Swinging door control system and control method thereof

Abstract

The present application relates to the technical field of hydraulic control, and particularly relates to a swing door control system and a control method thereof. The technical scheme of the present application is as follows: the swing door control system comprises a heavy load hydraulic cylinder and a control valve group, and is characterized in that: the control valve group comprises a main control valve group and a buffer control valve group, wherein the main control valve group comprises a pressure reducing valve and a main control valve; the buffer control valve group comprises a buffer control valve which is arranged to be opened when deceleration is required in the opening and closing process of the swing door; and the control method applied to the swing door control system. Compared with the prior art, the swing door control system has the advantages that: the swing door control system controls the buffer control valve to reduce the torsion force and make the swing door decelerate by shunting, and has the flexibility of simple operation and convenient adjustment. The control method applied to the swing door control system makes the swing door make a smooth deceleration movement in the opening or closing process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydraulic control, and particularly relates to a swing door control system and a control method thereof. BACKGROUND

[0002] In the industrial production process, some devices (for example, a rolling mill housing) are provided with some movable safety swing doors (for example, a swing door of a rolling mill housing) for safety consideration. On one hand, the safety swing doors block operators and the inside of the device during production, and on the other hand, the safety swing doors need to be opened during maintenance or replacement of parts. For safety consideration, the mass of the safety swing door is usually large, the space of the hinge position of the safety swing door is small, and therefore a large torque driving source (for example, a hydraulic oil cylinder) needs to be used to drive the safety swing door to open or close. When the safety swing door is opened or closed to a position, inertia formed due to the large mass of the safety swing door easily causes strong impact with the device, thereby damaging the device or causing a safety accident.

[0003] To solve the above problems, the patent No. CN201210393332.1 (publication No. CN102878044A) of Chinese invention patent "A mine-used concrete delivery pump with full hydraulic control" discloses a mine-used concrete delivery pump with full hydraulic control and hydraulic buffer circuit. In the buffer circuit, the position information of the piston triggers the pressure difference signaling valve to reverse, and at the same time, the overflow valve in series with the hydraulic cylinder on the high-pressure oil circuit is activated to reduce the system pressure and flow, slow down the cylinder and play a buffering role. However, the control method of the above-mentioned invention uses an overflow valve to release pressure protection. Before work, it must set a certain pressure value. The set pressure value must be able to meet the high pressure required for the valve to start. The safety swing door needs to be constantly slowed down until it stops during the process of gradually approaching the specified position. Due to the uniqueness of the set pressure value of the overflow valve, the set pressure value needs to be adjusted constantly to make the pressure fluctuate small during the safety swing door deceleration process. The set pressure value needs to be constantly changed by matching the values measured by the pressure measuring devices installed at both ends of the overflow valve. During this period, a series of processes such as adjustment, checking the pressure gauge, stable operation of the system, and repeated pressure increase are required, making the adjustment operation complicated. Further, due to the large mass of the safety swing door, a large power consumption is required for the repeated opening and closing of the safety swing door. Therefore, during the manual adjustment process, the pressure value for starting the opening and closing action will be consciously reduced as much as possible to reduce power consumption. However, the working conditions of the opening and closing are different for different mass safety swing doors or different opening and closing positions of the same safety swing door, so the starting torque is not fixed. Therefore, during the process of starting the safety swing door from high pressure to stopping, the pressure values at both ends of the swing cylinder need to be constantly adjusted to slow down until it stops to avoid strong impact with the equipment. During this period, if the pressure value is reduced too much, it will cause the pressure value to fluctuate too much and damage the valve group. If the pressure value is reduced too little, it will cause the swing door to still have too much momentum after slowing down, which will damage the equipment. If an overflow valve is used for adjustment, the overall adjustment process will be more complicated, which will greatly increase the risk of human operation and judgment errors. SUMMARY

[0004] The first technical problem to be solved by the present application is to provide a swing door control system with convenient opening and closing speed adjustment.

[0005] The second technical problem to be solved by the present application is to provide a control method of the swing door control system with convenient opening and closing speed adjustment.

[0006] The technical scheme adopted by the present application to solve the first technical problem is: the swing door control system comprises a heavy load hydraulic cylinder connected with a swing door, and a control valve group connected with the heavy load hydraulic cylinder, the control valve group is used for controlling the hydraulic oil pressure and flow of the heavy load hydraulic cylinder, thereby controlling the running speed of the swing door during opening or closing, characterized in that: the control valve group comprises a main control valve group and a buffer control valve group, wherein the main control valve group comprises:

[0007] a pressure reducing valve, an inlet of the pressure reducing valve being communicated with a hydraulic oil supply pipeline;

[0008] a main control valve, the main control valve being a three-position four-way directional valve, an oil inlet P of the main control valve being communicated with an outlet of the pressure reducing valve, an oil return port T of the main control valve being communicated with a hydraulic oil return pipeline, a first working port A of the main control valve being connected with the oil inlet of the heavy load hydraulic cylinder after a first throttle valve, and an oil outlet of the heavy load hydraulic cylinder being connected with a second working port B of the main control valve after a second throttle valve;

[0009] the buffer control valve group comprises:

[0010] a buffer control valve, an inlet of the buffer control valve being communicated with the outlet of the pressure reducing valve, the buffer control valve having at least one outlet communicated with the hydraulic oil return pipeline, the buffer control valve having at least two different working positions of opening and closing, wherein when the buffer control valve is opened, the hydraulic oil path passing through the buffer control valve is communicated, and when the buffer control valve is closed, the hydraulic oil path passing through the buffer control valve is disconnected;

[0011] the buffer control valve is arranged to be opened when deceleration is required during the opening and closing of the swing door, thereby shunting the hydraulic oil flowing out of the pressure reducing valve, and adjusting the hydraulic oil pressure and flow of the heavy load hydraulic cylinder.

