JP6223253B2 - Front loader - Google Patents

Description

  The present invention provides a boom actuator that swings the boom up and down around a first support shaft that is laterally oriented with respect to the traveling vehicle body, and a second support shaft that is laterally oriented with respect to the boom. The present invention relates to a front loader including a bucket actuator that swings in the vertical direction.

  In the front loader as described above, there is provided an inclination angle detection means for detecting the inclination angle of the bucket, and when the inclination angle detected by the inclination angle detection means enters a spilled area where spilled objects are spilled from the bucket, Some have provided an automatic dump control valve that stops the operation and dumps the bucket in conjunction with the boom raising operation (see, for example, Patent Document 1).

  In addition, there is a configuration in which the posture of the bucket (implement) is maintained constant regardless of the swinging displacement of the boom by the bending operation of the mechanical parallel guide mechanism (see, for example, Patent Document 2).

JP 2009-52287 A European Patent Application No. 1903147

  In the configuration described in Patent Document 1, for example, even when it is desired to swing the bucket greatly at a relatively low height position while the boom is rising, as the bucket tilt angle enters the spill area. Therefore, there is room for improvement in terms of workability.

  Further, in the configuration described in Patent Document 2, the relative angle between the boom and the bucket increases as the boom is moved up and down by maintaining the bucket posture constant regardless of the swinging displacement of the boom. In addition, the relative angle between the boom and the bucket becomes smaller as the boom is lowered and swung. Therefore, if the boom is swung down and swung while the boom is swung upward, the boom and the bucket have a smaller relative angle by maintaining the bucket posture constant. There is a possibility that the boom cannot be lowered and swung due to contact with or the like, and there is room for improvement in terms of workability.

  The object of the present invention is that when the height position of the bucket is relatively low, the bucket can be swung up and down, and when the boom is lowered and swung while the bucket is swung up and down. Even if it exists, it is providing the front loader excellent in workability | operativity which can make a boom fall and rock smoothly, without causing a contact with a boom and a bucket.

The problem solving means of the present invention is:
An actuator for a boom that swings up and down in a vertical direction with a first support shaft that is horizontally oriented with respect to the traveling vehicle body as a fulcrum;
A bucket actuator that swings the bucket up and down around a second support shaft that is laterally oriented with respect to the boom; and
A manual control unit for controlling the operation of the boom actuator and the bucket actuator based on an artificial operation of the operation tool;
A boom angle detector for detecting a vertical swing angle of the boom;
A bucket angle detector for detecting a vertical swing angle of the bucket with respect to the boom;
A calculation unit for calculating a ground swing angle of the bucket based on an output of the boom angle detector and an output of the bucket angle detector;
A storage unit storing relational data indicating a relation between the vertical swing angle of the boom and the limit scooping angle of the bucket;
A setting unit for setting the limit scooping angle according to the vertical swing angle of the boom based on the output of the boom angle detector and the relation data;
When the operation tool is artificially operated so as to actuate the bucket actuator in a direction in which the bucket oscillates and swings, the bucket swing angle with respect to the ground based on the output of the setting unit and the output of the calculation unit If There it is detected that has reached the angle rake before Symbol limit, ground rocking angle rake angle limitation control unit for controlling the operation of said actuator for bucket so as not to exceed the angle rake before Symbol limit of the bucket And.

  According to this means, for example, in the relational data, if the vertical swing angle of the boom is large, the limit scooping angle of the bucket is limited to a certain angle that prevents the scooping of scooping from the bucket to the boom side, and If the boom swing angle is small, the output of the setting unit can be set by setting the bucket limit angle to be larger than the spill prevention angle within the range where the bucket does not contact the boom. When the height position of the bucket is relatively low, the bucket can be swung largely and oscillated even when the boom is being raised by the control operation of the scooping angle limit control unit based on the output of the calculation unit. Thereby, the scooping operation | work with respect to scooping objects, such as earth and sand located in a position higher than the ground, can be performed favorably.

  After the scooping, if the boom is further swung up to transport the scooping object, the ground swinging angle of the bucket is limited to the limiting scooping angle to prevent spilling. It is possible to prevent an inconvenience from being spilled from the bucket to the boom side.

  Further, after the scooping, when the boom is swung downward with the bucket swung largely, if the bucket approaches the boom by this swiveling swing, it is based on the control operation of the scoop angle limit control unit. By operating the bucket actuator, the boom can be swung downward while automatically avoiding contact between the boom and the bucket.

  Therefore, when the height position of the bucket is relatively low, the bucket can be swung up and swung, and the spillage of the scooping object from the bucket being transported to the boom side can be prevented. Even when the boom is swung down and swung in a state where it is swung up and down, the workability that allows the boom to be swung down smoothly without causing contact between the boom and the bucket is excellent. A front loader can be provided.

