Cantilever crane damping system, dynamic compactor and control method

Abstract

The invention discloses a boom damping system, a dynamic compactor and a control method. A hydraulic pump, a first electromagnetic control valve and a second electromagnetic control valve of the boom damping system are all communicated with an electromagnetic control reversing valve, and the hydraulic pump is communicated with a hydraulic oil tank and used for providing hydraulic oil for the electromagnetic control reversing valve; the first electromagnetic control valve is communicated with a rodless cavity of the oil cylinder through a first oil way channel, a second oil way channel of the second electromagnetic control valve is communicated with a rod cavity of the oil cylinder, the energy accumulator is communicated with the rodless cavity of the oil cylinder through the first oil way channel, and the two ends of the electric proportional throttle valve are communicated with the first oil way channel and the second oil way channel respectively. One end of the electric proportional overflow valve is communicated with the first oil way channel, and the other end of the electric proportional overflow valve is communicated with the electromagnetic control reversing valve and the hydraulic oil tank through a third oil way channel. Therefore, the oil cylinder can achieve a good damping effect on the arm support, and the telescopic state of the oil cylinder can be actively controlled so as to achieve an auxiliary effect on arm rising and arm falling of the arm support.

Description

Technical Field

[0001] The invention relates to the technical field of dynamic compaction machines, and in particular to an arm shock absorbing system, a dynamic compaction machine and a control method. Background Art

[0002] Dynamic compaction machines are mainly used for dynamic compaction construction. Dynamic compaction machines mainly use the free fall of heavy hammers to generate strong impact force to strongly compact the foundation to improve the bearing capacity of the foundation and reduce the amount of settlement. Its working process is usually to lift the heavy hammer to a certain height, then let the heavy hammer fall freely, impact the ground, and repeat this process many times.

[0003] The dynamic tamping machine is mainly composed of the boom, tamping hammer, lifting winch, luffing winch, support rod, car body and other parts. The support rod is located between the boom and the car body and is connected by a hinge. The main function of the support rod is to prevent the boom from tilting backward. The wire rope of the luffing winch is connected to the end of the boom to control the raising and lowering of the boom. The wire rope of the lifting winch is connected to the unhooking device used to suspend the tamping hammer. The lifting height of the tamping hammer is adjusted by lifting the wire rope. When the tamping hammer reaches a certain height during the dynamic tamping operation, the unhooking device can be controlled to release the tamping hammer below. When the dynamic tamping machine lifts the heavy hammer, the boom is subjected to great stress and has a certain elastic deformation. At the moment of releasing the tamping hammer, the release of the tamping hammer load will cause a strong impact on the boom, causing the boom to produce a large rebound force, resulting in violent shaking of the boom.

[0004] Most existing support rods use mechanical spring devices. The support rod is a first-level sleeve rod, which consists of an inner rod, an outer rod and a spring. The inner rod can extend and retract. It extends when the arm is in the climbing state and retracts when the arm is in the raising state. In the normal state, the spring of the support rod is in a free state (uncompressed). Only when the arm angle is greater than a certain value, the spring will begin to compress. As the arm angle increases, the supporting force of the support rod also increases to prevent the arm from tilting backward. Under the condition of strong tamping, at the moment when the tamping hammer is released, the stress of the arm is suddenly released, causing the arm to rebound backward. At this time, the spring will be compressed, which plays an anti-tilting and certain buffering role. When the arm tilts backward, although the spring compression can play a certain buffering role, the spring will rebound after compression, causing the arm to shake repeatedly, and the frequency of shaking cannot be reduced. This results in the mechanical spring device having little and limited buffering effect. The spring can only play a buffering role when the arm angle is greater than a certain value. In addition, when the arm vibrates in both directions, the mechanical spring device cannot provide the damping force required by the arm well, and cannot obtain a good shock absorption effect, which in turn affects the service life of the arm and the stability and safety of the entire vehicle.

[0005] Therefore, the existing support rod support form cannot absorb the kinetic energy generated by the rebound well, causing the boom and the vehicle body to shake for a long time, seriously affecting the service life of the boom and the vehicle body, and also causing the risk of the vehicle body tipping over. Moreover, the existing support rod cannot play an auxiliary role in the arm raising and lowering of the arm. Summary of the invention

[0006] In order to overcome the shortcomings and deficiencies in the prior art, the purpose of the present invention is to provide a boom shock absorption system, a tamping machine, and a control method to solve the problem that the support rod in the prior art has a poor shock absorption effect on the boom and cannot assist in raising and lowering the boom.

[0007] The purpose of the present invention is achieved through the following technical solutions: The present invention provides a boom shock absorbing system, comprising: A hydraulic oil tank, a hydraulic pump, an electromagnetically controlled reversing valve, a first electromagnetically controlled valve and a second electromagnetically controlled valve, wherein the hydraulic pump, the first electromagnetically controlled valve and the second electromagnetically controlled valve are all connected to the electromagnetically controlled reversing valve, and an end of the hydraulic pump away from the electromagnetically controlled reversing valve is connected to the hydraulic oil tank and is used to provide hydraulic oil to the electromagnetically controlled reversing valve; An oil cylinder, the oil cylinder comprising a cylinder body with an inner cavity and a piston movable in the cylinder body, the piston dividing the inner cavity into a rodless cavity and a rod cavity, an end of the first electromagnetic control valve away from the electromagnetic control reversing valve is connected to the rodless cavity through a first oil passage, and an end of the second electromagnetic control valve away from the electromagnetic control reversing valve is connected to the rod cavity through a second oil passage; An electric proportional overflow valve and an electric proportional throttle valve, wherein both ends of the electric proportional throttle valve are respectively connected to the first oil channel and the second oil channel and are used to control the flow rate between the first oil channel and the second oil channel, one end of the electric proportional overflow valve is connected to the first oil channel, and the other end of the electric proportional overflow valve is respectively connected to the electromagnetic control reversing valve and the hydraulic oil tank through a third oil channel, and the electric proportional overflow valve is used to control the overflow pressure between the first oil channel and the third oil channel; An accumulator is connected to the rodless chamber through the first oil passage.