[0012] In order to realize the start and end of the swing door deceleration action during movement, preferably, the buffer control valve is a two-position four-way directional valve, an oil inlet P of the buffer control valve being communicated with the outlet of the pressure reducing valve, an oil return port T of the buffer control valve being communicated with the hydraulic oil return pipeline, a first working port A of the buffer control valve being communicated with the hydraulic oil return pipeline, and a second working port B of the buffer control valve being blocked. Thus, when the P port of the buffer control valve is communicated with the A port, the buffer control valve is opened, and when the P port of the buffer control valve is communicated with the B port, the swing door deceleration action starts; the buffer control valve is closed, and the swing door deceleration action ends.

[0013] In order to realize the adjustment of the acceleration after the swing door deceleration action starts, preferably, a third throttle valve is arranged between the buffer control valve and the hydraulic oil return pipeline, the third throttle valve is an oil inlet throttling type one-way adjustable flow valve, the first working port A of the buffer control valve is communicated with the inlet of the third throttle valve, and the outlet of the third throttle valve is communicated with the hydraulic oil return pipeline. After the swing door deceleration action starts, the increase and decrease of the flow of the hydraulic oil flowing through the heavy load hydraulic cylinder can be realized by reducing or increasing the opening degree of the throttle port of the third throttle valve, so that the torque of the heavy load hydraulic cylinder is increased or decreased, and the acceleration of the swing door deceleration action is controlled, and the increase and decrease of the acceleration of the swing door deceleration action after the swing door deceleration action starts only needs to reduce or increase the opening degree of the throttle port of the third throttle valve clockwise or counterclockwise, the adjustment action is simple, the risk of manual operation is reduced, the speed of adjustment is increased, and significant progress is achieved.

[0014] In order to realize the stable movement of the swing door during the opening and closing process, preferably, the first throttle valve and the second throttle valve are oil outlet throttling type one-way adjustable flow valves, the inlet of the first throttle valve is communicated with the oil inlet of the heavy load hydraulic cylinder, and the outlet is communicated with the A port of the main control valve; the inlet of the second throttle valve is communicated with the oil outlet of the heavy load hydraulic cylinder, and the outlet is communicated with the B port of the main control valve. The technical scheme makes the back pressure generated when the oil flows through the first throttle valve and the second throttle valve in the oil outlet direction, reduces the pressure fluctuation of the hydraulic oil path of the heavy load hydraulic cylinder, and further makes the swing door move stably.

[0015] In order to facilitate the daily maintenance of the heavy load hydraulic cylinder by the operator, preferably, a first stop valve is arranged between the inlet of the first throttle valve and the oil inlet of the heavy load hydraulic cylinder, and a second stop valve is arranged between the inlet of the second throttle valve and the oil outlet of the heavy load hydraulic cylinder. Thus, the oil path connected to the two ends of the heavy load hydraulic cylinder is disconnected when the operator closes the first stop valve and the second stop valve, so that the heavy load hydraulic cylinder can be maintained separately.

[0016] In order to realize the automatic deceleration movement of the swing door during the opening and closing process, preferably, a position detection switch arranged in the swing range of the swing door is further included, the position detection switch includes a first travel switch and a second travel switch 72, wherein the first travel switch is arranged to meet the following conditions: when the swing door moves to the first travel switch and triggers the first travel switch, the included angle between the swing door and the equipment body is 25°-35°; when the swing door moves to the second travel switch and triggers the second travel switch, the included angle between the swing door and the equipment body is 100°-110°.

[0017] In order to facilitate automatic control, that is, when the swing door needs to open deceleration in the opening and closing process, when the closing deceleration, the buffer control valve is set to be powered on when the main control valve is powered on after working for a first preset time or when the first stroke switch is triggered, and is powered off when the buffer control valve is powered off after working for a second preset time or when the second stroke switch is triggered. In the technical scheme, the control relationship between the first stroke switch, the second stroke switch, the first preset time, the second preset time, and the buffer control valve power-off and power-on behaviors is established to realize the automatic control of the swing door deceleration behavior.

[0018] In order to realize that the heavy load hydraulic cylinder does not work when the main control valve is not powered on, preferably, the main control valve is an "O" type three-position four-way valve. Thus, the main control valve 3 is in a normal working position, and the main control valve hydraulic oil circuit is disconnected.