As one of the means for making the present invention more suitable,
A ground angle maintenance control unit for controlling the operation of the bucket actuator so that the ground swing angle of the bucket is constant regardless of the vertical swing of the boom,
The manual control unit controls the operation of the bucket actuator in preference to the ground angle maintenance control unit,
The rake angle restriction control unit, in preference to pre-Symbol manual control unit for controlling the operation of the actuator for the bucket.

  According to this means, the ground swing angle of the bucket can be maintained constant regardless of the vertical swing of the boom by the control operation of the ground angle maintenance control unit. Thereby, prevention of the spilling of the scooping thing from a bucket can be performed more suitably.

  When the ground swing angle of the bucket is kept constant by the control operation of the ground angle maintenance control unit, if it becomes necessary to swing the bucket or swing the dump, it is necessary to manually operate the operation tool. By performing the above, the bucket can be easily swung or dumped.

Even in a state in which swung or dumped oscillating scooping the bucket by manual operation of the operation member, the control operation of the rake angle limitation control unit based on the output of the output operation of the setting unit, the boom from a bucket It is possible to satisfactorily prevent the spilling of the scooping material to the side and the contact between the boom and the bucket.

  Therefore, while allowing the bucket swing angle to be kept constant, it is possible to swing the bucket with priority over this maintenance, and to prevent spillage of the scooping object from the bucket and contact between the boom and the bucket. It is possible to provide a front loader that is more workable.

As one of the means for making the present invention more suitable,
When the boom swing angle is equal to or smaller than the set angle, the relational data indicates that the limit swing angle of the bucket increases as the boom swing angle approaches the set angle. When the moving angle exceeds the set angle, the bucket's limit scooping angle is a constant angle that prevents scooping of scooping objects from the bucket to the boom side, regardless of the boom swinging angle. It is set.

  This relational data shows that when the boom is swung up and down with the bucket swing angle maintained constant, the relative angle between the boom and the bucket increases as the boom is swung up and down. On the contrary, the relative angle between the boom and the bucket becomes smaller as the boom is lowered and swung, and the bucket becomes easier to contact the boom, and the relative angle between the boom and the bucket. When the boom is swung up and down in a constant state, the bucket rocking angle increases as the boom is swung up, and conversely, the bucket rocking angle increases as the boom is swung down. It is set in consideration of the small point.

  According to this means, when the height position of the bucket is relatively low, the bucket can be swung more suitably and more securely, and the spillage of the scooping material from the bucket being transported to the boom side can be more reliably ensured. In the case where the boom is swung down while the bucket is swung largely while being prevented, the boom can be swung down smoothly without causing contact between the boom and the bucket.

It is a left view of the tractor equipped with the front loader in 1st Embodiment. It is a left view which shows the operation state of the front loader in 1st Embodiment. It is a block diagram which shows the control structure regarding the front loader in 1st Embodiment. It is a left view which shows the operating state of the front loader in 2nd Embodiment. It is a block diagram which shows the control structure regarding the front loader in 2nd Embodiment.

  [First Embodiment]

  Hereinafter, as an example of an embodiment for carrying out the present invention, a first embodiment in which a front loader according to the present invention is mounted on a tractor that is an example of a traveling vehicle body will be described with reference to the drawings.

  As shown in FIG. 1, the tractor A exemplified as the traveling vehicle body A in the first embodiment includes a driving unit 2 and left and right front wheels 3 on the front side of the vehicle body frame 1. In addition, a cabin 5 that forms a boarding operation unit 4 and left and right rear wheels 6 are provided on the rear side of the body frame 1. Left and right support brackets 7 that allow the front loader B to be mounted are provided at the front and rear intermediate portions of the vehicle body frame 1. The boarding driver 4 includes a steering wheel 8 and a driver seat 9.

  As shown in FIGS. 1 to 3, the front loader B swings up and down via left and right fixed brackets 10 detachably attached to the corresponding support brackets 7, and the corresponding fixed brackets 10 via the first support shaft 11 facing left and right. The left and right swing brackets 14, the left and right swing brackets 14, the left and right swing brackets 14 connected to the free ends of the corresponding booms 12 via the second support shaft 13 facing left and right. Detachably connected bucket 15, hydraulic double-acting left and right boom cylinder 16 used as a boom actuator, hydraulic double-acting left and right bucket cylinder 17 used as a bucket actuator, either left or right A boom angle detector 18 that detects the vertical swing angle θa of one boom 12, and the vertical swing angle θ of the bucket 15 with respect to the left and right booms 12. A bucket angle detector 19 for detecting b is provided.