[0008] Furthermore, the arm shock absorption system includes a first variable damper and / or a second variable damper, the rodless chamber is connected to the first oil channel through the first variable damper, and the first variable damper is used to control the resistance to the flow of hydraulic oil between the rodless chamber and the first oil channel; the accumulator is connected to the first oil channel through the second variable damper, and the second variable damper is used to control the resistance to the flow of hydraulic oil between the accumulator and the first oil channel.

[0009] Furthermore, the arm shock absorption system includes a third variable damper, the rod chamber is connected to the second oil channel through the third variable damper, and the third variable damper is used to control the resistance of the hydraulic oil flow between the rod chamber and the second oil channel.

[0010] Furthermore, the arm shock absorption system includes a first pressure sensor and a second pressure sensor, the first pressure sensor is connected to the first oil channel and is used to detect the oil pressure in the first oil channel, and the second pressure sensor is connected to the second oil channel and is used to detect the oil pressure in the second oil channel.

[0011] Furthermore, the arm shock absorption system includes an oil return back pressure valve and / or a safety valve, the third oil circuit channel is connected to the hydraulic oil tank through the oil return back pressure valve, and the two ends of the safety valve are respectively connected to the oil outlet of the hydraulic oil tank and the hydraulic pump through the fourth oil circuit channel.

[0012] The present application provides a tamping machine, comprising a car body, a boom, a luffing winch, a lifting winch and the boom shock absorbing system as described above, wherein one end of the boom is pivotally connected to the car body, the lifting winch and the luffing winch are both installed on the body, the luffing winch is connected to the other end of the boom via a first steel wire rope and controls the raising and lowering of the boom, the lifting winch is connected to a decoupler via a second steel wire rope and is used to control the lifting height of the rammer, the boom shock absorbing system is installed on the body, and the oil cylinders of the boom shock absorbing system are pivotally connected to the car body and the boom, respectively.

[0013] The present application provides a control method for a boom shock absorption system, which is used for the boom shock absorption system as described above, and the control method includes: When the oil cylinder actively extends, the first solenoid control valve and the second solenoid control valve are controlled to be in a conducting state, the overflow pressure of the electric proportional overflow valve is adjusted to the maximum value, the electric proportional throttle valve is in a closed state, the solenoid controlled reversing valve controls the hydraulic pump to be connected to the first solenoid control valve and controls the second solenoid control valve to be connected to the third oil channel, the hydraulic pump supplies oil to the rodless chamber through the solenoid controlled reversing valve, the first solenoid control valve and the first oil channel, and the hydraulic oil in the rod chamber flows out through the second oil channel, the second solenoid control valve, the solenoid controlled reversing valve and the third oil channel; When the oil cylinder is actively shortened, the first solenoid control valve and the second solenoid control valve are controlled to be in a conducting state, the overflow pressure of the electric proportional overflow valve is adjusted to a maximum value, the electric proportional throttle valve is in a closed state, the solenoid control reversing valve controls the hydraulic pump to be connected to the second solenoid control valve and controls the first solenoid control valve to be connected to the third oil passage, the hydraulic pump supplies oil to the rod chamber through the solenoid control reversing valve, the second solenoid control valve and the second oil passage, and the hydraulic oil in the rodless chamber flows out through the first oil passage, the first solenoid control valve, the solenoid control reversing valve and the third oil passage; When the oil cylinder is in shock absorption, the first electromagnetic control valve and the second electromagnetic control valve are controlled to be in a closed state, and the rebound force of the arm is obtained, and the overflow pressure of the electric proportional overflow valve and the flow rate of the electric proportional throttle valve are adjusted according to the rebound force of the arm.

[0014] Furthermore, the control method includes: When the oil cylinder is absorbing shock, the overflow pressure of the electric proportional overflow valve and the flow rate of the electric proportional throttle valve when the rammer is released this time are adjusted according to the rebound force of the arm when the rammer was released last time.

[0015] Furthermore, the control method includes: When the oil cylinder is absorbing shock, the change trend of the boom swing amplitude is obtained, and the overflow pressure of the electric proportional overflow valve and the flow rate of the electric proportional throttle valve are adjusted in real time according to the change trend of the boom swing amplitude.

[0016] Furthermore, the control method includes: When the oil cylinder is passively extended, the first electromagnetic control valve and the second electromagnetic control valve are controlled to be in a conducting state, the electromagnetic control reversing valve controls the hydraulic pump to be connected to the first electromagnetic control valve and controls the second electromagnetic control valve to be connected to the third oil channel, the electric proportional throttle valve is in a closed state, and the overflow pressure of the electric proportional relief valve is inversely proportional to the extension of the oil cylinder; When the oil cylinder is passively shortened, the first electromagnetic control valve is controlled to be in a conducting state and the second electromagnetic control valve is controlled to be in a closed state, the electromagnetic control reversing valve controls the hydraulic pump to communicate with the first electromagnetic control valve and controls the second electromagnetic control valve to communicate with the third oil passage, the overflow pressure of the electric proportional overflow valve is proportional to the shortening amount of the oil cylinder, and the flow rate of the electric proportional throttle valve is proportional to the shortening amount of the oil cylinder; When the boom is lifting or lowering the load, the first solenoid control valve and the second solenoid control valve are both controlled to be in a conducting state, the solenoid control reversing valve controls the hydraulic pump to be connected to the first solenoid control valve and controls the second solenoid control valve to be connected to the third oil channel, the electric proportional throttle valve is in a closed state, and the overflow pressure of the electric proportional overflow valve is proportional to the weight of the load.

