Feller arm for forestry machinery and overload protection control method thereof

Abstract

The invention discloses a feller arm for forestry machinery. The feller arm comprises a fixed frame, a swing frame, a rotary mechanism, a rotary platform, a main arm, a telescopic arm oil cylinder, a main arm oil cylinder, an inclined swing oil cylinder, an outer arm, a telescopic oil cylinder, a middle arm, an inner arm, a suspended weight, a dynamic tilt angle sensor, a position sensor, a weighing system, an electromagnetic valve and a controller. The controller receives signals sent by the dynamic tilt angle sensor, the position sensor and the weighing system and sends an instruction to the electromagnetic valve; according to the working method, the load actually borne by the slewing mechanism is calculated according to the spatial positions and weights of all components forming the feller arm and compared with the allowable maximum load, if the load does not exceed the allowable maximum load, normal operation does not need to be adjusted, and if the load exceeds the allowable maximum load, the posture of the feller arm needs to be controlled and adjusted. Therefore, the load actually borne by the slewing mechanism is always within the allowable bearable maximum load range, the failure rate of the slewing mechanism is reduced, the service life of the slewing mechanism is prolonged, and the use requirements of forestry machinery are met.

Description

Technical Field

[0001] This invention relates to the field of forestry machinery technology, specifically to a logging boom for forestry machinery and its overload protection and control method. Based on the weight of the trees to be felled and lifted, the method automatically calculates the actual load borne by the slewing mechanism, keeping the actual load-bearing capacity of the slewing mechanism within the range of the maximum allowable load, thereby reducing the failure rate of the slewing mechanism and increasing its service life. Background Technology

[0002] When operating a logging boom, the operator often encounters difficulties in determining the maximum weight (including the weight of the logging equipment and the trees) that the boom can lift and cut under different operating conditions due to the boom's variable working posture. In such complex and changing operating environments, it is easy for the actual weight of the load lifted and cut by the logging boom to exceed the maximum allowable weight. This causes the actual stress on the slewing mechanism to exceed its maximum load-bearing capacity, placing the slewing mechanism in extremely unfavorable operating conditions, reducing its lifespan, and even causing frequent malfunctions and downtime.

[0003] When logging trees, operators of existing forestry machinery mostly rely on operation manuals and experience to determine the working posture of the logging arm, making it impossible to obtain the actual stress on the slewing mechanism. This often results in the slewing mechanism being in an overloaded state for a long time, which seriously affects its service life. At the same time, this technical solution relies entirely on manual operation by the operator, which is highly uncertain. It not only fails to achieve automatic adjustment of the logging arm posture, but also makes it difficult to ensure that the actual load-bearing capacity of the slewing mechanism is always kept within the maximum allowable load-bearing capacity range. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a logging arm for forestry machinery and its overload protection control method. Based on the spatial position and weight of each component of the logging arm, the controller calculates the actual load borne by the slewing mechanism and compares it with the maximum allowable load. If the load is within the limit, no adjustment is needed for normal operation. If the load is exceeded, the posture of the logging arm needs to be controlled and adjusted to ensure that the actual load borne by the slewing mechanism is always within the maximum allowable load range, thereby reducing the failure rate of the slewing mechanism, increasing its service life, and meeting the requirements for forestry machinery use.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is: a logging boom for forestry machinery, comprising: a fixed frame, a swing frame, a slewing mechanism, a slewing platform, a main boom, a telescopic boom cylinder, a main boom cylinder, a tilting swing cylinder, an outer boom, a telescopic cylinder, a middle boom, an inner boom, and a suspended load.

[0006] The fixed frame provides a load-bearing structure for each component;

[0007] One end of the swing frame is hinged to the fixed frame, and the other end is connected to the tilting swing cylinder, so that it can swing around the hinge point as the tilting swing cylinder extends and retracts.

[0008] The inner ring of the rotary mechanism is mounted on the swing frame, and the outer ring is mounted on the rotary platform, which can rotate relative to the swing frame.

[0009] The slewing platform, as the main load-bearing component of the logging boom, provides the mounting structure for the main boom, telescopic boom cylinder, and main boom cylinder.