  The left and right boom cylinders 16 swing and drive the corresponding boom 12 with respect to the tractor A in the vertical direction with the first support shaft 11 as a fulcrum. The left and right bucket cylinders 17 swing the bucket 15 together with the left and right swing brackets 14 in the vertical direction with respect to each boom 12 with the second support shaft 13 as a fulcrum. The boom angle detector 18 and the bucket angle detector 19 employ a rotary potentiometer.

  As shown in FIG. 3, the tractor A includes a valve unit 20 that controls the flow of oil to the left and right boom cylinders 16 and the left and right bucket cylinders 17, and the left and right boom cylinders 16 and the left and right buckets via the valve unit 20. A front loader electronic control unit (hereinafter referred to as LD-ECU) 21 for controlling the operation of the cylinder 17 is provided.

  Although not shown, the hydraulic control unit 20 includes an electronic control valve for the boom that controls the flow of oil to the left and right boom cylinders 16 and an electronic control for the bucket that controls the flow of oil to the left and right bucket cylinders 17. Valve, etc.

  As shown in FIGS. 2 and 3, the LD-ECU 21 is configured by a microcomputer including a CPU, an EEPROM, and the like. And the manual control part 22 which enables manual operation of the right and left boom 12 and the bucket 15, the calculating part 23 which performs various arithmetic processing, the memory | storage part 24 which memorize | stores various data, the setting part for bucket scooping angle restrictions 25, a ground angle maintaining control unit 26 that performs a ground angle maintaining control for maintaining the ground swing angle θc of the bucket 15 constant, and a scoop angle limit control for limiting the ground swing angle θc in the scooping direction of the bucket 15. A scooping angle limit control unit 27 is provided.

  The manual control unit 22 includes the left and right boom cylinders 16 and the left and right bucket cylinders based on an artificial operation of a cross swinging and neutral return type operation lever 30 provided as an operation tool for operating the front loader in the boarding operation unit 4. 17 operation is controlled. Specifically, manual operation control for controlling the operation of the left and right boom cylinders 16 and the left and right bucket cylinders 17 is performed based on the output of the lever operation detector 31 that detects the operation position of the operation lever 30.

  In the manual operation control, the operation position of the operation lever 30 is determined based on the output of the lever operation detector 31. When the operation position of the operation lever 30 is the raised position, the left and right boom cylinders 16 are extended so that the left and right booms 12 swing up and down while the operation to the raised position is continued. When the operation position of the operation lever 30 is the lowered position, the left and right boom cylinders 16 are contracted so that the left and right booms 12 swing downward while the operation to the lowered position is continued. When the operation position of the operation lever 30 is the scooping position, the left and right bucket cylinders 17 are contracted so that the bucket 15 swings up (crawls) while the operation to the scooping position is continued. . When the operation position of the operation lever 30 is the dump position, the left and right bucket cylinders 17 are extended so that the bucket 15 swings downward (dump swing) while the operation to the dump position is continued. . When the operation position of the operation lever 30 is the neutral position, the left and right boom cylinders 16 and the left and right bucket cylinders 17 are arranged so that the left and right booms 12 and the buckets 15 stop swinging up and down while being in the neutral position. Stops the expansion / contraction operation.

  The lever operation detector 31 includes a plurality of switches that detect a swing operation of the operation lever 30 to each operation position, or a rotary potentiometer that detects a swing operation of the operation lever 30 in the front-rear direction and a left-right direction. For example, a rotary potentiometer that detects a swinging operation to the head can be employed.

  The calculator 23 calculates the ground swing angle θc of the bucket 15 based on the output of the boom angle detector 18 and the output of the bucket angle detector 19. Then, the calculation result is output to the storage unit 24, the ground angle maintenance control unit 26, the scooping angle restriction control unit 27, and the like.

  When the setting switch 32 for setting the control target angle provided in the boarding operation unit 4 is pressed, the storage unit 24 sets the ground swing angle θc of the bucket 15 output by the calculation unit 23 at that time to the ground. It is stored as a control target angle θco for angle maintenance control. That is, by operating the operation lever 30 and operating the left and right boom cylinders 16 and the left and right bucket cylinders 17 to operate the bucket 15 to a desired ground swing angle θc, and then pressing the setting switch 32. The ground swing angle θc of the bucket 15 at this time can be stored in the storage unit 24 as the control target angle θco for ground angle maintenance control. 2 illustrates a state in which the control target angle θco for the ground angle maintenance control is set to an angle at which the bottom surface of the bucket 15 becomes horizontal.