[0019] The technical scheme adopted by the present application to solve the second technical problem is: the control method of the swing door control system, characterized in that it comprises the following steps:

[0020] S1: preparation before debugging: set the pressure of the pressure reducing valve so that the torque provided by the heavy load hydraulic cylinder can start the swing door;

[0021] S2: swing door opening control step:

[0022] S2-1, the main control valve is powered on, the buffer control valve is powered off, the heavy load hydraulic cylinder is started at high pressure, and the swing door is quickly opened;

[0023] S2-2, when the main control valve works for a first preset time or when the first stroke switch is triggered, the buffer control valve is powered on, and the swing door continues to open at a reduced speed;

[0024] S2-3, when the buffer control valve works for a second preset time or when the second stroke switch is triggered,

[0025] the main control valve and the buffer control valve are both powered off, and the swing door stops opening;

[0026] S3: swing door closing control step:

[0027] S3-1, the main control valve is powered on, the buffer control valve is powered off, the heavy load hydraulic cylinder is started at high pressure, and the swing door is quickly closed;

[0028] S3-2, when the main control valve works for a first preset time or when the second stroke switch is triggered, the buffer control valve is powered on, and the swing door continues to close at a reduced speed;

[0029] S3-3, when the buffer control valve is in operation for a second preset time or when the first travel switch is triggered, the main control valve and the buffer control valve are both powered off and closed, and the swing door stops closing.

[0030] In order to ensure the safety of the swing door during opening or closing, preferably, a third throttle valve is arranged between the buffer control valve and the hydraulic oil return pipeline, the third throttle valve is an oil inlet throttling type one-way adjustable flow valve, the first working port A of the buffer control valve is in communication with the inlet of the third throttle valve, and the outlet of the third throttle valve is in communication with the hydraulic oil return pipeline.

[0031] In the process of setting the pressure of the pressure reducing valve in the debugging preparation step S1, the following adjustments are also made: the throttling openings of the first throttle valve and the second throttle valve are opened to the maximum value; and the throttling opening of the third throttle valve is opened to a preset initial value.

[0032] In S2-2 of the swing door opening control step S2, after the buffer control valve is powered on, the following adjustments are made: the throttling openings of the first throttle valve and the second throttle valve are reduced but not closed to make the active opening movement smooth; and the throttling opening of the third throttle valve is reduced or increased to make the speed of the swing door opening movement smoothly reduced.

[0033] In S3-2 of the swing door closing control step S3, after the buffer control valve is powered on, the following adjustments are made: the throttling openings of the first throttle valve and the second throttle valve are reduced but not closed to make the swing door closing movement smooth; and the throttling opening of the third throttle valve is reduced or increased to make the speed of the swing door closing movement smoothly reduced. In this technical solution, the adjustments of the first throttle valve and the second throttle valve make the back pressure formed through the heavy load hydraulic oil cylinder oil way, and the pressure fluctuation of the hydraulic oil way is reduced; and the adjustment of the third throttle valve makes the torsion change of the heavy load hydraulic oil cylinder smooth, and then the speed of the swing door is slowly reduced, so that the safety hidden danger caused by the disengagement of the heavy load hydraulic oil cylinder and the swing door in the uncontrolled variable speed movement during the swing door deceleration process is avoided.

[0034] Compared with the prior art, the advantages of the present application are that the control system of the swing door can make the operator more simple and convenient during the deceleration movement adjustment process of the large mass swing door, specifically, the opening and closing state of the buffer control valve is controlled to divide the hydraulic oil flowing through the heavy load hydraulic oil cylinder to reduce the torsion and make the swing door decelerate, and the flexibility of simple operation and convenient adjustment is achieved.

[0035] The control method of the swing door control system provides a simple control method for the operator to adjust the deceleration of a large mass swing door during opening or closing, and specifically, the pressure of the two ends of the heavy swing cylinder is adjusted by setting the control relationship of the travel switch, the preset time, and the buffer control valve and the main control valve, so that the swing cylinder makes a smooth deceleration movement during opening or closing. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 The hydraulic schematic diagram of the embodiment 1 of the present application;

[0037] Figure 2 The angle-time relationship movement curve of the swing door of the control system of the embodiment 2 during opening (in the figure, ω is the instantaneous angle of the swing door and the equipment, t is the movement time of the swing door opening, ω1 is the instantaneous angle when the swing door deceleration action starts, t1 is the time when the swing door deceleration action starts, ω2 is the instantaneous angle when the swing door deceleration action ends, and t2 is the time when the swing door deceleration action ends);

[0038] Figure 3 The angle-time relationship movement curve of the swing door of the control system of the embodiment 2 during closing (in the figure, ω is the instantaneous angle of the swing door and the equipment, t is the movement time of the swing door closing, ω3 is the instantaneous angle when the swing door deceleration action starts, t3 is the time when the swing door deceleration action starts, ω4 is the instantaneous angle when the swing door deceleration action ends, and t4 is the time when the swing door deceleration action ends). DETAILED DESCRIPTION

[0039] The present application will be further described in detail below with reference to the embodiments of the drawings. Embodiment 1

[0040] As Figure 1As shown, it is embodiment 1 of the present application. The control system of the embodiment is mainly used for driving the opening or closing of the swing door. The mass of the swing door on general industrial equipment is very large (for example, the mass of the swing door of a rolling mill housing is 1t-3t). The swing door needs to be embedded in the rolling mill housing when closing and needs to open the whole roller space when opening. The space of the swing door hinge position is very small. Therefore, a large torque hydraulic motor or a swing cylinder must be used to drive the swing door to open or close. When the swing cylinder drives the swing door to open or close, the starting large torque and certain acceleration time will make the swing door have a large movement speed. Therefore, the torque of the swing cylinder needs to be controlled to continuously slow down in the movement process to prevent the swing door from colliding with the equipment body when opening or closing to the position and causing a safety accident. The existing oil circuit and valve group design control system for adjusting the torque of the swing cylinder have complicated operation steps and are prone to errors in the valve group adjustment process. Therefore, it is beneficial to provide a swing door control system which can slow down the large mass swing door and is convenient to adjust. The structure of the swing door control system in the embodiment of the present application will be described below:

[0041] Referring to Figure 1 The swing door control system comprises a heavy load hydraulic cylinder 1 drivingly connected with the swing door 7 and a control valve group connected with the heavy load hydraulic cylinder 1. The control valve group is used for controlling the hydraulic oil pressure and flow rate of the heavy load hydraulic cylinder 1, thereby controlling the running speed of the swing door 7 in the opening or closing process. The control valve group comprises a main control valve group and a buffer control valve group. The main control valve group comprises a pressure reducing valve 2 having an inlet communicated with a hydraulic oil supply pipeline and a main control valve 3 which is a three-position four-way directional valve. The oil inlet P of the main control valve 3 is communicated with the outlet of the pressure reducing valve 2, and the oil return port T is communicated with a hydraulic oil return pipeline. The first working port A of the main control valve 3 is connected with the first throttle valve 4 and then communicated with the oil inlet of the heavy load hydraulic cylinder 1. The oil outlet of the heavy load hydraulic cylinder 1 is connected with the second throttle valve 5 and then connected with the second working port B of the main control valve 3. The buffer control valve group comprises a buffer control valve 6 having an inlet communicated with the outlet of the pressure reducing valve 2. The buffer control valve 6 has at least one outlet communicated with the hydraulic oil return pipeline and at least two different working positions of opening and closing. When the buffer control valve 6 is opened, the hydraulic oil passing through the buffer control valve 6 can flow. When the buffer control valve 6 is closed, the hydraulic oil passing through the buffer control valve 6 is cut off. The buffer control valve 6 is set to be opened when the swing door 7 needs to slow down during the opening or closing process, thereby dividing the hydraulic oil flowing out of the pressure reducing valve 2, and then adjusting the hydraulic oil pressure and flow rate of the heavy load hydraulic cylinder 1. The main control valve 3 is a three-position four-way electromagnetic directional valve. The switching of the working position is controlled by magnets a and b. When the magnet a is powered, the P port and the B port of the main control valve 3 are communicated, and the T port and the A port are communicated. When the magnet b is powered, the P port and the A port of the main control valve 3 are communicated, and the T port and the B port are communicated. The product model of the main control valve 3 is D3H-GAT-01-1.

[0042] The start and end of the deceleration action of the swing door 7 during movement need to be realized by the buffer control valve 6 and the oil circuit connected thereto, so the buffer control valve 6 is a two-position four-way reversing valve in the embodiment, the oil inlet P of the buffer control valve 6 is communicated with the outlet of the pressure reducing valve 2, the oil return port T of the buffer control valve 6 is communicated with the hydraulic oil return pipeline, the first working port A of the buffer control valve 6 is communicated with the hydraulic oil return pipeline, and the second working port B of the buffer control valve 6 is blocked. Thus, when the P port and the A port of the buffer control valve 6 are communicated, the buffer control valve 6 is opened, and when the P port and the B port of the buffer control valve 6 are communicated, the swing door 7 starts to decelerate; the buffer control valve 6 is closed, and the swing door 7 ends to decelerate. The buffer control valve 6 is a two-position four-way electromagnetic reversing valve, and the product model is SSH-GAT-02-1; the B port of the buffer control valve 6 is communicated with the oil inlet of a one-way adjustable flow valve of the oil throttling type, the oil outlet of the one-way adjustable flow valve is blocked, and the throttling port is tightly closed without adjustment.

[0043] In order to realize the adjustment of the acceleration after the swing door 7 starts to decelerate, a third throttling valve 8 is arranged between the buffer control valve 6 and the hydraulic oil return pipeline in the embodiment, the third throttling valve 8 is a one-way adjustable flow valve of the oil throttling type, the first working port A of the buffer control valve 6 is communicated with the inlet of the third throttling valve 8, and the outlet of the third throttling valve 8 is communicated with the hydraulic oil return pipeline. Thus, after the swing door 7 starts to decelerate, the increase and decrease of the flow through the heavy load hydraulic cylinder 1 can be realized by reducing or increasing the opening degree of the throttling port of the third throttling valve 8, so that the torque of the heavy load hydraulic cylinder 1 is increased or decreased, and then the acceleration of the swing door 7 during deceleration is affected, and the increase and decrease of the acceleration after the swing door 7 starts to decelerate only needs to decrease or increase the opening degree of the throttling port of the third throttling valve 8 clockwise or counterclockwise, the adjustment action is simple, the risk of manual operation is reduced, the adjustment speed is increased, and significant progress is achieved.

[0044] The movement stability of the swing door 7 during opening or closing can enhance the safety of the surrounding construction personnel, so the first throttling valve 4 and the second throttling valve 5 are one-way adjustable flow valves of the oil throttling type in the embodiment, the inlet of the first throttling valve 4 is communicated with the oil inlet of the heavy load hydraulic cylinder 1, and the outlet is communicated with the A port of the main control valve 3; the inlet of the second throttling valve 5 is communicated with the oil outlet of the heavy load hydraulic cylinder 1, and the outlet is communicated with the B port of the main control valve 3. The technical scheme makes the back pressure generated when the oil flows through the first throttling valve 4 and the second throttling valve 5 in the oil outlet direction, the pressure fluctuation of the hydraulic oil circuit through the heavy load hydraulic cylinder 1 is reduced, and then the movement of the swing door 7 is stable.

