JP3744798B2 - Backhoe - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a backhoe provided with interference prevention control means for controlling the operation of a front device based on detection of the posture of the front device so as to prevent a bucket from entering a driving unit.
[0002]
[Prior art]
In the interference prevention control means, data such as the fulcrum dimension in the front device is input in advance to the controller, and the position of the bucket is recognized based on these data and the detection results such as the boom angle and arm angle. Thus, the interference prevention control for avoiding the bucket from interfering with the operating unit is performed.
[0003]
Also, in recent years, an option equipped with a function that can perform crane work using the front device has been put into practical use, and the posture of the front device is detected and swiveled so that safe crane work can be performed. Calculates the horizontal distance (hanging radius) from the center of turn of the platform to the load suspension point at the front end of the front device, detects the suspension load, displays them, and allows the operator to grasp the work status, To control the crane work such as limiting
Conventionally, when a crane work control means is optionally provided in a model equipped with the interference prevention control means, (a) a first controller for interference prevention control and a second controller for crane work control are provided. In addition to the parallel arrangement, the detection data of the angle sensor for detecting the attitude of the front device connected to the first controller is also input to the second controller, and the crane operation status is connected to the second controller based on the detection result. Display mode or (b): An angle sensor for posture detection of the front device is connected to each of the first controller and the second controller, and both angle sensors are mechanically coupled to each control system. A table that is configured to capture detection data separately and connects the crane work status to the second controller based on the detection results. Form to be displayed by the apparatus, and the like have been proposed.
[0005]
[Problems to be solved by the invention]
However, since the detection data of the angle sensor is directly transmitted to the second controller in the form (b) above, initialization such as input setting of data that absorbs the allowable mounting error of each angle sensor is performed. Processing is required separately for the first and second controllers.
[0006]
In the form (b), since the angle sensors are provided for the two control systems, the number of parts is increased, and the initialization process described above must be performed by each of the first and second controllers. , Production costs are even higher.
[0007]
In addition, it is possible to prepare a common controller that can perform interference prevention control and crane work control in advance and select and use both controls according to the model, but in models that only perform either control, The controller becomes more sophisticated than necessary, resulting in increased waste and overall cost.
[0008]
The present invention has been made paying attention to such points, and can share the angle sensor for detecting the attitude of the front device for the two control systems, and can be completed with a minimal initial set. By doing so, the main purpose.
[0009]
[Means for Solving the Problems]
[Configuration, operation and effect of the invention according to claim 1]
[0010]
(Configuration) In the invention according to claim 1, the boom, the arm, and the bucket are driven to bend and extend and undulate by the boom cylinder, the arm cylinder, and the bucket cylinder, respectively, and the boom is horizontally folded by the offset cylinder through a pair of joint fulcrums. The swivel includes a front device configured to drive, and includes an interference prevention control unit that controls the operation of the front device based on detection of the attitude of the front device so as to prevent the bucket from entering the driving unit. In a crane working mode in which a sensor for detecting the attitude of the front device is connected to the first controller for executing the interference prevention control in the backhoe and the load is suspended and supported at the front end of the front device, Based on the detection of the suspension load and the suspension load. A second controller for executing crane work control to prevent the body from overturning, and configured to enable communication of information processed for front posture detection by the first controller to the second controller; It is characterized by being.
[0011]
(Operation) According to the above configuration, only a first controller is equipped in a model that does not have a crane work function and only performs interference prevention control, and a second controller in addition to the first controller is equipped in a model that has an optional crane work function. Equipped. In this case, regardless of whether or not the second controller is attached, the first controller performs initialization processing on the detection data of the sensor. When the second controller is equipped, the first controller performs processing. Information for front device attitude determination is transmitted to the second controller, and in crane operation mode, display control and alarm control for crane operation are executed based on the information transmitted from the first controller to the second controller. Will be.
[0012]
(Effect) Therefore, according to the first aspect of the invention, the sensor for detecting the attitude of the front device can be shared for the two control systems, and a minimum initialization process can be performed. As compared with the case where a common controller capable of performing the above is prepared and used properly, it is possible to obtain a control system according to the specifications while reducing the production cost.
[0013]
[Configuration, operation and effect of invention of claim 2]
[0014]
(Structure) The invention according to claim 2 is the invention according to claim 1, wherein the suspension link on which the suspension tool is mounted is pivotally supported at the link fulcrum of the bracket provided on the back surface of the bucket. It is connected.