  Further, scoop angle limit map data, which is relational data indicating the relationship between the vertical swing angle θa of the left and right booms 12 and the limit scoop angle θd of the bucket 15, is stored. When the vertical swing angle θa of the left and right booms 12 is equal to or smaller than the set angle θao, the map data assumes that the bucket 15 is positioned in the lower scooping area, and the left and right buckets by the scooping operation of the bucket 15 In order to avoid contact with the 15 booms 12 or the left and right boom cylinders 16, the limit scoop angle θd of the bucket 15 increases as the vertical swing angle θa of the left and right booms 12 approaches the set angle θao ( For example, when the vertical swing angle θa of the left and right booms 12 is the set angle θao, the limit scoop angle θd of the bucket 15 is set to 55 degrees. When the vertical swing angle θa of the left and right booms 12 exceeds the set angle θao, it is considered that the bucket 15 is positioned in the upper conveyance dump region, and the vertical swing angle θa of the left and right booms 12 is assumed. Regardless of the limit, the limit scoop angle θd of the bucket 15 is set to a constant angle (for example, 45 degrees) that prevents spillage of dirt and sand from the bucket 15 to the boom side.

  This is because when the left and right booms 12 are swung up and down while the ground swing angle θc of the bucket 15 is kept constant, the left and right booms 12 and the buckets 15 The relative angle θe of the left and right booms 12 and the bucket 15 becomes smaller as the left and right booms 12 are swung downward. Thus, when the bucket 15 is easily brought into contact with the left and right booms 12 and the right and left booms 12 are swung up and down with the relative angle θe between the left and right booms 12 and the bucket 15 being constant. As the left and right booms 12 are swung upward, the ground swing angle θc of the bucket 15 increases. Conversely, as the left and right booms 12 are swung downward, the ground swing angle θc of the bucket 15 is increased. It is set in consideration of the smaller points. The setting angle θao can be variously changed, but here, the setting angle θao is set to an angle at which the bottom of the bucket 15 reaches the upper end position of the bonnet 33 provided in the prime mover 2 (see FIG. 1).

  The setting unit 25 sets the limit scoop angle θd of the bucket 15 according to the vertical swing angle θa of the left and right booms 12 based on the output of the boom angle detector 18 and the scoop angle limit map data. Hereinafter, the limit increase angle θd of the bucket 15 set by the setting unit 25 is referred to as a setting limit increase angle θd.

  The ground angle maintenance control unit 26 performs ground angle maintenance control when the command switch 34 for ground angle maintenance control provided in the boarding operation unit 4 is pressed while the execution of the ground angle maintenance control is stopped. If the command switch 34 for ground angle maintenance control is pressed during execution of the ground angle maintenance control, the ground angle maintenance control is terminated.

  In the ground angle maintenance control, the vertical swing of the left and right booms 12 is based on the control target angle θco for ground angle maintenance control stored in the storage unit 24 and the ground swing angle θc of the bucket 15 output from the calculation unit 23. Regardless of the operation, the operation of the left and right bucket cylinders 17 is controlled so that the ground swing angle θc of the bucket 15 matches the control target angle θco for ground angle maintenance control (contains within the dead zone width of the control target angle θco). .

  As a result, the ground swing angle θc of the bucket 15 is set to the control target for the ground angle maintenance control regardless of the vertical swing drive of the left and right booms 12 by the control operation of the manual control unit 22 based on the manual operation of the operation lever 30. The angle θco (desired ground swing angle) can be maintained.

  The scoop angle limit control unit 27 detects that the ground swing angle θc of the bucket 15 has reached the set limit scoop angle θd based on the output of the setting unit 25 and the output of the calculation unit 23 (the ground of the bucket 15 When the swing angle θc falls within the dead band width of the set limit scoop angle θd, the ground swing angle θc of the bucket 15 does not exceed the set limit scoop angle θd (the ground swing angle θc of the bucket 15 is set limit). The operation of the left and right bucket cylinders 17 is controlled so that the dead zone width of the scooping angle θd is not exceeded.

  The manual control unit 22, the ground angle maintenance control unit 26, and the scooping angle restriction control unit 27, the manual control unit 22 controls the operation of the left and right bucket cylinders 17 in preference to the ground angle maintenance control unit 26, The priority order of the control operations for the left and right bucket cylinders 17 is set so that the scooping angle restriction control unit 27 controls the operations of the left and right bucket cylinders 17 in preference to the manual control unit 22 and the ground angle maintenance control unit 26. ing.

  Thereby, for example, when the vertical swing angle θa of the left and right booms 12 is equal to or smaller than the set angle θao, the left and right bucket cylinders are controlled by the control operation of the manual control unit 22 based on the manual operation to the scooping position of the operation lever 30. When the bucket 15 approaches the left and right booms 12 and the ground swinging angle θc of the bucket 15 reaches the set limit scooping angle θd while the bucket 15 is swinging and swinging, The restriction control unit 27 has priority over the manual control unit 22 to stop the left and right bucket cylinders 17 to stop scooping the bucket 15.

  As a result, it is possible to avoid the possibility of the bucket 15 coming into contact with the left and right booms 12 or the left and right boom cylinders 16 by the scooping operation of the bucket 15 when the bucket 15 is located in the lower scooping region.