[0017] The beneficial effects of the present invention are as follows: through the mutual cooperation of the electromagnetically controlled reversing valve, the first electromagnetically controlled valve, the second electromagnetically controlled valve, the electric proportional overflow valve, the electric proportional throttle valve and the accumulator, the oil cylinder can have a better shock-absorbing effect on the boom, quickly attenuate the amplitude and frequency of the boom, and can also actively control the telescopic state of the oil cylinder, thereby assisting the raising and lowering of the boom, so as to reduce the power of the variable-length winch. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the dynamic compaction machine in the present invention.

[0019] Figure 2 It is a structural schematic diagram of the boom shock absorption system in the present invention.

[0020] Figure 3 It is a flowchart of the control method of the present invention during shock absorption.

[0021] In the figure: vehicle body 1, boom 2, luffing winch 3, lifting winch 4, rammer 5, first oil channel 11, second oil channel 12, third oil channel 13, fourth oil channel 14, hydraulic oil tank 21, hydraulic pump 22, solenoid-controlled reversing valve 23, return oil back pressure valve 24, safety valve 25, first solenoid control valve 31, second solenoid control valve 32, electric proportional overflow valve 41, electric proportional throttle valve 42, cylinder 50, rodless chamber 501, rod chamber 502, cylinder body 51, piston 52, accumulator 60, first variable damper 71, second variable damper 72, third variable damper 73, first pressure sensor 81, second pressure sensor 82. DETAILED DESCRIPTION

[0022] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the boom shock absorption system, dynamic tamping machine and control method proposed by the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments: Figure 1 Schematic diagram of the structure of the dynamic compaction machine in the present invention. Figure 1 As shown, a dynamic tamping machine provided by the present invention comprises a car body 1, a boom 2, a luffing winch 3, a lifting winch 4 and a boom shock absorbing system, wherein one end of the boom 2 is pivotally connected to the car body 1, the luffing winch 3 and the lifting winch 4 are both installed on the body 1, the luffing winch 3 is connected to the other end of the boom 2 through a first steel wire rope and controls the raising and lowering of the boom 2, the lifting winch 4 is connected to the unhooking device through a second steel wire rope and is used to control the lifting height of the rammer 5, the boom shock absorbing system is installed on the body 1, and the oil cylinder 50 of the boom shock absorbing system is pivotally connected to the car body 1 and the boom 2, respectively, thereby achieving a shock absorbing effect on the boom, and can also play an auxiliary role in the raising and lowering of the boom 2.

[0023] Furthermore, the tamping machine is also provided with an angle sensor and a tension sensor. The angle sensor is provided between the boom 2 and the vehicle body 1 and is used to detect the angle between the boom 2 and the vehicle body 1. The tension sensor can be provided on the first steel wire rope of the variable-length winch 3 to detect the tension of the first steel wire rope, that is, to detect the weight of the rammer 5. Of course, the tamping machine can also be provided with a balancing component, an anti-roll bar, etc. The balancing component is mainly used to maintain the balance state of the tamping machine, and the anti-roll bar is used to prevent the boom 2 from tipping backward, thereby improving the safety of the tamping machine. As for other structures of the tamping machine, reference can be made to the prior art and will not be repeated here.

[0024] Figure 2 Schematic diagram of the structure of the boom shock absorption system of the present invention. Figure 2 As shown, the present invention provides a boom shock absorbing system, which is used for the dynamic tamping machine as described above. The boom shock absorbing system includes: a hydraulic oil tank 21, a hydraulic pump 22, an electromagnetic control reversing valve 23, a first electromagnetic control valve 31, a second electromagnetic control valve 32, an electric proportional relief valve 41, an electric proportional throttle valve 42, a cylinder 50 and an accumulator 60.

[0025] The hydraulic pump 22, the first electromagnetic control valve 31 and the second electromagnetic control valve 32 are all connected to the electromagnetic control reversing valve 23, and the electromagnetic control reversing valve 23 is also connected to the third oil channel 13. The electromagnetic control reversing valve 23 can control the hydraulic pump 22 to be connected to the first electromagnetic control valve 31 and the second electromagnetic control valve 32 to be connected to the third oil channel 13, or the electromagnetic control reversing valve 23 can control the hydraulic pump 22 to be connected to the second electromagnetic control valve 32 and the first electromagnetic control valve 31 to be connected to the third oil channel 13. The end of the hydraulic pump 22 away from the electromagnetic control reversing valve 23 is connected to the hydraulic oil tank 21 and is used to provide hydraulic oil to the electromagnetic control reversing valve 23. The hydraulic oil tank 21 is used to store hydraulic oil. Among them, the first electromagnetic control valve 31 and the second electromagnetic control valve 32 are both two-position two-way electromagnetic control valves. The first electromagnetic control valve 31 is used to control the conduction and closing between the electromagnetic control reversing valve 23 and the first oil channel 11, and the second electromagnetic control valve 32 is used to control the conduction and closing between the electromagnetic control reversing valve 23 and the second oil channel 12. The electromagnetic control reversing valve 23 may be a three-position four-way electromagnetic control reversing valve, so that when the electromagnetic control reversing valve 23 controls the first electromagnetic control valve 31 and the second electromagnetic control valve 32 to be disconnected from the hydraulic pump 22, the electromagnetic control reversing valve 23 may control the hydraulic pump 22 to be connected to the third oil passage 13, so that the hydraulic oil pumped out by the hydraulic pump 22 flows back to the hydraulic oil tank 21 through the third oil passage 13. The hydraulic pump 22 may be a variable displacement pump or a fixed displacement pump, for example, a variable displacement pump. When the oil cylinder 50 needs to be actively extended and retracted, the displacement of the hydraulic pump 22 may be increased; when the oil cylinder 50 is in shock absorption, the displacement of the hydraulic pump 22 may be decreased to reduce power consumption.

