Crane winch follow-up hydraulic system and control method

Abstract

The invention discloses a crane winch follow-up hydraulic system and a control method, and the hydraulic system comprises a winch motor, a telescopic oil cylinder, a winch balance valve, a telescopic balance valve, a winch proportional directional valve, a telescopic proportional directional valve, a pressure reducing valve and a brake opening valve, a port P of the telescopic proportional reversing valve is communicated with a port P of the winch proportional reversing valve and a port P1 of the pressure reducing valve, a port T of the telescopic proportional reversing valve is communicated with a port T of the winch proportional reversing valve, a port A of the telescopic proportional reversing valve is communicated with a port V1 of the telescopic balance valve, a port B of the telescopic proportional reversing valve is communicated with a port V2 of the telescopic balance valve, and a port V of the telescopic balance valve is communicated with a port V3 of the pressure reducing valve. A C2 port of the telescopic balance valve is communicated with a rod cavity of the telescopic oil cylinder, and a C1 port of the telescopic balance valve is communicated with a rodless cavity of the telescopic oil cylinder. Linkage control over the telescopic arm action and the winch retracting and releasing action can be achieved, the automation degree is high, the working efficiency is improved, hoisting accidents can be effectively controlled, and the safety performance is high.

Description

Technical Field

[0001] The invention relates to the technical field of engineering machinery, and in particular discloses a crane winch follow-up hydraulic system and a control method. Background Art

[0002] When performing telescopic boom operations, crane operators generally only perform one operation. As the crane boom is extended, the hook gradually rises and approaches the boom head pulley while the winch does not move. At this time, the operator will stop telescoping the boom, and operate the winch mechanism to the appropriate position and then continue the suspended telescopic action until the telescopic operation is completed. This requires the operator to constantly stop and continue the telescopic action of the boom, which is inefficient. If the boom extension and winch are manually controlled to be retracted and released at the same time, the operator's operating quality is required to be high. If handled improperly, the height limit switch will be triggered, causing the main boom to stop extending, and in severe cases, the wire rope will break. In addition, when the boom is long and the operating environment is harsh, it is difficult for the operator to grasp the exact position of the hook, and manual operation is prone to cause hoisting accidents.

[0003] In the prior art, the operator needs to constantly stop the operation to retract and release the winch rope when telescoping the boom and changing the amplitude, which has low operation efficiency. In addition, when the boom is long or the weather is bad, it is difficult for the operator to grasp the exact position of the hook, which can easily cause hoisting accidents. Summary of the invention

[0004] The present invention provides a crane winch follow-up hydraulic system and a control method, aiming to solve at least one of the above-mentioned defects in the prior art.

[0005] One aspect of the present invention relates to a crane winch follow-up hydraulic system, comprising a winch motor, a telescopic oil cylinder, a winch balancing valve, a telescopic balancing valve, a winch proportional reversing valve, a telescopic proportional reversing valve, a pressure reducing valve and a brake opening valve, wherein the P port of the telescopic proportional reversing valve is respectively connected to the P port of the winch proportional reversing valve and the P1 port of the pressure reducing valve, the T port of the telescopic proportional reversing valve is connected to the T port of the winch proportional reversing valve, the A port of the telescopic proportional reversing valve is connected to the V1 port of the telescopic balancing valve, the B port of the telescopic proportional reversing valve is connected to the V2 port of the telescopic balancing valve, the C2 port of the telescopic balancing valve is connected to the The rod chamber is connected, and the C1 port of the telescopic balancing valve is connected to the rodless chamber of the telescopic cylinder; the A port of the winch proportional reversing valve is connected to the A port of the winch balancing valve and the winch motor respectively, and the B port of the winch proportional reversing valve is connected to the K port of the winch balancing valve and the B port of the winch motor respectively, and the B port of the winch balancing valve is connected to the A port of the winch motor; the P2 port of the pressure reducing valve is connected to the P port of the brake opening valve, the K port of the pressure reducing valve is connected to the T port of the brake opening valve, the A port of the brake opening valve is connected to the reducer of the winch motor, and the a port of the brake opening valve is connected to the Br port of the winch balancing valve.

