Tensioner and belt conveyor with hydraulic protection function

Abstract

The present application relates to the field of hydraulic control, and discloses a tensioning device and a belt conveyor with a hydraulic protection function. A tensioning winch is connected to a hydraulic motor, and the tensioning winch is connected to the output end of a hydraulic cylinder through a steel wire rope. The steel wire rope is used to tension the conveyor belt of the belt conveyor. The oil outlet end of the hydraulic cylinder when being pulled is connected to a hydraulically controlled reversing valve. An accumulator is also connected to the hydraulically controlled reversing valve. The two ends of the main valve of the pilot relief valve are respectively connected to the input end and the output end of the hydraulic motor. When the belt conveyor suddenly stops, the hydraulic cylinder is pulled by the inertia of the transported objects on the conveyor belt. When the oil outlet pressure of the hydraulic cylinder when being pulled is greater than or equal to the reversing pressure value of the hydraulically controlled reversing valve, the hydraulically controlled reversing valve switches to connect the accumulator and the logic valve. The logic valve switches to connect the control end of the proportional relief valve and the pilot relief valve under the action of pressure. The present application can protect the belt conveyor when the belt conveyor suddenly stops.

Description

Technical Field

[0001] The present application relates to the technical field of hydraulic control, and more specifically, to a tensioning device and a belt conveyor with a hydraulic protection function. Background Art

[0002] Belt conveyor is a commonly used material transportation equipment. Belt conveyor usually includes conveyor belt, drive device, tensioning device, support frame and roller. Belt conveyor transports materials through belt conveyor belt. Driven by the drive device, the conveyor belt circulates along the roller. The function of the tensioning device is to adjust the tension of the conveyor belt to keep the conveyor belt in the best working condition. The tensioning device can prevent the conveyor belt from slipping or excessive wear by adjusting the tension of the conveyor belt. At the same time, appropriate tension can ensure the normal operation of the conveyor belt and improve the conveying efficiency.

[0003] During the operation of the belt conveyor, when the belt conveyor suddenly stops, the transported objects on the conveyor belt will continue to move under the action of inertia. When the existing conveyor belt and tensioning device are working, when the mass of the transported objects on the conveyor belt is large, the inertia of the transported objects on the conveyor belt is also large, which may cause the conveyor belt of the belt conveyor to pull the tensioning device, causing the steel wire rope of the tensioning device to break, which may cause the steel wire rope of the tensioning device to become tangled due to excessive rope release, which may cause damage to the tensioning device. Therefore, the existing belt conveyor cannot protect the belt conveyor when the belt conveyor suddenly stops. Summary of the invention

[0004] The purpose of this application is to provide a tensioning device and a belt conveyor with a hydraulic protection function, which solves the technical problem that the belt conveyor cannot be protected when the belt conveyor suddenly stops running, and achieves the technical effect of protecting the belt conveyor when the belt conveyor suddenly stops running.

[0005] A tensioning device with a hydraulic protection function provided in an embodiment of the present application comprises a tension control oil circuit, the tension control oil circuit comprises a hydraulic motor, a hydraulic cylinder, a hydraulically controlled reversing valve, a logic valve, a proportional relief valve and a pilot relief valve, a tensioning winch is connected to the hydraulic motor, the tensioning winch is connected to the output end of the hydraulic cylinder through a wire rope, the wire rope is used to tension the conveyor belt of the belt conveyor, the oil outlet end of the hydraulic cylinder when being pulled is connected to the hydraulically controlled reversing valve, the hydraulically controlled reversing valve is also connected to an accumulator, and the pilot relief valve is connected The two ends of the main valve of the flow valve are connected to the input and output ends of the hydraulic motor respectively. The proportional relief valve is used to control the circuit back pressure of the hydraulic motor through the pilot relief valve; when the belt conveyor suddenly stops, the hydraulic cylinder is pulled by the inertia of the transported objects on the conveyor belt. When the pressure at the oil outlet end of the hydraulic cylinder is greater than or equal to the switching pressure value of the hydraulic control reversing valve, the hydraulic control reversing valve switches to connect the accumulator and the logic valve. Under the action of pressure, the logic valve switches to connect the control end of the proportional relief valve and the pilot relief valve.

[0006] In one possible implementation, a first sequence valve is provided between the hydraulically controlled reversing valve and the logic valve. The hydraulically controlled reversing valve can be switched to connect with the accumulator, the first sequence valve and the logic valve in sequence. When the hydraulically controlled reversing valve is not switched to connect with the accumulator, the first sequence valve relieves pressure on the external control port of the logic valve, and the logic valve is in a closed state; when the hydraulically controlled reversing valve is switched to connect with the accumulator, the first sequence valve connects the external control ports of the hydraulically controlled reversing valve and the logic valve, and the logic valve is in a conducting state.

[0007] In another possible implementation, it also includes a brake oil circuit, which includes a brake shuttle valve, a pressure reducing valve, a second sequence valve and a brake arranged in sequence. The oil outlet end of the hydraulic cylinder is connected to the brake shuttle valve when it is pulled. The pressure reducing valve is used to reduce the oil pressure of the brake oil circuit to within the working pressure range of the brake. The second sequence valve makes the oil pressure of the brake greater than the stop braking pressure of the brake, and the brake stops braking.