[0026] The oil cylinder 50 includes a cylinder body 51 having an inner cavity and a piston 52 that can move in the cylinder body 51. The piston 52 divides the inner cavity into a rodless cavity 501 and a rod cavity 502. When the oil cylinder 50 is extended, the piston 52 compresses the rod cavity 502 and reduces the volume of the rod cavity 502; when the oil cylinder 50 is shortened, the piston 52 compresses the rodless cavity 501 and reduces the volume of the rodless cavity 501. Among them, the end of the first electromagnetic control valve 31 away from the electromagnetic control reversing valve 23 is connected to the rodless cavity 501 through the first oil passage 11, and the end of the second electromagnetic control valve 32 away from the electromagnetic control reversing valve 23 is connected to the rod cavity 502 through the second oil passage 12.

[0027] The two ends of the electric proportional throttle valve 42 are respectively connected to the first oil channel 11 and the second oil channel 12 and are used to control the flow rate between the first oil channel 11 and the second oil channel 12. One end of the electric proportional relief valve 41 is connected to the first oil channel 11, and the other end of the electric proportional relief valve 41 is respectively connected to the electromagnetic control reversing valve 23 and the hydraulic oil tank 21 through the third oil channel 13. The electric proportional relief valve 41 is used to control the overflow pressure between the first oil channel 11 and the third oil channel 13. Among them, the electric proportional relief valve 41 can adopt an inverse proportional relief valve, that is, the larger the current, the smaller the overflow pressure. The electric proportional throttle valve 42 can adopt a positive proportional throttle valve, that is, the larger the current, the greater the flow rate.

[0028] The accumulator 60 is connected to the rodless chamber 501 through the first oil passage 11. When the oil cylinder 50 is shortened, the piston 52 will compress the rodless chamber 501 and squeeze the hydraulic oil in the rodless chamber 501, so that the hydraulic oil flows into the accumulator 60 through the first oil passage 11 to improve the shock absorption effect. Of course, in other embodiments, the accumulator 60 can also be arranged between the second oil passage 12 and the rod chamber 502. When the oil cylinder 50 is extended, the piston 52 will compress the rod chamber 502 and squeeze the hydraulic oil in the rod chamber 502, so that the hydraulic oil flows into the accumulator 60 through the second oil passage 12 to further improve the shock absorption effect. Among them, the number of accumulators 60 can be one or more, and can be increased or decreased according to the actual shock absorption effect required.

[0029] Furthermore, the arm shock absorption system includes a first variable damper 71 and a second variable damper 72. The rodless chamber 501 is connected to the first oil channel 11 through the first variable damper 71. The first variable damper 71 is used to control the resistance of the hydraulic oil flow between the rodless chamber 501 and the first oil channel 11. The accumulator 60 is connected to the first oil channel 11 through the second variable damper 72. The second variable damper 72 is used to control the resistance of the hydraulic oil flow between the accumulator 60 and the first oil channel 11. By setting variable dampers between the rodless chamber 501 and the accumulator 60 and the first oil channel 11, the shock absorption effect is further improved. Of course, in other embodiments, only the first variable damper 71 or only the second variable damper 72 may be set, but the shock absorption effect is slightly worse.

[0030] In one embodiment, the arm shock absorption system further includes a third variable damper 73, and the rod chamber 502 is connected to the second oil channel 12 through the third variable damper 73, and the third variable damper 73 is used to control the resistance of the hydraulic oil flow between the rod chamber 502 and the second oil channel 12. By also arranging a variable damper between the rod chamber 502 and the second oil channel 12, the shock absorption effect can be further improved. Among them, the first variable damper 71, the second variable damper 72 and the third variable damper 73 can manually adjust the resistance according to the required shock absorption effect. Of course, in other embodiments, the first variable damper 71, the second variable damper 72 and the third variable damper 73 can adopt an electric proportional throttle valve.

[0031] Furthermore, the arm shock absorption system includes a first pressure sensor 81 and a second pressure sensor 82. The first pressure sensor 81 is connected to the first oil channel 11 and is used to detect the oil pressure in the first oil channel 11. The second pressure sensor 82 is connected to the second oil channel 12 and is used to detect the oil pressure in the second oil channel 12.

[0032] Furthermore, the arm shock absorption system includes an oil return back pressure valve 24 and a safety valve 25. The third oil channel 13 is connected to the hydraulic oil tank 21 through the oil return back pressure valve 24. Both ends of the safety valve 25 are connected to the oil outlets of the hydraulic oil tank 21 and the hydraulic pump 22 through the fourth oil channel 14. The oil return back pressure valve 24 can be a one-way valve or a relief valve to ensure that the third oil channel 13 has a certain amount of hydraulic oil. The safety valve 25 can be a pressure relief valve. When the oil pressure at the oil outlet of the hydraulic pump 22 is too high, it can flow into the hydraulic oil tank 21 through the safety valve 25 to improve safety.

[0033] The present application also provides a control method for a boom shock absorption system, which is used for the boom shock absorption system as described above.

