Pipe hoist clamp control system and method

Abstract

The invention discloses a pipe hoist clamp control system and method. The pipe hoist clamp control system comprises an oil tank, a main pump, a main valve and a double-position switching valve set which are sequentially connected through an oil way. The two upper nipper oil cylinders and the two lower nipper oil cylinders are connected to the two-position switching valve set through the two-way hydraulic control one-way valves. A plurality of pressure sensors are used for detecting the oil port pressure of the two upper nipper oil cylinders and the oil port pressure of the two lower nipper oil cylinders respectively; the multiple pressure sensors are electrically connected with the input end of the controller, and the output end of the controller is electrically connected with the double-position switching valve set and the main valve. The controller controls the double-position switching valve set to act and switches the two upper grasping forceps device oil cylinders or the two lower grasping forceps device oil cylinders to act. The controller is used for controlling piston rods of the two upper nipper oil cylinders and the two lower nipper oil cylinders to extend or retract through the main valve; the clamping force of the clamp can be kept unchanged for a long time; the clamping force is detected, the situation that the surface coating of the steel pipe is damaged due to the too large clamping force is avoided, an alarm is given when the clamping force is lower than a set value, and the steel pipe is prevented from falling off from the clamp.

Description

Technical Field

[0001] This invention belongs to the field of clamp technology, specifically relating to a clamp control system and method for pipe-laying machines. Background Technology

[0002] Pipe-laying machines are specialized equipment used in oil and gas pipeline construction. They are mainly used for laying, aligning, and lowering large-diameter pipes into trenches, and are characterized by their large lifting capacity and ability to travel on flat surfaces. During oil and gas pipeline construction, specialized pipe transport vehicles or pipe-laying machines equipped with clamps are needed to transport steel pipes to designated transport locations. Currently, pipe-laying machines equipped with clamps cannot maintain appropriate clamping force for extended periods, easily causing damage to the pipe's surface coating or causing the pipe to detach. Summary of the Invention

[0003] This invention provides a pipe-laying machine clamp control system and method, which can maintain the clamping force of the clamp for a long time; detect the clamping force to avoid excessive clamping force that could damage the coating on the surface of the steel pipe; and issue an alarm when the clamping force is lower than the set value to prevent the steel pipe from falling out of the clamp.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0005] The first aspect of the present invention provides a pipe-laying machine clamp control system, comprising an oil tank, a main pump, a main valve and a two-position switching valve group connected in sequence via an oil circuit;

[0006] The two upper gripper cylinders and the two lower gripper cylinders are connected to the two-position switching valve group through a two-way hydraulic check valve; the rod chambers of the two lower gripper cylinders are interconnected, and the rodless chambers of the two lower gripper cylinders are interconnected.

[0007] Several pressure sensors detect the oil port pressure of the two upper gripper cylinders and the two lower gripper cylinders respectively; the several pressure sensors are electrically connected to the input terminal of the controller, and the output terminal of the controller is electrically connected to the two-position switching valve group and the main valve;

[0008] The controller controls the operation of the two-position switching valve group to switch the operation of the two upper gripper cylinders or the two lower gripper cylinders; the controller controls the piston rods of the two upper gripper cylinders and the two lower gripper cylinders to extend or retract through the main valve.

[0009] Furthermore, the plurality of pressure sensors include pressure sensor F1, pressure sensor F2, pressure sensor F3, pressure sensor F4, pressure sensor F5 and pressure sensor F6;

[0010] The two lower gripper cylinders are set as lower gripper cylinder G1 and lower gripper cylinder G2; the two upper gripper cylinders are set as upper gripper cylinder G3 and upper gripper cylinder G4.

[0011] The pressure sensor F1 is used to detect the rodless chamber of the lower gripper cylinder G1 and the lower gripper cylinder G2; the pressure sensor F2 is used to detect the rod chamber of the lower gripper cylinder G1 and the lower gripper cylinder G2.

[0012] The pressure sensors F3 and F4 are used to detect the rodless chamber and rod chamber of the upper gripper cylinder G3, respectively; the pressure sensors F5 and F6 are used to detect the rodless chamber and rod chamber of the upper gripper cylinder G4, respectively.

[0013] Furthermore, the dual-position switching valve assembly includes a first hydraulic control valve and a second hydraulic control valve;

[0014] The main valve's oil circuit connects to the first hydraulic control valve and the second hydraulic control valve; the main valve is configured as a three-position four-way solenoid valve; when the main valve is in the reverse position, the oil inlet path is from the main valve to the first hydraulic control valve, and the oil return path is from the main valve to the second hydraulic control valve; when the main valve is in the neutral position, the main valve interrupts the oil circuits of the first and second hydraulic control valves; when the main valve is in the forward position, the oil inlet path is from the main valve to the second hydraulic control valve, and the oil return path is from the main valve to the first hydraulic control valve.

[0015] The first hydraulic control valve and the second hydraulic control valve are configured as two-position three-way hydraulic control valves; the first hydraulic control valve and the second hydraulic control valve operate synchronously; when the first hydraulic control valve and the second hydraulic control valve are in the reverse position, they connect the oil inlet and return lines of the two lower gripper cylinders; when the first hydraulic control valve and the second hydraulic control valve are in the forward position, they connect the oil inlet and return lines of the two upper gripper cylinders.

