Automatic control method of hydraulic tensioning device of scraper conveyor

Abstract

The present invention discloses an automatic control method for a hydraulic tensioning device of a scraper conveyor, comprising the following steps: 1. The piston rod of the tensioning oil cylinder is extended to implement tensioning, and at the same time, hydraulic energy is charged into the accumulator; 2. The external internal control overflow valve is opened; 3. The internal pressure of the tensioning oil cylinder and the hydraulic energy of the accumulator are supplemented; 4. It is determined whether the pressure in the rodless chamber of the tensioning oil cylinder is greater than 14MPa; 5. The tensioning oil cylinder is retracted. The present invention can realize the automatic tensioning of the hydraulic tensioning device of the scraper conveyor without manual intervention; when the tensioning oil cylinder reaches the set pressure, the hydraulic mechanism can realize automatic pressure relief, so that the tensioning oil cylinder can maintain the pressure required for tensioning and continue to work without interference; at the same time, the hydraulic energy in the accumulator can be used to compensate for the energy loss of the two tensioning oil cylinders, and the tensioning time of the two tensioning oil cylinders can be extended.

Description

Technical Field

[0001] The invention belongs to the technical field of coke quenching chemical industry, and in particular relates to an automatic control method for a hydraulic tensioning device of a scraper conveyor. Background Art

[0002] At present, the environment of chemical plants is harsh, especially in the field of quenching chemical industry, where the temperature difference varies greatly. If coupled with a large load and uninterrupted operation for many years, it will have a significant impact on the expansion and contraction deformation of the chain. The existing tensioning device of the scraper conveyor is difficult to ensure that the chain is in the original tensioning state, and cannot compensate for the tensile deformation of the chain caused by the tension and the expansion and contraction deformation caused by the temperature difference. It is difficult to ensure that there is a moderate tension between the drive device and the tensioning device, and manual intervention is required, which makes it difficult to achieve automatic control of the tensioning device of the scraper conveyor; therefore, an automatic control method of the hydraulic tensioning device of the scraper conveyor should be provided. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide an automatic control method for the hydraulic tensioning device of a scraper conveyor in view of the deficiencies in the above-mentioned prior art. The method has a simple structure and a reasonable design and can realize automatic tensioning of the hydraulic tensioning device of the scraper conveyor without manual intervention. When the tensioning cylinder reaches the set pressure, the hydraulic mechanism can automatically release pressure so that the tensioning cylinder can maintain the pressure required for tensioning and continue to work without interference. At the same time, the hydraulic energy in the accumulator can be used to compensate for the energy loss of the two tensioning cylinders, thereby extending the tensioning time of the two tensioning cylinders.

[0004] To solve the above technical problems, the technical solution adopted by the present invention is: an automatic control method for a hydraulic tensioning device of a scraper conveyor, characterized in that: the hydraulic tensioning device includes two tensioning mechanisms with the same structure and symmetrically arranged at both ends of a mounting shaft and a hydraulic mechanism for controlling the action of the tensioning mechanism, the tensioning mechanism includes a box body, a square frame arranged in the box body, two guide rails arranged in parallel on the square frame, and a slider slidably mounted on the two guide rails and fixedly mounted on the end of the mounting shaft, a first push rod is installed at one end of the slider, a tensioning oil cylinder is connected to the first push rod, a second push rod is installed at the other end of the slider, the box body and The U-shaped frames are all fixedly mounted on the outer surface of the silo side plate, the hydraulic mechanism includes a total pressure oil circuit for controlling the linkage extension of the two tensioning oil cylinders, two tensioning oil cylinder retraction control oil circuits connected in parallel on the total pressure oil circuit, and a pressure relief oil circuit connected to the tensioning oil cylinder retraction control oil circuit, the total pressure oil circuit is provided with an accumulator, a one-way valve, an external internal control overflow valve and a first pressure overflow valve, the tensioning oil cylinder is connected to the accumulator through a first hydraulically controlled two-position two-way valve, the tensioning oil cylinder retraction control oil circuit is provided with a hydraulically controlled one-way valve, a second pressure overflow valve, a shuttle valve and a manual reversing valve, the shuttle valve is connected to the accumulator through a second hydraulically controlled two-position two-way valve; the control method includes:

[0005] Step 1: The piston rod of the tensioning cylinder is extended to implement tensioning, and at the same time, hydraulic energy is charged into the accumulator;

[0006] The pressure oil opens the one-way valve through the second hydraulically controlled two-position two-way valve, and part of the pressure oil enters the accumulator, and part of the pressure oil enters the rodless chambers of the two tensioning cylinders through the two first hydraulically controlled two-position two-way valves, so that the piston rods of the tensioning cylinders extend;

[0007] Step 2: Opening of the external internal control relief valve;

[0008] When the hydraulic energy in the accumulator reaches 10MPa, the internal control pressure at the front end of the one-way valve and the external control pressure at the rear end of the one-way valve act together on the external internal control relief valve, causing the external internal control relief valve to open. At this time, the pressure of the pressure oil in the total pressure oil circuit is reduced to below 1MPa, and the pressure oil in the total pressure oil circuit returns to the oil tank;

[0009] Step 3: replenishing the internal pressure of the tensioning cylinder and the hydraulic energy of the accumulator;

[0010] When the internal pressure of the tensioning cylinder is reduced to 8MPa, that is, the external control pressure at the rear end of the one-way valve is lower than 8MPa, the internal control pressure at the front end of the one-way valve and the external control pressure at the rear end of the one-way valve act together on the external internal control overflow valve, so that the external internal control overflow valve cannot be opened; the pressure oil opens the one-way valve through the second hydraulically controlled two-position two-way valve, and part of the pressure oil enters the accumulator to supplement the hydraulic energy of the accumulator; part of the pressure oil enters the rodless chamber of the tensioning cylinder through the two first hydraulically controlled two-position two-way valves to supplement the internal pressure of the tensioning cylinder;

[0011] Step 4: Determine whether the pressure in the rodless chamber of the tensioning cylinder is greater than 14 MPa;

[0012] Determine whether the pressure in the rodless chamber of the tensioning oil cylinder is greater than 14MPa. When the pressure in the rodless chamber of the tensioning oil cylinder is not greater than 14MPa, cycle steps 2 to 3 to keep the tensioning oil cylinder in an extended tensioning state until the tensioning oil cylinder is to be retracted; when the pressure in the rodless chamber of the tensioning oil cylinder increases to more than 14MPa instantaneously, the second pressure relief valve opens instantaneously to release the instantaneously increased pressure in the rodless chamber of the tensioning oil cylinder, so that the rodless chamber of the tensioning oil cylinder maintains a normal working pressure;

[0013] Step 5: Retract the tensioning cylinder;

[0014] When inspecting the scraper conveyor, it is necessary to retract the two tensioning cylinders one by one or at the same time. The specific process of retracting any one of the tensioning cylinders is as follows:

[0015] First open the manual reversing valve, and the pressure oil passes through the shuttle valve to close the second hydraulically controlled two-position two-way valve. At this time, the hydraulically controlled one-way valve opens and the first hydraulically controlled two-position two-way valve closes. At this time, the accumulator and the rodless chamber of the tensioning cylinder are disconnected, and the pressure oil enters the rod chamber of the tensioning cylinder, causing the piston rod of the tensioning cylinder to retract.

[0016] The above-mentioned automatic control method of the hydraulic tensioning device of a scraper conveyor is characterized in that: the oil inlet of the one-way valve and the oil inlet of the external internal control overflow valve are both connected to the oil outlet of the second hydraulically controlled two-position two-way valve, the first oil inlet of the accumulator and the two first hydraulically controlled two-position two-way valves are both connected to the oil outlet of the one-way valve, and the second oil inlet of the two first hydraulically controlled two-position two-way valves are respectively connected to the rod chambers of the two tensioning cylinders.

[0017] The above-mentioned automatic control method of the hydraulic tensioning device of a scraper conveyor is characterized in that: the manual reversing valve is a three-position four-way reversing valve, and the two oil inlets of the shuttle valve are respectively connected to the oil inlets of the two three-position four-way reversing valves.

[0018] The above-mentioned automatic control method of the hydraulic tensioning device of a scraper conveyor is characterized in that: the oil inlet of the first pressure relief valve is connected to the total pressure oil circuit, the oil outlet of the first pressure relief valve is connected to the oil tank, and the oil inlets of the two second pressure relief valves are respectively connected to the rodless chambers of the two tensioning cylinders.