[0045] In order to facilitate the operator to maintain the heavy hydraulic cylinder 1 daily, the first throttle valve 4 inlet and the heavy hydraulic cylinder 1 inlet between the oil port is provided with the first stop valve 91, the second throttle valve 5 inlet and the heavy hydraulic cylinder 1 between the oil port is provided with the second stop valve 92. Thus, the operator can close the first stop valve 91 and the second stop valve 92 after the oil circuit is disconnected with the heavy hydraulic cylinder 1, so that the heavy hydraulic cylinder 1 can be repaired alone.

[0046] The automatic deceleration of the swing door 7 during opening and closing can reduce the manual adjustment steps. Therefore, the embodiment further includes a position detection switch arranged in the swing range of the swing door 7, which includes a first travel switch 71 and a second travel switch 72. The first travel switch 71 is arranged to satisfy that when the swing door 7 moves to the first travel switch 71 and triggers the first travel switch 71, the included angle between the swing door 7 and the equipment body 10 is 25°-35°; when the swing door 7 moves to the second travel switch 72 and triggers the second travel switch 72, the included angle between the swing door 7 and the equipment body 10 is 100°-110°.

[0047] In order to facilitate automatic control, that is, when the swing door needs to open and close during opening and closing, the buffer control valve 6 is arranged to be powered on when the main control valve 3 is powered on after a first preset time or when the first travel switch 71 is triggered, and the buffer control valve 6 is powered off after a second preset time or when the second travel switch 72 is triggered. The technical scheme realizes the automatic control of the swing door 7 by establishing the control relationship between the first travel switch 71, the second travel switch 72, the first preset time, the second preset time, and the buffer control valve 6. The first preset time is 1.5 seconds, and the second preset time is 8-9 seconds. Finally, in order to make the heavy hydraulic cylinder 1 not work when the main control valve 3 is not powered on, that is, only through the main control valve 3 can control the working state of the heavy hydraulic cylinder 1, the main control valve 3 is an "O" type three-position four-way valve. Thus, the main control valve 3 is in the normal working position, and the hydraulic oil circuit is disconnected.

[0048] In summary, the heavy swing door 7 connected to the heavy hydraulic cylinder 1 can realize the following actions through the swing door control system:

[0049] The heavy hydraulic cylinder 1 does not work

[0050] The main control valve 3 and the buffer control valve 6 are in the normal working position, the oil circuit is disconnected, the oil circuit on both sides of the heavy hydraulic cylinder 1 is not connected, and the heavy hydraulic cylinder 1 does not work. At this time, the first stop valve 91 and the second stop valve 92 can be closed to maintain the heavy hydraulic cylinder 1 alone;

[0051] b, swing door 7 opens

[0052] The electromagnet b of the main control valve 3 is powered on, the swing door 7 opens counterclockwise at high pressure, and the buffer control valve 6 is powered on to start deceleration after the first preset time is reached when the travel switch 71 or the running time of the main control valve 3 is touched. The acceleration of deceleration can be adjusted by the third throttle valve 8 to make the movement speed decrease smoothly. When the second preset time is reached when the travel switch 72 or the running time of the buffer control valve 6 is touched, the buffer control valve 6 is de-energized to end the deceleration, and the main control valve 3 is also de-energized to close. The swing door 7 stops after moving a distance by inertia, and the opening operation is completed.

[0053] c, swing door 7 closes

[0054] The electromagnet a of the main control valve 3 is powered on, the swing door 7 closes clockwise at high pressure, and the buffer control valve 6 starts to decelerate after the first preset time is reached when the travel switch 72 or the running time of the main control valve 3 is touched. The acceleration of deceleration can be adjusted by the third throttle valve 8 to make the movement speed decrease smoothly. When the second preset time is reached when the travel switch 71 or the running time of the buffer control valve 6 is touched, the buffer control valve 6 is de-energized to end the deceleration, and the main control valve 3 is also de-energized to close. The swing door 7 stops after moving a distance by inertia, and the closing operation is completed.

[0055] The control system of the swing door can control the deceleration behavior of the swing door by energizing and de-energizing the buffer control valve 6. By adjusting the size of the throttle opening of the third throttle valve 8 connected in series with the buffer control valve 6, the acceleration of the swing door deceleration behavior can be further controlled to make it decelerate smoothly, and the flexibility of simple operation and convenient adjustment is achieved.

[0056] Example 2 Control method of swing door control system

[0057] As shown in Figures 2-3 , the control method of the swing door control system in Example 1 is applied. The control method is mainly used for speed regulation during the opening or closing process of the swing door 7, so that the speed slowly decreases from a high-speed state after high-pressure starting to a small-speed state or a speed of 0, avoiding the swing door 7 from being separated from the heavy-duty hydraulic cylinder 1 due to the large deceleration amplitude causing the oil pressure to fluctuate, and avoiding the swing door 7 from colliding with the equipment 10 after the deceleration ends due to the small deceleration amplitude, thereby enhancing safety. The following will describe the detailed steps of the control method:

[0058] The control method of the swing door control system includes the following steps:

[0059] S1: Preparation before debugging: Set the pressure of the pressure reducing valve 2 so that the torque provided by the heavy-duty hydraulic cylinder 1 can start the swing door 7;

[0060] S2: swing door opening control step:

[0061] S2-1, the main control valve 3 is powered on, the buffer control valve 6 is powered off, the heavy load hydraulic cylinder 1 is started at high pressure, and the swing door 7 is quickly opened;

[0062] S2-2, when the main control valve 3 works for a first preset time or when the first stroke switch 71 is triggered, the buffer control valve 6 is powered on, and the swing door 7 continues to open at a reduced speed;

[0063] S2-3, when the buffer control valve 6 works for a second preset time or when the second stroke switch 72 is triggered, the main control valve 3 and the buffer control valve 6 are both powered off, and the swing door 7 stops opening;

[0064] S3: swing door closing control step:

[0065] S3-1, the main control valve 3 is powered on, the buffer control valve 6 is powered off, the heavy load hydraulic cylinder 1 is started at high pressure, and the swing door 7 is quickly closed;

[0066] S3-2, when the main control valve 3 works for a first preset time or when the second stroke switch 72 is triggered, the buffer control valve 6 is powered on, and the swing door 7 continues to close at a reduced speed;

[0067] S3-3, when the buffer control valve 6 works for a second preset time or when the first stroke switch 71 is triggered, the main control valve 3 and the buffer control valve 6 are both powered off, and the swing door 7 stops closing. In step S2, the electromagnet of the main control valve 3 is powered on, when the swing door 7 is opened, the b electromagnet of the main control valve 3 is powered on; when the swing door 7 is closed, the a electromagnet of the main control valve 3 is powered on.

[0068] In order to ensure the safety of the swing door 7 during opening or closing, please refer to Figures 2-3 In the embodiment, the third throttle valve 8 is arranged between the buffer control valve 6 and the hydraulic oil return pipeline, the third throttle valve 8 is an oil inlet throttling type one-way adjustable flow valve, the first working port A of the buffer control valve 6 is in communication with the inlet of the third throttle valve 8, and the outlet of the third throttle valve 8 is in communication with the hydraulic oil return pipeline;

[0069] During the process of setting the pressure of the pressure reducing valve 2 in the debugging preparation step S1, the following adjustment is also performed: the first throttle valve 4 and the second throttle valve 5 are both counterclockwise loosened to open the throttle port; the third throttle valve 8 is counterclockwise loosened to open the throttle port;

[0070] In step S2-2 of the swing door opening control step S2, the buffer control valve 6 is energized and opened, and the following adjustments are performed: the first throttle valve 4 and the second throttle valve 5 are both tightened clockwise to reduce the throttle opening degree but not to close the throttle opening, so that the movable opening movement is smooth; the third throttle valve 8 is tightened or loosened so that the speed of the swing door 7 opening movement is steadily reduced;

[0071] In step S3-2 of the swing door closing control step S3, after the buffer control valve 6 is energized and opened, the following adjustments are made: the first throttle valve 4 and the second throttle valve 5 are both tightened clockwise to reduce the throttle opening, but the throttle opening is not closed, allowing the swing door 7 to close smoothly. Tightening or loosening the third throttle valve 8 allows the speed of the swing door 7 to decrease steadily. In this technical solution, the adjustment of the first throttle valve 4 and the second throttle valve 5 creates back pressure in the oil circuit of the heavy-duty hydraulic cylinder 1, reducing pressure fluctuations in the hydraulic circuit. The adjustment of the third throttle valve 8 ensures a smooth change in torque through the heavy-duty hydraulic cylinder 1, thereby slowly reducing the speed of the swing door 7 and avoiding the potential safety hazard of the heavy-duty hydraulic cylinder 1 and the swing door 7 being separated due to uncontrollable speed changes during the deceleration of the swing door 7. The operation of tightening or loosening the third throttle valve 8 in steps S2-2 and S3-2 is as follows: adjust the pressure of the pressure reducing valve 2 according to the setting of step S1. When the pressure of the pressure reducing valve 2 is between 5 and 8 MPa, the opening of the third throttle valve 8 is adjusted counterclockwise by 3 to 4 turns; when the pressure setting value of the pressure reducing valve 2 is between 3 and 4 MPa, the opening of the throttle valve 5 can be adjusted counterclockwise by 1 to 2 turns. The total deceleration time shall not exceed 10 seconds, otherwise the oil circuit load will be too large, the operation will be abnormal, and the swing door 7 will easily fall off.

[0072] In summary, the swing door 7 can achieve the following actions through this control method:

[0073] a. Quick opening of swing door

[0074] The solenoid b of the main control valve 3 is energized, and the buffer control valve 6 is de-energized. At this time, the main control valve 3 is in a high-pressure state. The oil flows through the P port and A port of the main control valve, and then through the second throttle valve 5 to reach the heavy-duty hydraulic cylinder 1, and the swing door 7 opens quickly.