[0015]
( Operation ) According to the above configuration, since the suspension link is pivotally connected to the link fulcrum of the bracket, the front device is stored and held behind the bracket when used in normal excavation work. When carrying out the crane work using, it swings out to the back of the bucket in the scraped posture and the hanging tool is attached.
[0016]
(Effect) Therefore, according to the invention which concerns on Claim 2, a crane operation | work can be performed by swinging out a suspension link and mounting | wearing a suspension tool with the said suspension link.
[0017]
(Structure) According to a third aspect of the present invention, in the first or second aspect of the present invention, a display device for displaying crane work is incorporated in the second controller.
[0018]
(Operation) According to the above configuration, various displays for performing a safe operation at the time of crane work, for example, a display of a suspended load, a suspended radius, a rated load, and the like can be performed on the display device.
[0019]
(Effect) Therefore, according to the invention according to claim 3 , in the crane work, not only a warning can be issued, but the actual work status can be accurately grasped by looking at the display, and the work efficiency and safety can be improved. It becomes effective in raising. Further, by incorporating the display device into the second controller itself, the wiring process can be simplified as compared with a mode in which a separate display device is connected to the second controller by wiring.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows the entire side surface of a backhoe according to the present invention. The basic configuration of the backhoe is not particularly different from that of a known one, and a swivel 4 can be swung around a vertical axis X on a track frame 3 provided with a pair of left and right crawler travel devices 1 and a soil discharge plate 2. The driving unit 7 with the driving unit 5 and the awning 6 is provided on the swivel base 4, and a front device 8 for excavation work is provided on the right side of the driving unit 7.
[0021]
The front device 8 drives the boom 10, the arm 11, and the bucket 12 that are sequentially connected to each other with the boom cylinder C 1, the arm cylinder C 2, and the bucket cylinder C 3. C4 is configured so as to be driven to be folded in parallel through a pair of joint fulcrums Y1 and Y2, and the front device 8 can be folded into the right side of the operating unit 7 and swiveled together with the swivel 4 with a small radius. A so-called ultra-small swirl type backhoe is constructed.
[0022]
Angle sensors S1, S2, S3 using potentiometers are respectively provided at the base of the boom cylinder C1, the base of the arm 11, and the joint fulcrum Y1 of the boom 10, and detection of these angle sensors S1, S2, S3 is provided. From the result, the position of the bucket pin 17 provided at the tip of the arm is recognized, and the bucket pin 18 enters and moves to the driving unit 7 side from the regulation surfaces Z1, Z2 set in front of the driving unit 7 and the right side. so as to prevent the boom cylinder C1 based on the information from the angle sensors S1, S2, S3, and an arm cylinder C2, and, by regulating the operation of the offset cylinder C4, that the bucket 12 from interfering with the operation section 7 Interference prevention control to be avoided is executed.
[0023]
2 and 3 schematically show a hydraulic circuit for driving the backhoe and an operation pilot circuit. In the figure, V1 and V2 are control valves for the traveling hydraulic motors M1 and M2 for driving the left and right crawler traveling devices 1, V3 is a control valve for the swinging hydraulic motor M3 for driving the swivel 4, and V4 is for the boom cylinder C1. Control valve, V5 is a control valve for the arm cylinder C2, V6 is a control valve for the bucket cylinder C3, V7 is a control valve for the offset cylinder C4, V8 is a control valve for the dozer cylinder C5 that raises and lowers the soil discharge plate 2, and V9 is a service port It is a control valve for. P1 and P2 are working pumps, and P3 is a pilot pump that supplies pilot pressure for operating the control valve, and each is driven by an engine (not shown) accommodated in the prime mover 5.
