectively. The return oils from the hydraulic cylinders 24 to 26 flow into the return oil pipe 49 via the control valves 45 to 47 and are returned to the tank T. The discharge pipes 42a to 44a are provided with relief valves (not shown) that regulate the maximum pressure of the discharge pipes 42a to 44a. Although not shown in FIG. 4, when an attachment such as a grapple having a hydraulic actuator is attached to the work machine 20, the hydraulic actuator provided in the attachment is also driven by the same circuit configuration. In the present embodiment, an example in which hydraulic oil is supplied to the hydraulic cylinders 24 to 26 from different hydraulic pumps 42 to 44 is shown. It may be configured to supply hydraulic oil.

The control valves 45 to 47 are hydraulically driven flow rate control valves that control the flow (direction and flow rate) of hydraulic oil supplied from the hydraulic pumps 42 to 44 to the corresponding actuators, and are hydraulic signals input to the hydraulic drive unit. Driven by. The control valve 45 is a boom control valve that controls the flow of hydraulic oil to the boom cylinder 24. The control valve 46 is an arm control valve that controls the flow of hydraulic oil to the arm cylinder 25. The control valve 47 is an attachment control valve that controls the flow of hydraulic oil to the attachment cylinder 26. Control valves for other actuators such as a swing motor and a traveling motor are not shown. The hydraulic drive of the control valves 45 to 47 is connected to the corresponding operating lever device. When a hydraulic signal is input to the hydraulic drive unit, the control valves 45 to 47 move to the right (to the left switching position side) or to the left (to the right switching position side) in the figure, and the input of the hydraulic signal is stopped. Then, the force of the spring returns to the neutral position. At each neutral position of the control valves 45 to 47, the discharge pipes 42a to 44a are connected to the return oil pipe 49, the supply and discharge of hydraulic oil to and from the hydraulic cylinders 24 to 26 are stopped, and the expansion and contraction operations of these hydraulic cylinders 24 to 26 are performed. Stop. For example, when a hydraulic pressure signal is input to the hydraulic drive unit on the left side of the control valve 45 for the boom cylinder, the spool of the control valve 45 moves rightward in FIG. 4 by a distance corresponding to the magnitude of the hydraulic pressure signal. As a result, hydraulic oil having a flow rate according to the hydraulic signal is supplied to the bottom side oil chamber of the boom cylinder 24, the boom cylinder 24 extends at a speed corresponding to the magnitude of the hydraulic signal, and the boom 21 rises.

The pilot pump 48 is a fixed displacement pump that outputs the source pressure of a hydraulic signal that drives control valves such as the control valves 45 to 47, and is driven by the prime mover 41 like the hydraulic pumps 42 to 44. The pilot pump 48 may be driven by a power source different from the prime mover 41. The pilot line 48a is a discharge pipe of the pilot pump 48, and is branched and connected to the lever devices 31 to 33. The hydraulic oil discharged from the pilot pump 48 is supplied to the signal output valves (pressure reducing valves) of the lever devices 31 to 33 through the pilot line 48a.

The lever devices 31 to 33 are hydraulic lever lever devices that generate and output hydraulic signals for driving the corresponding control valves 45 to 47 in response to an operation, and are provided in the cab 14 (FIG. 1) as described above. Has been. The lever device 31 is for operating the boom, the lever device 32 is for operating the arm, the lever device 33 is for operating the attachment, and there is also a lever device for turning operation. In the case of a hydraulic excavator, as described above, the lever devices 31 to 33 are generally cross-operated lever devices.

The boom operation lever device 31 includes a boom up command signal output valve 31a and a boom down command signal output valve 31b. A pilot line 48a is connected to the input ports of the signal output valves 31a and 31b. The output port of the signal output valve 31a for boom raising command is connected to the hydraulic drive unit on the left side of the control valve 45 for the boom cylinder. The output port of the signal output valve 31b for boom down command is connected to the hydraulic drive unit on the right side of the control valve 45. For example, when the lever device 31 is tilted to the boom raising command side, the signal output valve 31a opens at an opening degree according to the operation amount. As a result, the oil discharged from the pilot pump 48 is reduced in pressure by the signal output valve 31a according to the operation amount, and is output as a hydraulic signal to the hydraulic drive unit on the left side of the control valve 45.