[0019] The above-mentioned automatic control method of the hydraulic tensioning device of a scraper conveyor is characterized in that a pull rope displacement sensor is arranged on the outer surface of the silo side plate, and the pull rope of the pull rope displacement sensor is wound on the installation shaft.

[0020] The above-mentioned automatic control method of the hydraulic tensioning device of a scraper conveyor is characterized in that: in step 2 and step 3, the pressure of the external internal control overflow valve ranges from 90 bar to 210 bar.

[0021] The above-mentioned automatic control method of the hydraulic tensioning device of a scraper conveyor is characterized in that: in step four, the pressure of the second pressure relief valve is 140 bar.

[0022] The above-mentioned automatic control method of the hydraulic tensioning device of a scraper conveyor is characterized in that the U-shaped frame includes two first installation frames arranged in parallel, a second installation frame arranged at one end of the two first installation frames, and a support plate arranged at the other end of the two first installation frames.

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] 1. The present invention provides a total pressure oil circuit, two tensioning oil cylinder retraction control oil circuits and a pressure relief oil circuit, and provides an accumulator, a one-way valve and a second hydraulically controlled two-position two-way valve on the total pressure oil circuit. The two tensioning oil cylinders are respectively connected to the total pressure oil circuit through two first hydraulically controlled two-position two-way valves. Therefore, the total pressure circuit can not only realize the simultaneous extension of the piston rods of the two tensioning oil cylinders, but also realize the purpose of charging the hydraulic energy into the accumulator. In the process of controlling the two tensioning oil cylinders to tension at the same time, the hydraulic energy is synchronously charged into the accumulator; in the process of continuous tensioning of the two tensioning oil cylinders, the hydraulic energy in the accumulator can be used to compensate for the energy loss of the two tensioning oil cylinders, and the tensioning time of the two tensioning oil cylinders can be extended, with good use effect.

[0025] 2. The present invention arranges an external internal control relief valve on the total pressure oil circuit, and an internal control oil circuit is arranged between the external internal control relief valve and the one-way valve. Under the joint action of the one-way valve and the internal control oil circuit, the on-off of the external internal control relief valve can be controlled. When the external internal control relief valve is opened, the pressure of the pressure oil in the total pressure oil circuit is reduced to below 1MPa, and the pressure oil in the total pressure oil circuit can be returned to the oil tank in a low-pressure state, so that the pressure oil in the total pressure oil circuit can be circulated.

[0026] 3. When the accumulator pressure of the hydraulic mechanism of the present invention is lower than 8MPa or the tensioning cylinder is in the tensioning process, the hydraulic pump is in high-pressure operation, and is in low-pressure unloading for the rest of the time, thereby avoiding long-term high-pressure operation of the hydraulic pump, saving energy and protecting the environment, and reducing wear of the hydraulic pump.

[0027] 4. The present invention has a simple structure, reasonable design, low manufacturing cost and is easy to promote and apply.

[0028] To sum up, the present invention has a simple structure and a reasonable design, and can realize automatic tensioning of the hydraulic tensioning device of the scraper conveyor without manual intervention; when the tensioning cylinder reaches the set pressure, the hydraulic mechanism can realize automatic pressure relief, so that the tensioning cylinder can maintain the pressure required for tensioning and continue to work without interference; at the same time, the hydraulic energy in the accumulator can be used to compensate for the energy loss of the two tensioning cylinders, and the tensioning time of the two tensioning cylinders can be extended.

[0029] The present invention is further described in detail below through the accompanying drawings and examples. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the structure of the present invention.

[0031] Figure 2 for Figure 1 AA section view.

[0032] Figure 3 It is a control principle diagram of the hydraulic mechanism of the present invention.

[0033] Figure 4 It is a flow chart of the present invention.