[0016] Furthermore, the dual-position switching valve assembly also includes an upper and lower clamp switching solenoid valve, an overflow pressure reducing valve, and a shuttle valve; the first oil inlet of the shuttle valve is connected to the oil circuit between the main valve and the first hydraulic control valve; the second oil inlet of the shuttle valve is connected to the oil circuit between the main valve and the second hydraulic control valve; the oil outlet of the shuttle valve is connected to the oil inlet of the overflow pressure reducing valve through an oil circuit.

[0017] The return port of the overflow pressure reducing valve is connected to the oil tank, and the outlet port of the overflow pressure reducing valve is connected to the control terminals of the first hydraulic control valve and the second hydraulic control valve through an upper and lower clamp switching solenoid valve.

[0018] The upper and lower clamp switching solenoid valve is a two-position three-way solenoid valve. When the upper and lower clamp switching solenoid valve is in the positive position, the control terminals of the first hydraulic control valve and the second hydraulic control valve are connected to the oil tank, and the first hydraulic control valve and the second hydraulic control valve are in the positive position.

[0019] When the upper and lower clamp switching solenoid valve is in the reverse position, the control terminals of the first hydraulic control valve and the second hydraulic control valve are connected to the oil outlet of the overflow pressure reducing valve, and the first hydraulic control valve and the second hydraulic control valve are in the reverse position.

[0020] Furthermore, the number of the bidirectional hydraulic control check valves is set to four groups, namely bidirectional hydraulic control check valve V3, bidirectional hydraulic control check valve V4, bidirectional hydraulic control check valve V5 and bidirectional hydraulic control check valve V6.

[0021] The rodless chamber port and the rod chamber port of the lower gripper cylinder G1 are connected to a two-way hydraulic control check valve V3, and the rodless chamber port and the rod chamber port of the lower gripper cylinder G2 are connected to a two-way hydraulic control check valve V4.

[0022] Two-way hydraulic control check valves V3 and V4 are connected to the first hydraulic control valve and the second hydraulic control valve via oil circuits, so that the rodless chamber oil port of the lower gripper cylinder G1 and the rodless chamber oil port of the lower gripper cylinder G2 are connected to the same port of the first hydraulic control valve, and the rod chamber oil port of the lower gripper cylinder G1 and the rod chamber oil port of the lower gripper cylinder G2 are connected to the same port of the second hydraulic control valve.

[0023] The rodless chamber port and the rod chamber port of the upper gripper cylinder G3 are connected to a two-way hydraulic control check valve V5, and the rodless chamber port and the rod chamber port of the upper gripper cylinder G4 are connected to a two-way hydraulic control check valve V6.

[0024] Two-way hydraulic control check valves V5 and V6 are connected to the first hydraulic control valve and the second hydraulic control valve via oil circuits, so that the rodless chamber oil port of the upper gripper cylinder G3 and the rodless chamber oil port of the upper gripper cylinder G4 are connected to the same port of the first hydraulic control valve, and the rod chamber oil port of the upper gripper cylinder G3 and the rod chamber oil port of the upper gripper cylinder G4 are connected to the same port of the second hydraulic control valve.

[0025] Furthermore, the controller is electrically connected to the display. The controller's pressure sensor detects the oil port pressure of the two upper gripper cylinders and the two lower gripper cylinders respectively, and calculates the clamping status of the two upper gripper cylinders and the two lower gripper cylinders. The clamping status of the two upper gripper cylinders and the two lower gripper cylinders is displayed on the display.

[0026] A second aspect of the present invention provides a control method for a pipe-laying machine clamp control system, comprising:

[0027] When the automatic clamping operation command and the automatic upper clamping operation command are received, the two-position switching valve group is controlled to operate and connect the two upper clamping cylinders; the main valve is controlled to operate so that the rodless chamber of the two upper clamping cylinders is connected to the oil inlet and the rod chamber is connected to the oil return. The main pump drives the hydraulic oil to enter the two upper clamping cylinders through the main valve and the two-position switching valve group, and the two upper clamping cylinders extend.

[0028] During the extension process of the two upper gripper cylinders, the oil port pressure of the two upper gripper cylinders is detected by pressure sensors, and the clamping force T2 and clamping force T3 output by the two upper gripper cylinders are calculated. When the clamping force T2 and clamping force T3 reach the set clamping threshold T5, the main valve is controlled to act, interrupting the oil inlet and return lines of the two upper gripper cylinders, and the two upper gripper cylinders stop extending.

[0029] When the automatic clamping operation command and the automatic lower clamping operation command are received, the two-position switching valve group is controlled to operate and connect the two lower clamping cylinders; the main valve is controlled to operate so that the rodless chamber of the two lower clamping cylinders is connected to the oil inlet and the rod chamber is connected to the oil return. The main pump drives the hydraulic oil to enter the two lower clamping cylinders through the main valve and the two-position switching valve group, and the two lower clamping cylinders extend.