[0008] In another possible implementation, it also includes a cylinder oil supply circuit, which is connected to the oil outlet end of the hydraulic cylinder when it is pulled. The cylinder oil supply circuit includes a first solenoid reversing valve, a second solenoid reversing valve, an oil supply overflow valve and a protection overflow valve which are connected in sequence. The oil supply overflow valve is arranged between the first solenoid reversing valve and the second solenoid reversing valve. The overflow pressure value of the oil supply overflow valve is less than the switching pressure value of the hydraulically controlled reversing valve. The protection overflow valve is arranged between the oil outlet end of the hydraulic cylinder when it is pulled and the second solenoid reversing valve. The overflow pressure value of the protection overflow valve is greater than the switching pressure value of the hydraulically controlled reversing valve.

[0009] In another possible implementation, it also includes an accumulator pressure-compensating oil circuit, which includes a third electromagnetic reversing valve and an accumulator pressure sensor. The third electromagnetic reversing valve is connected to the first electromagnetic reversing valve and the accumulator, respectively. The accumulator pressure sensor is used to detect the pressure of the accumulator. When the detected accumulator pressure is lower than the pressure threshold of the first sequence valve that switches the hydraulically controlled reversing valve and the logic valve, the first electromagnetic reversing valve and the third electromagnetic reversing valve switch states to compensate for the accumulator pressure.

[0010] In another possible implementation, the hydraulic motor provides power source pressure through the first oil pump, the cylinder oil replenishment circuit replenishes oil through the second oil pump, and the input and output ends of the hydraulic motor are also connected to the high-pressure filter reversing valve group and the balancing valve group.

[0011] In another possible implementation, the hydraulically controlled reversing valve is connected to the input and output ends of the hydraulic motor respectively through two oil replenishing check valves, and the oil replenishing check valves are used to control the unidirectional flow of oil from the hydraulically controlled reversing valve to the input and output ends of the hydraulic motor.

[0012] In another possible implementation, the proportional relief valve is an electrically controlled proportional relief valve.

[0013] In another possible implementation, both ends of the pressure reducing valve are connected to brake one-way valves, and the brake one-way valves are used to control the one-way flow of oil from the second sequence valve to the brake shuttle valve.

[0014] An embodiment of the present application also provides a belt conveyor, which includes a support frame, a roller, a conveyor belt and a driving device, wherein the support frame is used to support the roller, the roller is used to carry the conveyor belt, the driving device is used to drive the conveyor belt to move, and also includes a tensioning device with a hydraulic protection function as described in any of the above items, and the tensioning device is used to provide tensioning force to the conveyor belt.

[0015] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0016] The embodiment of the present application provides a tensioning device with a hydraulic protection function, including a tension control oil circuit, the tension control oil circuit including a hydraulic motor, a hydraulic cylinder, a hydraulically controlled reversing valve, a logic valve, a proportional relief valve and a pilot relief valve, the hydraulic motor is connected to a tensioning winch, the tensioning winch is connected to the output end of the hydraulic cylinder through a wire rope, the wire rope is used to tension the conveyor belt of the belt conveyor, the oil outlet end of the hydraulic cylinder when being pulled is connected to the hydraulically controlled reversing valve, the hydraulically controlled reversing valve is also connected to an accumulator, the pilot relief valve The two ends of the main valve of the flow valve are connected to the input and output ends of the hydraulic motor respectively. The proportional relief valve is used to control the circuit back pressure of the hydraulic motor through the pilot relief valve; when the belt conveyor suddenly stops, the hydraulic cylinder is pulled by the inertia of the transported objects on the conveyor belt. When the pressure at the oil outlet end of the hydraulic cylinder is greater than or equal to the switching pressure value of the hydraulic control reversing valve, the hydraulic control reversing valve switches to connect the accumulator and the logic valve. Under the action of pressure, the logic valve switches to connect the control end of the proportional relief valve and the pilot relief valve. When the tensioning device in the embodiment of the present application is in use, when the pressure at the oil outlet end of the hydraulic cylinder when being pulled is greater than the switching pressure value of the hydraulically controlled reversing valve, the action of the hydraulically controlled reversing valve can connect the input end and the output end of the hydraulic motor, so that the hydraulic motor can rotate to release the wire rope, thereby preventing the wire rope from being broken, and providing a buffer for the conveyor belt to protect the conveyor belt; at the same time, through the set pressure control circuit back pressure of the proportional relief valve, resistance can be provided for the wire rope releasing process of the tensioning device, thereby preventing the wire rope of the tensioning device from being tangled due to excessive wire rope release, thereby achieving a protective effect on the tensioning device. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0018] Figure 1 A schematic diagram of the system structure of a tensioning device with a hydraulic protection function provided in an embodiment of the present application;

[0019] Figure 2 A schematic diagram of the system structure of a tension control oil circuit and a brake oil circuit provided in an embodiment of the present application;

[0020] Figure 3 A schematic diagram of the system structure of an oil replenishment circuit provided in an embodiment of the present application;

[0021] Figure 4 A schematic diagram of the system structure of a high-pressure filter oil circuit provided in an embodiment of the present application;

[0022] In the figure, 1, tension control oil circuit; 11, hydraulic motor; 111, tensioning winch; 111a, wire rope; 112, tensioning end; 12, hydraulic cylinder; 13, hydraulically controlled reversing valve; 131, accumulator; 132, third solenoid reversing valve; 14, logic valve; 15, proportional relief valve; 16, pilot relief valve; 17, first sequence valve; 18, oil replenishment check valve; 19, first oil pump; 2, brake oil circuit; 21, brake shuttle valve; 22, pressure reducing valve; 23, second sequence valve; 24, brake; 25, brake check valve; 3, cylinder oil replenishment oil circuit; 31, first solenoid reversing valve; 32, second solenoid reversing valve; 33, oil replenishment overflow valve; 34, protection overflow valve; 35, second oil pump. DETAILED DESCRIPTION

[0023] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0024] It should be noted that when a component or structure is referred to as being "fixed to" or "disposed on" another component or structure, it may be directly on the other component or structure or indirectly on the other component or structure. When a component or structure is referred to as being "connected to" another component or structure, it may be directly connected to the other component or structure or indirectly connected to the other component or structure.