[0010] One end of the main boom is hinged to the rotary platform, and the other end is hinged to the outer boom, which can swing as the main boom cylinder extends and retracts.

[0011] The telescopic boom cylinder is hinged at both ends to the rotary platform and the outer boom, respectively, to realize the swing of the outer boom;

[0012] The two ends of the main boom cylinder are hinged to the rotary platform and the main boom respectively, so as to realize the swing of the main boom;

[0013] The tilting swing cylinder is hinged at both ends to the fixed frame and the swing frame respectively, so as to realize the swing frame swinging around the fixed frame;

[0014] The inner arm is slidably mounted in the middle arm, and the middle arm is slidably mounted in the outer arm.

[0015] The two ends of the telescopic cylinder are connected to the outer arm and the middle arm respectively, and are used to drive the middle arm to extend and retract inside the outer arm, and drive the inner arm to extend and retract inside the middle arm through the transmission mechanism.

[0016] Furthermore, the transmission mechanism is a chain drive mechanism.

[0017] Furthermore, a logging arm for forestry machinery also includes: a dynamic tilt sensor, a position sensor, a weighing system, a solenoid valve, and a controller;

[0018] The dynamic tilt sensor is installed on the slewing platform. When the slewing platform forms an angle with the reference horizontal plane, it transmits the angle parameter to the controller. Multiple position sensors are used to measure the lever arm value of each component of the logging arm to the center point O of the slewing mechanism under different postures, and transmit the lever arm value to the controller.

[0019] The weighing system is installed at the end of the logging arm to weigh the logging equipment and trees, and transmit the weight parameters to the controller.

[0020] The solenoid valve receives instructions from the controller and controls the movement of the telescopic cylinder;

[0021] The controller is used for the implementation and calculation of logging arm adjustment control, receiving signals from the dynamic tilt sensor, position sensor and weighing system, and sending commands to the solenoid valve.

[0022] Furthermore, multiple position sensors are respectively installed on the slewing platform, main boom, telescopic boom cylinder, main boom cylinder, outer boom, telescopic cylinder, middle boom, inner boom, and the center of gravity of the suspended load.

[0023] Furthermore, the suspended load includes logging equipment and felled trees, and is connected to the inner arm at the end away from the middle arm.

[0024] Furthermore, the controller calculates the load state of the logging arm by receiving angle parameters, lever arm value, and weight parameters, and sends adjustment commands to the solenoid valve based on the load state to control the extension and retraction speed and stroke of the telescopic cylinder.

[0025] An overload protection control method for a logging boom used in forestry machinery includes: the slewing mechanism being subjected to an equivalent central axial force F'. a The combined effect of the equivalent overturning moment M'; the center point O of the slewing mechanism is the intersection of the plane containing the center of the slewing ball and the center line of rotation of the logging arm; the load on the slewing mechanism varies under different operating conditions; through force analysis of the slewing mechanism in different working postures, the equivalent central axial force F' is obtained. a and equivalent overturning moment M';

[0026] For a given slewing mechanism, there is a certain functional relationship between the equivalent central axial force and the equivalent overturning moment. The magnitude of the equivalent central axial force is mainly determined by the mass property parameters and tilt angle of the logging arm itself. After the vehicle controller is powered on, the weighing system and the dynamic tilt sensor transmit the weight and angle signals of the suspended load to the controller, respectively. The controller calculates the equivalent central axial force F' borne by the slewing mechanism in a certain posture of the logging arm. a The controller determines the maximum equivalent overturning moment M that the slewing mechanism can withstand at a certain posture of the logging arm based on the functional relationship between the equivalent central axial force and the equivalent overturning moment. max Meanwhile, multiple position sensors transmit the lever arm information of each component to the controller, which calculates the equivalent overturning moment M' borne by the slewing mechanism in a certain posture of the logging arm.