[0030] The pressure sensors detect the oil port pressure of the two lower gripper cylinders respectively, and calculate the clamping force T1 output by the two lower gripper cylinders. When the clamping force T1 reaches the set clamping threshold T4, the main valve is controlled to act, interrupting the oil inlet and return lines of the two lower gripper cylinders, and the two lower gripper cylinders stop extending.

[0031] Furthermore, when the two upper gripper cylinders are in the automatic walking mode of the upper gripper, the oil port pressure of the two upper gripper cylinders is detected by the pressure sensor, and the clamping force T2 and clamping force T3 output by the two upper gripper cylinders are calculated.

[0032] When the clamping force T2 or clamping force T3 is less than the set clamping threshold T5 and the duration is less than the time threshold G, the main valve is controlled to activate so that the rodless chamber of the two upper gripper cylinders is connected to the oil inlet and the rod chamber is connected to the oil return. The main pump drives the hydraulic oil to enter the two upper gripper cylinders through the main valve and the two-position switching valve group, and the two upper gripper cylinders extend.

[0033] When the clamping force T2 or clamping force T3 is less than the set clamping threshold T5 and the duration is greater than the time threshold G, an alarm for abnormal clamping of the hydraulic cylinders of the two upper grippers will be output.

[0034] Furthermore, when the two lower gripper cylinders are in the automatic lower gripper walking mode, the oil port pressure of the two lower gripper cylinders is detected by the pressure sensor, and the clamping force T1 output by the two lower gripper cylinders is calculated.

[0035] When the clamping force T1 is less than the set clamping threshold T4 and the duration is less than the time threshold G, the main valve is controlled to connect the rodless chamber of the two lower gripper cylinders to the oil inlet and the rod chamber to the oil return. The main pump drives the hydraulic oil to enter the two lower gripper cylinders through the main valve and the two-position switching valve group, and the two lower gripper cylinders extend.

[0036] When the clamping force T1 is less than the set clamping threshold T5 and the duration is greater than the time threshold G, two clamping cylinder clamping abnormality alarms will be output.

[0037] Furthermore, the two upper gripper cylinders are designated as upper gripper cylinder G3 and upper gripper cylinder G4; the oil port pressure of the two upper gripper cylinders is detected by pressure sensors, and the clamping forces T2 and T3 output by the two upper gripper cylinders are calculated, specifically including:

[0038] T2 = A3 * P3 - A4 * P4

[0039] T3 = A3 * P5 - A4 * P6

[0040] The formula is as follows: T2 is the clamping force of the upper gripper cylinder G3; T3 is the clamping force of the upper gripper cylinder G4; A3 is the area of ​​the rodless chamber of the upper gripper cylinders G3 and G4; A4 is the area of ​​the rod chamber of the upper gripper cylinders G3 and G4; P3 is the pressure of the rodless chamber of the upper gripper cylinder G3; P4 is the pressure of the rod chamber of the upper gripper cylinder G3; P5 is the pressure of the rodless chamber of the upper gripper cylinder G4; and P6 is the pressure of the rod chamber of the upper gripper cylinder G4.

[0041] Furthermore, the two lower gripper cylinders are designated as lower gripper cylinder G1 and lower gripper cylinder G2; the oil port pressure of the two lower gripper cylinders is detected by pressure sensors, and the clamping force T1 output by the two lower gripper cylinders is calculated, specifically including:

[0042] T1 = A1 * P1 - A2 * P2

[0043] In the formula, A1 is the rodless cavity area of ​​the lower gripper cylinders G1 and G2; P1 is the rodless cavity pressure of the lower gripper cylinders G1 and G2; A2 is the rod cavity area of ​​the lower gripper cylinders G1 and G2; and P2 is the rod cavity pressure of the lower gripper cylinders G1 and G2.

[0044] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0045] The present invention uses several pressure sensors to detect the oil port pressure of the two upper gripper cylinders and the two lower gripper cylinders respectively; and controls the operation of the control two-position switching valve group and the main valve according to the oil port pressure to complete the automatic operation of the upper clamp, avoid excessive clamping force to damage the coating on the surface of the steel pipe, and alarm when the clamping force is lower than the set value to prevent the steel pipe from falling out of the clamp.

[0046] In this invention, the two upper gripper cylinders and the two lower gripper cylinders are connected to the two-position switching valve group through a two-way hydraulic control check valve; this can maintain the clamping force of the two upper gripper cylinders and the two lower gripper cylinders unchanged for a long time. Attached Figure Description

[0047] Figure 1 This is the oil circuit diagram of the pipe-laying machine clamp control system provided in Embodiment 1 of the present invention;

[0048] Figure 2 This is the control electrical schematic diagram of the pipe-laying machine clamp control system provided in Embodiment 1 of the present invention;

[0049] Figure 3 This is a flowchart of the static state clamping control of the pipe-laying machine clamping control system provided in Embodiment 2 of the present invention;

[0050] Figure 4 The flowchart shows the walking state clamping control of the pipe-laying machine clamping control system provided in Embodiment 2 of the present invention. Detailed Implementation

[0051] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0052] Example 1

[0053] like Figures 1 to 2 As shown, this embodiment provides a pipe-laying machine clamp control system, including an oil tank, a main pump, a main valve V1, and a two-position switching valve group V2 connected in sequence via oil circuits; two upper clamping cylinders and two lower clamping cylinders are connected to the two-position switching valve group V2 via bidirectional hydraulic check valves;

[0054] The dual-position switching valve group V2 includes a first hydraulic control valve, a second hydraulic control valve, an upper and lower clamp switching solenoid valve, an overflow pressure reducing valve, and a shuttle valve.