[0025] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or a component or structure referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0026] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0027] During the operation of the belt conveyor, when the belt conveyor suddenly stops running, the transported objects on the conveyor belt will continue to move under the action of inertia. The existing belt conveyor cannot protect the tensioning device when the belt conveyor suddenly stops running.

[0028] Based on the above reasons, the embodiment of the present application provides a tensioning device with a hydraulic protection function, including a tension control oil circuit, the tension control oil circuit includes a hydraulic motor, a hydraulic cylinder, a hydraulically controlled reversing valve, a logic valve, a proportional relief valve and a pilot relief valve, the hydraulic motor is connected to a tensioning winch, the tensioning winch is connected to the output end of the hydraulic cylinder through a wire rope, the wire rope is used to tension the conveyor belt of the belt conveyor, the oil outlet end of the hydraulic cylinder when being pulled is connected to the hydraulically controlled reversing valve, and the hydraulically controlled reversing valve is also connected to an accumulator, The two ends of the main valve of the pilot relief valve are connected to the input and output ends of the hydraulic motor respectively. The proportional relief valve is used to control the circuit back pressure of the hydraulic motor through the pilot relief valve; when the belt conveyor stops suddenly, the hydraulic cylinder is pulled by the inertia of the transported objects on the conveyor belt. When the pressure at the oil outlet end of the hydraulic cylinder is greater than or equal to the switching pressure value of the hydraulic control reversing valve, the hydraulic control reversing valve switches to connect the accumulator and the logic valve. Under the action of pressure, the logic valve switches to connect the control end of the proportional relief valve and the pilot relief valve. When the tensioning device in the embodiment of the present application is in use, when the pressure at the oil outlet end of the hydraulic cylinder when being pulled is greater than the switching pressure value of the hydraulically controlled reversing valve, the action of the hydraulically controlled reversing valve can connect the input end and the output end of the hydraulic motor, so that the hydraulic motor can rotate to release the wire rope, thereby preventing the wire rope from being broken, and providing a buffer for the conveyor belt to protect the conveyor belt; at the same time, through the set pressure control circuit back pressure of the proportional relief valve, resistance can be provided for the wire rope releasing process of the tensioning device, thereby preventing the wire rope of the tensioning device from being tangled due to excessive wire rope release, thereby achieving a protective effect on the tensioning device.

[0029] In some scenarios, a tensioning device with a hydraulic protection function in an embodiment of the present application can be applied to a tensioning device of a conveyor belt. When the belt conveyor suddenly stops running, the input and output ends of the hydraulic motor can be connected to release the rope, which can provide a buffering effect for the conveyor belt and prevent the wire rope from breaking, thereby achieving a protective effect on the conveyor belt. At the same time, the back pressure of the control circuit set by the proportional relief valve can provide resistance for the rope-releasing process of the tensioning device, thereby preventing the wire rope of the tensioning device from being tangled due to excessive rope release, thereby achieving a protective effect on the tensioning device.

[0030] A tensioning device with a hydraulic protection function provided in an embodiment of the present application is described in detail below with reference to specific examples.

[0031] Figure 1 A schematic diagram of the system structure of a tensioning device with a hydraulic protection function provided in an embodiment of the present application, Figure 2 A schematic diagram of the system structure of a tension control oil circuit and a brake oil circuit provided in an embodiment of the present application is shown in FIG. Figure 1 and Figure 2As shown, the tensioning device includes a tension control oil circuit 1, which includes a hydraulic motor 11, a hydraulic cylinder 12, a hydraulically controlled reversing valve 13, a logic valve 14, a proportional relief valve 15 and a pilot relief valve 16. The hydraulic motor 11 is connected to a tensioning winch 111, which is connected to the output end of the hydraulic cylinder 12 through a wire rope 111a. The wire rope 111a is used to tension the conveyor belt of the belt conveyor. The oil outlet end of the hydraulic cylinder 12 when under tension is connected to the hydraulically controlled reversing valve 13. The hydraulically controlled reversing valve 13 is also connected to an accumulator 131. The two ends of the main valve of the pilot relief valve 16 are respectively connected to the input end and the output end of the hydraulic motor 11. The proportional relief valve 15 is used to control the circuit back pressure of the hydraulic motor 11 through the pilot relief valve 16.

[0032] When the belt conveyor stops suddenly, the hydraulic cylinder 12 is pulled by the inertia of the transported objects on the conveyor belt. When the oil outlet pressure of the hydraulic cylinder 12 is greater than or equal to the switching pressure value of the hydraulic control reversing valve 13, the hydraulic control reversing valve 13 switches to connect the accumulator 131 and the logic valve 14. The logic valve 14 switches to connect the control end of the proportional relief valve 15 and the pilot relief valve 16 under the action of pressure.

[0033] like Figure 1 and Figure 2 As shown, the tensioning device includes a tension control oil circuit 1, which includes a hydraulic motor 11, a hydraulic cylinder 12, a first hydraulically controlled reversing valve 13, a logic valve 14, a proportional relief valve 15 and a pilot relief valve 16. The various valves that constitute the tension control oil circuit 1 are connected through oil pipelines.