[0034]

[0035] The above table is the corresponding control table when the boom shock absorption system is controlled in various modes. Figure 2 In the above table, Y1a and Y1b represent two control terminals on the electromagnetic control reversing valve 23, Y2 represents the control terminal of the first electromagnetic control valve 31, Y3 represents the control terminal of the second electromagnetic control valve 32, EP1 represents the control terminal of the electric proportional relief valve 41, and EP2 represents the control terminal of the electric proportional throttle valve 42. Please refer to Figure 2 and the above table, the control method includes: When the oil cylinder 50 is passively shortened (i.e., corresponding to the boom luffing in the above table), the first electromagnetic control valve 31 is controlled to be in the on state, and the second electromagnetic control valve 32 is controlled to be in the off state, that is, the Y2 control end of the first electromagnetic control valve 31 is energized, and the Y3 control end of the second electromagnetic control valve 32 is not applied with current. The electromagnetic control reversing valve 23 controls the hydraulic pump 22 to communicate with the first electromagnetic control valve 31 and controls the second electromagnetic control valve 32 to communicate with the third oil channel 13, that is, the Y1b control end of the electromagnetic control reversing valve 23 is energized. The overflow pressure of the electric proportional overflow valve 41 is proportional to the shortening amount of the oil cylinder 50, and the flow rate of the electric proportional throttle valve 42 is proportional to the shortening amount of the oil cylinder 50. Specifically, when the variable-length winch 3 controls the boom 2 to raise the arm, the boom 2 will actively compress the oil cylinder 50, causing the oil cylinder 50 to passively shorten. At this time, the hydraulic pump 22 supplies oil to the rodless chamber 501 through the electromagnetically controlled reversing valve 23, the first electromagnetically controlled valve 31, and the first oil passage 11. As the angle of the boom 2 rises, the shortening of the oil cylinder 50 increases, and the current applied to the EP1 control end of the electric proportional overflow valve 41 decreases (the downward arrow in the above table) to control the overflow pressure of the electric proportional overflow valve 41 to increase, so that the supporting force provided by the oil cylinder 50 to the boom 2 becomes larger, so as to ensure that the boom 2 rises slowly and prevent the boom 2 from tipping backward. At the same time, the current applied to the EP2 control end of the electric proportional throttle valve 42 increases (the upward arrow in the above table) to control the flow rate of the electric proportional throttle valve 42 to increase, so as to replenish oil to the rod chamber 502.

[0036] When the oil cylinder 50 is passively extended (i.e., corresponding to the boom luffing in the above table), the first electromagnetic control valve 31 and the second electromagnetic control valve 32 are both controlled to be in the conducting state, i.e., the Y2 control end of the first electromagnetic control valve 31 and the Y3 control end of the second electromagnetic control valve 32 are both energized. The electromagnetic control reversing valve 23 controls the hydraulic pump 22 to be connected to the first electromagnetic control valve 31 and controls the second electromagnetic control valve 32 to be connected to the third oil channel 13, i.e., the Y1b control end of the electromagnetic control reversing valve 23 is energized. The electric proportional throttle valve 42 is in the closed state, and the overflow pressure of the electric proportional relief valve 41 is inversely proportional to the extension of the oil cylinder 50. Specifically, when the boom 2 is lowered by the variable-length winch 3, the boom 2 will actively stretch the oil cylinder 50, causing the oil cylinder 50 to passively extend. At this time, the hydraulic pump 22 supplies oil to the rodless chamber 501 through the electromagnetically controlled reversing valve 23, the first electromagnetically controlled valve 31, and the first oil passage 11, and the hydraulic oil in the rod chamber 502 flows out through the second oil passage 12, the second electromagnetically controlled valve 32, the electromagnetically controlled reversing valve 23, and the third oil passage 13. As the angle at which the boom 2 falls increases, the extension of the oil cylinder 50 increases, and the current applied to the EP1 control end of the electric proportional relief valve 41 increases (the upward arrow in the table above) to control the relief pressure of the electric proportional relief valve 41 to decrease. However, no current is applied to the EP2 control end of the electric proportional throttle valve 42, so that the electric proportional throttle valve 42 is in a closed state, preventing the first oil passage 11 from being connected to the second oil passage 12.

[0037] When the oil cylinder 50 actively extends (i.e., the oil cylinder in the above table actively extends), the first electromagnetic control valve 31 and the second electromagnetic control valve 32 are both controlled to be in the on state, i.e., the Y2 control end of the first electromagnetic control valve 31 and the Y3 control end of the second electromagnetic control valve 32 are both energized. The overflow pressure of the electric proportional relief valve 41 is adjusted to the maximum value, and the electric proportional throttle valve 42 is in the closed state, i.e., no current is applied to the EP1 control end of the electric proportional relief valve 41 and the EP2 control end of the electric proportional throttle valve 42. The electromagnetic control reversing valve 23 controls the hydraulic pump 22 to be connected to the first electromagnetic control valve 31 and controls the second electromagnetic control valve 32 to be connected to the third oil channel 13, i.e., the Y1b control end of the electromagnetic control reversing valve 23 is energized. The hydraulic pump 22 supplies oil to the rodless chamber 501 through the electromagnetically controlled reversing valve 23, the first electromagnetically controlled valve 31 and the first oil channel 11, and the hydraulic oil in the rod chamber 502 flows out through the second oil channel 12, the second electromagnetically controlled valve 32, the electromagnetically controlled reversing valve 23 and the third oil channel 13.

[0038] When the oil cylinder 50 is actively shortened (i.e., the oil cylinder in the above table is actively retracted), the first electromagnetic control valve 31 and the second electromagnetic control valve 32 are controlled to be in the on state, i.e., the Y2 control end of the first electromagnetic control valve 31 and the Y3 control end of the second electromagnetic control valve 32 are both energized. The overflow pressure of the electric proportional relief valve 41 is adjusted to the maximum value, and the electric proportional throttle valve 42 is in the closed state, i.e., no current is applied to the EP1 control end of the electric proportional relief valve 41 and the EP2 control end of the electric proportional throttle valve 42. The electromagnetic control reversing valve 23 controls the hydraulic pump 22 to be connected to the second electromagnetic control valve 32 and controls the first electromagnetic control valve 31 to be connected to the third oil channel 13, i.e., the Y1a control end of the electromagnetic control reversing valve 23 is energized. The hydraulic pump 22 supplies oil to the rod chamber 502 through the electromagnetically controlled reversing valve 23, the second electromagnetically controlled valve 32 and the second oil channel 12, and the hydraulic oil in the rodless chamber 501 flows out through the first oil channel 11, the first electromagnetically controlled valve 31, the electromagnetically controlled reversing valve 23 and the third oil channel 13.