[0006] Furthermore, the hoisting motor adopts a variable displacement piston motor.

[0007] Furthermore, a pressure sensor is installed at the G port of the hoisting motor, and the pressure sensor is connected to the controller for importing the measured motor pressure value into the controller.

[0008] Another aspect of the present invention relates to a control method for the above-mentioned crane hoisting servo hydraulic system, the control method for the crane hoisting servo hydraulic system comprising the following steps:

[0009] When the arm is extended and retracted, the arm extension length sensor captures the arm length ΔL1, and the hoisting mechanism synchronously retracts and releases the same length of wire rope ΔL2 to keep the distance between the hook and the ground unchanged;

[0010] The controller converts the telescopic cylinder flow of the hydraulic system to the telescopic cylinder under the same time T according to the arm length ΔL1. The telescopic cylinder flow includes the arm extension flow Q1 and the arm retraction flow Q2.

[0011] The controller calculates the speed N1 of the winch reducer, the speed N2 of the winch motor, and the flow rate Q3 required by the winch motor according to the length ΔL2 of the wire rope, the circumference L3 of one circle of the wire rope on the drum, and the reduction ratio K between the winch motor and the reducer;

[0012] According to the speed N1 of the winch reducer, the speed N2 of the winch motor, the flow rate Q3 required by the winch motor, and the condition ΔL1=ΔL2, the flow rate distribution of the two combined actions of the telescopic arm action and the winch retracting and extending action is calculated;

[0013] According to the flow distribution of the two combined actions of the telescopic arm action and the winch retracting and extending action, the telescopic arm is operated, and the telescopic proportional reversing valve and the winch proportional reversing valve are energized synchronously to complete the telescopic arm winch follow-up combined action.

[0014] Further, the controller converts the telescopic cylinder flow of the hydraulic system to the telescopic cylinder under the same time T according to the arm length ΔL1, and the telescopic cylinder flow includes the arm extension flow Q1 and the arm retraction flow Q2, including the following steps:

[0015] Determine whether the winch follow-up function is turned on;

[0016] If it is identified that the hoisting follow-up function is turned on and the first preset current is equal to the telescopic preset current and the second preset current is equal to the hoisting preset current, the hoisting motor pressure P1 and the hoisting motor displacement Vg are obtained;

[0017] The arm extension flow rate Q1 and arm retraction flow rate Q2 are obtained according to the winch motor displacement Vg, the first preset current and the second preset current.

[0018] Furthermore, after the step of determining whether the winch follow-up function is turned on, the step further includes:

[0019] If it is identified that the hoisting follow-up function is turned on and the first preset current is equal to the telescopic preset current and the second preset current is equal to zero, the single telescopic arm is controlled to move.

[0020] Furthermore, the boom flow rate Q1 is calculated by the following formula:

[0021]

[0022] Among them, Q1 is the flow rate of the arm, D1 is the diameter of the cylinder, ΔL1 is the length of the arm, and T is the equal time;

[0023] The retracted arm flow rate Q2 is calculated by the following formula:

[0024]

[0025] Among them, Q2 is the arm retraction flow rate, D1 is the cylinder diameter, D2 is the cylinder rod diameter, ΔL1 is the arm length, and T is the equal time.

[0026] Furthermore, the speed N1 of the winch reducer is calculated by the following formula:

[0027]

[0028] Among them, N1 is the speed of the winch reducer, ΔL2 is the length of the wire rope, L3 is the circumference of one circle of wire rope on the drum, and T is the equivalent time.

[0029] The speed N2 of the winch motor is calculated by the following formula:

[0030]

[0031] Among them, N2 is the speed of the winch motor, N1 is the speed of the winch reducer, and K is the reduction ratio between the winch motor and the reducer;

[0032] The flow rate Q3 required by the winch motor is calculated by the following formula:

[0033]

[0034] Among them, Q3 is the flow rate required by the hoisting motor, N2 is the speed of the hoisting motor, Vg is the displacement of the hoisting motor, and η is the volumetric efficiency of the hoisting motor.