[0034] like Figure 1 As shown, a tensioning winch 111 is connected to the hydraulic motor 11, and the hydraulic motor 11 is used to drive the tensioning winch 111 to rotate, and the tensioning winch 111 is used to pull the conveyor belt through the wire rope 111a to tension the conveyor belt. In terms of structure, the tensioning winch 111 is connected to the output end of the hydraulic cylinder 12 through the wire rope 111a, and the hydraulic cylinder 12 is used to control the tensioning force. The wire rope 111a is wound on the pulley, and the pulley is fixedly connected to the roller for carrying the conveyor belt. The wire rope 111a can pull the roller through the pulley to achieve the tensioning of the conveyor belt. When the tensioning winch 111 pulls the wire rope 111a, the wire rope 111a can apply tension to the tensioning end 112.

[0035] When the tensioning device in the embodiment of the present application is working, when the tensioning device is in the tension adjustment stage, the hydraulic motor 11 in the tension control oil circuit 1 is driven by the power source oil circuit to operate, and the hydraulic motor 11 drives the tensioning winch 111 to rotate to achieve the tensioning of the conveyor belt. After the tensioning device completes the tension adjustment, the input and output ends of the hydraulic motor 11 are in a closed state under the action of the double balance valve to maintain the stability of the tension of the conveyor belt, and the tensioning winch 111 is in a stationary state.

[0036] When the belt conveyor operates normally, the tension winch 111 is in a stationary state to maintain the tension of the conveyor belt stable, and the hydraulic cylinder 12 generates pressure fluctuations under the pulling force of the conveyor belt to achieve buffering of the conveyor belt.

[0037] During the operation of the belt conveyor, when the belt conveyor suddenly stops, the transported objects on the conveyor belt will continue to move under the action of inertia, and the tensioning winch 111 and the hydraulic cylinder 12 will be subjected to tension under the action of inertia of the transported objects on the conveyor belt. When the existing belt conveyor suddenly stops, the steel wire rope of the tensioning device may be broken by the inertia of the transported objects on the conveyor belt, and the conveyor belt and the tensioning device cannot be protected.

[0038] In the embodiment of the present application, the oil outlet end of the hydraulic cylinder 12 when under tension is connected to the hydraulically controlled reversing valve 13 , so that the oil pressure at the oil outlet end of the hydraulic cylinder 12 when under tension can control the working position of the hydraulically controlled reversing valve 13 .

[0039] Structurally, the hydraulically controlled reversing valve 13 is also connected to an accumulator 131 , so that the accumulator 131 can transmit oil pressure to the oil circuit connected to the hydraulically controlled reversing valve 13 .

[0040] Structurally, both ends of the main valve of the pilot relief valve 16 are respectively connected to the input end and the output end of the hydraulic motor 11, so that the pilot relief valve 16 can overflow between the input end and the output end of the hydraulic motor 11. The proportional relief valve 15 is used to control the circuit back pressure of the hydraulic motor 11 through the pilot relief valve 16, so that the pilot relief valve 16 can achieve overflow pressure control of the pilot relief valve 16 under the control of the proportional relief valve 15.

[0041] like Figure 2 As shown, when the belt conveyor does not stop suddenly, since the double balance valve connected to the hydraulic motor is in a locked state, the input end and the output end of the hydraulic motor 11 are in a closed state.

[0042] During operation, when the belt conveyor suddenly stops, the transported objects on the conveyor belt will continue to move due to inertia, and the hydraulic cylinder 12 will be pulled under the inertia of the transported objects on the conveyor belt, which will increase the pressure at the oil outlet end of the hydraulic cylinder 12 when it is pulled. When the pressure at the oil outlet end of the hydraulic cylinder 12 when it is pulled is greater than or equal to the switching pressure value of the hydraulic control reversing valve 13, the hydraulic control reversing valve 13 switches to the control port connecting the accumulator 131 and the logic valve 14. Under the action of pressure, the logic valve 14 switches to the control end of the proportional relief valve 15 and the pilot relief valve 16, so that the proportional relief valve 15 can control the relief pressure of the pilot relief valve 16.

[0043] During operation, oil is accumulated in the accumulator 131 . When the hydraulically controlled reversing valve 13 is switched to connect the accumulator 131 and the logic valve 14 , the accumulator 131 acts on the logic valve 14 to activate the logic valve 14 .

[0044] When the tension control oil circuit 1 in the embodiment of the present application is working, when the tension applied to the hydraulic cylinder 12 is large and reaches the switching pressure threshold of the hydraulically controlled reversing valve 13, the hydraulically controlled reversing valve 13 switches to the oil outlet end when the hydraulic cylinder 12 is pulled and is connected to the logic valve 14. The logic valve 14 is actuated under the action of the oil circuit pressure, so that the logic valve 14 switches to the proportional relief valve 15 and is connected to the control end of the pilot relief valve 16, thereby enabling the proportional relief valve 15 to control the working state of the pilot relief valve 16. The two ends of the pilot relief valve 16 are respectively connected to the input end and the output end of the hydraulic motor 11, so that the hydraulic motor 11 can rotate under the tension of the wire rope to prevent the wire rope from being broken. At the same time, the pilot relief valve 16 can control the circuit back pressure of the hydraulic motor 11 under the control of the proportional relief valve 15, thereby realizing the control of the tension of the hydraulic motor 11 when the wire rope is released.

[0045] When working, the proportional relief valve 15 can receive a control signal (such as a current signal), and the control signal is proportional to the desired pressure value of the proportional relief valve 15. The input signal can be provided by a control system, and the control ends of the proportional relief valve 15 and the pilot relief valve 16 are connected, that is, the pilot valve of the proportional relief valve 15 and the pilot relief valve 16 are connected.