[0024]
Here, the driving control valves V1 and V2 are mechanically linked to the left and right control levers 14 provided at the front of the driving unit 7, and are directly operated by the driver, and the dozer cylinder C5. The control valve V8 and the service port control valve V9 are mechanically linked to a pedal or lever (not shown) provided in the operation unit 7 and directly operated by the driver. Further, the swing control valve V3, the boom control valve V4 that controls the posture change of the front device 8, the arm control valve V5, and the bucket control valve V6 are configured in a pilot operated manner. A pair of pilot valves PV1 and PV2 for supplying pilot pressure are operated by a pair of left and right working levers 15 and 16 provided at the front portion of the operating section 7. Further, the control valve V7 for offset is also constructed in a pilot operated manner, and a pilot valve PV3 for supplying pilot pressure thereto is operated by a pedal 17 provided at the foot of the operating unit 7. The operation levers 15 and 16 are each configured to be a cross operation type. The boom is lowered by the forward operation of the right operation lever 16, the boom is raised by the rear operation, the bucket is scraped by the left operation, and the bucket dump is performed by the right operation. The arm is set to swing out by forward operation of the left work lever 15, rake in the arm by backward operation, turn left by left operation, and turn right by right operation.
[0025]
As shown in FIG. 3, the pilot hydraulic circuit connecting the pilot valves PV1, PV2, PV3 and the control valves V3, V4, V5, V6, V7 has an electromagnetic proportional control valve MV1 for performing the interference prevention control. , MV2, MV3, and MV4 are connected to the controller 20 together with the angle sensors S1, S2, and S3.
[0026]
The electromagnetic proportional pressure control valve MV1 is interposed in the pilot oil passage a for raising the boom, and the raising operation of the boom 10 is controlled. The electromagnetic proportional control valve MV2 is interposed in the pilot oil passage c for arm scraping, and the scraping operation of the arm 11 is controlled. The electromagnetic proportional pressure control valve MV3 is interposed in the pilot oil path i for the boom left offset, and the left offset operation of the boom 10 is controlled. Further, the electromagnetic proportional pressure control valve MV4 is interposed in the pilot oil passage d for arm swinging, and the swinging operation of the arm 11 forward is controlled.
[0027]
The electromagnetic proportional pressure control valves MV1, MV2, MV3, MV4 are controlled based on the detection results of the angle sensors S1, S2, S3, and are recognized from the detection results of the angle sensors S1, S2, S3. When the position of the bucket pin 18 approaches the control surface set in advance in the front and right lateral sides of the operating unit 7, the pilot oil passages a, c, i are respectively driven by the electromagnetic proportional pressure control valves MV1, MV2, MV3. When the pressure on the boom is suppressed, the boom raising operation, the arm scraping operation, and the left offset operation are decelerated and the bucket pin 18 reaches the regulation surfaces Z1, Z2, the pilot oil passages a, c, i are controlled to be cut off. Thus, further boom raising operation, arm scraping operation, and left offset operation are prevented. When the boom is raised and the arm is scraped at the same time, when the position of the bucket pin 18 approaches from the regulating surface Z1 to a position closer to the set distance, the electromagnetic proportional pressure control valve MV4 is activated and the arm 11 is automatically moved. The boom raising operation is continued by operating in the swing-out direction, and as a result, control is performed in which the bucket pin 18 moves upward along the plane set before the set distance from the regulation plane without being stopped.
[0028]
Specifically, the fact that the bucket pin 18 has reached the region where the boom raising operation and the arm scraping operation are restrained is based on a judgment criterion in which the angle information of the angle sensors S1, S2, S3 is converted into map data in advance. Compared to a form in which the position of the bucket pin 18 is mathematically calculated based on an arithmetic expression based on the detection results of the angle sensors S1, S2, and S3, the recognition process is simpler. And it comes to be done quickly.
[0029]
Further, in the boom raising operation, when the boom 10 reaches near the raising limit, the following impact mitigation control is performed.
[0030]
When it is detected from the detection result from the angle sensor S1 that detects the boom angle that the boom 10 is close to its ascent limit, that is, close to the stroke end in the extending direction of the boom cylinder C1, the application to the electromagnetic proportional control valve MV1 is performed. The current is controlled with a predetermined characteristic, the opening degree of the control valve is gradually reduced, the boom raising speed is gradually lowered, and the rising limit is reached without impact.
[0031]
As shown in FIG. 1, a suspension link 22 is pivotally connected to a link fulcrum R of a bracket 12a provided on the back surface of the bucket 12. The suspension link 22 is stored and held behind the bracket 12a when the front device 8 is used for normal excavation work. When the crane is used for the crane operation using the front device 8, as shown in the drawing, the hanging link 22 is held. It swings out in the back part of the bucket 12, and a hanging tool 23 such as a hook is attached.