[0039] When the boom 2 is lifting or lowering the load (i.e., corresponding to the normal lifting / lowering of the load in the above table), the first electromagnetic control valve 31 and the second electromagnetic control valve 32 are controlled to be in the conducting state, that is, the Y2 control end of the first electromagnetic control valve 31 and the Y3 control end of the second electromagnetic control valve 32 are both energized. The electromagnetic control reversing valve 23 controls the hydraulic pump 22 to communicate with the first electromagnetic control valve 31 and controls the second electromagnetic control valve 32 to communicate with the third oil channel 13, that is, the Y1b control end of the electromagnetic control reversing valve 23 is energized. The electric proportional throttle valve 42 is in the closed state, that is, the EP2 control end of the electric proportional throttle valve 42 is not applied with current. The overflow pressure of the electric proportional relief valve 41 is proportional to the weight of the load. For example, the greater the weight of the load on the boom 2, the smaller the current applied to the EP1 control end of the electric proportional relief valve 41, so as to control the overflow pressure of the electric proportional relief valve 41 to increase, so that the oil cylinder 50 provides a greater supporting force to the boom 2.

[0040] When the oil cylinder 50 is in shock absorption (i.e., corresponding to the release of the heavy hammer in the above table), the first solenoid control valve 31 and the second solenoid control valve 32 are both controlled to be in a closed state, that is, no current is applied to the Y2 control end of the first solenoid control valve 31 and the Y3 control end of the second solenoid control valve 32. At this time, the first oil circuit channel 11 and the second oil circuit channel 12 are both disconnected from the solenoid control reversing valve 23. Therefore, no current is applied to the Y1a control end and the Y1b control end of the solenoid control reversing valve 23. Then, the rebound force of the boom 2 is obtained, and the overflow pressure of the electric proportional overflow valve 41 and the flow rate of the electric proportional throttle valve 42 are adjusted according to the rebound force of the boom 2, so that the electric proportional overflow valve 41, the electric proportional throttle valve 42, the first variable damper 71, the second variable damper 72, the third variable damper 73 and the accumulator 60 together form a buffer damping network, which can effectively absorb the rebound force generated by the ramming machine when releasing the heavy hammer (rammer 5), reduce the swing amplitude and frequency of the boom 2, so as to extend the service life of the boom 2 and the body 1 of the ramming machine and improve the safety of the ramming machine.

[0041] Among them, the calculation of the rebound force of the arm 2 when the rammer 5 is released is relatively complicated. According to the knowledge of material mechanics, when the end of the arm is subjected to concentrated force F, its bending strain energy is:

[0042] In the formula, U is the bending strain energy; F is the tension; L is the arm length; α is the arm inclination angle; E is the material elastic modulus; I is the section moment of inertia.

[0043] According to the law of conservation of energy, the rebound force is estimated. When the stress is released, the strain energy will be converted into other forms of energy such as kinetic energy and the work done by the rebound force. If the energy loss is ignored, assuming that the rebound force is Fr and the displacement generated at the end of the boom is △x, then according to the law of conservation of energy:

[0044] From this we can deduce the rebound force:

[0045] It should be noted that the calculation here is only a relatively idealized theoretical derivation. In actual situations, the rebound force will be affected by other factors and will have certain errors.

[0046] In this embodiment, when the oil cylinder 50 is absorbing shock, the overflow pressure of the electric proportional overflow valve 41 and the flow rate of the electric proportional throttle valve 42 when the rammer 5 is released this time are adjusted according to the rebound force of the arm 2 when the rammer 5 was released last time, so that the shock absorption effect of the arm shock absorption system is better.

[0047] Furthermore, when the oil cylinder 50 is absorbing shock, the change trend of the swing amplitude of the boom 2 is obtained, and the overflow pressure of the electric proportional overflow valve 41 and the flow rate of the electric proportional throttle valve 42 are adjusted in real time according to the change trend of the swing amplitude of the boom 2. The swing amplitude of the boom 2 can be detected by an angle sensor, and the change trend of the swing amplitude of the boom 2 can be estimated. For example, data can be collected in advance through multiple tests to derive the change trend corresponding to the swing amplitude of different booms 2. As the swing amplitude of the boom 2 gradually decreases, the overflow pressure of the electric proportional overflow valve 41 can be adjusted to gradually decrease, and the flow rate of the electric proportional throttle valve 42 can be adjusted to gradually decrease.

[0048] Figure 3 This is a flowchart of the control method of the present invention during shock absorption. Figure 3 As shown, when the oil cylinder 50 is absorbing shock, that is, when the ramming machine is working, the computer will obtain the working condition information such as the arm length L, the arm angle α, and the pulling force F generated by the lifting hammer. Before the first release of the ramming hammer, an initial support buffer pressure P will be given to the oil cylinder. When the ramming hammer is released for the first time, the maximum rebound displacement △x generated in the process will be recorded to calculate the rebound force Fr generated in the process, and then the buffer support pressure of the oil cylinder will be adjusted according to the calculation result (that is, the support buffer pressure of the oil cylinder each time depends on the rebound force when the ramming hammer was released last time). Among them, the angle of the arm is obtained by the arm inclination sensor; the length of the arm is selected or input by the customer on the computer according to the working conditions; the pulling force generated by the arm head of the arm depends on the weight of the ramming hammer, which is obtained through the tension sensor; the maximum rebound displacement is calculated by obtaining the maximum angle change of the arm and the arm length when the heavy hammer is released.