[0046] During operation, the switching pressure value of the first hydraulically controlled switching valve 13 can be preset and adjusted.

[0047] The beneficial effect brought about by the above-mentioned implementation method is that when the conveyor belt suddenly stops and the transported objects on the conveyor belt continue to move forward due to inertia, the tensioning device in the embodiment of the present application can connect the input and output ends of the hydraulic motor of the tensioning device under the action of oil pressure to release the wire rope, thereby preventing the wire rope of the tensioning device from being broken, providing a buffer for the conveyor belt, and protecting the conveyor belt.

[0048] The beneficial effect brought about by the above-mentioned implementation method is that the proportional relief valve and the pilot relief valve of the tensioning device in the embodiment of the present application can control the size of the circuit back pressure, can provide resistance for the hydraulic motor to release the rope, and thus can keep the wire rope of the tensioning device in a taut state, so that the wire rope of the tensioning device will not be excessively released and uncontrollable.

[0049] The beneficial effect brought about by the above-mentioned implementation method is that by controlling the working pressure of the proportional relief valve, the proportional relief valve can control the working state of the pilot relief valve, and the pilot relief valve can control the pilot valve through the proportional relief valve to achieve control of the relief pressure, that is, the control of the circuit back pressure of the hydraulic motor is achieved, which facilitates the control of the circuit back pressure of the hydraulic motor through the proportional relief valve.

[0050] The beneficial effect brought about by the above implementation method is that by setting an accumulator to store energy and pressure, the accumulator can drive the logic valve to act instantaneously when the hydraulically controlled reversing valve is switched, thereby ensuring the sensitivity of protecting the conveyor belt.

[0051] In some implementations, a first sequence valve 17 is provided between the hydraulically controlled reversing valve 13 and the logic valve 14. The hydraulically controlled reversing valve 13 can be switched to sequentially connect to the accumulator 131, the first sequence valve 17 and the logic valve 14. When the hydraulically controlled reversing valve 13 is not switched to connect to the accumulator 131, the first sequence valve 17 releases pressure from the external control port of the logic valve 14, and the logic valve 14 is in a closed state. When the hydraulically controlled reversing valve 13 is switched to connect to the accumulator 131, the first sequence valve 17 connects the external control ports of the hydraulically controlled reversing valve 13 and the logic valve 14, and the logic valve 14 is in a conducting state.

[0052] Structurally, a first sequence valve 17 is provided between the hydraulically controlled reversing valve 13 and the logic valve 14, and the hydraulically controlled reversing valve 13 can be switched to sequentially connect the accumulator 131, the first sequence valve 17 and the logic valve 14. During operation, when the hydraulically controlled reversing valve 13 is not switched to connect the accumulator 131, the accumulator 131 is not transmitted to the first sequence valve 17 through the hydraulically controlled reversing valve 13, and the first sequence valve 17 is switched to release pressure on the external control port of the logic valve 14, and the logic valve 14 is in a closed state. At this time, the external control port of the logic valve 14 can be released through the first sequence valve 17 to avoid the logic valve 14 being in a state of connecting the proportional relief valve 15 and the pilot relief valve 16.

[0053] During operation, when the hydraulically controlled reversing valve 13 switches to connect with the accumulator 131, the pressure of the accumulator 131 is transmitted to the first sequence valve 17 through the hydraulically controlled reversing valve 13, so that the first sequence valve 17 switches to the external control port connecting the hydraulically controlled reversing valve 13 and the logic valve 14, and the logic valve 14 is in a conducting state, thereby realizing the state in which the logic valve 14 connects with the proportional relief valve 15 and the pilot relief valve 16.

[0054] The beneficial effect brought about by the above-mentioned implementation method is that by setting the first sequence valve to release pressure on the side where the logic valve is located in time, it is possible to avoid the logic valve from being continuously connected to the proportional relief valve and the pilot relief valve. The proportional relief valve and the pilot relief valve are connected only when the hydraulically controlled reversing valve and the accumulator are already connected, thereby achieving control of the back pressure of the hydraulic motor and improving the control effect of the tensioning device.

[0055] In some implementations, the tensioning device also includes a brake oil circuit 2, which includes a brake shuttle valve 21, a pressure reducing valve 22, a second sequence valve 23 and a brake 24 arranged in sequence. The oil outlet end of the hydraulic cylinder 12 is connected to the brake shuttle valve 21 when it is pulled. The pressure reducing valve 22 is used to reduce the oil pressure of the brake oil circuit 2 to within the working pressure range of the brake 24. The second sequence valve 23 makes the oil pressure of the brake 24 greater than the stop braking pressure of the brake 24, and the brake 24 stops braking.

[0056] like Figure 1 and Figure 2 As shown, structurally, the tensioning device also includes a brake oil circuit 2, which is used to control the braking process. When the conveyor belt stops suddenly and the transported objects on the conveyor belt continue to move forward due to inertia, in order to protect the conveyor belt and the tensioning device, the brake 24 can be released to avoid wear of the brake 24, which can ensure smooth release of the wire rope, avoid the wire rope of the tensioning device from being broken, and provide a buffer for the conveyor belt.

[0057] Structurally, the brake oil circuit 2 includes a brake shuttle valve 21, a pressure reducing valve 22, a second sequence valve 23 and a brake 24 which are arranged in sequence. The oil outlet end of the hydraulic cylinder 12 when it is pulled is connected to the brake shuttle valve 21, so that the oil pressure of the hydraulic cylinder 12 when it is pulled can be transmitted to the brake shuttle valve 21, the pressure reducing valve 22, the second sequence valve 23 and the brake 24 in sequence. The second sequence valve 23 makes the oil pressure of the brake 24 greater than the stop braking pressure of the brake 24. The brake 24 stops braking, which can avoid wear of the brake 24 when the wire rope is released, thereby extending the service life of the brake 24.

