JP2013189849A - Control system for front loader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control system for a front loader, capable of automatically controlling a front loader and improving operability and cargo handling workability.SOLUTION: A control system for a front loader which is provided with a swing arm connected to a work vehicle body and an attachment detachably attached to the tip of the swing arm comprises: operation angle detection means 81 which detects the operation angle of a control lever 80 of hydraulic pressure control means; attachment rotation angle detection means 72 which detects the rotation angle of the attachment; and control means 91 which automatically switches priorities of the maximum working speed and the maximum working load of the attachment on the basis of information detected from the operation angle detection means 81 and the attachment rotation angle detection means 72.

Description

  The present invention relates to a front loader as a work machine such as farm work, construction work, civil engineering work, and the like.

  For example, when carrying out farming work, it is a desired working machine at the tip of a swinging arm (arm) that can be undulated on a traveling vehicle such as a tractor for unloading and transporting grass, compost, earth and sand, etc. A front loader equipped with an attachment such as a bucket or fork is used.

  As shown in FIG. 11, the front loader according to this embodiment is detachably attached to the working vehicle main body 101. The working vehicle main body 101 has a pair of left and right brackets 102, and a main frame 111 of a front loader is detachably attached to the brackets 102 via docking pins 104. And the base end part of the arm 103 made into the character-like shape by the side view is pivotally attached to this main frame 111 so that vertical rotation is possible.

  A snap hitch 106 is pivotally attached to the tip of the arm 103 so as to be rotatable up and down, and a bucket 110 as an attachment is detachably attached to the snap hitch 106. Further, an arm hydraulic cylinder 105 for raising and lowering the arm 103 is disposed between the lower portion of the main frame 111 and the intermediate body 112 of the arm 103. Accordingly, the arm 103 can be raised by extending the arm hydraulic cylinder 105, and the arm 103 can be lowered by contracting the arm hydraulic cylinder 105.

  The front loader attaches the base end portion of the crank 108 to the front end portion of the arm 103 so as to be rotatable up and down, and changes the posture of the attachment by rotating the attachment between the front end portion of the crank 108 and the intermediate body 112. An attachment hydraulic cylinder 109 is provided for this purpose. A connecting rod 107 is disposed between the tip of the crank 108 and the upper portion of the snap hitch 106. Thereby, by extending the attachment hydraulic cylinder 109, the tip of the attachment can be rotated downward, and by contracting the attachment hydraulic cylinder 109, the tip of the attachment is directed upward. It can be rotated.

  By the way, when the front loader is detached from the work vehicle main body 101, the operator operates the work lever by himself and moves the front loader to a position where the docking pin 104 connecting the front loader and the work vehicle main body 101 is released. (Patent Document 1). That is, the operator operates the operation lever to expand (or contract) the attachment hydraulic cylinder 109, rotate the bucket 110 downward (or upward), and rotate the arm 103 to dock. The pin 104 is pulled up (or pulled down). In this manner, the docking pin 104 is operated so as to be in a disengagement position that is disengaged from a hook (not shown) provided on the bracket 102, so that the docking pin 104 is disengaged from the hook. Then, the hydraulic pipe is disconnected from the hydraulic source of the work vehicle main body 101, and the work vehicle main body 101 is moved backward to a place away from the front loader. In this manner, the front loader can be detached from the work vehicle main body 101.

  Also, when switching the hydraulic circuit in order to give priority to either the maximum operating speed or the maximum operating load of the attachment, it is necessary to stop the work and switch the hydraulic circuit by operating the switch or volume by the operator. It was. That is, when priority is given to the maximum operating speed, the attachment hydraulic cylinder 109 is a differential circuit. The differential circuit is a circuit in which the supply line of the hydraulic pump is connected to both the expansion and contraction ports of the attachment hydraulic cylinder 109, and the operation speed is fast but the operable load is small. On the other hand, when giving priority to the maximum operating load, the attachment hydraulic cylinder 109 is a double-action circuit. In the double-action circuit, a hydraulic pump supply circuit is connected to only one port.