[0034] Description of reference numerals:

[0035] 1—silo side plate; 2—mounting shaft; 3—tail wheel;

[0036] 4—Box body; 5-1—First installation frame; 5-2—Second installation frame;

[0037] 5-3—support plate; 6—guide rail; 7—slider;

[0038] 8—first push rod; 9—tensioning cylinder; 10—second push rod;

[0039] 11—first pressure relief valve; 12—second pressure relief valve; 13—hydraulic controlled one-way valve;

[0040] 14—One-way valve; 15—External internal control relief valve;

[0041] 16—first hydraulically controlled two-position two-way valve; 17—accumulator;

[0042] 18—Second hydraulically controlled two-position two-way valve; 19—Manual reversing valve; 20—Shuttle valve;

[0043] 21—Throttle valve. DETAILED DESCRIPTION

[0044] like Figures 1 to 4 The automatic control method of the hydraulic tensioning device of the scraper conveyor shown in the figure, the hydraulic tensioning device used in the method includes two tensioning mechanisms with the same structure and symmetrically arranged at both ends of the installation shaft 2 and a hydraulic mechanism for controlling the action of the tensioning mechanism, the tensioning mechanism includes a box body 4, a square frame arranged in the box body 4, two guide rails 6 arranged in parallel on the square frame, and a slider 7 slidably mounted on the two guide rails 6 and fixedly mounted on the end of the installation shaft 2, one end of the slider 7 is installed with a first push rod 8, the first push rod 8 is connected to a tensioning cylinder 9, the other end of the slider 7 is installed with a second push rod 10, the box body 4 and the square frame are fixedly mounted on the silo side plate 1 On the outer surface of , the hydraulic mechanism includes a total pressure oil circuit for controlling the linkage extension of the two tensioning oil cylinders 9, two tensioning oil cylinder retraction control oil circuits connected in parallel on the total pressure oil circuit, and a pressure relief oil circuit connected to the tensioning oil cylinder retraction control oil circuit. The total pressure oil circuit is provided with an accumulator 17, a one-way valve 14, an external internal control relief valve 15 and a first pressure relief valve 11. The tensioning oil cylinder 9 is connected to the accumulator 17 through a first hydraulically controlled two-position two-way valve 16. The tensioning oil cylinder retraction control oil circuit is provided with a hydraulically controlled one-way valve 13, a second pressure relief valve 12, a shuttle valve 20 and a manual reversing valve 19. The shuttle valve 20 is connected to the accumulator 17 through a second hydraulically controlled two-position two-way valve 18. The control method includes:

[0045] Step 1: The piston rod of the tensioning cylinder 9 is extended to implement tensioning, and at the same time, hydraulic energy is charged into the accumulator 17;

[0046] The pressure oil opens the check valve 14 through the second hydraulically controlled two-position two-way valve 18, and a part of the pressure oil enters the accumulator 17, and a part of the pressure oil enters the rodless chambers of the two tensioning cylinders 9 through the two first hydraulically controlled two-position two-way valves 16, so that the piston rods of the tensioning cylinders 9 extend;

[0047] like Figure 1 and Figure 2 As shown, in this embodiment, the piston rod of the tensioning cylinder 9 is fixedly connected to the first push rod 8. Since the first push rod 8 is fixedly connected to the slider 7, the fixed connection between the piston rod of the tensioning cylinder 9 and the slider 7 can be achieved. Since the slider 7 is fixedly mounted on the end of the mounting shaft 2, and two parallel tail wheels 3 are mounted on the mounting shaft 2, and the scraper chain is mounted on the tail wheel 3, when the piston rod of the tensioning cylinder 9 is extended, it can drive the slider 7 to move to the right along the length direction of the two guide rails 6, and the slider 7 can drive the mounting shaft 2 and the tail wheel 3 to move to the right at the same time, thereby achieving the tensioning of the scraper chain.

[0048] like Figure 3 As shown, in this embodiment, by setting a total pressure oil circuit, two tensioning cylinder retraction control oil circuits and a pressure relief oil circuit, by setting an accumulator 17, a one-way valve 14 and a second hydraulically controlled two-position two-way valve 18 on the total pressure oil circuit, the two tensioning cylinders 9 are respectively connected to the total pressure oil circuit through two first hydraulically controlled two-position two-way valves 16. Therefore, the total pressure circuit can not only achieve the purpose of controlling the simultaneous extension of the piston rods of the two tensioning cylinders 9, but also achieve the purpose of charging hydraulic energy into the accumulator 17. In the process of controlling the two tensioning cylinders 9 to implement tensioning at the same time, hydraulic energy is charged into the accumulator 17 synchronously; in the process of continuous tensioning of the two tensioning cylinders 9, the hydraulic energy in the accumulator 17 can be used to compensate for the energy loss of the two tensioning cylinders 9, and the tensioning time of the two tensioning cylinders 9 can be extended, with good use effect.