Similarly, the lever device 32 for arm operation includes a signal output valve 32a for arm cloud command and a signal output valve 32b for arm dump command. The lever device 33 for operating an attachment includes a signal output valve 33a for an attachment cloud command and a signal output valve 33b for an attachment dump command. The input ports of the signal output valves 32a, 32b, 33a, 33b are connected to the pilot line 48a. The output ports of the signal output valves 32b and 33a of the lever devices 32 and 33 are connected to the hydraulic drive units on the left side of the control valves 46 and 47. The output ports of the signal output valves 32a and 33b of the lever devices 32 and 33 are connected to the hydraulic drive units on the right side of the control valves 46 and 47. The principle of outputting the hydraulic signals of the lever devices 32 and 33 is similar to that of the lever device 31 for operating the boom.

Further, the switching valves 51a, 51b, 52a, 52b, 53a, 53b are respectively provided in the hydraulic signal lines 31a1, 31b1, 32a1, 32b1, 33a1, 33b1 of the signal output valves 31a, 31b, 32a, 32b, 33a, 33b. Correspondingly provided. Hereinafter, when referring to all six of the switching valves 51a, 51b, 52a, 52b, 53a, 53b, they are described as "switching valves 51a, 51b... ".

The switching valves 51a and 51b are switching valves for booms that switch between enabling and disabling of boom operation by switching supply and cutoff of pilot pressure to the hydraulic drive unit of the control valve 45 for booms. In the present embodiment, normally closed proportional electromagnetic pressure reducing valves capable of shutting off the hydraulic signal lines 31a1 and 31b1 are used as the switching valves 51a and 51b. When the solenoid is excited by the signal from the control device 60, the switching valve 51a is switched to the communicating position, the signal output valve 31a and the left hydraulic drive of the control valve 45 are connected, and the boom raising operation by the lever device 31 is performed. validate. When the output of the signal from the control device 60 is stopped and the solenoid is demagnetized, the switching valve 51a is switched to the shut-off position, the connection between the signal output valve 31a and the hydraulic drive unit on the left side of the control valve 45 is shut off, and the lever device The boom raising operation by 31 is invalid. Similarly, when the solenoid is excited by a signal from the control device 60, the switching valve 51b is switched to the communication position, the signal output valve 31b and the hydraulic drive unit on the right side of the control valve 45 are connected, and the lever device 31 lowers the boom. The operation becomes effective. When the output of the signal from the control device 60 is stopped and the solenoid is demagnetized, the switching valve 51b is switched to the cutoff position, the connection between the signal output valve 31b and the hydraulic drive section on the right side of the control valve 45 is cut off, and the lever device The boom lowering operation by 31 is invalid.

The switching valves 52a and 52b are switching valves for the arm that switch between supplying and blocking pilot pressure to and from the hydraulic drive of the control valve 46 for the arm to switch between valid and invalid arm operation. In this embodiment, normally closed type proportional electromagnetic pressure reducing valves capable of shutting off the hydraulic signal lines 32a1 and 32b1 are used as the switching valves 52a and 52b. When the solenoid is excited by a signal from the control device 60, the switching valve 52a is switched to the communication position, the signal output valve 32a and the hydraulic drive unit on the right side of the control valve 46 are connected, and the arm cloud operation by the lever device 32 is performed. validate. When the output of the signal from the control device 60 is stopped and the solenoid is demagnetized, the switching valve 52a is switched to the cutoff position, the connection between the signal output valve 32a and the hydraulic drive unit on the right side of the control valve 46 is cut off, and the lever device The arm cloud operation by 32 is disabled. Similarly, when the solenoid is excited by a signal from the control device 60, the switching valve 52b is switched to the communicating position, the signal output valve 32b and the left hydraulic drive unit of the control valve 46 are connected, and the lever device 32 causes an arm dump. The operation becomes effective. When the output of the signal from the control device 60 is stopped and the solenoid is demagnetized, the switching valve 52b is switched to the cutoff position, the connection between the signal output valve 32b and the hydraulic drive unit on the left side of the control valve 46 is cut off, and the lever device. The arm dump operation by 32 becomes invalid.