[0032]
As described above, in the model in which the front device 8 is used for crane work, as shown in FIG. 6, the airframe is overturned by a suspension load separately from the first controller 20 for performing the interference prevention control. The second controller device 21 for performing control for avoiding the occurrence of the operation is provided, and the crane work mode is activated by turning on the crane work mode ON / OFF switch 24 provided in the second controller 26. It is configured to be able to. When the crane operation mode is activated, the patrol light 27 provided in the operation unit 7 is turned on and rotated to notify surrounding workers that the crane operation is being performed.
[0033]
Here, the angle sensors S1, S2, S3 for detecting the attitude of the front device 8 are connected to the first controller 20, and the detection information obtained from the angle sensors S1, S2, S3 is digitized by A / D conversion. After being captured and initialized, it is used for the interference prevention control. Further, the attitude information of the front device 8 determined by the first controller 20 based on the detection information from each angle sensor S1, S2, S3 is multiplexed using a communication method known to the communication port of the second controller 21. Sent by communication.
[0034]
Further, in the pilot hydraulic circuit connecting the pilot valves PV1, PV2 and the control valves V3, V4, V5, V6, V7, electromagnetic proportional control valves MV5, MV6, MV7 for performing crane work control are interposed, Each is connected to the second controller 26. In addition, a liquid crystal display device 28 is integrated into the second controller 21 and an alarm device 29 such as the patrol light 27 and a buzzer is connected.
[0035]
In addition, a pressure sensor PS is connected to the oil passage on the pressure oil supply side when the boom cylinder C1 is raised, and the load pressure generated in the boom cylinder C1 during crane operation is detected. . In the crane work mode, the horizontal position of the suspension point (link fulcrum) R from the turning center X is determined based on the front device attitude information communicated from the first controller 20, and the boom cylinder C1. The suspension load acting on the suspension point R is calculated from the load pressure acting on the suspension. The calculated suspension load, the calculated suspension radius, and the rated suspension load that can be safely suspended by the front device 8 are displayed. It is displayed in parallel or sequentially on the device 28 so that the driving worker can accurately grasp the current working situation. Further, in the crane work mode, the pilot oil passage f is blocked by the electromagnetic proportional control valve MV5 so that the dumping operation of the bucket 12 is inhibited to prevent the bucket 12 in the scraping posture from being accidentally dumped. At the same time, the maximum pilot pressure that can be applied to the turning control valve V3 by the electromagnetic proportional control valves MV6 and MV7 is limited to a low value, and the maximum turning speed is suppressed. In addition, when the calculated suspension load approaches the rated suspension load by more than a set value, the alarm device 29 is activated to draw attention.
[0036]
In addition, only the 1st controller 20 will be equipped in the model of the specification which does not perform crane work control. In addition, in a model with a specification for performing only crane work control, various sensors are connected to the second controller 21 and crane work control is performed based on information digitized by A / D conversion.
[Brief description of the drawings]
1 is an overall side view of a backhoe. FIG. 2 is a hydraulic circuit diagram. FIG. 3 is a pilot circuit diagram for operation. FIG. 4 is a side view illustrating an interference prevention control operation. [Fig. 6] Control block diagram [Explanation of symbols]
7 Operation part 8 Front device 12 Bucket 20 First controller 21 Second controller 28 Display device S1, S2, S3 sensor (angle sensor)

Claims (3)

The boom, arm, and bucket are driven to bend and extend by the boom cylinder, arm cylinder, and bucket cylinder, respectively, and the front device that is configured to be driven in parallel by the offset cylinder via a pair of joint fulcrum is swung. In a backhoe comprising an interference prevention control means for checking and controlling the operation of the front device based on the attitude detection of the front device so as to prevent the bucket from entering the driving unit.
A sensor for detecting the attitude of the front device is connected to the first controller for executing the interference prevention control,
In the crane work mode in which the load is suspended and supported at the front end of the front device, the crane work control is executed based on the detection of the suspension radius and the suspension load in order to avoid the aircraft from falling due to the suspension load. A backhoe characterized by comprising: a second controller for transmitting information transmitted for front posture detection by the first controller to the second controller. 2. The backhoe according to claim 1, wherein a suspension link on which a suspension tool is attached is pivotally connected to a link fulcrum of a bracket provided on the back surface of the bucket. The backhoe according to claim 1 or 2 , wherein a display device for displaying crane work is incorporated in the second controller.

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