[0055] The main valve V1 is connected to the first hydraulic control valve and the second hydraulic control valve in the oil circuit; the main valve V1 is set as a three-position four-way solenoid valve; solenoid coils Y1 and Y2 drive the main valve V1 to operate; solenoid coils Y1 and Y2 are electrically connected to the controller;

[0056] When the electromagnetic coil Y1 is energized and the electromagnetic coil Y2 is de-energized, and the main valve V1 is in the reverse position, the oil inlet path is from the main valve V1 to the first hydraulic control valve, and the oil return path is from the main valve V1 to the second hydraulic control valve.

[0057] When the electromagnetic coil Y1 is de-energized and the electromagnetic coil Y2 is de-energized, the main valve V1 is in the neutral position, and the main valve V1 interrupts the oil circuit of the first hydraulic control valve and the second hydraulic control valve.

[0058] When the electromagnetic coil Y1 is de-energized and the electromagnetic coil Y2 is energized, and the main valve V1 is in the positive position, the oil inlet path is from the main valve V1 to the second hydraulic control valve, and the oil return path is from the main valve V1 to the first hydraulic control valve.

[0059] The first hydraulic control valve and the second hydraulic control valve are configured as two-position three-way hydraulic control valves; the first hydraulic control valve and the second hydraulic control valve operate synchronously; when the first hydraulic control valve and the second hydraulic control valve are in the reverse position, they connect the oil inlet and return lines of the two lower gripper cylinders; when the first hydraulic control valve and the second hydraulic control valve are in the forward position, they connect the oil inlet and return lines of the two upper gripper cylinders.

[0060] The first oil inlet of the shuttle valve is connected to the oil passage between the main valve V1 and the first hydraulic control valve; the second oil inlet of the shuttle valve is connected to the oil passage between the main valve V1 and the second hydraulic control valve; the oil outlet of the shuttle valve is connected to the oil inlet of the overflow pressure reducing valve through an oil passage.

[0061] The return port of the overflow pressure reducing valve is connected to the oil tank, and the outlet port of the overflow pressure reducing valve is connected to the control terminals of the first hydraulic control valve and the second hydraulic control valve through an upper and lower clamp switching solenoid valve.

[0062] The upper and lower clamp switching solenoid valve is a two-position three-way solenoid valve. The solenoid coil Y3 drives the two-position three-way solenoid valve to operate. The solenoid coil Y3 is electrically connected to the controller. When the solenoid coil Y3 is de-energized and the upper and lower clamp switching solenoid valve is in the positive position, the control terminals of the first hydraulic control valve and the second hydraulic control valve are connected to the oil tank, and the first hydraulic control valve and the second hydraulic control valve are in the positive position, thus opening the oil inlet and return lines of the two upper clamp cylinders.

[0063] When the electromagnetic coil Y3 is energized and the upper and lower clamp switching solenoid valve is in the reverse position, the control terminals of the first hydraulic control valve and the second hydraulic control valve are connected to the oil outlet of the overflow pressure reducing valve. The first hydraulic control valve and the second hydraulic control valve are in the reverse position, so that the oil inlet and return lines of the two lower clamp cylinders are connected.

[0064] The controller controls the switching valve group to switch the operation of the two upper gripper cylinders or the two lower gripper cylinders; the controller controls the piston rods of the two upper gripper cylinders and the two lower gripper cylinders to extend or retract through the main valve V1.

[0065] The rod-side chambers of the two lower gripper cylinders are interconnected, and the rodless chambers of the two lower gripper cylinders are interconnected; the plurality of pressure sensors include pressure sensor F1, pressure sensor F2, pressure sensor F3, pressure sensor F4, pressure sensor F5 and pressure sensor F6.

[0066] The two lower gripper cylinders are set as lower gripper cylinder G1 and lower gripper cylinder G2; the two upper gripper cylinders are set as upper gripper cylinder G3 and upper gripper cylinder G4.

[0067] The pressure sensor F1 is used to detect the rodless chamber of the lower gripper cylinder G1 and the lower gripper cylinder G2; the pressure sensor F2 is used to detect the rod chamber of the lower gripper cylinder G1 and the lower gripper cylinder G2.

[0068] The pressure sensors F3 and F4 are used to detect the rodless chamber and rod chamber of the upper gripper cylinder G3, respectively; the pressure sensors F5 and F6 are used to detect the rodless chamber and rod chamber of the upper gripper cylinder G4, respectively.

[0069] The number of bidirectional hydraulic control check valves is set to four groups, namely bidirectional hydraulic control check valve V3, bidirectional hydraulic control check valve V4, bidirectional hydraulic control check valve V5 and bidirectional hydraulic control check valve V6.