[0049] Step 2: Opening of the external internal control relief valve 15;

[0050] When the hydraulic energy in the accumulator 17 reaches 10MPa, the internal control pressure at the front end of the one-way valve 14 and the external control pressure at the rear end of the one-way valve 14 act together on the external internal control relief valve 15, so that the external internal control relief valve 15 opens. At this time, the pressure of the pressure oil in the total pressure oil circuit drops below 1MPa, and the pressure oil in the total pressure oil circuit returns to the oil tank.

[0051] In this embodiment, an external internally controlled overflow valve 15 is provided on the total pressure oil circuit, and an internal control oil circuit is provided between the external internally controlled overflow valve 15 and the one-way valve 14. In actual use, under the joint action of the one-way valve 14 and the internal control oil circuit, the on-off of the external internally controlled overflow valve 15 can be controlled. When the external internally controlled overflow valve 15 is opened, the pressure of the pressure oil in the total pressure oil circuit is reduced to below 1 MPa, and the pressure oil in the total pressure oil circuit can be returned to the oil tank in a low-pressure state, so that the pressure oil in the total pressure oil circuit can be circulated.

[0052] Step 3: replenishing the internal pressure of the tensioning cylinder 9 and the hydraulic energy of the accumulator 17;

[0053] When the internal pressure of the tensioning cylinder 9 is reduced to 8MPa, that is, the external control pressure at the rear end of the one-way valve 14 is lower than 8MPa, the internal control pressure at the front end of the one-way valve 14 and the external control pressure at the rear end of the one-way valve 14 act together on the external internal control overflow valve 15, so that the external internal control overflow valve 15 cannot be opened; the pressure oil opens the one-way valve 14 through the second hydraulically controlled two-position two-way valve 18, and a part of the pressure oil enters the accumulator 17 to supplement the hydraulic energy of the accumulator 17; a part of the pressure oil enters the rodless chamber of the tensioning cylinder 9 through the two first hydraulically controlled two-position two-way valves 16 to supplement the internal pressure of the tensioning cylinder 9;

[0054] Step 4: Determine whether the pressure in the rodless chamber of the tensioning cylinder is greater than 14 MPa;

[0055] Determine whether the pressure in the rodless chamber of the tensioning oil cylinder 9 is greater than 14MPa. When the pressure in the rodless chamber of the tensioning oil cylinder 9 is not greater than 14MPa, cycle steps 2 to 3 to keep the tensioning oil cylinder 9 in an extended tensioned state until the tensioning oil cylinder 9 is to be retracted; when the pressure in the rodless chamber of the tensioning oil cylinder 9 increases to more than 14MPa instantaneously, the second pressure relief valve 12 opens instantaneously to release the instantaneously increased pressure in the rodless chamber of the tensioning oil cylinder 9, so that the rodless chamber of the tensioning oil cylinder 9 maintains a normal working pressure;

[0056] In this embodiment, during the continuous tensioning of the two tensioning cylinders 9, after the pressure oil in the total pressure oil circuit returns to the oil tank in a low-pressure state, it is necessary to replenish the internal pressure of the two tensioning cylinders 9 and the hydraulic energy of the accumulator 17, so as to compensate for the energy loss during the continuous tensioning of the two tensioning cylinders 9 and make the hydraulic energy of the accumulator 17 in a full state.

[0057] In this embodiment, the number of the second pressure relief valves 12 is two, and the two second pressure relief valves 12 correspond one to one to the two tensioning cylinders 9 respectively.

[0058] In this embodiment, in step four, by judging whether the pressure in the rodless chamber of the tensioning cylinder 9 is greater than 14 MPa, the safety of the entire hydraulic control system is enhanced. When the pressure in the rodless chamber of the tensioning cylinder 9 instantly increases to above 14 MPa, the second pressure relief valve 12 opens instantly to release the instantly increased pressure in the rodless chamber of the tensioning cylinder 9. At this time, the second pressure relief valve 12 acts as a safety protection valve in the pressure relief oil circuit to avoid excessive pressure in the rodless chamber of the tensioning cylinder 9, thereby ensuring that the normal working pressure can be maintained in the rodless chamber of the tensioning cylinder 9.