Furthermore, the ascending / descending of the arm 103 and the moving speed of the attachment are determined by an output proportional to the angle of the operation lever operated by the operator or an output obtained by a calculation formula using the angle as a variable. It did not depend on the operation speed. That is, _assuming that the angle of the operation lever in the initial state is θ ₀ and the angle of the operation lever in a predetermined time is θ _n , the hydraulic device is controlled by a function determined by X _n that X _n = (θ _n −θ ₀ ) I was driving. Assuming that the current signal to the solenoid to the hydraulic device is given as a direct proportional value of X _n , the current value to the solenoid is A × X _n . A is a constant.

JP 2000-170199 A

  When the operator switches the hydraulic circuit by operating the switch or volume, the operator determines whether to give priority to the maximum operation speed or the maximum operation load, and operates the switch to operate the maximum operation speed and the maximum operation. The load was switched. As a result, when an erroneous determination, an erroneous operation, or the like occurs, the maximum operating speed and the maximum operating load cannot be appropriately switched. In addition, when switching the hydraulic circuit, the work must be stopped once, resulting in poor work efficiency.

  In view of the above problems, the present invention provides a front loader control system that can automatically control a front loader and can improve operability and cargo handling workability.

  A front loader control system according to the present invention is a front loader control system including a swing arm connected to a working vehicle body and an attachment removably attached to a tip of the swing arm. Detected from an operation angle detection means for detecting an operation angle of the operation lever of the control means, an attachment rotation angle detection means for detecting the rotation angle of the attachment, and the operation angle detection means and the attachment rotation angle detection means. And a control means for automatically switching the priority between the maximum operating speed and the maximum operating load of the attachment based on the obtained information.

  The front loader control system according to the present invention includes the operation angle detection means and the arm rotation angle detection means, so that the operation angle of the operation lever of the hydraulic control means can be detected and the rotation angle of the arm can be detected. can do. Based on this detected information, the priority of the maximum operating speed and the maximum operating load of the attachment can be automatically switched by the control means.

  The control means gives priority to the maximum operating load when the value of the operation angle detection means is a certain value or more and the angular velocity of the attachment calculated based on the value of the attachment rotation angle detection means is within a certain range. You can do it. That is, normally, the maximum operating speed is given priority, and when the above conditions are satisfied, the maximum operating load is given priority.

  In the front loader control system according to the present invention, the priority of the maximum operating speed and the maximum operating load of the attachment can be automatically switched by the control means, so that it is not necessary for the operator to determine which is prioritized. Thus, the work of switching the priority between the maximum operation speed and the maximum operation load by operating the operation button by the operator can be omitted. As a result, misjudgment, erroneous operation, and the like by the operator can be prevented, and the maximum operation speed and the maximum operation load can be appropriately switched. In addition, it is not necessary to interrupt the work for switching, work can be performed continuously, and work efficiency can be improved.

  The control means can perform switching accurately when the priority of the maximum operation speed and the maximum operation load is switched based on the value of the operation angle detection means and the angular velocity of the attachment. Further, since the maximum operating speed is usually given priority and the maximum operating load is given priority when the above conditions are satisfied, the working efficiency can be further improved.

It is a side view of the front loader using the control system which shows embodiment of this invention. It is a principal part enlarged side view of the front loader of the said FIG. It is a principal part enlarged plan view of the front loader of the said FIG. It is another principal part enlarged side view of the front loader of the said FIG. It is a block diagram which shows the control mechanism of the front loader of a reference example. It is process drawing which shows the removal process of the front loader of a reference example. It is a side view which shows the operation site | part of the front loader using the control system which shows embodiment of this invention. It is a block diagram which shows the control mechanism of the front loader using the control system which shows embodiment of this invention. It is a block diagram which shows the control mechanism of the front loader using the control system which shows another reference example. It is a graph which shows the operation angle of the operation lever of the front loader using the control system which shows another reference example. It is a side view which shows the conventional front loader.