[0027] Furthermore, when M'>M maxAt this point, the equivalent overturning moment actually borne by the slewing mechanism has exceeded the maximum equivalent overturning moment. If operation continues, the slewing mechanism will be overloaded, and prolonged overload will cause damage or even shutdown of the slewing mechanism. At this time, the logging arm needs to be adjusted. The controller transmits the action command to the solenoid valve to control the extension cylinder to shorten. At the same time, multiple position sensors retransmit the torque information of each component to the controller. The controller calculates the equivalent overturning moment M' borne by the slewing mechanism after the logging arm is adjusted, until the calculated equivalent overturning moment M' does not exceed M. max At this time, the telescopic cylinder stops operating, and the logging arm resumes normal operation.

[0028] Furthermore, when M'≤M max When the slewing mechanism operates within the allowable load range, the telescopic cylinder does not need to move, and the logging arm operates normally.

[0029] Furthermore, when the dynamic tilt sensor detects the tilt angle 'a' of the slewing mechanism, multiple position sensors detect the lever arm of each component, or the weighing system detects the weight of the suspended load, if any of these parameters changes, the controller must recalculate the equivalent central axial force and equivalent overturning moment of the slewing mechanism, and adjust the control according to the aforementioned rules to ensure that the actual load-bearing capacity of the slewing mechanism is always within the allowable range.

[0030] The beneficial effects of this invention are:

[0031] (1) The actual load borne by the slewing mechanism is automatically calculated based on the posture of the logging arm and the weight of the suspended load. It is compared with the maximum allowable load. By adjusting the posture of the logging arm, the actual load borne by the slewing mechanism is always within the maximum allowable load range, thereby reducing the failure rate of the slewing mechanism and increasing its service life.

[0032] (2) By collecting information on the tilt angle of the slewing platform, the weight of the suspended load, and the position information of each component of the logging arm, the actual load borne by the slewing mechanism is calculated in real time. The maximum allowable load of the slewing mechanism is determined based on the load-bearing capacity curve of the slewing mechanism. The position information of each component is adjusted by adjusting the posture of the logging arm to ensure that the slewing mechanism is in a state of not being overloaded.

[0033] (3) The present invention can also be applied to other equipment, including but not limited to forestry machinery, such as telescopic boom engineering machinery with a slewing mechanism. Attached Figure Description

[0034] Figure 1 Diagram showing the components of a logging machine arm;

[0035] Figure 2 The force analysis diagram is shown when the swing angle of the logging boom is α = 0.

[0036] Figure 3 The force analysis diagram is shown when the swing angle α of the logging boom is greater than 0.

[0037] Figure 4 Force analysis diagram for logging boom yaw angle α < 0;

[0038] Figure 5 For control logic diagram;

[0039] In the diagram: 1. Fixed frame; 2. Swing frame; 3. Slewing mechanism; 4. Slewing platform; 5. Main boom; 6. Telescopic boom cylinder; 7. Main boom cylinder; 8. Tilting swing cylinder; 9. Outer boom; 10. Telescopic cylinder; 11. Middle boom; 12. Inner boom; 13. Suspended load. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. However, it should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of the invention.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention.

[0042] like Figure 1 As shown, a logging boom for forestry machinery includes: a fixed frame 1, a swing frame 2, a slewing mechanism 3, a slewing platform 4, a main boom 5, a telescopic boom cylinder 6, a main boom cylinder 7, a tilting swing cylinder 8, an outer boom 9, a telescopic cylinder 10, a middle boom 11, an inner boom 12, a suspended load 13, a dynamic tilt sensor, a position sensor, a weighing system, a solenoid valve, and a controller.

[0043] Wherein: the fixed frame 1 is directly connected to the swing frame 2 and the tilting swing cylinder 8, providing a load-bearing structure for each component;

[0044] One end of the swing frame 2 is hinged to the fixed frame 1, and the other end is connected to the tilting swing cylinder 8. The swing frame 2 can swing around the hinge point as the tilting swing cylinder 8 extends and retracts.

[0045] The inner ring of the rotary mechanism 3 is mounted on the swing frame 2, and the outer ring is mounted on the rotary platform 4. The rotary platform 4 rotates relative to the swing frame 2.

[0046] The rotary platform 4 serves as the main load-bearing component of the logging boom, providing an installation structure for the main boom 5, telescopic boom cylinder 6, and main boom cylinder 7.