[0059] Step 5: retracting the tensioning cylinder 9;

[0060] When the scraper conveyor is inspected, the two tensioning cylinders 9 need to be retracted separately in sequence or simultaneously. The specific process of retracting any one of the tensioning cylinders 9 is as follows:

[0061] First open the manual reversing valve 19, and the pressure oil passes through the shuttle valve 20 to close the second hydraulically controlled two-position two-way valve 18. At this time, the hydraulically controlled one-way valve 13 is opened, and the first hydraulically controlled two-position two-way valve 16 is closed. At this time, the accumulator 17 is disconnected from the rodless chamber of the tensioning cylinder 9, and the pressure oil enters the rod chamber of the tensioning cylinder 9, causing the piston rod of the tensioning cylinder 9 to retract.

[0062] In this embodiment, the number of manual reversing valves 19 and the number of hydraulically controlled one-way valves 13 are both two. The two manual reversing valves 19 are respectively arranged in the retraction control oil circuits of the two tensioning cylinders, and correspond one-to-one to the two tensioning cylinders 9 respectively. The two hydraulically controlled one-way valves 13 also correspond one-to-one to the two tensioning cylinders 9 respectively, that is, the two manual reversing valves 19 also correspond one-to-one to the two hydraulically controlled one-way valves 13 respectively.

[0063] When the two tensioning cylinders 9 are retracted separately and in sequence, when any one of the hydraulically controlled one-way valves 13 is opened and the first hydraulically controlled two-position two-way valve 16 corresponding to any one of the hydraulically controlled one-way valves 13 is closed, the rodless chamber of the tensioning cylinder 9 corresponding to any one of the hydraulically controlled one-way valves 13 can be disconnected from the accumulator 17. Afterwards, during the smooth retraction of the tensioning cylinder 9 corresponding to any one of the hydraulically controlled one-way valves 13, the normal operation of the other tensioning cylinder 9 will not be affected.

[0064] When retracting the two tensioning cylinders 9 at the same time, it is only necessary to open the two manual reversing valves 19 at the same time, close the two second hydraulically controlled two-position two-way valves 18 at the same time, open the two hydraulically controlled one-way valves 13 at the same time, and close the two first hydraulically controlled two-position two-way valves 16 at the same time. At this time, the accumulator 17 is disconnected from the rodless chambers of the two tensioning cylinders 9, and the pressure oil enters the rod chambers of the two tensioning cylinders 9 at the same time, causing the piston rods of the two tensioning cylinders 9 to retract at the same time.

[0065] like Figure 3 As shown, in this embodiment, the oil inlet of the one-way valve 14 and the oil inlet of the external internal controlled overflow valve 15 are both connected to the oil outlet of the second hydraulically controlled two-position two-way valve 18, the first oil inlets of the accumulator 17 and the two first hydraulically controlled two-position two-way valves 16 are both connected to the oil outlet of the one-way valve 14, and the second oil inlets of the two first hydraulically controlled two-position two-way valves 16 are respectively connected to the rod chambers of the two tensioning cylinders 9.

[0066] In this embodiment, the manual reversing valve 19 is a three-position four-way reversing valve, and the two oil inlets of the shuttle valve 20 are respectively connected to the oil inlets of the two three-position four-way reversing valves.

[0067] In this embodiment, the oil inlet of the first pressure relief valve 11 is connected to the total pressure oil circuit, the oil outlet of the first pressure relief valve 11 is connected to the oil tank, and the oil inlets of the two second pressure relief valves 12 are respectively connected to the rodless chambers of the two tensioning cylinders 9.

[0068] In this embodiment, a throttle valve 21 is provided on the total pressure oil circuit, and the throttle valve 21 is arranged in parallel with the one-way valve 14 .

[0069] In this embodiment, a pull-wire displacement sensor is provided on the outer surface of the silo side plate 1 , and the pull wire of the pull-wire displacement sensor is wound around the mounting shaft 2 .

[0070] In actual use, the pull rope displacement sensor can be used to detect the tensioning distance in real time, and the real-time detection data can be transmitted to the controller, so that the working status of the tensioning device can be remotely monitored and the working status of the tensioning device can be reflected in real time.