  As shown in FIG. 1, a front loader 1 according to the present embodiment is detachably attached to a work vehicle main body 2.

  The working vehicle main body 2 includes a body frame 20 and a driving operation unit 22. The body frame 20 is provided with a pair of left and right front and rear wheels 23, 24, and a motor unit 21 is provided at the front of the body frame 20. Is provided. A driving operation unit 22 is provided at a rear position of the prime mover unit 21. A pair of left and right brackets 26 are erected on the body frame 20.

  The front loader 1 includes a swing arm (arm) 4 connected to the work vehicle main body 2 and an attachment that is detachably attached to the tip of the arm 4. In other words, the main frame 10 is detachably attached to the bracket 26 of the work vehicle main body 2 via the docking pin 3, and the base end portion of the arm 4 having a square shape in a side view can be vertically rotated on the bracket 10. It is pivotally attached to. A snap hitch 50 is pivotally attached to the tip of the arm 4 so as to be rotatable up and down, and a bucket 5 as an attachment is detachably attached to the snap hitch 50.

  Further, in the front loader 1, an arm hydraulic cylinder 6 that constitutes hydraulic operating means for moving the arm 4 up and down is disposed between the lower portion of the main frame 10 and the intermediate body 51 of the arm 4. Accordingly, the arm 4 can be raised by extending the arm hydraulic cylinder 6, and the arm 4 can be lowered by contracting the arm hydraulic cylinder 6.

  Further, a base end portion of the crank 13 is attached to the distal end portion of the arm 4 so as to be rotatable up and down, and a hydraulic pressure for changing the posture by rotating an attachment between the distal end portion of the crank 13 and the intermediate body 51. An attachment hydraulic cylinder 7 constituting the operating means is provided. A connecting rod 44 is disposed between the tip of the crank 13 and the upper portion of the snap hitch 50. Thereby, the front-end | tip part of an attachment can be rotated below by extending the hydraulic cylinder 7 for attachments. That is, the crank 13 is in contact with the tip of the cylinder rod and one end of the connecting rod 44, and the other end of the connecting rod 44 is in contact with one point of the snap hitch 50. When the attachment hydraulic cylinder 7 expands and contracts, the crank 13 rotates around one end, and an angle change occurs between the crank 13 and the attachment hydraulic cylinder 7, and the snap hitch 50 is connected via the connecting rod 44. Rotate. As a result, when the attachment hydraulic cylinder 7 is extended, a dumping operation is performed in which the tip of the bucket 5 is swung downward. On the other hand, if the attachment hydraulic cylinder 7 is contracted, a tilting operation in which the tip of the bucket 5 is swung upward is performed.

  The main frame 10 is provided with arm rotation angle detection means 71 for detecting the rotation angle of the arm 4. As shown in FIG. 2, the arm rotation angle detection means 71 includes a sensor main body 73 and a sensor guide 74. The sensor guide 74 rotates following the rotation of the arm 4. Thereby, the sensor guide 74 rotates with respect to the sensor main body 73, and the rotation angle of the arm 4 can be detected. The arm rotation angle detection means 71 can be disposed at any position as long as it is a movable part of the arm 4 or a part that follows the movement of the arm 4.

  The crank 13 is provided with attachment rotation angle detection means 72 for detecting the rotation angle of the attachment. As shown in FIGS. 3 and 4, the attachment rotation angle detection means 72 includes a sensor main body 75 and a sensor guide 76. The sensor guide 76 rotates following the tip of the cylinder rod of the attachment hydraulic cylinder 7. Thereby, the sensor guide 76 rotates with respect to the sensor main-body part 75, and the rotation angle of an attachment can be detected. Note that the attachment rotation angle detection means 72 can be disposed at any position as long as it is a movable part of the attachment or a part that follows the movement of the attachment.