[0049] When the oil cylinder 50 is absorbing shock, that is, when the tamping machine is working, specifically, when the rammer 5 is lifted for the first time, the Y1b control terminal, the Y2 control terminal, the Y3 control terminal and the EP1 control terminal are powered. In this process, the computer will automatically assign an initial current value to the EP1 control terminal according to the information such as the weight of the rammer 5 to give the initial support buffer pressure P of the oil cylinder. When the rammer 5 is lifted and is about to reach the set height (the set height is the height of the rammer 5 released to fall freely), the Y1b control terminal, the Y2 control terminal and the Y3 control terminal lose power. At the same time, an initial current value is given to the EP2 control terminal to connect the rod chamber 502 and the rodless chamber 501 of the oil cylinder 50. At this time, the electric proportional relief valve 41, the electric proportional throttle valve 42, the first variable damper 71, the second variable damper 72, the third variable damper 73 and the accumulator 60 together form a buffer damping network. When the rammer 5 is released, the boom 2 will generate a backward rebound force to make the boom 2 tilt backward. At this time, the oil cylinder 50 is compressed, the volume of the rodless chamber 501 decreases, and the pressure increases. A part of the oil in the rodless chamber 501 enters the rod chamber 502 through the electric proportional throttle valve 42, and the excess oil enters the accumulator 60, which can effectively absorb the impact; when the instantaneous pressure is too high, the oil can overflow through the electric proportional relief valve 41. In addition to replenishing the rod chamber 502, the oil entering the rod chamber 502 also makes the rod chamber 502 generate a certain pressure, which can provide a certain support force for the boom 2 when it tilts forward after rebounding. This reciprocating process can effectively reduce the amplitude and frequency of the boom 2 rebounding.

[0050] When the first rammer is released, the computer will calculate the rebound force generated in this process, and adjust the current values ​​of the EP1 control terminal and the EP2 control terminal according to the magnitude of the rebound force to change the support force, buffer pressure and buffer effect of the oil cylinder 50. Under normal circumstances, when the rebound force is relatively large, the current value of the EP1 control terminal is reduced, and the current of the EP2 control terminal is increased to increase the overflow pressure of the electric proportional overflow valve 41 and the flow rate of the electric proportional throttle valve 42; when the rebound force is relatively small, the current value of the EP1 control terminal is increased, and the current of the EP2 control terminal is reduced to reduce the overflow pressure of the electric proportional overflow valve 41 and the flow rate of the electric proportional throttle valve 42. The support buffer pressure of the oil cylinder 50 each time depends on the rebound when the rammer is released last time.

[0051] In this document, the directional words such as up, down, left, right, front, and back are defined by the positions of the structures in the drawings and the positions of the structures relative to each other, just for the sake of clarity and convenience in expressing the technical solution. It should be understood that the use of the directional words should not limit the scope of protection claimed in this application. It should also be understood that the terms "first" and "second" used in this document are only used to distinguish names and are not used to limit quantity and order.

[0052] The above is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modifications to the technical contents disclosed above without departing from the scope of the technical solution of the present invention, which are equivalent embodiments of equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A boom shock absorption system, characterized in that: include: A hydraulic oil tank (21), a hydraulic pump (22), an electromagnetically controlled reversing valve (23), a first electromagnetically controlled valve (31) and a second electromagnetically controlled valve (32), wherein the hydraulic pump (22), the first electromagnetically controlled valve (31) and the second electromagnetically controlled valve (32) are all in communication with the electromagnetically controlled reversing valve (23), and an end of the hydraulic pump (22) away from the electromagnetically controlled reversing valve (23) is in communication with the hydraulic oil tank (21) and is used to supply hydraulic oil to the electromagnetically controlled reversing valve (23); An oil cylinder (50), the oil cylinder (50) comprising a cylinder body (51) having an inner cavity and a piston (52) movable in the cylinder body (51), the piston (52) dividing the inner cavity into a rodless cavity (501) and a rod cavity (502), the end of the first electromagnetic control valve (31) away from the electromagnetic control reversing valve (23) being connected to the rodless cavity (501) through a first oil passage (11), and the end of the second electromagnetic control valve (32) away from the electromagnetic control reversing valve (23) being connected to the rod cavity (502) through a second oil passage (12); an electric proportional overflow valve (41) and an electric proportional throttle valve (42), wherein two ends of the electric proportional throttle valve (42) are respectively connected to the first oil passage (11) and the second oil passage (12) and are used to control the flow rate between the first oil passage (11) and the second oil passage (12); one end of the electric proportional overflow valve (41) is connected to the first oil passage (11); the other end of the electric proportional overflow valve (41) is respectively connected to the electromagnetic control reversing valve (23) and the hydraulic oil tank (21) through a third oil passage (13); and the electric proportional overflow valve (41) is used to control the overflow pressure between the first oil passage (11) and the third oil passage (13); An accumulator (60), the accumulator (60) being in communication with the rodless chamber (501) via the first oil passage (11).

2. The boom shock absorption system according to claim 1, characterized in that: The arm shock absorbing system includes a first variable damper (71) and / or a second variable damper (72); the rodless chamber (501) is connected to the first oil passage (11) through the first variable damper (71); the first variable damper (71) is used to control the resistance of the hydraulic oil flow between the rodless chamber (501) and the first oil passage (11); the accumulator (60) is connected to the first oil passage (11) through the second variable damper (72); the second variable damper (72) is used to control the resistance of the hydraulic oil flow between the accumulator (60) and the first oil passage (11).

3. The boom shock absorption system according to claim 1, characterized in that: The arm shock absorbing system includes a third variable damper (73), and the rod chamber (502) is connected to the second oil passage (12) through the third variable damper (73). The third variable damper (73) is used to control the resistance of the hydraulic oil flow between the rod chamber (502) and the second oil passage (12).

4. The boom shock absorption system according to claim 1, characterized in that: The arm shock absorption system comprises a first pressure sensor (81) and a second pressure sensor (82), wherein the first pressure sensor (81) is connected to the first oil passage (11) and is used to detect the oil pressure in the first oil passage (11), and the second pressure sensor (82) is connected to the second oil passage (12) and is used to detect the oil pressure in the second oil passage (12).