[0058] During operation, the pressure reducing valve 22 is used to reduce the oil pressure of the brake oil circuit 2 to within the working pressure range of the brake 24 , thereby protecting the brake 24 .

[0059] When working, the second sequence valve 23 makes the oil pressure of the brake 24 change instantaneously during braking, so that the contact time between the brake pad and the brake disc of the brake 24 is shorter, reducing the wear and thermal damage of the brake pad and extending the service life of the brake 24.

[0060] The beneficial effect brought about by the above-mentioned implementation method is that when the conveyor belt stops suddenly and the transported objects on the conveyor belt continue to move forward due to inertia, the brake can be controlled in time to stop braking through the brake oil circuit, which can prevent the brake from braking the tensioning winch and affecting the rope release of the tensioning device, and can prevent the wire rope of the tensioning device from being broken, thereby providing a buffer for the conveyor belt.

[0061] The beneficial effect brought about by the above-mentioned implementation method is that the brake can be protected from the working pressure perspective through the pressure reducing valve, and the second sequence valve ensures that the oil pressure during brake braking is greater than the pressure at which the brake stops braking, which can avoid wear of the brake when the wire rope is released and extend the service life of the brake.

[0062] In some implementations, the tensioning device also includes a cylinder oil replenishing circuit 3, which is connected to the oil outlet end of the hydraulic cylinder 12 when it is pulled. The cylinder oil replenishing circuit 3 includes a first solenoid reversing valve 31, a second solenoid reversing valve 32, an oil replenishing overflow valve 33 and a protective overflow valve 34 which are connected in sequence. The oil replenishing overflow valve 33 is arranged between the first solenoid reversing valve 31 and the second solenoid reversing valve 32, and the overflow pressure value of the oil replenishing overflow valve 33 is less than the switching pressure value of the hydraulically controlled reversing valve 13. The protective overflow valve 34 is arranged between the oil outlet end of the hydraulic cylinder 12 when it is pulled and the second solenoid reversing valve 32, and the overflow pressure value of the protective overflow valve 34 is greater than the switching pressure value of the hydraulically controlled reversing valve 13.

[0063] like Figure 3 As shown, during operation, after the conveyor belt stops suddenly, the hydraulic cylinder 12 is subjected to tension and enters a rapid release stage. When the rapid release of the hydraulic cylinder 12 ends, the oil in the hydraulic cylinder 12 flows out, and the oil in the hydraulic cylinder 12 can be replenished through the cylinder oil replenishment circuit 3.

[0064] Figure 3 A schematic diagram of the system structure of a cylinder oil replenishment circuit provided in an embodiment of the present application is shown in FIG. Figure 3 As shown, the tensioning device also includes a cylinder oil replenishing circuit 3, which is connected to the oil outlet end of the hydraulic cylinder 12 when it is under tension. The cylinder oil replenishing circuit 3 is used to replenish oil to the chamber connected to the oil outlet end of the hydraulic cylinder 12 when it is under tension after the conveyor belt suddenly stops and the tensioning force is adjusted, thereby ensuring that the protection function of the tensioning device is restored.

[0065] Structurally, the cylinder oil replenishment circuit 3 includes a first solenoid reversing valve 31, a second solenoid reversing valve 32, an oil replenishment overflow valve 33 and a protective overflow valve 34 which are connected in sequence. The first solenoid reversing valve 31 and the second solenoid reversing valve 32 are used to control the oil replenishment process of the hydraulic cylinder 12.

[0066] Structurally, the oil replenishment relief valve 33 is disposed between the first electromagnetic reversing valve 31 and the second electromagnetic reversing valve 32. By setting the oil replenishment relief pressure value of the oil replenishment relief valve 33, the oil replenishment pressure can be prevented from being too high. At the same time, the relief pressure value of the oil replenishment relief valve 33 is less than the reversing pressure value of the hydraulic control reversing valve 13, so that the oil replenishment pressure of the oil cylinder oil replenishment oil circuit 3 will not trigger the reversing of the hydraulic control reversing valve 13, which can prevent the hydraulic control reversing valve 13 from being triggered by mistake, thereby improving the stability and reliability of the system during operation.

[0067] Structurally, the protective overflow valve 34 is arranged between the oil outlet end when the hydraulic cylinder 12 is pulled and the second solenoid reversing valve 32. The overflow pressure value of the protective overflow valve 34 is greater than the reversing pressure value of the hydraulic control reversing valve 13, so that the hydraulic control reversing valve 13 can be triggered normally, and the oil with excessive pressure in the hydraulic cylinder 12 can overflow from the protective overflow valve 34, so that the pressure of the hydraulic cylinder 12 will not be instantaneously overloaded, thereby realizing the protection of the hydraulic cylinder 12.

[0068] Exemplarily, the overflow pressure value of the protection overflow valve 34 may be 2-3 MPa greater than the switching pressure value of the hydraulically controlled reversing valve 13 .

[0069] The beneficial effect brought about by the above implementation method is that the oil replenishment pressure of the cylinder oil replenishment circuit will not trigger the reversal of the hydraulically controlled reversing valve, which can avoid the hydraulically controlled reversing valve from being triggered incorrectly, thereby improving the stability and reliability of the system during operation.