  FIG. 5 is a block diagram showing a control mechanism of a reference example, and as shown in FIG. 5, control means 90 is provided. The control means 90 controls the operation speeds of the hydraulic operation means 6 and 7 based on information detected from the arm rotation angle detection means 71 and the attachment rotation angle detection means 72, and sequentially performs preset operations. In this manner, the front loader 1 is controlled so as to be moved to a detachable position.

  Next, a method for removing the front loader 1 using the front loader control method of the reference example will be described. First, when the operator depresses the switch 79, the control means 90 can perform control so that preset operations are sequentially performed, and the front loader 1 can be automatically detached. That is, as shown in FIG. 6A, in order to avoid a collision with the ground at the lowermost end of the arm 4, the bucket 5 which is the tip is horizontal with respect to the ground. As shown by the arrow, the arm 4 is lowered to the lowest end. Next, as shown by the arrow in FIG. 6 (c), the arm 4 is raised and the port of the arm hydraulic cylinder 6 constituting the hydraulic operation means is connected to the tank circuit 77 to fill the rod end side with oil. . Thereafter, as shown by the arrow in FIG. 6D, the attachment hydraulic cylinder 7 is extended, and the tip of the bucket 5 is shaken downward to be dumped. As a result, the arm 4 is rotated, and the docking pin 3 is pulled upward, so that the arm 4 can be separated from the hook (not shown) provided on the main frame 26. In this way, the docking pin 3 is released from the hook.

  6 (a) to 6 (d), the arm rotation angle detection means 71 detects the rotation angle of the arm 4, and the attachment rotation angle detection means 72 rotates the attachment. An angle is detected. And based on this detected information, the control means 90 determines the operation amount in each said operation | movement.

  In addition, the operation of lowering the arm 4, the operation of filling the hydraulic operation means with oil, and the operation of stopping the arm 4 at the disengagement position are changed (decelerated) by the control means 90 in the vicinity of the target value. . The change in the operation speed changes the time at which the speed change is started and the rate of change depending on the operation speed at the stage before the operation speed is changed. Thereby, the stop precision of each operation | movement can be improved. Further, at the start of these operations, the speed is reduced and the operation speed is gradually increased during the operation. As a result, it is possible to prevent a decrease in operation stop accuracy due to vibration of the work vehicle main body 1.

  As described above, in the front loader control system according to the reference example, the front loader 1 can be detached automatically by the control means 90, and therefore, the operation of the operator operating the lever 80 for the separation is omitted. Thus, the front loader 1 can be detached without the operator recognizing the separation position. As a result, it is possible to prevent failure of the detachment operation due to the operator making a mistake in the detachment position.

  If the control unit 90 automatically performs preset operations in sequence, the actuator can be prevented from expanding and contracting, and the separation posture can be prevented from being lost. Therefore, the failure of the separation work due to the collapse of the separation posture can be prevented. be able to.

  If the operation speed of each operation can be controlled, each operation can be performed with high accuracy, so that it is possible to perform a separation work with high accuracy.

  Next, a front loader control system according to an embodiment of the present invention will be described. In this case, attachment rotation angle detection means 72 for detecting the rotation angle of the attachment is provided, and operation angle detection means 81 for detecting the operation angle of the operation lever 80 is provided as shown in FIG. . Then, as shown in FIG. 8, based on the information detected from the operation angle detection means 81 and the attachment rotation angle detection means 72, the control means 91 that switches the priority between the maximum operation speed and the maximum operation load of the attachment. It is equipped with.

  As shown in FIG. 7, the operation angle detection means 81 includes a sensor body 85 and a sensor guide (not shown). The sensor guide rotates following the movable part of the operation lever 80. Thereby, a sensor guide will rotate with respect to the sensor main-body part 85, and the rotation angle of an attachment can be detected. The operation angle detection means 81 can be disposed at any position as long as it is a movable part of the operation lever 80 or a part that follows the movement of the operation lever 80.