[0035] Furthermore, the flow distribution of the combined action of telescopic arm action and winch retracting and releasing action includes the flow distribution when the arm is extended, and the flow distribution when the arm is extended is calculated by the following formula:

[0036]

[0037] Among them, Q1 is the arm extension flow rate, Q2 is the arm retraction flow rate, D1 is the cylinder diameter of the oil cylinder, K is the reduction ratio between the winch motor and the reducer; L3 is the circumference of one circle of wire rope on the drum, and Vg is the displacement of the winch motor.

[0038] Furthermore, the flow distribution of the combined action of telescopic arm action and winch retracting and releasing action includes the flow distribution when the arm is retracted, and the flow distribution when the arm is retracted is calculated by the following formula:

[0039]

[0040] Among them, Q2 is the retracted arm flow rate, Q3 is the flow rate required by the winch motor, D1 is the cylinder diameter of the cylinder, D2 is the rod diameter of the cylinder, K is the reduction ratio between the winch motor and the reducer; L3 is the circumference of one circle of wire rope on the drum, and Vg is the displacement of the winch motor.

[0041] The beneficial effects achieved by the present invention are:

[0042] The present invention provides a crane winch follow-up hydraulic system and control method. The hydraulic system adopts a winch motor, a telescopic oil cylinder, a winch balance valve, a telescopic balance valve, a winch proportional reversing valve, a telescopic proportional reversing valve, a pressure reducing valve and a brake opening valve. The P port of the telescopic proportional reversing valve is connected with the P port of the winch proportional reversing valve and the P1 port of the pressure reducing valve respectively, the T port of the telescopic proportional reversing valve is connected with the T port of the winch proportional reversing valve, the A port of the telescopic proportional reversing valve is connected with the V1 port of the telescopic balance valve, the B port of the telescopic proportional reversing valve is connected with the V2 port of the telescopic balance valve, the C2 port of the telescopic balance valve is connected with the The rod chamber of the oil cylinder is connected, and the C1 port of the telescopic balancing valve is connected to the rodless chamber of the telescopic oil cylinder; the A port of the winch proportional reversing valve is connected to the A port of the winch balancing valve and the winch motor respectively, and the B port of the winch proportional reversing valve is connected to the K port of the winch balancing valve and the B port of the winch motor respectively, and the B port of the winch balancing valve is connected to the A port of the winch motor; the P2 port of the pressure reducing valve is connected to the P port of the brake opening valve, the K port of the pressure reducing valve is connected to the T port of the brake opening valve, the A port of the brake opening valve is connected to the reducer of the winch motor, and the a port of the brake opening valve is connected to the Br port of the winch balancing valve. The crane winch follow-up hydraulic system and control method provided by the present invention provide a relationship formula for the flow rate required for the hydraulic drive of the telescopic and winch retracting and releasing combined actions under different working conditions. After the winch follow-up function is turned on, the hydraulic system will match the speed according to different lifting working conditions; turning on the winch follow-up function means opening the telescopic proportional reversing valve and the winch proportional reversing valve at the same time, not connecting the oil ports at both ends of the winch motor to be in a floating state, which is not suitable for winch following under lifting working conditions; the application range is wider, and it can be applied to domestic large-tonnage crane electric proportional multi-way valves, and can also be used on small and medium-tonnage pilot proportional valves. The principle is to control the size of the reversing current, and it can be directly operated using a remote control, and can also be used on an operating panel with a direction identification rocker, and is not limited to application in a hydraulic pilot handle; it can realize the linkage control of the telescopic arm action and the winch retracting and releasing action, with a high degree of automation, improved work efficiency, and effective control of the occurrence of lifting accidents, and high safety performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a schematic diagram of the principle of an embodiment of a crane winch follow-up hydraulic system of the present invention;

[0044] Figure 2 The present invention is a flowchart of a method for a crane winch follow-up hydraulic system according to an embodiment of the present invention.