[0047] One end of the main boom 5 is hinged to the rotary platform 4, and the other end is hinged to the outer boom 9, and swings with the extension and retraction of the main boom cylinder 7.

[0048] The telescopic boom cylinder 6 connects the rotary platform 4 and the outer boom 9, enabling the outer boom 9 to swing.

[0049] The main boom cylinder 7 connects the rotary platform 4 and the main boom 5, enabling the main boom 5 to swing.

[0050] The tilting swing cylinder 8 connects the fixed frame 1 and the swing frame 2, enabling the swing frame 2 to swing around the fixed frame 1;

[0051] The outer arm 9 connects the main arm 5 and the middle arm 11;

[0052] The telescopic cylinder 10 connects the outer arm 9 and the middle arm 11, enabling relative movement between the outer arm 9 and the middle arm 11;

[0053] The middle arm 11 is connected to the outer arm 9 via a telescopic cylinder 10. Under the action of the telescopic cylinder 10, the middle arm 11 can extend and retract within the outer arm 9.

[0054] The inner arm 12 is connected to the outer arm 9 by a chain. Under the action of the telescopic cylinder 10, the inner arm 12 can extend and retract within the middle arm 11.

[0055] The suspended weight 13 includes logging equipment and felled trees;

[0056] The dynamic tilt sensor is installed on the rotary platform 4. When the rotary platform 4 forms an angle with the reference horizontal plane, it transmits the angle parameter to the controller.

[0057] Nine position sensors are provided, and these nine position sensors are respectively installed at the center of gravity positions of the rotary platform 4, main boom 5, telescopic boom cylinder 6, main boom cylinder 7, outer boom 9, telescopic boom cylinder 10, middle boom 11, inner boom 12, and suspended load 13. Figure 2-4 As shown, nine position sensors measure the lever arm values ​​from each component of the logging arm to the center point O of the slewing mechanism 3 under different postures. The nine lever arm values ​​are L1 to L9. The lever arm values ​​L1 to L9 are then transmitted to the controller.

[0058] The weighing system is installed at the end of the logging arm to weigh the logging equipment and trees, and transmit the weight parameters to the controller.

[0059] The solenoid valve receives instructions from the controller and controls the movement of the telescopic cylinder 10;

[0060] The controller is used for the implementation and calculation of logging boom adjustment control, receiving signals from the dynamic tilt sensor, position sensor and weighing system, and sending instructions to the solenoid valve;

[0061] The controller is connected to the dynamic tilt sensor, position sensor, weighing system, and solenoid valve respectively. It is used to receive signals from the dynamic tilt sensor, position sensor, and weighing system, and send commands to the solenoid valve to realize the adjustment control and calculation of the logging arm.

[0062] Its working principle is as follows:

[0063] As shown in Figure 2-4, during the operation of the logging arm, the slewing mechanism 3 is subjected to an equivalent central axial force F'. a The combined effect of the equivalent overturning moment M'; the center point O of the slewing mechanism 3 is the intersection of the plane containing the center of the ball of the slewing mechanism 3 and the center line of the slewing of the logging arm; the load borne by the slewing mechanism 3 varies under different working conditions of the logging arm;

[0064] The overturning moment M experienced by the slewing mechanism 3:

[0065]

[0066] The axial force Fa acting on the rotary mechanism 3:

[0067]

[0068] The radial force Fr acting on the rotary mechanism 3:

[0069]

[0070] In the formula:

[0071] K—Working condition coefficient of slewing mechanism 3; G1—Self-weight of slewing platform 4; G2—Self-weight of main boom 5; G3—Self-weight of main boom cylinder 7; G4—Self-weight of telescopic boom cylinder 6; G5—Self-weight of outer boom 9; G6—Self-weight of telescopic boom cylinder 10; G7—Self-weight of middle boom 11; G8—Self-weight of inner boom 12; G9—Total weight of logging equipment and trees; a—Angle between slewing mechanism 3 and the horizontal plane; L1 to L9—Lever arms from G1 to G9 to point O. When G1 to G9 are to the left of point O, the value of L is negative; when G1 to G9 are to the right of point O, the value of L is positive; when the center of mass is directly above point O, the value of L is 0.