The switching valves 53a and 53b are switching valves for attachment that switch supply and cutoff of pilot pressure to the hydraulic drive unit of the control valve 47 for attachment to switch between valid and invalid of the attachment operation. In the present embodiment, normally closed proportional electromagnetic pressure reducing valves capable of shutting off the hydraulic signal lines 33a1 and 33b1 are used as the switching valves 53a and 53b. When the solenoid is excited by the signal from the control device 60, the switching valve 53a is switched to the communication position, the signal output valve 33a and the left hydraulic drive of the control valve 47 are connected, and the attachment cloud operation by the lever device 33 is performed. validate. When the output of the signal from the control device 60 is stopped and the solenoid is demagnetized, the switching valve 53a is switched to the cutoff position, the connection between the signal output valve 33a and the hydraulic drive section on the left side of the control valve 47 is cut off, and the lever device The attachment cloud operation by 33 is disabled. Similarly, when the solenoid is excited by a signal from the control device 60, the switching valve 53b is switched to the communication position, the signal output valve 33b and the hydraulic drive on the right side of the control valve 47 are connected, and the attachment dump by the lever device 33 is connected. The operation becomes effective. When the output of the signal from the control device 60 is stopped and the solenoid is demagnetized, the switching valve 53b is switched to the cutoff position, the connection between the signal output valve 33b and the hydraulic drive unit on the right side of the control valve 47 is cut off, and the lever device The attachment dump operation by 33 becomes invalid.

-Control device-
The hydraulic excavator of this embodiment includes a control device 60 that controls the switching valves 51a, 51b,.... A specific example of the control device 60 is a computer, and as shown in FIG. 3, it can be installed in a space behind the driver's seat (not shown) in the driver's cab 14, for example. As shown in FIG. 5, the control device 60 includes an input interface 60a, a ROM (for example, EPROM) 60b, a RAM 60c, a CPU 60d, a timer 60e, and an output interface 60f. The sensors 27 to 29, the traveling mode switch 35, the attachment selection switch 36, and the like are connected to the input interface. When the input signals from these sensors and the like are analog signals, the input interface is equipped with an AD converter, but when they are digital signals, the AD conversion function is not always necessary. The output interface includes a DA converter and is connected to each solenoid of the switching valves 51a, 51b,....

When the main functions of the control device 60 are structurally grasped, the control device 60, as shown in FIG. 4, has a coordinate calculation unit 61, a function switching unit 62, storage units 63 to 65, an interference prevention control unit 66, A running posture calculation unit 67, a flow rate calculation unit 68, and an output unit 69 are provided. The coordinate calculation unit 61, the function switching unit 62, the interference prevention control unit 66, the traveling posture calculation unit 67, and the flow rate calculation unit 68 correspond to hardware such as the CPU 60d. These functions may be executed by one CPU, or may be shared by a plurality of CPUs. A configuration in which a CPU corresponding to each function is provided may be used. The storage unit 63 to 65 corresponds to the ROM 60b or the RAM 60c, and the output unit 69 corresponds to the output interface 60f as hardware. A configuration in which the storage units 63 to 65 are also used as one memory, a configuration in which the storage units 63 to 65 are shared by two memories, and a configuration in which three memories corresponding to the storage units 63 to 65 are provided are all conceivable. Further, for example, in the ROM 60b, in addition to the size and shape data of the boom 21 and the arm 22, the size and shape of each type of attachment, the maximum turning radius, and the like, the proximity area A1 set on the front side of the cab 14 (see FIG. 6). The information such as the coordinates) is stored.

The coordinate calculation unit 61 calculates the coordinates of a specific point of the attachment 23 (for example, the support point P3 of the attachment 23) based on the signals from the sensors 27 to 29 and the attachment selection switch 36 input via the input interface 60a. Function or circuit. For example, the dimension data of the boom 21 and the arm 22 stored in the ROM 60b is read, and the coordinate calculation unit 61 calculates the coordinate value of the specific point of the attachment 23 based on the signals from the sensors 27 to 29. The detection values input from the sensors 27 to 29 are stored in the memory (for example, the RAM 60c or the ROM 60b) together with the coordinates calculated by the coordinate calculation unit 61.

The function switching unit 62 is a function or a circuit that selectively enables the functions of the interference prevention control unit 66 and stop command units 67a to 67c (running posture calculation unit 67 in the present embodiment) described later. Specifically, when an incoming signal from the traveling mode switch 35 is input via the input interface 60a, the function switching unit 62 disables the function of the interference prevention control unit 66 and the function of the traveling posture calculation unit 67. To enable. In this case, for example, the function switching unit 62 does not output the input signals from the sensors 27 to 29 or the attachment selection switch 36 and the calculation result of the coordinate calculation unit 61 to the interference prevention control unit 66, but only to the traveling posture calculation unit 67. Output. As a result, the interference prevention control unit 66 does not function, but only the traveling posture calculation unit 67 functions. When the signal input from the travel mode switch 35 is stopped, the function switching unit 62 enables the function of the interference prevention control unit 66 and disables the function of the traveling posture calculation unit 67. In this case, for example, the function switching unit 62 does not output the input signals from the sensors 27 to 29 or the attachment selection switch 36 and the calculation result of the coordinate calculation unit 61 to the traveling posture calculation unit 67, but only to the interference prevention control unit 66. Output. As a result, the traveling posture calculation unit 67 does not function, but only the interference prevention control unit 66 functions.