  Next, a method of switching the priority between the maximum operation speed and the maximum operation load of the attachment using the front loader control method of the embodiment of the present invention will be described. First, during normal operation, the hydraulic device for the operation lever 80 operates with priority on the maximum operating speed. At this time, the attachment hydraulic cylinder 7 is a differential circuit. The differential circuit is a circuit in which the supply line of the hydraulic pump is connected to both expansion and contraction ports of the attachment hydraulic cylinder 7. Although the operation speed is fast, the operable load is small, and in the case of the operation in the pressurizing direction, the drive allowable load may be insufficient. Therefore, the insufficient state of the allowable operating load is detected by the attachment rotation angle detection means 72 and the operation angle detection means 81.

  Based on the angle information of the attachment detected by the attachment rotation angle detection means 72, the control means 91 calculates the angular velocity at predetermined intervals, and detects the operation state of the attachment. Further, the operation angle detection means 81 detects the operation angle of the operation lever 80.

  When the value of the operation angle detection unit 81 is equal to or greater than a certain value and the angular velocity of the attachment is within a certain range, the control unit 91 determines that the drive allowable load is insufficient and determines the maximum operating load. Priority. Specifically, the control circuit 91 switches the differential circuit to a double-action circuit. In the double-action circuit, a hydraulic pump supply circuit is connected to only one port. On the other hand, when the value of the operation angle detection unit 81 is smaller than a certain value or the angular velocity of the attachment is outside the certain range, the control unit 91 determines that the drive allowable load is not insufficient and gives priority to the maximum operation speed. .

  As described above, in the front loader control system according to the embodiment of the present invention, the priority of the maximum operation speed and the maximum operation load of the attachment can be automatically switched by the control means 91, so the worker gives priority to which one. This eliminates the need for the operator to switch the priority between the maximum operation speed and the maximum operation load by operating the operation button. As a result, misjudgment, erroneous operation, and the like by the operator can be prevented, and the maximum operation speed and the maximum operation load can be appropriately switched. In addition, it is not necessary to interrupt the work for switching, work can be performed continuously, and work efficiency can be improved.

  When the control unit 91 switches the priority between the maximum operation speed and the maximum operation load based on the value of the operation angle detection unit 81 and the angular velocity of the attachment, the switching can be performed accurately. Further, since the maximum operating speed is usually given priority and the maximum operating load is given priority when the above conditions are satisfied, the working efficiency can be further improved.

  Next, a front loader control system of another reference example will be described. In this case, as shown in FIG. 9, the operation angle detecting means 81 for detecting the operation angle of the operation lever 80 of the hydraulic control means is provided, and the operation angle detection means 81 uses the operation lever of the hydraulic control means. Operation speed detection means 82 for detecting the operation speed is provided. Then, based on the information of the operation angle detection means 81 and the operation speed detection means 82, a control means 92 is provided for controlling the operation of the front loader according to the change in the operation speed of the operation lever 80.

Next, a method for controlling the operation of the front loader 1 according to a change in the operation speed using the front loader control method of another reference example will be described. First, the operation angle of the operation lever 80 in the initial state is set to θ ₀ . Then, the operation angle detection means 81 detects the operation angles θ ₁ , θ ₂ , θ ₃ ,... Θ _(n−1) , θn of the operation lever 80 at predetermined intervals.