[0045] Description of Figure Numbers:

[0046] 10. Winch motor; 20. Telescopic cylinder; 30. Winch balance valve; 40. Telescopic balance valve; 50. Winch proportional reversing valve; 60. Telescopic proportional reversing valve; 70. Pressure reducing valve; 80. Brake opening valve. DETAILED DESCRIPTION

[0047] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0048] like Figure 1 and Figure 2 As shown, the first embodiment of the present invention proposes a crane winch follow-up hydraulic system, including a winch motor 10, a telescopic cylinder 20, a winch balance valve 30, a telescopic balance valve 40, a winch proportional reversing valve 50, a telescopic proportional reversing valve 60, a pressure reducing valve 70 and a brake opening valve 80, wherein the P port of the telescopic proportional reversing valve 60 is connected to the P port of the winch proportional reversing valve 50 and the P1 port of the pressure reducing valve 70 respectively, the T port of the telescopic proportional reversing valve 60 is connected to the T port of the winch proportional reversing valve 50, the A port of the telescopic proportional reversing valve 60 is connected to the V1 port of the telescopic balance valve 40, the B port of the telescopic proportional reversing valve 60 is connected to the V2 port of the telescopic balance valve 40, and the C2 port of the telescopic balance valve 40 is connected to the telescopic cylinder The rod chamber of the telescopic balancing valve 40 is connected, and the C1 port of the telescopic balancing valve 40 is connected with the rodless chamber of the telescopic oil cylinder 20; the A port of the hoisting proportional reversing valve 50 is connected with the A port of the hoisting balancing valve 30 and the hoisting motor 10 respectively, and the B port of the hoisting proportional reversing valve 50 is connected with the K port of the hoisting balancing valve 30 and the B port of the hoisting motor 10 respectively, and the B port of the hoisting balancing valve 30 is connected with the A port of the hoisting motor 10; the P2 port of the pressure reducing valve 70 is connected with the P port of the brake opening valve 80, the K port of the pressure reducing valve 70 is connected with the T port of the brake opening valve 80, the A port of the brake opening valve 80 is connected with the reducer of the hoisting motor 10, and the a port of the brake opening valve 80 is connected with the Br port of the hoisting balancing valve 30. The crane winch follow-up hydraulic system provided in this embodiment controls the distance between the hook and the ground to remain unchanged, and the winch motor drives the winch mechanism to control the length of the wire rope during the arm extension and retraction process. The telescopic arm action and the winch retraction and extension action share the main oil circuit, so only the telescopic arm needs to be operated, and the telescopic proportional reversing valve 60 is synchronously associated with the winch proportional reversing valve 50 to be energized. Before this, the measured relationship between the proportional reversing valve and the current has been introduced into the controller. The preset current sizes I1 and I2 of the two actions are adjusted according to the relationship between the proportional reversing valve and the current to complete the telescopic arm winch follow-up combined action.

[0049] In the above structure, see Figure 1 , Figure 1The crane winch servo hydraulic system proposed in this embodiment adopts a variable piston motor for the winch motor 10, and the displacement change is related to the hoisting force. A pressure sensor is installed at the G port of the winch motor 10, and the pressure sensor is connected to the controller, which is used to import the measured motor pressure value into the controller, and the controller converts the motor pressure value into the displacement value in real time according to the preset variable relationship between the motor pressure and the displacement. The crane winch servo hydraulic system proposed in this embodiment can realize the linkage control of the telescopic arm action and the winch retracting and releasing action, has a high degree of automation, improves work efficiency, and can effectively control the occurrence of hoisting accidents, and has high safety performance.

[0050] like Figure 2 As shown, this embodiment also relates to a control method for the above-mentioned crane winch follow-up hydraulic system, comprising the following steps:

[0051] Step S100: When the arm is extended or retracted, the arm extension length sensor captures the arm length ΔL1, and the hoisting mechanism synchronously retracts and releases the same length of wire rope ΔL2 to keep the distance between the hook and the ground unchanged.

[0052] In order to meet this condition, the hydraulic system needs to use a controller to determine how much hydraulic oil to provide to the proportional valve to drive the winch motor, and control the speed of the winch motor and winch reducer to control the retraction and release length of the wire rope.