[0070] The rodless chamber port and the rod chamber port of the lower gripper cylinder G1 are connected to a two-way hydraulic control check valve V3, and the rodless chamber port and the rod chamber port of the lower gripper cylinder G2 are connected to a two-way hydraulic control check valve V4.

[0071] Two-way hydraulic control check valves V3 and V4 are connected to the first hydraulic control valve and the second hydraulic control valve via oil circuits, so that the rodless chamber oil port of the lower gripper cylinder G1 and the rodless chamber oil port of the lower gripper cylinder G2 are connected to the same port of the first hydraulic control valve, and the rod chamber oil port of the lower gripper cylinder G1 and the rod chamber oil port of the lower gripper cylinder G2 are connected to the same port of the second hydraulic control valve.

[0072] The rodless chamber port and the rod chamber port of the upper gripper cylinder G3 are connected to a two-way hydraulic control check valve V5, and the rodless chamber port and the rod chamber port of the upper gripper cylinder G4 are connected to a two-way hydraulic control check valve V6.

[0073] Two-way hydraulic control check valves V5 and V6 are connected to the first hydraulic control valve and the second hydraulic control valve via oil circuits, so that the rodless chamber oil port of the upper gripper cylinder G3 and the rodless chamber oil port of the upper gripper cylinder G4 are connected to the same port of the first hydraulic control valve, and the rod chamber oil port of the upper gripper cylinder G3 and the rod chamber oil port of the upper gripper cylinder G4 are connected to the same port of the second hydraulic control valve.

[0074] Pressure sensors F1, F2, F3, F4, F5, and F6 are electrically connected to the input terminal of the controller, and the output terminal of the controller is electrically connected to the display.

[0075] The controller is electrically connected. The controller pressure sensor detects the oil port pressure of the two upper gripper cylinders and the two lower gripper cylinders respectively, calculates the clamping status of the two upper gripper cylinders and the two lower gripper cylinders, and displays the clamping status of the two upper gripper cylinders and the two lower gripper cylinders through the display.

[0076] Example 2

[0077] like Figures 3 to 4 As shown, this embodiment provides a control method for a pipe-laying machine clamp control system. The control method is applied to the pipe-laying machine clamp control system described in Embodiment 1, and includes:

[0078] The controller is also electrically connected to a manual / automatic clamp control switch S1, an upper / lower clamp switching switch S2, and a travel pilot pressure sensor F7. The manual / automatic clamp control switch S1 inputs automatic clamp operation commands and manual clamp operation commands to the controller. The upper / lower clamp switching switch S2 inputs upper clamp automatic operation commands and lower clamp automatic operation commands to the controller. The controller uses the travel pilot pressure sensor F7 to determine whether the vehicle is in a traveling state.

[0079] When the automatic clamping operation command and the automatic upper clamping operation command are received, the two-position switching valve group is controlled to operate and connect the two upper clamping cylinders; the main valve is controlled to operate so that the rodless chamber of the two upper clamping cylinders is connected to the oil inlet and the rod chamber is connected to the oil return. The main pump drives the hydraulic oil to enter the two upper clamping cylinders through the main valve and the two-position switching valve group, and the two upper clamping cylinders extend.

[0080] During the extension process of the two upper gripper cylinders, the oil port pressure of the two upper gripper cylinders is detected by pressure sensors, and the clamping force T2 and clamping force T3 output by the two upper gripper cylinders are calculated. When the clamping force T2 and clamping force T3 reach the set clamping threshold T5, the main valve is controlled to act, interrupting the oil inlet and return lines of the two upper gripper cylinders, and the two upper gripper cylinders stop extending.

[0081] When the automatic clamping operation command and the automatic lower clamping operation command are received, the two-position switching valve group is controlled to operate and connect the two lower clamping cylinders; the main valve is controlled to operate so that the rodless chamber of the two lower clamping cylinders is connected to the oil inlet and the rod chamber is connected to the oil return. The main pump drives the hydraulic oil to enter the two lower clamping cylinders through the main valve and the two-position switching valve group, and the two lower clamping cylinders extend.

[0082] The pressure sensors detect the oil port pressure of the two lower gripper cylinders respectively, and calculate the clamping force T1 output by the two lower gripper cylinders. When the clamping force T1 reaches the set clamping threshold T4, the main valve is controlled to act, interrupting the oil inlet and return lines of the two lower gripper cylinders, and the two lower gripper cylinders stop extending.

[0083] When the two upper gripper cylinders are in the automatic clamping movement mode, the oil port pressure of the two upper gripper cylinders is detected by pressure sensors, and the clamping forces T2 and T3 output by the two upper gripper cylinders are calculated; the formula is as follows:

[0084] T2 = A3 * P3 - A4 * P4

[0085] T3 = A3 * P5 - A4 * P6

[0086] The formula is as follows: T2 is the clamping force of the upper gripper cylinder G3; T3 is the clamping force of the upper gripper cylinder G4; A3 is the area of ​​the rodless chamber of the upper gripper cylinders G3 and G4; A4 is the area of ​​the rod chamber of the upper gripper cylinders G3 and G4; P3 is the pressure of the rodless chamber of the upper gripper cylinder G3; P4 is the pressure of the rod chamber of the upper gripper cylinder G3; P5 is the pressure of the rodless chamber of the upper gripper cylinder G4; and P6 is the pressure of the rod chamber of the upper gripper cylinder G4.