  When the vertical swing angle θa of the left and right booms 12 exceeds the set angle θao, the left and right boom cylinders 16 are moved by the control operation of the manual control unit 22 based on the manual operation to raise the operation lever 30. If the ground swing angle θc of the bucket 15 reaches the setting limit scooping angle θd while the left and right booms 12 are swinging upward due to the extension operation, even if the operation lever 30 is not operated to the dump position. The scooping angle limiting control unit 27 has priority over the manual control unit 22, and the ground swinging angle θc of the bucket 15 is a constant limiting scooping angle θd for preventing the spilling regardless of the vertical swinging angle θa of the left and right booms 12. The bucket 15 is dumped and rocked by extending the left and right bucket cylinders 17 so as not to exceed.

  As a result, the lifting operation of the left and right booms 12 when the bucket 15 is located in the upper conveyance dump region causes the ground swing angle θc of the bucket 15 to exceed a certain limit scooping angle θd for preventing spilling, and the bucket 15 It is possible to prevent a fear that ugly objects such as earth and sand fall into the boom side.

  Further, the control operation of the ground angle maintenance control unit 26 maintains the ground swing angle θc of the bucket 15 at the control target angle θco for the ground angle maintenance control regardless of the vertical swing drive of the left and right booms 12. When the operation lever 30 is moved to the scooping position or the dumping position, the manual control unit 22 takes precedence over the ground angle maintenance control unit 26 based on the operation, and the left and right bucket cylinders 17 The bucket 15 is swung or dumped by controlling the operation.

  As a result, in the state where the ground swing angle θc of the bucket 15 is kept constant by the control operation of the ground angle maintenance control unit 26, the driver wants to remove soil and sand by the swinging swing of the bucket 15 a little more. If it is thought that there is no need to press the command switch 34 for ground angle maintenance control and finish the ground angle maintenance control, earth and sand due to swaying of the bucket 15 by manual operation of the operation lever 30, etc. You can make an ugly take.

  Even when the ground swing angle θc of the bucket 15 reaches the set limit scoop angle θd due to the scooping of the bucket 15, the scoop angle limit control unit 27 has priority over the manual control unit 22 and left and right buckets. The cylinder 17 is stopped and the scooping of the bucket 15 is stopped.

  As a result, even in the state where the manual control unit 22 controls the operation of the left and right bucket cylinders 17 in preference to the ground angle maintenance control unit 26, the bucket 15 becomes the left and right booms 12 or the left and right boom cylinders 16 or the like. The possibility of contact can be avoided.

  Further, the control operation of the ground angle maintenance control unit 26 maintains the ground swing angle θc of the bucket 15 at the control target angle θco for the ground angle maintenance control regardless of the vertical swing drive of the left and right booms 12. The left and right boom cylinders 16 are contracted by the control operation of the manual control unit 22 based on the operation of the operation lever 30 to the lowered position, and the left and right booms 12 are swinging downward. When the vertical swing angle θa of 12 is equal to or smaller than the set angle θao and the ground swing angle θc of the bucket 15 reaches the setting limit scooping angle θd, the operation lever 30 is not operated to the dump position. However, the scooping angle limit control unit 27 has priority over the manual control unit 22, and the ground swing angle θc of the bucket 15 does not exceed the limit scooping angle θd in conjunction with the downward swinging of the left and right booms 12. Then, the left and right bucket cylinders 17 are extended and the bucket 15 is dumped.

  Accordingly, the bucket 15 is moved to the left and right booms 12 or left and right by the lowering operation of the left and right booms 12 while the ground swing angle θc of the bucket 15 is kept constant by the control operation of the ground angle maintenance control unit 26. The possibility of contact with the boom cylinder 16 or the like can be avoided.

  [Second Embodiment]

  Hereinafter, as an example of a mode for carrying out the present invention, a second embodiment in which a front loader according to the present invention is mounted on a tractor that is an example of a traveling vehicle body will be described with reference to the drawings.

  Since the second embodiment is different from the first embodiment only in the configuration related to the front loader, only the configuration of the front loader will be described.

  As shown in FIGS. 4 and 5, the front loader B is mounted on the corresponding support bracket 7 so as to be detachably attached to the left and right fixed brackets 10, and the corresponding fixed bracket 10 is vertically moved via a first support shaft 11 facing left and right. Left and right booms 12 connected to be swingable, left and right swing brackets 14 connected to the free ends of the corresponding booms 12 via a second support shaft 13 facing left and right, and left and right swing brackets 14 detachably connected to a bucket 15, hydraulic double-acting left and right boom cylinders 16 used as boom actuators, hydraulic double-acting left and right bucket cylinders 17 used as bucket actuators, either left or right The boom angle detector 18 for detecting the vertical swing angle θa of one boom 12 and the vertical swing of the bucket 15 with respect to the left and right booms 12. Bucket angle detector 19 for detecting the degree .theta.b, and a like.