[0053] Step S200, the controller converts the telescopic cylinder flow of the hydraulic system to the telescopic cylinder under the same time T according to the arm length ΔL1, and the telescopic cylinder flow includes the arm extension flow Q1 and the arm retraction flow Q2.

[0054] Step S300, the controller calculates the speed N1 of the hoisting reducer, the speed N2 of the hoisting motor and the flow Q3 required by the hoisting motor according to the wire rope length ΔL2, the circumference L3 of one circle of wire rope on the drum and the reduction ratio K between the hoisting motor and the reducer.

[0055] Step S400, the flow distribution of the combined action of the telescopic arm action and the hoisting retracting and extending action is calculated according to the speed N1 of the hoisting reducer, the speed N2 of the hoisting motor, the flow Q3 required by the hoisting motor, and the condition ΔL1=ΔL2.

[0056] The flow distribution of the combined action of telescopic arm action and winch retraction and extension action includes the flow distribution when the arm is extended. Flow distribution when the arm is retracted In this embodiment, the flow distribution when the arm is extended is calculated based on the speed N1 of the hoisting reducer, the speed N2 of the hoisting motor, the flow rate Q3 required by the hoisting motor, and the condition ΔL1 = ΔL2. Or flow distribution when the arm is retracted

[0057] Step S500, according to the flow distribution of the two combined actions of the telescopic arm action and the winch retracting and extending action, the telescopic arm is operated, the telescopic proportional reversing valve is synchronously associated with the winch proportional reversing valve to be energized, and the telescopic arm winch follow-up combined action is completed.

[0058] Further, see Figure 2 The control method of the crane hoisting follow-up hydraulic system provided in this embodiment, step S200 includes:

[0059] Step S210: determine whether the winch follow-up function is turned on.

[0060] Step S220: If it is identified that the hoisting follow-up function is turned on and the first preset current is equal to the telescopic preset current and the second preset current is equal to the hoisting preset current, the hoisting motor pressure P1 and the hoisting motor displacement Vg are obtained.

[0061] If the controller recognizes that the hoisting follow-up function is turned on and I1=Id, I2=Ic, the hoisting motor pressure P1 and the hoisting motor displacement Vg are obtained.

[0062] Step S230, obtaining the arm extension flow rate Q1 and the arm retracting flow rate Q2 according to the winch motor displacement Vg, the first preset current and the second preset current.

[0063] Preferably, see Figure 2 The control method of the crane hoisting follow-up hydraulic system provided in this embodiment further includes after step S210:

[0064] Step S240: If it is identified that the hoisting follow-up function is turned on and the first preset current is equal to the telescopic preset current and the second preset current is equal to zero, then the single telescopic arm is controlled to move.

[0065] If the controller recognizes that the winch follow-up function is not turned on and I1=Id, I1=0, it controls the single telescopic arm to move.

[0066] Furthermore, in the control method of the crane winch follow-up hydraulic system provided in this embodiment, the boom flow Q1 is calculated by the following formula:

[0067]

[0068] In formula (1), Q1 is the arm extension flow rate, D1 is the cylinder diameter, ΔL1 is the arm length, and T is the equivalent time.

[0069] The retracted arm flow rate Q2 is calculated by the following formula:

[0070]

[0071] In formula (2), Q2 is the arm retraction flow rate, D1 is the cylinder diameter, D2 is the cylinder rod diameter, ΔL1 is the arm length, and T is the equivalent time.

[0072] Furthermore, the speed N1 of the winch reducer is calculated by the following formula:

[0073]

[0074] In formula (3), N1 is the speed of the winch reducer, ΔL2 is the length of the wire rope, L3 is the circumference of one circle of the wire rope on the drum, and T is the equivalent time.

[0075] The speed N2 of the winch motor is calculated by the following formula:

[0076]

[0077] In formula (4), N2 is the speed of the hoisting motor, N1 is the speed of the hoisting reducer, and K is the reduction ratio between the hoisting motor and the reducer;

[0078] The flow rate Q3 required by the winch motor is calculated by the following formula:

[0079]

[0080] In formula (5), Q3 is the flow rate required by the hoisting motor, N2 is the speed of the hoisting motor, Vg is the displacement of the hoisting motor, and η is the volumetric efficiency of the hoisting motor.