[0087] When the clamping force T2 or clamping force T3 is less than the set clamping threshold T5 and the duration is less than the time threshold G, the main valve is controlled to activate so that the rodless chamber of the two upper gripper cylinders is connected to the oil inlet and the rod chamber is connected to the oil return. The main pump drives the hydraulic oil to enter the two upper gripper cylinders through the main valve and the two-position switching valve group, and the two upper gripper cylinders extend.

[0088] When the clamping force T2 or clamping force T3 is less than the set clamping threshold T5 and the duration is greater than the time threshold G, an alarm for abnormal clamping of the hydraulic cylinders of the two upper grippers will be output.

[0089] When both gripper cylinders are in the automatic lower clamping mode, the pressure at the oil inlets of both gripper cylinders is detected by pressure sensors, and the clamping force T1 output by the two gripper cylinders is calculated; the formula is as follows:

[0090] T1 = A1 * P1 - A2 * P2

[0091] In the formula, A1 is the rodless cavity area of ​​the lower gripper cylinders G1 and G2; P1 is the rodless cavity pressure of the lower gripper cylinders G1 and G2; A2 is the rod cavity area of ​​the lower gripper cylinders G1 and G2; and P2 is the rod cavity pressure of the lower gripper cylinders G1 and G2.

[0092] When the clamping force T1 is less than the set clamping threshold T4 and the duration is less than the time threshold G, the main valve is controlled to connect the rodless chamber of the two lower gripper cylinders to the oil inlet and the rod chamber to the oil return. The main pump drives the hydraulic oil to enter the two lower gripper cylinders through the main valve and the two-position switching valve group, and the two lower gripper cylinders extend.

[0093] When the clamping force T1 is less than the set clamping threshold T5 and the duration is greater than the time threshold G, two clamping cylinder clamping abnormality alarms will be output.

[0094] This embodiment can maintain a constant clamping force of the clamp for a long time; it detects the clamping force to avoid excessive clamping force that could damage the coating on the surface of the steel pipe; and it alarms when the clamping force is lower than the set value to prevent the steel pipe from falling out of the clamp.

[0095] The main valve is controlled by a controller.

[0096] When the main valve is in the reverse position, the oil inlet circuit is from the main valve to the first hydraulic control valve, and the oil return circuit is from the main valve to the second hydraulic control valve.

[0097] When the main valve is in the neutral position, the main valve interrupts the oil circuit of the first hydraulic control valve and the second hydraulic control valve;

[0098] When the main valve is in the positive position, the oil inlet path is from the main valve to the second hydraulic control valve, and the oil return path is from the main valve to the first hydraulic control valve.

[0099] The controller controls the operation of the upper and lower clamp switching solenoid valves;

[0100] When the upper and lower clamp switching solenoid valve is in the positive position, the control ends of the first hydraulic control valve and the second hydraulic control valve are connected to the oil tank. When the first hydraulic control valve and the second hydraulic control valve are in the positive position, the oil inlet and return lines of the two upper clamp cylinders are connected.

[0101] When the upper and lower clamp switching solenoid valve is in the reverse position, the control terminals of the first hydraulic control valve and the second hydraulic control valve are connected to the oil outlet of the overflow pressure reducing valve. The first hydraulic control valve and the second hydraulic control valve operate synchronously, so that the first hydraulic control valve and the second hydraulic control valve are in the reverse position, thus opening the oil inlet and return lines of the two lower clamp cylinders.

[0102] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0103] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A pipe-laying machine clamp control system, characterized in that, This includes an oil tank, main pump, main valve, and two-position switching valve assembly connected sequentially via an oil circuit; The two upper gripper cylinders and the two lower gripper cylinders are connected to the two-position switching valve group through a two-way hydraulic check valve; the rod chambers of the two lower gripper cylinders are interconnected, and the rodless chambers of the two lower gripper cylinders are interconnected. Several pressure sensors detect the oil port pressure of the two upper gripper cylinders and the two lower gripper cylinders respectively; the several pressure sensors are electrically connected to the input terminal of the controller, and the output terminal of the controller is electrically connected to the two-position switching valve group and the main valve; The controller controls the operation of the two-position switching valve group to switch the operation of the two upper gripper cylinders or the two lower gripper cylinders; the controller controls the piston rods of the two upper gripper cylinders and the two lower gripper cylinders to extend or retract through the main valve.

2. The pipe-laying machine clamp control system according to claim 1, characterized in that, The plurality of pressure sensors include pressure sensor F1, pressure sensor F2, pressure sensor F3, pressure sensor F4, pressure sensor F5 and pressure sensor F6; The two lower gripper cylinders are set as lower gripper cylinder G1 and lower gripper cylinder G2; the two upper gripper cylinders are set as upper gripper cylinder G3 and upper gripper cylinder G4. The pressure sensor F1 is used to detect the rodless chamber of the lower gripper cylinder G1 and the lower gripper cylinder G2; the pressure sensor F2 is used to detect the rod chamber of the lower gripper cylinder G1 and the lower gripper cylinder G2. The pressure sensors F3 and F4 are used to detect the rodless chamber and rod chamber of the upper gripper cylinder G3, respectively; the pressure sensors F5 and F6 are used to detect the rodless chamber and rod chamber of the upper gripper cylinder G4, respectively.