  The left and right bucket cylinders 17 include left and right swing arms 40 that are mounted on the left and right booms 12 so as to be able to swing back and forth, and a link link 41 that extends between the corresponding fixed bracket 10 and the swing arm 40. 12 is a mechanical ground angle maintaining mechanism 42 that substantially maintains the ground swing angle θc of the bucket 15 at a desired ground swing angle θco corresponding to the expansion / contraction length of the left and right bucket cylinders 17 regardless of the vertical swing of the bucket 12. Is configured.

  As shown in FIG. 5, the tractor A includes a valve unit 20 that controls the flow of oil to the left and right boom cylinders 16 and the left and right bucket cylinders 17, and the left and right boom cylinders 16 and the left and right buckets via the valve unit 20. A front loader electronic control unit (hereinafter referred to as LD-ECU) 21 for controlling the operation of the cylinder 17 is provided.

  Although not shown, the hydraulic control unit 20 includes a boom control valve that controls the flow of oil to the left and right boom cylinders 16, a bucket control valve that controls the flow of oil to the left and right bucket cylinders 17, and the like. I have.

  As shown in FIG. 5, the LD-ECU 21 is configured by a microcomputer including a CPU, an EEPROM, and the like. And the manual control part 22 which enables manual operation of the right and left boom 12 and the bucket 15, the calculating part 23 which performs various arithmetic processing, the memory | storage part 24 which memorize | stores various data, the setting part for bucket scooping angle restrictions 25, and a scooping angle limiting control unit 27 for performing scooping angle limiting control for limiting the ground swing angle θc in the scooping direction of the bucket 15.

  The manual control unit 22 includes the left and right boom cylinders 16 and the left and right bucket cylinders based on an artificial operation of a cross swinging and neutral return type operation lever 30 provided as an operation tool for operating the front loader in the boarding operation unit 4. 17 operation is controlled. Specifically, manual operation control for controlling the operation of the left and right boom cylinders 16 and the left and right bucket cylinders 17 is performed based on the output of the lever operation detector 31 that detects the operation position of the operation lever 30.

  In the manual operation control, the operation position of the operation lever 30 is determined based on the output of the lever operation detector 31. When the operation position of the operation lever 30 is the raised position, the left and right boom cylinders 16 are extended so that the left and right booms 12 swing up and down while the operation to the raised position is continued. When the operation position of the operation lever 30 is the lowered position, the left and right boom cylinders 16 are contracted so that the left and right booms 12 swing downward while the operation to the lowered position is continued. When the operation position of the operation lever 30 is the scooping position, the left and right bucket cylinders 17 are contracted so that the bucket 15 swings up (crawls) while the operation to the scooping position is continued. . When the operation position of the operation lever 30 is the dump position, the left and right bucket cylinders 17 are extended so that the bucket 15 swings downward (dump swing) while the operation to the dump position is continued. . When the operation position of the operation lever 30 is the neutral position, the left and right boom cylinders 16 and the left and right bucket cylinders 17 are arranged so that the left and right booms 12 and the buckets 15 stop swinging up and down while being in the neutral position. Stops the expansion / contraction operation.

  The lever operation detector 31 includes a plurality of switches that detect a swing operation of the operation lever 30 to each operation position, or a rotary potentiometer that detects a swing operation of the operation lever 30 in the front-rear direction and a left-right direction. For example, a rotary potentiometer that detects a swinging operation to the head can be employed.

  The calculator 23 calculates the ground swing angle θc of the bucket 15 based on the output of the boom angle detector 18 and the output of the bucket angle detector 19. Then, the calculation result is output to the storage unit 24, the scoop angle limit control unit 27, and the like.

  The storage unit 24 stores scoop angle limit map data, which is relational data indicating the relationship between the vertical swing angle θa of the left and right booms 12 and the limit scoop angle θd of the bucket 15. When the vertical swing angle θa of the left and right booms 12 is equal to or smaller than the set angle θao, the map data assumes that the bucket 15 is positioned in the lower scooping area, and the left and right buckets by the scooping operation of the bucket 15 In order to avoid contact with the 15 booms 12 or the left and right boom cylinders 16, the limit scoop angle θd of the bucket 15 increases as the vertical swing angle θa of the left and right booms 12 approaches the set angle θao ( For example, when the vertical swing angle θa of the left and right booms 12 is the set angle θao, the limit scoop angle θd of the bucket 15 is set to 55 degrees. When the vertical swing angle θa of the left and right booms 12 exceeds the set angle θao, it is considered that the bucket 15 is positioned in the upper conveyance dump region, and the vertical swing angle θa of the left and right booms 12 is assumed. Regardless of the limit, the limit scoop angle θd of the bucket 15 is set to a constant angle (for example, 45 degrees) that prevents spillage of dirt and sand from the bucket 15 to the boom side.