[0072] Taking a single-row four-point contact ball rotary mechanism 3 with a contact angle of 60 degrees as an example,

[0073] Equivalent central axial force of rotary mechanism 3: F' a =(F a +5.046F r )f d

[0074] Equivalent overturning moment of slewing mechanism 3: M'=Mf d

[0075] f d The safety factor is the dynamic working condition of the rotary mechanism 3.

[0076] like Figure 5 As shown, an overload protection control method for a logging boom used in forestry machinery includes:

[0077] For a certain type of slewing mechanism 3, there is a certain functional relationship between the equivalent central axial force and the equivalent overturning moment. The magnitude of the equivalent central axial force is mainly determined by the mass property parameters and tilt angle of the logging arm itself. After the vehicle controller is powered on, the weighing system and the dynamic tilt sensor transmit the weight and angle signals of the suspended load 13 to the controller, respectively. The controller calculates the equivalent central axial force F' borne by the slewing mechanism 3 in a certain posture of the logging arm. a The controller determines the maximum equivalent overturning moment M that the slewing mechanism 3 can withstand at a certain posture of the logging arm based on the functional relationship between the equivalent central axial force and the equivalent overturning moment. max Meanwhile, nine position sensors transmit the lever arm information of each component to the controller, which calculates the equivalent overturning moment M' borne by the slewing mechanism 3 in a certain posture of the logging arm.

[0078] When M'>M max At this point, the equivalent overturning moment actually borne by the slewing mechanism 3 has exceeded the maximum equivalent overturning moment. If operation continues, the slewing mechanism 3 will be overloaded, and prolonged overload will cause damage to the slewing mechanism 3 or even shutdown. At this time, the logging arm needs to be adjusted. The controller transmits the action command to the solenoid valve to control the extension cylinder 10 to shorten. At the same time, the nine position sensors retransmit the torque information of each component to the controller. The controller calculates the equivalent overturning moment M' borne by the slewing mechanism 3 after the logging arm is adjusted, until the calculated equivalent overturning moment M' does not exceed M. max When the telescopic cylinder 10 stops moving, the logging arm can operate normally.

[0079] When M'≤M max When the slewing mechanism 3 operates within the allowable load range, the telescopic cylinder 10 does not need to move, and the logging arm operates normally;

[0080] When the dynamic tilt sensor detects the tilt angle α of the slewing mechanism 3, the nine position sensors detect the lever arms L1 to L9 of each component, and the weighing system detects the weight G9 of the suspended weight 13, if any of these parameters change, the controller must recalculate the equivalent central axial force and equivalent overturning moment of the slewing mechanism 3, and adjust the control according to the aforementioned rules to ensure that the actual load-bearing capacity of the slewing mechanism 3 is always within the allowable range.

[0081] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A logging arm for forestry machinery, characterized in that, include: Fixed frame, swing frame, slewing mechanism, slewing platform, main boom, telescopic boom cylinder, main boom cylinder, tilting swing cylinder, outer boom, telescopic cylinder, middle boom, inner boom, suspended load; The fixed frame provides a load-bearing structure for each component; One end of the swing frame is hinged to the fixed frame, and the other end is connected to the tilting swing cylinder, so that it can swing around the hinge point as the tilting swing cylinder extends and retracts. The inner ring of the rotary mechanism is mounted on the swing frame, and the outer ring is mounted on the rotary platform, which can rotate relative to the swing frame. The slewing platform, as the main load-bearing component of the logging boom, provides the mounting structure for the main boom, telescopic boom cylinder, and main boom cylinder. One end of the main boom is hinged to the rotary platform, and the other end is hinged to the outer boom, which can swing as the main boom cylinder extends and retracts. The telescopic boom cylinder is hinged at both ends to the rotary platform and the outer boom, respectively, to realize the swing of the outer boom; The two ends of the main boom cylinder are hinged to the rotary platform and the main boom respectively, so as to realize the swing of the main boom; The tilting swing cylinder is hinged at both ends to the fixed frame and the swing frame, respectively, to enable the swing frame to swing around the fixed frame; the inner arm is slidably mounted in the middle arm, and the middle arm is slidably mounted in the outer arm. The two ends of the telescopic cylinder are connected to the outer arm and the middle arm respectively, and are used to drive the middle arm to extend and retract inside the outer arm, and drive the inner arm to extend and retract inside the middle arm through the transmission mechanism.