[0081] According to the above formula, we can deduce:

[0082]

[0083] In formula (6), ΔL2 is the length of the wire rope, η is the volumetric efficiency of the hoisting motor, Q3 is the flow rate required by the hoisting motor, K is the reduction ratio between the hoisting motor and the reducer; L3 is the circumference of one circle of wire rope on the drum, and Vg is the displacement of the hoisting motor.

[0084] Furthermore, in order to save energy, the flow of the hydraulic system of the crane often only meets the working conditions of a single working joint or has a slight surplus. Excessive output flow flows out of the overflow valve, which is wasteful and generates serious heat. In this case, the winch follow-up involves the distribution of flow under combined actions. The flow distribution of the two combined actions of telescopic arm action and winch retraction and extension action includes the flow distribution when the arm is extended. According to the above formula and the condition ΔL1=ΔL2, the flow distribution when the arm is extended is calculated by the following formula:

[0085]

[0086] In formula (7), Q1 is the boom flow rate, Q3 is the flow rate required by the winch motor, D1 is the cylinder diameter of the oil cylinder, K is the reduction ratio between the winch motor and the reducer; L3 is the circumference of one circle of wire rope on the drum, and Vg is the displacement of the winch motor.

[0087] Furthermore, the flow distribution of the combined action of telescopic arm action and winch retracting and releasing action includes the flow distribution when the arm is retracted, and the flow distribution when the arm is retracted is calculated by the following formula:

[0088]

[0089] In formula (8), Q2 is the retracted arm flow rate, Q3 is the flow rate required by the winch motor, D1 is the cylinder diameter of the oil cylinder, D2 is the rod diameter of the oil cylinder, K is the reduction ratio between the winch motor and the reducer; L3 is the circumference of one circle of wire rope on the drum, and Vg is the displacement of the winch motor.

[0090] It can be seen that the flow distribution of the two combined actions only changes with the displacement change of the winch motor. The winch motor used in the crane is a variable piston motor. The displacement change is related to the lifting force. The G port of the winch motor is equipped with a pressure sensor that can import the measured motor pressure value into the controller. Moreover, the telescopic arm action and the winch retraction and extension action share the main oil circuit. Therefore, it is only necessary to operate the telescopic arm, and the telescopic proportional reversing valve is synchronously associated with the winch proportional reversing valve to be energized. Prior to this, the relationship between the measured proportional reversing valve and the current has been imported into the controller. The preset current sizes I1 and I2 of the two actions are adjusted according to the flow relationship of the above formula to complete the telescopic arm winch follow-up combined action. See the logical flow. Figure 2 .

[0091] The present embodiment provides a crane winch follow-up hydraulic system and control method. Compared with the prior art, the hydraulic system adopts a winch motor, a telescopic oil cylinder, a winch balance valve, a telescopic balance valve, a winch proportional reversing valve, a telescopic proportional reversing valve, a pressure reducing valve and a brake opening valve. The P port of the telescopic proportional reversing valve is respectively connected with the P port of the winch proportional reversing valve and the P1 port of the pressure reducing valve, the T port of the telescopic proportional reversing valve is connected with the T port of the winch proportional reversing valve, the A port of the telescopic proportional reversing valve is connected with the V1 port of the telescopic balance valve, the B port of the telescopic proportional reversing valve is connected with the V2 port of the telescopic balance valve, and the C2 of the telescopic balance valve is connected with the V3 port of the telescopic balance valve. The C1 port of the telescopic balancing valve is connected with the rod chamber of the telescopic cylinder, and the A port of the winch proportional reversing valve is connected with the A port of the winch balancing valve and the winch motor respectively, and the B port of the winch proportional reversing valve is connected with the K port of the winch balancing valve and the B port of the winch motor respectively, and the B port of the winch balancing valve is connected with the A port of the winch motor; the P2 port of the pressure reducing valve is connected with the P port of the brake opening valve, the K port of the pressure reducing valve is connected with the T port of the brake opening valve, the A port of the brake opening valve is connected with the reducer of the winch motor, and the a port of the brake opening valve is connected with the Br port of the winch balancing valve. The crane winch follow-up hydraulic system and control method provided in this embodiment give the relationship between the flow rate required for the hydraulic drive of the telescopic and winch retracting and releasing combined actions under different working conditions. After the winch follow-up function is turned on, the hydraulic system will match the speed according to different lifting conditions; turning on the winch follow-up function means opening the telescopic proportional reversing valve and the winch proportional reversing valve at the same time, not connecting the oil ports at both ends of the winch motor to be in a floating state, which is not suitable for winch following under lifting conditions; the application range is wider, and it can be applied to domestic large-tonnage crane electric proportional multi-way valves, and can also be used on small and medium-tonnage pilot proportional valves. The principle is to control the size of the reversing current, and can be directly operated using a remote control, or used on an operating panel with a direction recognition rocker, and is not limited to application in hydraulic pilot handles.