  This is because when the left and right booms 12 are swung up and down while the ground swing angle θc of the bucket 15 is kept constant, the left and right booms 12 and the buckets 15 The relative angle θe of the left and right booms 12 and the bucket 15 becomes smaller as the left and right booms 12 are swung downward, and the relative relationship between the left and right booms 12 and the bucket 15 is reversed. When the left and right booms 12 are swung up and down while the angle θe is constant, the ground rocking angle θc of the bucket 15 increases as the left and right booms 12 are swung up and down. Is set in consideration of the point that the ground swing angle θc of the bucket 15 becomes smaller as the swing is lowered. The setting angle θao can be variously changed. Here, the setting angle θao is set to an angle at which the bottom of the bucket 15 reaches the upper end position of the bonnet 33 provided in the prime mover 2.

  The setting unit 25 sets the limit scoop angle θd of the bucket 15 according to the vertical swing angle θa of the left and right booms 12 based on the output of the boom angle detector 18 and the scoop angle limit map data. Hereinafter, the limit increase angle θd of the bucket 15 set by the setting unit 25 is referred to as a setting limit increase angle θd.

  The scoop angle limit control unit 27 detects that the ground swing angle θc of the bucket 15 has reached the set limit scoop angle θd based on the output of the setting unit 25 and the output of the calculation unit 23 (the ground of the bucket 15 When the swing angle θc falls within the dead band width of the set limit scoop angle θd, the ground swing angle θc of the bucket 15 does not exceed the set limit scoop angle θd (the ground swing angle θc of the bucket 15 is set limit). The operation of the left and right bucket cylinders 17 is controlled so that the dead zone width of the scooping angle θd is not exceeded.

  The manual control unit 22 and the scooping angle restriction control unit 27 control the left and right bucket cylinders 17 so that the scooping angle restriction control unit 27 controls the operation of the left and right bucket cylinders 17 in preference to the manual control unit 22. The priority of operation is set.

  Thereby, for example, when the vertical swing angle θa of the left and right booms 12 is equal to or smaller than the set angle θao, the left and right buckets are controlled by the control operation of the manual control unit 22 based on the manual operation to the scooping position of the operation lever 30. If the bucket 15 approaches the left and right booms 12 and the ground swinging angle θc of the bucket 15 reaches the set limit scooping angle θd while the cylinder 17 contracts and the bucket 15 swings crawls, The angle limit control unit 27 stops the left and right bucket cylinders 17 in preference to the manual control unit 22 to stop the scooping of the bucket 15.

  As a result, it is possible to avoid the possibility of the bucket 15 coming into contact with the left and right booms 12 or the left and right boom cylinders 16 by the scooping operation of the bucket 15 when the bucket 15 is located in the lower scooping region.

  In addition, the control operation of the manual control unit 22 based on the manual operation to the lowered position of the operation lever 30 causes the left and right boom cylinders 16 to contract and the left and right booms 12 are swung downward. When 15 approaches the left and right booms 12 and the ground swing angle θc of the bucket 15 reaches the set limit scoop angle θd, the scoop angle limit control unit 27 is manually operated even if the operation lever 30 is not operated to the dump position. Prior to the control unit 22, the left and right bucket cylinders 17 are extended so that the ground swing angle θc of the bucket 15 does not exceed the limit scoop angle θd in conjunction with the downward swing of the left and right booms 12. The bucket 15 is rocked by dumping.

  As a result, it is possible to avoid the possibility of the bucket 15 coming into contact with the left and right booms 12 or the left and right boom cylinders 16 by the lowering operation of the left and right booms 12 when the bucket 15 is located in the lower scooping region. .

  [Another embodiment]

[1] The traveling vehicle body A may be a dedicated vehicle for loader work, a loader mowing combined vehicle equipped with a front loader B and a mower, a loader excavation combined vehicle equipped with a front loader B and a backhoe, and the like.

[2] A hydraulic motor or the like may be employed as the boom actuator 16 and the bucket actuator 17.

[3] As the operation tool 30, an operation tool dedicated to the boom and an operation tool dedicated to the bucket may be provided. Further, as the operation tool 30, a switch for instructing the upward swing of the boom 12, a switch for instructing a downward swing of the boom 12, a switch for instructing a scooping swing of the bucket 15, and a dump swing of the bucket 15 are instructed. You may make it provide the switch to do.

[4] As the boom angle detector 18, a sliding potentiometer that detects the expansion / contraction length of the boom cylinder 16 as the vertical swing angle θa of the boom 12 may be adopted. The bucket angle detector 19 may be a sliding potentiometer that detects the expansion / contraction length of the bucket cylinder 17 as the vertical swing angle θb of the bucket 15.