The storage unit 63 is a traveling boom angle storage unit that stores a preset angle θAT of the boom 21 when the working posture of the work machine 20 is preset for each type of attachment (an example is shown in FIG. 6 ). The storage unit 64 is a traveling arm angle storage unit that stores a preset angle θBT of the arm 22 when the working machine 20 is in the traveling posture, which is preset for each type of attachment. The storage unit 65 is a traveling attachment angle storage unit that stores a preset angle θCT of the attachment 23 when the working machine 20 is traveling in a preset posture for each type of attachment. The set angles θAT, θBT, and θCT are values set for the detection values of the sensors 27 to 29, and are prepared for each type of attachment 23. The set angles θAT, θBT, and θCT may have common values for different attachments, or may have different values depending on the type of attachment.

The interference prevention control unit 66 is a function or a circuit that limits the operation of the work machine 20 in order to prevent the work machine 20 and the cab 14 from interfering with each other. When this function is effective, the interference prevention control unit 66 calculates an operation range A2 (FIG. 6) of the attachment 23 centered on a specific point of the attachment 23 input from the coordinate calculation unit 61 via the function switching unit 62. To do. The movement range A2 is a spherical space centered on the coordinates of a specific point of the attachment 23, and its radius is the maximum movement radius of the attachment 23 read from the RAM 60c. The interference prevention control unit 66 determines whether the operation range A2 interferes with the proximity area A1 of the cab 14, and if there is interference, controls the switching valves 51a, 51b... And depending on the degree of interference. A command for decelerating or stopping the operation of the work machine 20 is generated. On the contrary, when the operation range A2 does not interfere with the proximity area A1 of the operator's cab 14, the interference prevention control unit 66 generates a command to open the switching valves 51a, 51b... The interference prevention control is described in, for example, JP-A-7-109750.

The traveling posture calculation unit 67 is a function or circuit for calculating the traveling posture of the work machine 20, and in the present embodiment, includes stop command units 67a to 67c, and has a function or a function of assisting the work machine 20 to shift to the traveling posture. It is also a circuit. However, the stop command units 67a to 67c only have to be provided in the control device 60, and do not necessarily have to be provided in the traveling posture calculation unit 67. In this embodiment, the arm 22 is extended downward (the line L2 is substantially vertical), and the attachment 23 is in a running posture in which the attachment 23 floats above the ground by a predetermined distance (FIG. 6). As described above, in the running posture, θA=θAT (or θA≈θAT), θB=θBT (or θB≈θBT), and θC=θCT (or θC≈θCT).

The stop command unit 67a is a stop command unit for the boom, and constantly compares the set angle θAT of the boom 21 in the traveling posture stored in the storage unit 63 with the boom angle θA detected by the sensor 27 when the function is valid. When the difference (|θAT-θA|) between θAT and θA is less than or equal to the set value θAS, the stop command unit 67a generates a command to switch the switching valves 51a and 51b to the shutoff position, and stops the operation of the boom cylinder 24. When the difference (|θAT-θA|) is larger than the set value θAS, the stop command unit 67a sets the switching valves 51a and 51b to the maximum opening degree.

The stop command unit 67b is a stop command unit for the arm, and similarly to the stop command unit 67a, the set angle θB of the arm 22 during the traveling posture stored in the storage unit 64 and the arm detected by the sensor 28 when the function is valid. The angle θB is constantly compared. When the difference between θBT and θB (|θBT−θB|) is equal to or less than the set value θBS, the stop command unit 67b generates a command to switch the switching valves 52a and 52b to the shutoff position, and stops the operation of the arm cylinder 25. When the difference (|θBT-θB|) is larger than the set value θBS, the stop command unit 67b sets the switching valves 52a and 52b to the maximum opening degree.