3. The pipe-laying machine clamp control system according to claim 3, characterized in that, The dual-position switching valve group includes a first hydraulic control valve and a second hydraulic control valve; The main valve's oil circuit connects to the first hydraulic control valve and the second hydraulic control valve; the main valve is configured as a three-position four-way solenoid valve; when the main valve is in the reverse position, the oil inlet path is from the main valve to the first hydraulic control valve, and the oil return path is from the main valve to the second hydraulic control valve; when the main valve is in the neutral position, the main valve interrupts the oil circuits of the first and second hydraulic control valves; when the main valve is in the forward position, the oil inlet path is from the main valve to the second hydraulic control valve, and the oil return path is from the main valve to the first hydraulic control valve. The first hydraulic control valve and the second hydraulic control valve are configured as two-position three-way hydraulic control valves; the first hydraulic control valve and the second hydraulic control valve operate synchronously; when the first hydraulic control valve and the second hydraulic control valve are in the reverse position, they connect the oil inlet and return lines of the two lower gripper cylinders; when the first hydraulic control valve and the second hydraulic control valve are in the forward position, they connect the oil inlet and return lines of the two upper gripper cylinders.

4. The pipe-laying machine clamp control system according to claim 3, characterized in that, The dual-position switching valve assembly also includes an upper and lower clamp switching solenoid valve, an overflow pressure reducing valve, and a shuttle valve; the first oil inlet of the shuttle valve is connected to the oil circuit between the main valve and the first hydraulic control valve; the second oil inlet of the shuttle valve is connected to the oil circuit between the main valve and the second hydraulic control valve; the oil outlet of the shuttle valve is connected to the oil inlet of the overflow pressure reducing valve through an oil circuit. The return port of the overflow pressure reducing valve is connected to the oil tank, and the outlet port of the overflow pressure reducing valve is connected to the control terminals of the first hydraulic control valve and the second hydraulic control valve through an upper and lower clamp switching solenoid valve. The upper and lower clamp switching solenoid valve is a two-position three-way solenoid valve. When the upper and lower clamp switching solenoid valve is in the positive position, the control terminals of the first hydraulic control valve and the second hydraulic control valve are connected to the oil tank, and the first hydraulic control valve and the second hydraulic control valve are in the positive position. When the upper and lower clamp switching solenoid valve is in the reverse position, the control terminals of the first hydraulic control valve and the second hydraulic control valve are connected to the oil outlet of the overflow pressure reducing valve, and the first hydraulic control valve and the second hydraulic control valve are in the reverse position.

5. The pipe-laying machine clamp control system according to claim 3, characterized in that, The number of bidirectional hydraulic control check valves is set to four groups, namely bidirectional hydraulic control check valve V3, bidirectional hydraulic control check valve V4, bidirectional hydraulic control check valve V5 and bidirectional hydraulic control check valve V6. The rodless chamber port and the rod chamber port of the lower gripper cylinder G1 are connected to a two-way hydraulic control check valve V3, and the rodless chamber port and the rod chamber port of the lower gripper cylinder G2 are connected to a two-way hydraulic control check valve V4. Two-way hydraulic control check valves V3 and V4 are connected to the first hydraulic control valve and the second hydraulic control valve via oil circuits, so that the rodless chamber oil port of the lower gripper cylinder G1 and the rodless chamber oil port of the lower gripper cylinder G2 are connected to the same port of the first hydraulic control valve, and the rod chamber oil port of the lower gripper cylinder G1 and the rod chamber oil port of the lower gripper cylinder G2 are connected to the same port of the second hydraulic control valve. The rodless chamber port and the rod chamber port of the upper gripper cylinder G3 are connected to a two-way hydraulic control check valve V5, and the rodless chamber port and the rod chamber port of the upper gripper cylinder G4 are connected to a two-way hydraulic control check valve V6. Two-way hydraulic control check valves V5 and V6 are connected to the first hydraulic control valve and the second hydraulic control valve via oil circuits, so that the rodless chamber oil port of the upper gripper cylinder G3 and the rodless chamber oil port of the upper gripper cylinder G4 are connected to the same port of the first hydraulic control valve, and the rod chamber oil port of the upper gripper cylinder G3 and the rod chamber oil port of the upper gripper cylinder G4 are connected to the same port of the second hydraulic control valve.

6. The pipe-laying machine clamp control system according to claim 1, characterized in that, The controller is electrically connected to the display. The controller's pressure sensor detects the oil port pressure of the two upper gripper cylinders and the two lower gripper cylinders respectively, and calculates the clamping status of the two upper gripper cylinders and the two lower gripper cylinders. The clamping status of the two upper gripper cylinders and the two lower gripper cylinders is displayed on the display.