Then, the control unit 92 adds the weight α _n to the amount of change in the operating angle of the operating lever 80 (θ _n −θ _(n−1) ) and the sum X _n = α _n (θ _n −θ _{(n− 1)} ) + ... + α ₃ (θ ₃ −θ ₂ ) + α ₂ (θ ₂ −θ ₁ ) + α ₁ (θ ₁ −θ ₀ ) is obtained. FIG. 10 is a graph in which θ is replaced with X. The hydraulic device is driven by a function determined by X _n . In other words, if the current signal to the solenoid to the hydraulic device is given as a direct proportional value of X _n , the current value to the solenoid is A × X _n . That is, A {α _n (θ _n −θ _(n−1) ) +... + Α ₃ (θ ₃ −θ ₂ ) + α ₂ (θ ₂ −θ ₁ ) + α ₁ (θ ₁ −θ ₀ ) }. A is a constant, and α _n is a value determined by the inclinations of the operation angles θ ₁ , θ ₂ , θ ₃ ,... Θ _(n−1) , θ _n of the operation lever 80 with respect to time. It is. The inclination of the operation angle of the operation lever 80 with respect to time represents the operation speed at which the operation lever 80 is operated. For this reason, this system becomes a system which considered the operation speed of the operation lever.

For example, when the operator operates the operation lever slowly, the inclination of the lever with respect to time decreases. In this case, the change in the current value to the solenoid with respect to the change in the lever angle can be reduced by reducing α _n at time n to 1 or less. As a result, when the operation is performed slowly, the change in the current value can be made smaller, facilitating a minute change in the current value. Thus, by reducing α _n to 1 or less, it becomes possible to increase the resolution of the speed change by increasing the limited operation angle in a pseudo manner. Further, when α _n is within 1, the maximum angle of the lever and X _n do not coincide with each other, and the maximum current value may not be reached. At this time, the lever angle theta ₁ with respect to _{time, θ 2, θ 3, ·····} θ (n-1), from the slope of theta _n, determine the optimum X _n increase, the X _n over time Increase to reach the maximum current value by matching the maximum lever angle. Further, when the lever change amount (θ _n −θ _(n−1) ) is small and α _n is also small, X _n may not change. At this time, _Xn is changed by regulating _Xn with respect to the lever angle.

On the other hand, when the operator operates the operation lever quickly, the inclination of the lever with respect to time increases. In this case, the change in the current value to the solenoid with respect to the change in the lever angle can be suppressed by reducing α _n at time n to 1 or less. As a result, when an operation is performed too early, a change in the current value can be suppressed, and a delay in response of the hydraulic equipment can be avoided. In addition, by setting α _n at time n to 1, lever current θ ₁ , θ ₂ , θ ₃ ,..., Θ _(n-1) , θ _n changes the current value to the solenoid in accordance with changes in θ _n. Can be the same.

  Thus, in the control system of the front loader of another reference example, the operation of the front loader 1 can be controlled automatically according to the change of the operation speed by the control means, so that a minute change can be easily performed. it can. Further, even when the attachment is operated to move in small increments, the hydraulic cylinder can respond, so that a response delay of the front loader 1 can be prevented.

  As described above, the embodiment of the present invention has been described. However, the present invention is not limited to the above-described embodiment, and various modifications are possible. For example, an operation for releasing the front loader 1 (lowering the arm 4) The operation, the operation of filling the hydraulic operation means with oil, the operation of stopping the arm 4 at the disengagement position, etc.) may not be continuous, and may be stopped for each operation. Further, it is not always necessary to perform each operation at the same speed, and the speed may be different for each operation.

DESCRIPTION OF SYMBOLS 1 Front loader 2 Work vehicle main body 4 Swing arm 72 Attachment rotation angle detection means 81 Operation angle detection means 91 Control means

Claims (2)

A front loader control system comprising a swing arm coupled to a work vehicle main body and an attachment detachably attached to the tip of the swing arm,
An operation angle detection means for detecting an operation angle of the operation lever of the hydraulic control means;
An attachment rotation angle detecting means for detecting the rotation angle of the attachment;
Front comprising a control means for automatically switching the priority between the maximum operation speed and the maximum operation load of the attachment based on information detected from the operation angle detection means and the attachment rotation angle detection means. Loader control system.   The control means gives priority to the maximum operating load when the value of the operation angle detection means is a certain value or more and the angular velocity of the attachment calculated based on the value of the attachment rotation angle detection means is within a certain range. The front loader control system according to claim 1, wherein:

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