[0071] In this embodiment, in step 2 and step 3, the pressure of the external internal control relief valve 15 ranges from 90 bar to 210 bar.

[0072] In this embodiment, in step 4, the pressure of the second pressure relief valve 12 is 140 bar.

[0073] In this embodiment, the first pressure relief valve 11 is a pressure relief valve installed on the total pressure oil circuit, which can realize overflow and pressure relief of the total pressure oil circuit. In actual use, the pressure of the first pressure relief valve 11 is 130 bar.

[0074] like Figure 2 As shown, in this embodiment, the U-shaped frame includes two first installation frames 5-1 arranged in parallel, a second installation frame 5-2 arranged at one end of the two first installation frames 5-1, and a support plate 5-3 arranged at the other end of the two first installation frames 5-1.

[0075] During actual installation, the support plate 5-3 is fixedly mounted on the inner surface of the side plate of the box body 4, the cylinder body of the tensioning cylinder 9 is fixedly mounted on the outer surface of the side plate of the box body 4, the piston rod of the tensioning cylinder 9 passes through the side plate of the box body 4 and the support plate 5-3, and is fixedly connected to the first push rod 8.

[0076] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent structural change made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. An automatic control method for a hydraulic tensioning device of a scraper conveyor, the hydraulic tensioning device comprising two tensioning mechanisms of identical structure and symmetrically arranged at two ends of a mounting shaft (2) and a hydraulic mechanism for controlling the action of the tensioning mechanisms, the tensioning mechanism comprising a box (4), a square frame arranged in the box (4), two guide rails (6) arranged in parallel on the square frame, and a slider (7) slidably mounted on the two guide rails (6) and fixedly mounted on the end of the mounting shaft (2), one end of the slider (7) being mounted with a first push rod (8), the first push rod (8) being connected with a tensioning oil cylinder (9), the other end of the slider (7) being mounted with a second push rod (10), the box (4) and the square frame being fixedly mounted on the side plate (1) of a silo On the outer surface, the hydraulic mechanism comprises a total pressure oil circuit for controlling the linkage extension of the two tensioning oil cylinders (9), two tensioning oil cylinder retraction control oil circuits connected in parallel on the total pressure oil circuit, and a pressure relief oil circuit connected to the tensioning oil cylinder retraction control oil circuit. The total pressure oil circuit is provided with an accumulator (17), a one-way valve (14), an external internal control overflow valve (15) and a first pressure overflow valve (11). The tensioning oil cylinder (9) is connected to the accumulator (17) through a first hydraulically controlled two-position two-way valve (16). The tensioning oil cylinder retraction control oil circuit is provided with a hydraulically controlled one-way valve (13), a second pressure overflow valve (12), a shuttle valve (20) and a manual reversing valve (19). The shuttle valve (20) is connected to the accumulator (17) through a second hydraulically controlled two-position two-way valve (18). The characteristics are: The control method includes: Step 1: The piston rod of the tensioning cylinder (9) is extended to implement tensioning, and at the same time, hydraulic energy is charged into the accumulator (17); The pressure oil opens the one-way valve (14) through the second hydraulically controlled two-position two-way valve (18), a part of the pressure oil enters the accumulator (17), and a part of the pressure oil enters the rodless chambers of the two tensioning oil cylinders (9) through the two first hydraulically controlled two-position two-way valves (16), so that the piston rods of the tensioning oil cylinders (9) extend; Step 2: Opening of the external internal control relief valve (15); When the hydraulic energy in the accumulator (17) reaches 10 MPa, the internal control pressure at the front end of the one-way valve (14) and the external control pressure at the rear end of the one-way valve (14) act together on the external internal control relief valve (15), causing the external internal control relief valve (15) to open. At this time, the pressure of the pressure oil in the total pressure oil circuit is reduced to below 1 MPa, and the pressure oil in the total pressure oil circuit returns to the oil tank; Step 3: replenishing the internal pressure of the tensioning cylinder (9) and the hydraulic energy of the accumulator (17); When the internal pressure of the tensioning oil cylinder (9) decreases to 8 MPa, that is, the external control pressure at the rear end of the one-way valve (14) is lower than 8 MPa, the internal control pressure at the front end of the one-way valve (14) and the external control pressure at the rear end of the one-way valve (14) act together on the external internal control overflow valve (15), so that the external internal control overflow valve (15) cannot be opened; the pressure oil opens the one-way valve (14) through the second hydraulically controlled two-position two-way valve (18), and a part of the pressure oil enters the accumulator (17) to supplement the hydraulic energy of the accumulator (17); a part of the pressure oil enters the rodless chamber of the tensioning oil cylinder (9) through the two first hydraulically controlled two-position two-way valves (16) to supplement the internal pressure of the tensioning oil cylinder (9); Step 4: Determine whether the pressure in the rodless chamber of the tensioning cylinder is greater than 14 MPa; Determine whether the pressure in the rodless chamber of the tensioning oil cylinder (9) is greater than 14 MPa. When the pressure in the rodless chamber of the tensioning oil cylinder (9) is not greater than 14 MPa, cycle steps 2 to 3 to keep the tensioning oil cylinder (9) in an extended tensioned state until the tensioning oil cylinder (9) is to be retracted; when the pressure in the rodless chamber of the tensioning oil cylinder (9) increases instantaneously to above 14 MPa, the second pressure relief valve (12) opens instantaneously to release the instantaneously increased pressure in the rodless chamber of the tensioning oil cylinder (9), so that the rodless chamber of the tensioning oil cylinder (9) maintains a normal working pressure; Step 5: retracting the tensioning cylinder (9); When the scraper conveyor is being repaired, the two tensioning cylinders (9) need to be retracted individually in sequence or simultaneously. The specific process of retracting any one of the tensioning cylinders (9) is as follows: First, the manual reversing valve (19) is opened, and the pressure oil passes through the shuttle valve (20) to close the second hydraulically controlled two-position two-way valve (18). At this time, the hydraulically controlled one-way valve (13) is opened, and the first hydraulically controlled two-position two-way valve (16) is closed. At this time, the accumulator (17) and the rodless chamber of the tensioning cylinder (9) are disconnected, and the pressure oil enters the rod chamber of the tensioning cylinder (9), causing the piston rod of the tensioning cylinder (9) to retract.