7. The control method of the pipe-laying machine clamp control system according to any one of claims 1 to 6, characterized in that, include: When the automatic clamping operation command and the automatic upper clamping operation command are received, the two-position switching valve group is controlled to operate and connect the two upper clamping cylinders; the main valve is controlled to operate so that the rodless chamber of the two upper clamping cylinders is connected to the oil inlet and the rod chamber is connected to the oil return. The main pump drives the hydraulic oil to enter the two upper clamping cylinders through the main valve and the two-position switching valve group, and the two upper clamping cylinders extend. During the extension process of the two upper gripper cylinders, the oil port pressure of the two upper gripper cylinders is detected by pressure sensors, and the clamping force T2 and clamping force T3 output by the two upper gripper cylinders are calculated. When the clamping force T2 and clamping force T3 reach the set clamping threshold T5, the main valve is controlled to act, interrupting the oil inlet and return lines of the two upper gripper cylinders, and the two upper gripper cylinders stop extending. When the automatic clamping operation command and the automatic lower clamping operation command are received, the two-position switching valve group is controlled to operate and connect the two lower clamping cylinders; the main valve is controlled to operate so that the rodless chamber of the two lower clamping cylinders is connected to the oil inlet and the rod chamber is connected to the oil return. The main pump drives the hydraulic oil to enter the two lower clamping cylinders through the main valve and the two-position switching valve group, and the two lower clamping cylinders extend. The pressure sensors detect the oil port pressure of the two lower gripper cylinders respectively, and calculate the clamping force T1 output by the two lower gripper cylinders. When the clamping force T1 reaches the set clamping threshold T4, the main valve is controlled to act, interrupting the oil inlet and return lines of the two lower gripper cylinders, and the two lower gripper cylinders stop extending.

8. The control method according to claim 7, characterized in that, When the two upper gripper cylinders are in the automatic walking mode of the upper gripper, the oil port pressure of the two upper gripper cylinders is detected by the pressure sensor, and the clamping force T2 and clamping force T3 output by the two upper gripper cylinders are calculated. When the clamping force T2 or clamping force T3 is less than the set clamping threshold T5 and the duration is less than the time threshold G, the main valve is controlled to activate so that the rodless chamber of the two upper gripper cylinders is connected to the oil inlet and the rod chamber is connected to the oil return. The main pump drives the hydraulic oil to enter the two upper gripper cylinders through the main valve and the two-position switching valve group, and the two upper gripper cylinders extend. When the clamping force T2 or clamping force T3 is less than the set clamping threshold T5 and the duration is greater than the time threshold G, an alarm for abnormal clamping of the hydraulic cylinders of the two upper grippers will be output.

9. The control method according to claim 7, characterized in that, When the two lower gripper cylinders are in the automatic lower gripper walking mode, the pressure of the oil port of the two lower gripper cylinders is detected by the pressure sensor, and the clamping force T1 output by the two lower gripper cylinders is calculated. When the clamping force T1 is less than the set clamping threshold T4 and the duration is less than the time threshold G, the main valve is controlled to connect the rodless chamber of the two lower gripper cylinders to the oil inlet and the rod chamber to the oil return. The main pump drives the hydraulic oil to enter the two lower gripper cylinders through the main valve and the two-position switching valve group, and the two lower gripper cylinders extend. When the clamping force T1 is less than the set clamping threshold T5 and the duration is greater than the time threshold G, two clamping cylinder clamping abnormality alarms will be output.

10. The control method according to claim 7, characterized in that, The two upper gripper cylinders are set as upper gripper cylinder G3 and upper gripper cylinder G4; the oil port pressure of the two upper gripper cylinders is detected by pressure sensors, and the clamping forces T2 and T3 output by the two upper gripper cylinders are calculated, specifically including: T2 = A3 * P3 - A4 * P4; T3 = A3 * P5 - A4 * P6; The formula is as follows: T2 is the clamping force of the upper gripper cylinder G3; T3 is the clamping force of the upper gripper cylinder G4; A3 is the area of ​​the rodless chamber of the upper gripper cylinders G3 and G4; A4 is the area of ​​the rod chamber of the upper gripper cylinders G3 and G4; P3 is the pressure of the rodless chamber of the upper gripper cylinder G3; P4 is the pressure of the rod chamber of the upper gripper cylinder G3; P5 is the pressure of the rodless chamber of the upper gripper cylinder G4; and P6 is the pressure of the rod chamber of the upper gripper cylinder G4.

11. The control method according to claim 7, characterized in that, The two lower gripper cylinders are set as lower gripper cylinder G1 and lower gripper cylinder G2; the oil port pressure of the two lower gripper cylinders is detected by pressure sensors, and the clamping force T1 output by the two lower gripper cylinders is calculated, specifically including: T1 = A1 * P1 - A2 * P2; In the formula, A1 is the rodless cavity area of ​​the lower gripper cylinders G1 and G2; P1 is the rodless cavity pressure of the lower gripper cylinders G1 and G2; A2 is the rod cavity area of ​​the lower gripper cylinders G1 and G2; and P2 is the rod cavity pressure of the lower gripper cylinders G1 and G2.

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