5. The boom shock absorption system according to claim 1, characterized in that: The boom shock absorption system comprises an oil return back pressure valve (24) and / or a safety valve (25); the third oil passage (13) is connected to the hydraulic oil tank (21) via the oil return back pressure valve (24); and both ends of the safety valve (25) are respectively connected to the hydraulic oil tank (21) and the oil outlet of the hydraulic pump (22) via a fourth oil passage (14).

6. A dynamic compaction machine, characterized in that: It comprises a vehicle body (1), a boom (2), a luffing winch (3), a lifting winch (4) and a boom shock absorbing system as claimed in any one of claims 1 to 5, wherein one end of the boom (2) is pivotally connected to the vehicle body (1), the luffing winch (3) and the lifting winch (4) are both mounted on the vehicle body (1), the luffing winch (3) is connected to the other end of the boom (2) via a first steel wire rope and controls the raising and lowering of the boom (2), the lifting winch (4) is connected to a decoupler via a second steel wire rope and is used to control the lifting height of a rammer (5), the boom shock absorbing system is mounted on the vehicle body (1), and the oil cylinder (50) of the boom shock absorbing system is pivotally connected to the vehicle body (1) and the boom (2), respectively.

7. A control method for a boom shock absorption system, characterized in that: For the boom shock absorption system according to any one of claims 1 to 5, the control method comprises: When the oil cylinder (50) actively extends, the first electromagnetic control valve (31) and the second electromagnetic control valve (32) are controlled to be in a conducting state, the overflow pressure of the electric proportional overflow valve (41) is adjusted to a maximum value, the electric proportional throttle valve (42) is in a closed state, the electromagnetic control reversing valve (23) controls the hydraulic pump (22) to communicate with the first electromagnetic control valve (31) and controls the second electromagnetic control valve (32) to communicate with the third oil passage (13), the hydraulic pump (22) supplies oil to the rodless chamber (501) through the electromagnetic control reversing valve (23), the first electromagnetic control valve (31) and the first oil passage (11), and the hydraulic oil in the rod chamber (502) flows out through the second oil passage (12), the second electromagnetic control valve (32), the electromagnetic control reversing valve (23) and the third oil passage (13); When the oil cylinder (50) is actively shortened, the first electromagnetic control valve (31) and the second electromagnetic control valve (32) are controlled to be in a conducting state, the overflow pressure of the electric proportional overflow valve (41) is adjusted to a maximum value, the electric proportional throttle valve (42) is in a closed state, the electromagnetic control reversing valve (23) controls the hydraulic pump (22) to communicate with the second electromagnetic control valve (32) and controls the first electromagnetic control valve (31) to communicate with the third oil passage (13), the hydraulic pump (22) supplies oil to the rod chamber (502) through the electromagnetic control reversing valve (23), the second electromagnetic control valve (32) and the second oil passage (12), and the hydraulic oil in the rodless chamber (501) flows out through the first oil passage (11), the first electromagnetic control valve (31), the electromagnetic control reversing valve (23) and the third oil passage (13); When the oil cylinder (50) is in shock absorption, the first electromagnetic control valve (31) and the second electromagnetic control valve (32) are controlled to be in a closed state, and the rebound force of the arm (2) is obtained, and the overflow pressure of the electric proportional overflow valve (41) and the flow rate of the electric proportional throttle valve (42) are adjusted according to the rebound force of the arm (2).

8. The control method of the boom shock absorption system according to claim 7, characterized in that: The control method comprises: When the oil cylinder (50) is absorbing shock, the overflow pressure of the electric proportional overflow valve (41) and the flow rate of the electric proportional throttle valve (42) when the rammer (5) is released this time are adjusted according to the rebound force of the arm (2) when the rammer (5) was released last time.

9. The control method of the boom shock absorption system according to claim 7, characterized in that: The control method comprises: When the oil cylinder (50) is absorbing shock, the change trend of the swing amplitude of the boom (2) is obtained, and the overflow pressure of the electric proportional overflow valve (41) and the flow rate of the electric proportional throttle valve (42) are adjusted in real time according to the change trend of the swing amplitude of the boom (2).

10. The control method of the boom shock absorption system according to claim 7, characterized in that: The control method comprises: When the oil cylinder (50) is passively extended, the first electromagnetic control valve (31) and the second electromagnetic control valve (32) are controlled to be in a conducting state, the electromagnetic control reversing valve (23) controls the hydraulic pump (22) to communicate with the first electromagnetic control valve (31) and controls the second electromagnetic control valve (32) to communicate with the third oil passage (13), the electric proportional throttle valve (42) is in a closed state, and the overflow pressure of the electric proportional overflow valve (41) is inversely proportional to the extension amount of the oil cylinder (50); When the oil cylinder (50) is passively shortened, the first electromagnetic control valve (31) is controlled to be in an on state and the second electromagnetic control valve (32) is controlled to be in a closed state, the electromagnetic control reversing valve (23) controls the hydraulic pump (22) to communicate with the first electromagnetic control valve (31) and controls the second electromagnetic control valve (32) to communicate with the third oil passage (13), the overflow pressure of the electric proportional overflow valve (41) is proportional to the shortening amount of the oil cylinder (50), and the flow rate of the electric proportional throttle valve (42) is proportional to the shortening amount of the oil cylinder (50); When the boom (2) is lifting or lowering a load, the first electromagnetic control valve (31) and the second electromagnetic control valve (32) are controlled to be in a conducting state, the electromagnetic control reversing valve (23) controls the hydraulic pump (22) to be connected to the first electromagnetic control valve (31) and controls the second electromagnetic control valve (32) to be connected to the third oil channel (13), the electric proportional throttle valve (42) is in a closed state, and the overflow pressure of the electric proportional overflow valve (41) is proportional to the weight of the load.

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