2. The automatic control method of the hydraulic tensioning device of a scraper conveyor according to claim 1 is characterized in that: The oil inlet of the one-way valve (14) and the oil inlet of the external internal control overflow valve (15) are both connected to the oil outlet of the second hydraulically controlled two-position two-way valve (18); the first oil inlets of the accumulator (17) and the two first hydraulically controlled two-position two-way valves (16) are both connected to the oil outlet of the one-way valve (14); and the second oil inlets of the two first hydraulically controlled two-position two-way valves (16) are respectively connected to the rod chambers of the two tensioning cylinders (9).

3. The automatic control method of the hydraulic tensioning device of a scraper conveyor according to claim 1 is characterized in that: The manual reversing valve (19) is a three-position four-way reversing valve, and the two oil inlets of the shuttle valve (20) are respectively connected to the oil inlets of the two three-position four-way reversing valves.

4. The automatic control method of the hydraulic tensioning device of a scraper conveyor according to claim 1 is characterized in that: The oil inlet of the first pressure relief valve (11) is connected to the total pressure oil circuit, the oil outlet of the first pressure relief valve (11) is connected to the oil tank, and the oil inlets of the two second pressure relief valves (12) are respectively connected to the rodless chambers of the two tensioning cylinders (9).

5. The automatic control method of the hydraulic tensioning device of a scraper conveyor according to claim 1 is characterized in that: A pull-wire displacement sensor is provided on the outer surface of the silo side plate (1), and the pull wire of the pull-wire displacement sensor is wound around the mounting shaft (2).

6. The automatic control method of the hydraulic tensioning device of a scraper conveyor according to claim 1 is characterized in that: In step 2 and step 3, the pressure of the external internal control overflow valve (15) ranges from 90 bar to 210 bar.

7. The automatic control method of the hydraulic tensioning device of a scraper conveyor according to claim 1 is characterized in that: In step 4, the pressure of the second pressure relief valve (12) is 140 bar.

8. The automatic control method of the hydraulic tensioning device of a scraper conveyor according to claim 1 is characterized in that: The U-shaped frame comprises two first installation frames (5-1) arranged in parallel, a second installation frame (5-2) arranged at one end of the two first installation frames (5-1), and a support plate (5-3) arranged at the other end of the two first installation frames (5-1).

Images