[5] The storage unit 24 stores a relational expression for scooping angle restriction as relational data indicating the relation between the vertical swing angle θa of the boom 12 and the restricting scooping angle θd of the bucket 15, and the setting part 25 The limit scoop angle θd of the bucket 15 may be calculated based on the formula and the output of the boom angle detector 18.

[6] The relational data indicating the relationship between the vertical swing angle θa of the boom 12 and the limit scoop angle θd of the bucket 15 includes the boom of the bucket 15 when the vertical swing angle θa of the boom 12 is equal to or less than the set angle θao. For example, if the vertical swing angle θa of the boom 12 approaches the set angle θao, the limit angle θd of the bucket 15 continuously increases or the boom 12 moves vertically. The limit angle θd of the bucket 15 may be set to increase stepwise as the swing angle θa approaches the set angle θao. Further, when the vertical swing angle θa of the boom 12 is equal to or smaller than the set angle θao, the limit scoop angle θd of the bucket 15 that changes according to the vertical swing angle θa of the boom 12 is the contact of the boom 15 with the boom 12 and the like. Can be changed in accordance with the shape of the boom 12 and the bucket 15, for example, the limit angle of the bucket 15 when the vertical swing angle θa of the boom 12 is the set angle θao. You may set so that (theta) d may be 60 degree | times.

[7] In each of the above embodiments, 45 degrees is exemplified as the spill prevention angle set when the vertical swing angle θa of the boom 12 exceeds the set angle θao, but from the bucket 15 to the boom side. Various angles can be changed according to the shape of the bucket 15 as long as the angle can prevent the scooping of the scooping object. For example, the angle may be set to 40 degrees or 50 degrees.

[8] As the front loader B, in the first embodiment, the configuration including the ground angle maintenance control unit 26 is illustrated, and in the second embodiment, the configuration including the ground angle maintenance mechanism 42 is illustrated. The configuration may be such that neither the angle maintenance control unit 26 nor the ground angle maintenance mechanism 42 is provided.

  The present invention can be applied to a front loader installed in a traveling vehicle body such as a tractor.

DESCRIPTION OF SYMBOLS 11 1st spindle 12 Boom 13 2nd spindle 15 Bucket 16 Boom actuator 17 Bucket actuator 18 Boom angle detector 19 Bucket angle detector 22 Manual control part 23 Calculation part 24 Storage part 25 Setting part 26 Ground angle maintenance Control unit 27 Crawling angle limit control unit 30 Operating tool A Traveling vehicle body θa Boom vertical swing angle θb Bucket vertical swing angle θc Bucket ground swing angle θd Bucket limit scoop angle

Claims (3)

An actuator for a boom that swings up and down in a vertical direction with a first support shaft that is horizontally oriented with respect to the traveling vehicle body as a fulcrum;
A bucket actuator that swings the bucket up and down around a second support shaft that is laterally oriented with respect to the boom; and
A manual control unit for controlling the operation of the boom actuator and the bucket actuator based on an artificial operation of the operation tool;
A boom angle detector for detecting a vertical swing angle of the boom;
A bucket angle detector for detecting a vertical swing angle of the bucket with respect to the boom;
A calculation unit for calculating a ground swing angle of the bucket based on an output of the boom angle detector and an output of the bucket angle detector;
A storage unit storing relational data indicating a relation between the vertical swing angle of the boom and the limit scooping angle of the bucket;
A setting unit for setting the limit scooping angle according to the vertical swing angle of the boom based on the output of the boom angle detector and the relation data;
When the operation tool is artificially operated so as to actuate the bucket actuator in a direction in which the bucket oscillates and swings, the bucket swing angle with respect to the ground based on the output of the setting unit and the output of the calculation unit If There it is detected that has reached the angle rake before Symbol limit, ground rocking angle rake angle limitation control unit for controlling the operation of said actuator for bucket so as not to exceed the angle rake before Symbol limit of the bucket And a front loader. A ground angle maintenance control unit for controlling the operation of the bucket actuator so that the ground swing angle of the bucket is constant regardless of the vertical swing of the boom,
The manual control unit controls the operation of the bucket actuator in preference to the ground angle maintenance control unit,
The rake angle restriction control unit, front loader according to claim 1, in preference to pre-Symbol manual control unit for controlling the operation of the actuator for the bucket.   When the boom swing angle is equal to or smaller than the set angle, the relational data indicates that the limit swing angle of the bucket increases as the boom swing angle approaches the set angle. When the moving angle exceeds the set angle, the bucket's limit scooping angle is a constant angle that prevents scooping of scooping objects from the bucket to the boom side, regardless of the boom swinging angle. The front loader according to claim 1 or 2, wherein the front loader is set.

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