[0070] The beneficial effect brought about by the above-mentioned implementation method is that the hydraulically controlled reversing valve can be triggered normally, so that the excess oil in the hydraulic cylinder can overflow from the protective overflow valve, so that the pressure of the hydraulic cylinder will not be overloaded instantaneously.

[0071] In some implementations, the above-mentioned tensioning device also includes an accumulator pressure-compensating oil circuit, which includes a third electromagnetic reversing valve 132 and an accumulator pressure sensor. The third electromagnetic reversing valve 132 is connected to the first electromagnetic reversing valve 31 and the accumulator 131 respectively. The accumulator pressure sensor is used to detect the pressure of the accumulator 131. When the detected pressure of the accumulator 131 is lower than the pressure threshold of the first sequence valve 17 that switches to connect the hydraulic control reversing valve 13 and the logic valve 14, the first electromagnetic reversing valve 31 and the third electromagnetic reversing valve 132 switch states to compensate for the pressure of the accumulator 131.

[0072] Structurally, the accumulator pressure replenishing oil circuit includes a third electromagnetic reversing valve 132 and an accumulator pressure sensor. The third electromagnetic reversing valve 132 is connected to the first electromagnetic reversing valve 31 and the accumulator 131 respectively. The first electromagnetic reversing valve 31 and the third electromagnetic reversing valve 132 can replenish pressure to the accumulator 131.

[0073] During operation, the accumulator pressure sensor is used to detect the pressure of the accumulator 131. When the detected pressure of the accumulator 131 is lower than the pressure threshold of the switching connection between the hydraulic control reversing valve 13 and the logic valve 14 of the first sequence valve 17, it means that the oil pressure of the accumulator 131 is too low. At this time, the accumulator 131 can be pressurized by switching the states of the first electromagnetic reversing valve 31 and the third electromagnetic reversing valve 132.

[0074] The beneficial effect brought about by the above-mentioned implementation method is that the accumulator 131 can be pressurized through the oil cylinder replenishing oil circuit, thereby ensuring that the conveyor belt protection function of the tensioning device can be reused.

[0075] In some implementations, the hydraulic motor 11 provides power source pressure through the first oil pump 19, the cylinder oil replenishment circuit 3 replenishes oil through the second oil pump 35, and the input and output ends of the hydraulic motor are also connected to a high-pressure filter reversing valve group and a balancing valve group.

[0076] like Figure 1 As shown, structurally, the hydraulic motor 11 is replenished with oil through the first oil pump 19, and the cylinder replenishing oil circuit 3 is replenished with oil through the second oil pump 35. The power of the first oil pump 19 can be greater than the power of the second oil pump 35, so that the tensioning device supplies oil to the winch through the first oil pump 19 and can use a low-power second oil pump 35 to replenish oil for the hydraulic cylinder 12, thereby reducing costs to the greatest extent.

[0077] Structurally, the input and output ends of the hydraulic motor 11 are also connected to a high-pressure filter reversing valve group and a balancing valve group. The high-pressure filter reversing valve group is used to filter the high-pressure oil, and the balancing valve group is used to close the input and output ends of the hydraulic motor 11.

[0078] Figure 4 A schematic diagram of the system structure of a high-pressure filter oil circuit provided in an embodiment of the present application is shown in FIG. Figure 4 As shown, the high-pressure filtering oil circuit can provide guarantee for the stable operation of the entire circuit.

[0079] The beneficial effect brought about by the above-mentioned implementation method is that a low-power second oil pump is used to replenish oil for the winch during tensioning, and the first oil pump cooperates with the high-pressure filter reversing valve group and the balance valve group to control the working state of the hydraulic motor, thereby ensuring normal control of the hydraulic motor during tension adjustment.

[0080] In some implementations, the hydraulically controlled reversing valve 13 is connected to the input end and the output end of the hydraulic motor 11 respectively through two oil replenishing check valves 18. The oil replenishing check valves 18 are used to control the unidirectional flow of oil from the hydraulically controlled reversing valve 13 to the input end and the output end of the hydraulic motor 11.

[0081] like Figure 2As shown, during the operation of the hydraulic motor 11, the hydraulic motor 11 itself will have oil leakage. Therefore, in order to prevent the hydraulic motor 11 from being damaged by air suction during the operation of releasing the rope, it is necessary to replenish the oil to the hydraulic motor 11 in time. The hydraulically controlled reversing valve 13 is connected to the input end and the output end of the hydraulic motor 11 through two oil replenishing one-way valves 18. The oil replenishing one-way valve 18 is used to control the unidirectional flow of oil from the hydraulically controlled reversing valve 13 to the input end and the output end of the hydraulic motor 11, so that the oil can be replenished to the hydraulic motor 11 in time, thereby achieving the protection effect of the hydraulic motor 11.

[0082] In some implementations, the proportional relief valve 15 is an electrically controlled proportional relief valve.

[0083] In terms of control method, the proportional relief valve 15 is an electrically controlled proportional relief valve, so that the proportional relief valve 15 can be integrated into the operating table, and the proportional relief valve 15 can be centrally controlled, which is convenient for remote and precise control of the tension of the tensioning device when releasing the rope, thereby improving the protection effect of the tensioning device.

[0084] In some implementations, both ends of the pressure reducing valve 22 are connected to brake one-way valves 25 , and the brake one-way valve 25 is used to control the one-way flow of oil from the second sequence valve 23 to the brake shuttle valve 21 .

[0085] like Figure 2 As shown, brake one-way valves 25 are connected to both ends of the pressure reducing valve 22. The brake one-way valves 25 are used to control the one-way flow of oil from the second sequence valve 23 to the brake shuttle valve 21, so that the oil can flow one-way from the second sequence valve 23 to the brake shuttle valve 21. When braking is required, the hydraulic oil in the brake 24 can return oil and release pressure through the brake one-way valve 25, thereby completing the instantaneous braking of the brake 24.