[0092] Although preferred embodiments of the present invention have been described, additional changes and modifications may be made to these embodiments by those skilled in the art once the basic inventive concepts are known. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention. Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A crane winch follow-up hydraulic system, characterized in that: The invention comprises a hoisting motor (10), a telescopic oil cylinder (20), a hoisting balance valve (30), a telescopic balance valve (40), a hoisting proportional reversing valve (50), a telescopic proportional reversing valve (60), a pressure reducing valve (70) and a brake opening valve (80), wherein the P port of the telescopic proportional reversing valve (60) is respectively connected to the P port of the hoisting proportional reversing valve (50) and the P1 port of the pressure reducing valve (70), the T port of the telescopic proportional reversing valve (60) is connected to the T port of the hoisting proportional reversing valve (50), the A port of the telescopic proportional reversing valve (60) is connected to the V1 port of the telescopic balance valve (40), the B port of the telescopic proportional reversing valve (60) is connected to the V2 port of the telescopic balance valve (40), the C2 port of the telescopic balance valve (40) is connected to the rod chamber of the telescopic oil cylinder (20), and the telescopic balance valve (40) is connected to the rod chamber of the telescopic oil cylinder (20). ) is connected to the rodless chamber of the telescopic oil cylinder (20); the A port of the hoisting proportional reversing valve (50) is connected to the A port of the hoisting balancing valve (30) and the hoisting motor (10), respectively; the B port of the hoisting proportional reversing valve (50) is connected to the K port of the hoisting balancing valve (30) and the B port of the hoisting motor (10), respectively; the B port of the hoisting balancing valve (30) is connected to the The A port of the pressure reducing valve (70) is connected to the P port of the brake opening valve (80); the K port of the pressure reducing valve (70) is connected to the T port of the brake opening valve (80); the A port of the brake opening valve (80) is connected to the reducer of the hoisting motor (10); and the a port of the brake opening valve (80) is connected to the Br port of the hoisting balance valve (30).

2. The crane winch follow-up hydraulic system according to claim 1, characterized in that: The hoisting motor (10) is a variable displacement piston motor.

3. The crane winch follow-up hydraulic system according to claim 1, characterized in that: A pressure sensor is installed at the G port of the hoisting motor (10), and the pressure sensor is connected to the controller and is used to import the measured motor pressure value into the controller.

4. A control method for a crane winch follow-up hydraulic system according to any one of claims 1 to 3, characterized in that: The control method of the crane winch follow-up hydraulic system comprises the following steps: When the arm is extended and retracted, the arm extension length sensor captures the arm length ΔL1, and the hoisting mechanism synchronously retracts and releases the same length of wire rope ΔL2 to keep the distance between the hook and the ground unchanged; The controller converts the telescopic cylinder flow of the hydraulic system to the telescopic cylinder under the same time T according to the arm length ΔL1, and the telescopic cylinder flow includes the arm extension flow Q1 and the arm retraction flow Q2; The controller calculates the speed N1 of the winch reducer, the speed N2 of the winch motor, and the flow rate Q3 required by the winch motor according to the length ΔL2 of the wire rope, the circumference L3 of one circle of the wire rope on the drum, and the reduction ratio K between the winch motor and the reducer; According to the speed N1 of the winch reducer, the speed N2 of the winch motor, the flow rate Q3 required by the winch motor, and the condition ΔL1=ΔL2, the flow rate distribution of the combined action of the telescopic arm action and the winch retracting and extending action is calculated; According to the flow distribution of the two combined actions of the telescopic arm action and the winch retracting and extending action, the telescopic arm is operated, and the telescopic proportional reversing valve is synchronously associated with the winch proportional reversing valve to be energized to complete the telescopic arm winch follow-up combined action.