2. The logging arm for forestry machinery according to claim 1, characterized in that, Also includes: Dynamic tilt sensor, position sensor, weighing system, solenoid valve, controller; The dynamic tilt sensor is installed on the slewing platform. When the slewing platform forms an angle with the reference horizontal plane, it transmits the angle parameter to the controller. Multiple position sensors are used to measure the lever arm value of each component of the logging arm to the center point O of the slewing mechanism under different postures, and transmit the lever arm value to the controller. The weighing system is installed at the end of the logging arm to weigh the logging equipment and trees, and transmit the weight parameters to the controller. The solenoid valve receives instructions from the controller and controls the movement of the telescopic cylinder; The controller is used for the implementation and calculation of logging arm adjustment control, receiving signals from the dynamic tilt sensor, position sensor and weighing system, and sending commands to the solenoid valve.

3. A logging arm for forestry machinery according to claim 2, characterized in that, Multiple position sensors are respectively installed on the slewing platform, main boom, telescopic boom cylinder, main boom cylinder, outer boom, telescopic cylinder, middle boom, inner boom, and the center of gravity of the suspended load.

4. A logging arm for forestry machinery according to claim 2, characterized in that, The suspended load includes logging equipment and felled trees, and is connected to the inner arm at the end away from the middle arm.

5. A logging arm for forestry machinery according to claim 2, characterized in that, The controller calculates the load state of the logging arm by receiving angle parameters, lever arm value, and weight parameters, and sends adjustment commands to the solenoid valve based on the load state to control the extension and retraction speed and stroke of the telescopic cylinder.

6. The overload protection and control method for a logging boom used in forestry machinery according to claim 3, characterized in that, include: After the vehicle controller is powered on, the weighing system and the dynamic tilt sensor transmit the weight and angle signals of the suspended load to the controller, which then calculates the equivalent central axial force F' borne by the slewing mechanism in a certain posture of the logging arm. a The controller determines the maximum equivalent overturning moment M that the slewing mechanism can withstand at a certain posture of the logging arm based on the functional relationship between the equivalent central axial force and the equivalent overturning moment. max Meanwhile, multiple position sensors transmit the lever arm information of each component to the controller, which calculates the equivalent overturning moment M' borne by the slewing mechanism in a certain posture of the logging arm.

7. The overload protection control method for a logging boom used in forestry machinery according to claim 6, characterized in that, When M'>M max At this point, the equivalent overturning moment actually borne by the slewing mechanism has exceeded the maximum equivalent overturning moment. If operation continues, the slewing mechanism will be overloaded, and prolonged overload will cause damage or even shutdown of the slewing mechanism. At this time, the logging arm needs to be adjusted. The controller transmits the action command to the solenoid valve to control the extension cylinder to shorten. At the same time, multiple position sensors retransmit the torque information of each component to the controller. The controller calculates the equivalent overturning moment M' borne by the slewing mechanism after the logging arm is adjusted, until the calculated equivalent overturning moment M' does not exceed M. max At this time, the telescopic cylinder stops operating, and the logging arm resumes normal operation.

8. The overload protection control method for a logging boom used in forestry machinery according to claim 6, characterized in that, When M'≤M max When the slewing mechanism operates within the allowable load range, the telescopic cylinder does not need to move, and the logging arm operates normally.

9. The overload protection control method for a logging boom used in forestry machinery according to claim 8, characterized in that, When the dynamic tilt sensor detects the tilt angle 'a' of the slewing mechanism, multiple position sensors detect the lever arm of each component, and the weighing system detects the weight of the suspended load, if any of these parameters changes, the controller must recalculate the equivalent central axial force and equivalent overturning moment of the slewing mechanism, and adjust the control according to the aforementioned rules to ensure that the actual load-bearing capacity of the slewing mechanism is always within the allowable range.

Images