[0086] The beneficial effect brought about by the above implementation method is that the brake one-way valve can control the one-way flow of oil from the second sequence valve to the brake shuttle valve, and can complete the instantaneous braking of the brake when braking is required, ensuring the normal use of the brake function of the tensioning device.

[0087] An embodiment of the present application also provides a belt conveyor, which includes a support frame, a roller, a conveyor belt and a driving device, wherein the support frame is used to support the roller, the roller is used to carry the conveyor belt, the driving device is used to drive the conveyor belt to move, and also includes a tensioning device with a hydraulic protection function as described in any of the above items, and the tensioning device is used to provide tensioning force to the conveyor belt.

[0088] When the belt conveyor is working, the tensioning device can be protected by the tensioning device with hydraulic protection function, thereby increasing the service life of the tensioning device and improving the stability of the belt conveyor during operation.

[0089] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A tensioning device with hydraulic protection function, characterized in that: It includes a tension control oil circuit, which includes a hydraulic motor, a hydraulic cylinder, a hydraulically controlled reversing valve, a logic valve, a proportional relief valve and a pilot relief valve. The hydraulic motor is connected to a tension winch, which is connected to the output end of the hydraulic cylinder through a steel wire rope. The steel wire rope is used to tension the conveyor belt of the belt conveyor. The oil outlet end of the hydraulic cylinder when under tension is connected to the hydraulically controlled reversing valve. The hydraulically controlled reversing valve is also connected to an accumulator. Both ends of the main valve of the pilot relief valve are respectively connected to the input end and the output end of the hydraulic motor. The proportional relief valve is used to control the circuit back pressure of the hydraulic motor through the pilot relief valve. When the belt conveyor stops suddenly, the hydraulic cylinder is pulled by the inertia of the transported objects on the conveyor belt. When the pressure at the oil outlet of the hydraulic cylinder is greater than or equal to the switching pressure value of the hydraulic control reversing valve, the hydraulic control reversing valve switches to connect the accumulator and the logic valve. The logic valve switches to connect the control end of the proportional relief valve and the pilot relief valve under the pressure. A first sequence valve is provided between the hydraulically controlled reversing valve and the logic valve. The hydraulically controlled reversing valve can be switched to connect with the accumulator, the first sequence valve and the logic valve in sequence. When the hydraulically controlled reversing valve is not switched to connect with the accumulator, the first sequence valve releases pressure on the external control port of the logic valve, and the logic valve is in a closed state; when the hydraulically controlled reversing valve is switched to connect with the accumulator, the first sequence valve connects the external control ports of the hydraulically controlled reversing valve and the logic valve, and the logic valve is in a conducting state.

2. The tensioning device according to claim 1, characterized in that: It also includes a brake oil circuit, which includes a brake shuttle valve, a pressure reducing valve, a second sequence valve and a brake arranged in sequence. The oil outlet end of the hydraulic cylinder when pulled is connected to the brake shuttle valve. The pressure reducing valve is used to reduce the oil pressure of the brake oil circuit to within the working pressure range of the brake. The second sequence valve makes the oil pressure of the brake greater than the stop braking pressure of the brake, and the brake stops braking.

3. The tensioning device according to claim 2, characterized in that: The directional control valve is used to control the oil pressure of the hydraulic cylinder to move the oil pump to the hydraulic cylinder bottom plate, and the directional control valve is used to control the oil pressure of the hydraulic cylinder to move the oil pump to the hydraulic cylinder bottom plate.

4. The tensioning device according to claim 3, characterized in that: It also includes an accumulator pressure-compensating oil circuit, which includes a third electromagnetic reversing valve and an accumulator pressure sensor. The third electromagnetic reversing valve is connected to the first electromagnetic reversing valve and the accumulator respectively. The accumulator pressure sensor is used to detect the pressure of the accumulator. When the detected accumulator pressure is lower than the pressure threshold of the first sequence valve that switches the hydraulically controlled reversing valve and the logic valve, the first electromagnetic reversing valve and the third electromagnetic reversing valve switch states to compensate for the accumulator pressure.

5. The tensioning device according to claim 4, characterized in that: The hydraulic motor is provided with power source pressure through the first oil pump, and the oil cylinder replenishing oil circuit is replenished with oil through the second oil pump. The input and output ends of the hydraulic motor are also connected to the high-pressure filter reversing valve group and the balancing valve group.

6. The tensioning device according to claim 5, characterized in that: The hydraulically controlled reversing valve is connected to the input end and the output end of the hydraulic motor through two oil replenishing check valves. The oil replenishing check valve is used to control the one-way flow of oil from the hydraulically controlled reversing valve to the input end and the output end of the hydraulic motor.

7. The tensioning device according to claim 6, characterized in that The proportional relief valve is an electrically controlled proportional relief valve.

8. The tensioning device according to claim 7, characterized in that: Both ends of the pressure reducing valve are connected with brake one-way valves, which are used to control the one-way flow of oil from the second sequence valve to the brake shuttle valve.

9. A belt conveyor, characterized in that: It includes a support frame, a roller, a conveyor belt and a driving device, the support frame is used to support the roller, the roller is used to carry the conveyor belt, the driving device is used to drive the conveyor belt to move, and also includes a tensioning device with a hydraulic protection function as described in any one of claims 1 to 8, the tensioning device is used to provide tensioning force to the conveyor belt.

Images