The stop command unit 67c is a stop command unit for the attachment, and like the stop command unit 67a, when the function is valid, the set angle θCT of the attachment 23 in the traveling posture stored in the storage unit 65 and the attachment detected by the sensor 29. The angle θC is constantly compared. When the difference between θCT and θC (|θCT-θC|) is less than or equal to the set value θCS, the stop command unit 67c generates a command to switch the switching valves 53a and 53b to the shutoff position, and stops the operation of the attachment cylinder 26. When the difference (|θCT-θC|) is larger than the set value θCS, the stop command unit 67c sets the switching valves 53a and 53b to the maximum opening degree.

The set values θAS, θBS, and θCS set for |θAT-θA|, |θBT-θB|, and |θCT-θC| are 0 (zero) or a value slightly larger than 0.

The flow rate calculation unit 68 calculates the flow rate of the hydraulic signal to the control valves 45 to 47 or the opening degree of the switching valves 51a, 51b... Based on the command of the interference prevention control unit 66 or the traveling posture calculation unit 67, and the switching valve It is a function or circuit for calculating the numerical values (command values) of the signals for 51a, 51b,.... The output unit 69 outputs a command from the interference prevention control unit 66 or the traveling posture calculation unit 67 to the switching valves 51a, 51b... An analog signal (voltage signal) corresponding to the command value calculated by the flow rate calculation unit 68 is output to each solenoid of the switching valves 51a, 51b..., And the switching valves 51a, 51b... Are controlled.

-Operation-
After starting the prime mover 41, by appropriately operating the lever devices 31 to 33 and the like, the actuators such as the hydraulic cylinders 24 to 26 are driven, and the working machine 20, the swinging body 12, the traveling body 11 and the like operate. At that time, the boom raising operation, the arm crowd operation, and the attachment crowd operation are operations in a direction of bringing the attachment 23 closer to the operator's cab 14. When the traveling mode switch 35 is in the OFF state, the operation range A2 of the attachment 23 is constantly calculated as described above. When the operation range A2 interferes with the proximity area A1 of the operator's cab 14 due to an arm cloud operation or the like, the interference prevention control unit 66 functions to control the switching valves 51a, 51b... And the operation of the work machine 20 is decelerated or stopped. It During this time, since the function of the traveling posture calculation unit 67 is invalid, the operation of the boom 21 does not stop even if the boom angle θA matches the set angle θAT during work, for example.

When the traveling mode switch 35 is in the on state, the function of the interference prevention control unit 66 is disabled, and instead of this, the function of the traveling posture calculation unit 67, specifically, each stop of boom operation, arm operation, and attachment operation is stopped. The functions of the command units 67a to 67c become effective.

FIG. 7 is a flowchart showing a procedure of boom stop control in the traveling mode by the control device 60. FIG. 8 is a flowchart showing a procedure of arm stop control in the traveling mode by the control device 60. FIG. 9 is a flowchart showing the procedure of the attachment stop control in the traveling mode by the control device 60. While the traveling mode switch 35 is in the ON state, the control device 60 independently executes the controls shown in FIGS. 7 to 9 in parallel.

The procedure of the boom stop control in the traveling mode by the control device 60 will be described as a representative. The control device 60 determines whether the signal from the traveling mode switch 35 is input during operation (while the control device 60 is energized) (step S11). When the traveling mode switch 35 is in the off state and no signal is input, the control device 60 repeats the procedure of step S11 while keeping the function of the interference prevention control unit 66 enabled by the function switching unit 62. When the traveling mode switch 35 is turned on and operated to prepare for traveling work, a signal is input from the traveling mode switch 35. When this signal is input, the control device 60 causes the function switching unit 62 to stop the function of the interference prevention control unit 66 and enables the function of the traveling posture calculation unit 67 (here, the stop command unit 67a) (step S12).