[0075] b. During the swing door opening process, perform a smooth deceleration motion until it stops:

[0076] like Figure 2 As shown, after the electromagnet b of the reversing valve 4 is energized for 1.5 seconds or the first travel switch 71 (corresponding to Figure 2When the point of time t1 and the angle ω1 in the motion curve are reached, the buffer control valve 6 is powered, at which time the oil is divided into two routes, one route is through the main control valve 3 from P-A, and then through the second throttle valve 5, at this time, according to the size of the impact on the spot, the size of the back pressure of the heavy load hydraulic cylinder 1 at this time can be adjusted by adjusting the adjusting screw of the second throttle valve 5, clockwise adjustment, the opening degree of the second throttle valve 5 is reduced, the greater the back pressure generated, the more stable the swing door 7 opens, but it cannot be completely cut off; the other route is through the buffer control valve 6 from P-A-T, and then through the third throttle valve 8, the size of the shunt can be adjusted by adjusting the adjusting screw of the third throttle valve 8, clockwise adjusting screw, reducing the shunt flow; after shunting, the pressure and flow of the heavy load hydraulic cylinder 1 are reduced, and the speed of the swing door 7 opening is reduced; after the buffer control valve 6 is powered for 8-9s or the second travel switch 72 is triggered (corresponding to Figure 2 When the point of time t2 and the angle ω2 in the motion curve are reached, the main control valve 3 and the buffer control valve 6 are simultaneously powered off, the main control valve 3 is in the middle position, at this time the swing door 7 stops slowly relying on inertia; if the swing door 7 does not close to the position of 135° with the equipment 10, the swing door 7 is restarted and then the main control valve 3 and the buffer control valve 6 and the third throttle valve 8 are manually adjusted to 135° opening to the position.

[0077] c, the swing door is quickly closed

[0078] The a electromagnet of the main control valve 3 is powered, and the buffer control valve 6 is not powered, at this time the oil at the P port of the main control valve 3 is not shunted from the buffer control valve 6, the main control valve 3 is in a high pressure state, the oil passes through the main control valve 3 from P-B, and then through the first throttle valve 4, the swing door 7 is quickly closed at high pressure;

[0079] d, the swing door makes a smooth deceleration motion until it stops during the closing process:

[0080] After the a electromagnet of the main control valve 3 is powered for 1.5s or the second travel switch 72 is triggered (corresponding to Figure 3 When the point of time t3 and the angle ω3 in the motion curve are reached, the buffer control valve 6 is powered, at which time the oil is divided into two routes, one route is through the main control valve 3 from P-B, and then through the first throttle valve 4, at this time the size of the back pressure of the heavy load hydraulic cylinder 1 at this time can be adjusted by adjusting the adjusting screw of the first throttle valve 4, clockwise adjustment, the opening degree of the first throttle valve 4 is reduced, the greater the back pressure generated, the more stable the swing door 7 closes, but it cannot be completely cut off; the other route is through the buffer control valve 6 from P-A-T, and then through the third throttle valve 8, the size of the shunt can be adjusted by adjusting the adjusting screw of the third throttle valve 8, clockwise adjusting screw, reducing the shunt flow; after shunting, the pressure and flow of the heavy load hydraulic cylinder 1 are reduced, and the speed of the swing door 7 closing is reduced; after the buffer control valve 6 is powered for 8-9s or the first travel switch 71 is triggered (corresponding to Figure 3At the point of time t3 and angle ω3 in the motion curve, the main control valve 3 and the buffer control valve 6 are simultaneously de-energized, the main control valve is in the neutral position, and the swing door 7 is closed to the position by inertia.

[0081] The control method of the application of Embodiment 1 provides the operator with a simple control method for adjusting the opening or closing action of the heavy swing door 7, specifically, by setting the control method of the buffer control valve 6, the main control valve 3, the third throttle valve 8, the first throttle valve 4 and the second throttle valve 5 in different motion states of the swing door 7 to regulate the pressure and flow of the hydraulic oil flowing through the heavy swing cylinder 1, so that the swing door 7 makes a smooth deceleration motion during the opening or closing process.

Claims

1. A swing door control system comprising a heavy-duty hydraulic cylinder (1) drivingly connected to a swing door (7), and a control valve group connected to the heavy-duty hydraulic cylinder (1) for controlling the hydraulic oil pressure and flow rate into and out of the heavy-duty hydraulic cylinder (1) to control the speed of the swing door (7) during opening or closing, characterized in that: The control valve group comprises a main control valve group and a buffer control valve group, wherein the main control valve group comprises: a pressure reducing valve (2) whose inlet is communicated with a hydraulic oil supply pipeline; a main control valve (3) which is a three-position four-way directional valve, an oil inlet P of the main control valve (3) is communicated with an outlet of the pressure reducing valve (2), an oil return port T of the main control valve (3) is communicated with a hydraulic oil return pipeline, a first working port A of the main control valve (3) is connected with the oil inlet of the heavy load hydraulic cylinder (1) after being connected with a first throttle valve (4), and an oil outlet of the heavy load hydraulic cylinder (1) is connected with the second working port B of the main control valve (3) after being connected with a second throttle valve (5); the buffer control valve group comprises: a buffer control valve (6) whose inlet is communicated with the outlet of the pressure reducing valve (2), at least one outlet of the buffer control valve (6) is communicated with the hydraulic oil return pipeline, and the buffer control valve (6) has at least two different working positions of opening and closing, wherein when the buffer control valve (6) is opened, the hydraulic oil path passing through the buffer control valve (6) is communicated, and when the buffer control valve (6) is closed, the hydraulic oil path passing through the buffer control valve (6) is disconnected; the buffer control valve (6) is arranged to be opened when deceleration is required in the opening and closing process of the swing door (7), so as to shunt the hydraulic oil flowing out of the pressure reducing valve (2), and further adjust the hydraulic oil pressure and flow entering and exiting the heavy load hydraulic cylinder (1); the buffer control valve (6) is a two-position four-way directional valve, an oil inlet P of the buffer control valve (6) is communicated with the outlet of the pressure reducing valve (2), an oil return port T of the buffer control valve (6) is communicated with the hydraulic oil return pipeline, a first working port A of the buffer control valve (6) is communicated with the hydraulic oil return pipeline, and a second working port B of the buffer control valve (6) is blocked; a third throttle valve (8) is arranged between the buffer control valve (6) and the hydraulic oil return pipeline, the third throttle valve (8) is an oil inlet throttling type one-way adjustable flow valve, a first working port A of the buffer control valve (6) is communicated with an inlet of the third throttle valve (8), and an outlet of the third throttle valve (8) is communicated with the hydraulic oil return pipeline; the first throttle valve (4) and the second throttle valve (5) are oil outlet throttling type one-way adjustable flow valves, an inlet of the first throttle valve (4) is communicated with the oil inlet of the heavy load hydraulic cylinder (1), and an outlet of the first throttle valve (4) is communicated with the A port of the main control valve (3), an inlet of the second throttle valve (5) is communicated with the oil outlet of the heavy load hydraulic cylinder (1), and an outlet of the second throttle valve (5) is communicated with the B port of the main control valve (3).