5. The crane winch follow-up hydraulic system according to claim 4, characterized in that: The controller converts the telescopic cylinder flow of the hydraulic system to the telescopic cylinder under the same time T according to the arm length ΔL1, and the telescopic cylinder flow includes the arm extension flow Q1 and the arm retraction flow Q2, including: Determine whether the winch follow-up function is turned on; If it is identified that the hoisting follow-up function is turned on and the first preset current is equal to the telescopic preset current and the second preset current is equal to the hoisting preset current, the hoisting motor pressure P1 and the hoisting motor displacement Vg are obtained; The arm extension flow rate Q1 and the arm retraction flow rate Q2 are obtained according to the hoisting motor displacement Vg, the first preset current and the second preset current.

6. The crane winch follow-up hydraulic system according to claim 5, characterized in that: The step of determining whether the winch follow-up function is turned on also includes: If it is identified that the hoisting follow-up function is turned on and the first preset current is equal to the telescopic preset current and the second preset current is equal to zero, the single telescopic arm is controlled to move.

7. The crane winch follow-up hydraulic system according to claim 4, characterized in that: The boom flow rate Q1 is calculated by the following formula: Among them, Q1 is the flow rate of the arm, D1 is the diameter of the cylinder, ΔL1 is the length of the arm, and T is the equal time; The retracted arm flow rate Q2 is calculated by the following formula: Among them, Q2 is the arm retraction flow rate, D1 is the cylinder diameter, D2 is the cylinder rod diameter, ΔL1 is the arm length, and T is the equal time.

8. The crane winch follow-up hydraulic system according to claim 4, characterized in that: The speed N1 of the winch reducer is calculated by the following formula: Among them, N1 is the speed of the winch reducer, ΔL2 is the length of the wire rope, L3 is the circumference of one circle of wire rope on the drum, and T is the equivalent time. The speed N2 of the winch motor is calculated by the following formula: Among them, N2 is the speed of the winch motor, N1 is the speed of the winch reducer, and K is the reduction ratio between the winch motor and the reducer; The flow rate Q3 required by the winch motor is calculated by the following formula: Among them, Q3 is the flow rate required by the hoisting motor, N2 is the speed of the hoisting motor, Vg is the displacement of the hoisting motor, and η is the volumetric efficiency of the hoisting motor.

9. The crane winch follow-up hydraulic system according to claim 8, characterized in that: The flow distribution of the combined action of telescopic arm action and winch retracting and releasing action includes the flow distribution when the arm is extended. The flow distribution when the arm is extended is calculated by the following formula: Among them, Q1 is the boom flow rate, Q3 is the flow rate required by the winch motor, D1 is the cylinder diameter of the oil cylinder, K is the reduction ratio between the winch motor and the reducer; L3 is the circumference of one circle of wire rope on the drum, and Vg is the displacement of the winch motor.

10. The crane winch follow-up hydraulic system according to claim 8, characterized in that: The flow distribution of the combined action of telescopic arm action and winch retracting and releasing action includes the flow distribution when the arm is retracted. The flow distribution when the arm is retracted is calculated by the following formula: Among them, Q2 is the retracted arm flow rate, Q3 is the flow rate required by the winch motor, D1 is the cylinder diameter of the cylinder, D2 is the rod diameter of the cylinder, K is the reduction ratio between the winch motor and the reducer; L3 is the circumference of one circle of wire rope on the drum, and Vg is the displacement of the winch motor.

Images