When the traveling mode switch 35 is turned on, the operator operates the boom device 21 by operating the lever device 31 targeting the set angle θAT in order to shift the working machine 20 to the traveling posture. During this period, the control device 60 determines by the stop command unit 67a whether the difference (|θA−θAT|) between the boom angle θA input from the sensor 27 and the set angle θAT is less than or equal to the set value θAS (step S13). When the stop command unit 67a determines that |θA−θAT|> θAS, the control device 60 returns the procedure to step S11. As the boom angle θA approaches the set angle θAT, |θA−θAT|≦θAS. When this is determined by the stop command unit 67a, the control device 60 generates a command to stop the boom operation by the stop command unit 67a, and the switching valves 51a, 51b are output via the flow rate calculation unit 68 and the output unit 69. The signal for instructing to fully close is output. Since the switching valves 51a and 51b of the present embodiment are normally-closed type solenoid valves, outputting a signal instructing the switching valves 51a and 51b to be fully closed means demagnetizing the solenoids of the switching valves 51a and 51b. Point to. When the switching valves 51a and 51b are closed and the hydraulic signal lines 31a and 31b1 are shut off, the control valve 45 is forcibly returned to the neutral position, and the operation of the boom cylinder 24 is stopped. Thereafter, the boom 21 is restrained at the set angle θAT while the traveling mode switch 35 is turned on.

The procedure of the arm stop control and the attachment stop control in the traveling mode by the control device 60 are the same as the procedure of the boom stop control. That is, the control device 60 determines whether or not the signal from the traveling mode switch 35 is input (steps S21 and S31), and if the signal is input, enables the functions of the stop command units 67b and 67c (step S22). , S32). Subsequently, the control device 60 determines whether |?B-?BT|??BS or |?C-?CT|??CS by the stop command units 67b and 67c, respectively (steps S23 and S33). Then, when |θB−θBT|≦θBS and |θC−θCT|≦θCS, the control device 60 causes the stop command units 67b and 67c to generate commands for stopping the arm operation and the attachment operation, respectively, and switch them. The valves 52a, 52b, 53a, 53b are closed. By disconnecting the hydraulic signal lines 32a, 32b1, 33a1, 33b1 in this way, the control valves 46, 47 are returned to the neutral position, and the operation of the hydraulic cylinders 25, 26 is stopped. After that, while the traveling mode switch 35 is in the on state, the arm 22 and the attachment 23 are restrained at the set angles θBT and θCT.

As described above, when the lever devices 31 to 33 are appropriately operated with the traveling posture set as a target, the operation is sequentially stopped from the boom 21, the arm 22, and the attachment 23 at the set angles θAT, θBT, and θCT. If none of the boom 21, the arm 22, and the attachment 23 operates even if the lever devices 31 to 33 are operated, the transition of the working machine 20 to the working posture is completed.

-Effect-
In the hydraulic excavator according to the present embodiment, the function of the interference prevention control is stopped and the function of the running posture calculation is enabled by turning on the running mode switch 35 prior to running work. As a result, the work implement 20 can be moved to a traveling posture corresponding to the type of the attachment 23 without causing interference with the interference prevention control. At that time, the operator does not need to operate while confirming the angle of the boom 21 or the like constituting the working machine 20 with a monitor or the like, and may appropriately operate the lever devices 31 to 33 in an image of bringing the working machine 20 closer to the traveling posture. .. In the process of this operation, the boom 21, the arm 22, and the attachment 23 are sequentially stopped from the one that matches the angle at the time of traveling posture, so that the working machine 20 can be easily traveling posture without operating the operator while checking the monitor or the like. Can be moved to. Therefore, it is possible to smoothly shift the working machine 20 to an accurate traveling posture according to the type of the attachment 23 while mounting the interference prevention control.

-Modification-
In the above-described embodiment, the case where the angle sensor that detects the boom angle θA, the arm angle θB, and the attachment angle θC is used as an example has been described. However, for example, a stroke sensor that detects each stroke of the hydraulic cylinders 24 to 26. Can also be used. The boom angle θA can be detected based on the signal of the stroke sensor, and the same effect can be obtained.

The configuration in which the attachment selection switch 36 is provided and the type of the attachment 23 is recognized by the control device 60 by the signal of the attachment selection switch 36 has been described as an example, but the configuration is not limited to this. For example, a configuration may be considered in which an electronic contact is provided at the connecting portion between the attachment 23 and the arm 22 and the type of the attached attachment 23 is automatically recognized by the control device 60.

Further, when the working machine 20 completes the transition to the running posture, it can be easily configured to visually or audibly notify the operator of the fact by a monitor or a buzzer.

Although the hydraulic operation type is illustrated as the lever devices 31 to 33, the present invention is also applicable to a hydraulic excavator adopting an electrically operated lever device such as an electric lever device. In a hydraulic excavator using an electrically operated lever device, a command signal is generally output from a controller according to an electric signal output from the lever device, and a control valve is operated by a hydraulic signal generated by a solenoid valve driven by this. The work machine operates by being driven. In this case, a program for switching the solenoid valve to the shut-off position when the boom angle θA or the like matches the set angle while the traveling mode switch 35 is in the ON state is stored in, for example, the ROM 60b of the control device 60. As a result, even in a hydraulic excavator that employs an electrically operated lever device, it is possible to execute the same function as in the above embodiment.