2. A swing door control system according to claim 1, characterized in that: A first stop valve (91) is arranged between the inlet of the first throttle valve (4) and the oil inlet of the heavy load hydraulic cylinder (1), and a second stop valve (92) is arranged between the inlet of the second throttle valve (5) and the oil outlet of the heavy load hydraulic cylinder (1).

3. The swing door control system of claim 1, wherein: The position detection switch arranged in the swing range of the swing door (7) comprises a first travel switch (71) and a second travel switch (72), wherein the first travel switch (71) is arranged to meet the following conditions: when the swing door (7) moves to the first travel switch (71) and triggers the first travel switch (71), the included angle between the swing door (7) and the equipment body (10) is 25°-35°; when the swing door (7) moves to the second travel switch (72) and triggers the second travel switch (72), the included angle between the swing door (7) and the equipment body (10) is 100°-110°. The buffer control valve (6) is arranged to be powered on and opened after the main control valve (3) is powered on and opened after working for a first preset time or after the first travel switch (71) is triggered, and the buffer control valve (6) is powered off and closed after working for a second preset time or after the second travel switch (72) is triggered.

4. The swing door control system of claim 1, wherein: The three-position four-way reversing valve is an "O" type.

5. A control method of the swing door control system as claimed in claim 3, characterized by, The method comprises the following steps: S1: preparation before debugging: set the pressure of the pressure reducing valve (2) so that the torsional force provided by the heavy load hydraulic oil cylinder (1) can start the swing door (7); S2: swing door opening control step: S2-1, the main control valve (3) is powered on and works, the buffer control valve (6) is powered off and closed, the heavy load hydraulic oil cylinder (1) is started at high pressure, and the swing door (7) is quickly opened; S2-2, when the main control valve (3) works for a first preset time or when the first travel switch (71) is triggered, the buffer control valve (6) is powered on and opened, and the swing door (7) continues to open at a reduced speed; S2-3, when the buffer control valve (6) works for a second preset time or when the second travel switch (72) is triggered, the main control valve (3) and the buffer control valve (6) are both powered off and closed, and the swing door (7) stops opening; S3: swing door closing control step: S3-1, the main control valve (3) is powered on and works, the buffer control valve (6) is powered off and closed, the heavy load hydraulic oil cylinder (1) is started at high pressure, and the swing door (7) is quickly closed; S3-2, when the main control valve (3) works for a first preset time or when the second travel switch (72) is triggered, the buffer control valve (6) is powered on and opened, and the swing door (7) continues to close at a reduced speed; S3-3, when the buffer control valve (6) works for a second preset time or when the first travel switch (71) is triggered, the main control valve (3) and the buffer control valve (6) are both powered off and closed, and the swing door (7) stops closing.

6. The control method of the swing door control system according to claim 5, characterized in that: The third throttle valve (8) is arranged between the buffer control valve (6) and the hydraulic oil return pipeline, and is an oil inlet throttling type one-way adjustable throttle valve, a first working port A of the buffer control valve (6) is communicated with an inlet of the third throttle valve (8), and an outlet of the third throttle valve (8) is communicated with the hydraulic oil return pipeline; during the process of setting the pressure of the pressure reducing valve (2) in the debugging preparation step S1, the following adjustment is also performed: the throttle openings of the first throttle valve (4) and the second throttle valve (5) are opened to the maximum value; the throttle opening of the third throttle valve (8) is opened to a preset initial value; In S2-2 of the swing door opening control step S2, after the buffer control valve (6) is powered on and opened, the following adjustment is performed: the throttle opening degrees of the first throttle valve (4) and the second throttle valve (5) are reduced, but the throttle openings are not closed, so that the active opening movement is stable; the throttle opening degree of the third throttle valve (8) is reduced or increased, so that the speed of the swing door (7) opening movement is stably reduced; In S3-2 of the swing door closing control step S3, after the buffer control valve (6) is powered on and opened, the following adjustment is performed: the throttle opening degrees of the first throttle valve (4) and the second throttle valve (5) are reduced, but the throttle openings are not closed, so that the swing door (7) closing movement is stable; the throttle opening degree of the third throttle valve (8) is reduced or increased, so that the speed of the swing door (7) closing movement is stably reduced.

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