Further, the case where the present invention is applied to a hydraulic excavator including a crawler type traveling body has been described as an example, but the present invention is also applicable to a hydraulic excavator including a wheel type traveling body, and the same. The effect can be obtained.

11... Traveling body, 12... Revolving structure, 14... Driver's cab, 20... Working machine, 21... Boom, 22... Arm, 23... Attachment, 24... Boom cylinder, 25... Arm cylinder, 26... Attachment cylinder, 27... Sensor (Boom sensor), 28... Sensor (arm sensor), 29... Sensor (attachment sensor), 31... Lever device (boom lever device), 32... Lever device (arm lever device), 33... Lever device (attachment lever device) , 35... Running mode switch, 41... Engine (motor), 42-44... Hydraulic pump, 45... Control valve (boom control valve), 46... Control valve (arm control valve), 47... Control valve (for attachment) Control valve), 51a, 51b... switching valve (boom switching valve), 52a, 52b... switching valve (arm switching valve), 53a, 53b... switching valve (attachment switching valve), 60... control device, 62... Function switching unit, 63 to 65... Storage unit, 66... Interference prevention control unit, 67... Running posture calculation unit, 67a... Stop command unit (boom stop command unit), 67b... Stop command unit (arm stop command unit), 67c ... stop command section (attachment stop command section), 69... output section, θA... boom angle, θAS... set value, θAT... boom angle when traveling posture, θB... arm angle, θBS... set value, θBT... traveling posture Arm angle, θC... Attachment angle, θCS... Set value, θCT... Attachment angle during running posture

Claims (2)

A traveling body, a revolving structure which has a driver's cab and is provided above the traveling structure so as to be revolvable, and a working machine provided in a front portion of the revolving structure, and the working machine comprises a boom, an arm, an attachment, and a boom. In a hydraulic excavator including a cylinder, an arm cylinder, an attachment cylinder, a boom angle, a boom sensor that detects the boom angle, an arm sensor that detects the arm angle, and an attachment sensor that detects the attachment angle,
A storage unit that stores each set angle of the boom, arm, and attachment in a traveling posture, an interference prevention control unit that prevents interference between the working machine and the cab, and a traveling posture calculation that calculates the traveling posture of the working machine And a function switching unit that inputs a command signal from a traveling mode switch provided in the operator's cab to invalidate the function of the interference prevention control unit and activate the function of the traveling posture calculation unit. Equipped with a control device,
The control device further comprises
A boom stop command unit that stops the operation of the boom cylinder when the difference between the boom setting angle stored in the storage unit and the boom angle detected by the boom sensor is a set value or less,
An arm stop command unit that stops the operation of the arm cylinder when the difference between the set angle of the arm stored in the storage unit and the arm angle detected by the arm sensor is a set value or less,
An attachment stop command unit that stops the operation of the attachment cylinder when the difference between the attachment angle stored in the storage unit and the attachment angle detected by the attachment sensor is equal to or less than a set value. And hydraulic excavator. The hydraulic excavator according to claim 1,
The revolving structure is
At least one hydraulic pump,
A boom control valve, an arm control valve, and an attachment control valve that respectively control the flow of hydraulic oil to the boom cylinder, the arm cylinder, and the attachment cylinder;
A boom lever device, an arm lever device and an attachment lever device for instructing operations of the boom control valve, the arm control valve and the attachment control valve, respectively,
The boom control valve, the arm control valve, and a boom switching valve that switches between supplying and shutting off pilot pressure to each hydraulic drive unit of the attachment control valve, an arm switching valve, and an attachment switching valve,
The boom stop command unit switches the boom switching valve to a shutoff position to stop the operation of the boom cylinder when the difference between the boom setting angle and the boom angle is less than or equal to a setting value,
The arm stop command unit switches the arm switching valve to a shutoff position to stop the operation of the arm cylinder when the difference between the arm angle and the arm angle is less than or equal to a set value.
The attachment stop command unit switches the attachment switching valve to a shutoff position to stop the operation of the attachment cylinder when the difference between the attachment angle and the attachment angle is less than or equal to a set value. Shovel.

Images