阅读说明：本技术 一种蒙皮张拉装置、控制系统及控制方法 (Skin tensioning device, control system and control method ) 是由 张雷 王宇 麻彬彬 张彤阳 赵保春 李江吉 于 2019-09-30 设计创作，主要内容包括：本发明属于铁路工程车辆车体制造装置,为解决现有技术中张拉机工作效率低,不利于批量流水线生产,以及长时间保持夹紧和张拉状态消耗设备各部件影响使用寿命的技术问题,提供一种蒙皮张拉装置、控制系统及控制方法。其中的蒙皮张拉装置通过第一夹紧机构和第二夹紧机构夹持待张拉蒙皮,液压泵站驱动拉伸装置并带动第二夹紧机构沿滑轨移动,完成对蒙皮的张拉,安装于液压泵站的压力传感器和安装于拉伸机构的位移传感器,实时检测张拉工况,操作便利。另外,基于蒙皮张拉装置的控制系统对蒙皮张拉和后续焊接实现闭环控制,相应的控制方法,先将蒙皮与工艺支撑焊接吊离后再与车体框架焊接,有效提高了加工效率,降低了蒙皮持续张拉的时间。(The invention belongs to a device for manufacturing a railway engineering vehicle body, and provides a skin tensioning device, a control system and a control method, which are used for solving the technical problems that a tensioning machine in the prior art is low in working efficiency, is not beneficial to batch production line production, and consumes all parts of equipment to influence the service life when the clamping and tensioning states are kept for a long time. The skin tensioning device clamps the skin to be tensioned through the first clamping mechanism and the second clamping mechanism, the hydraulic pump station drives the stretching device and drives the second clamping mechanism to move along the sliding rail, tensioning of the skin is completed, the pressure sensor mounted on the hydraulic pump station and the displacement sensor mounted on the stretching mechanism detect the tensioning working condition in real time, and operation is convenient. In addition, the control system based on the skin tensioning device realizes closed-loop control on skin tensioning and subsequent welding, and the corresponding control method firstly hangs the skin from the process support welding and then welds the skin with the vehicle body frame, so that the processing efficiency is effectively improved, and the time for continuously tensioning the skin is reduced.)

1. A covering tensioning device is characterized in that: comprises a hydraulic pump station (5) and a support (1);

a first clamping mechanism (2), a second clamping mechanism (3) and a stretching mechanism (4) are coaxially and sequentially arranged on the support (1);

the first clamping mechanism (2) comprises a first lever (202), a first base (201), a first oil cylinder (204) arranged on the first base (201), a first supporting seat (203) and a first lower clamping block (206); the middle part of the first lever (202) is hinged with the first supporting seat (203), one end of the first lever (202) is hinged with the output end of the first oil cylinder (204), the other end of the first lever is connected with a first upper clamping block (205), and the first upper clamping block (205) is positioned right above the first lower clamping block (206); the lengths of the first upper clamping block (205) and the first lower clamping block (206) are the same and are both larger than the width of the skin to be tensioned;

the second clamping mechanism (3) comprises a second lever (302), a second base (301), a second oil cylinder (304), a second supporting seat (303) and a second lower clamping block (306), wherein the second oil cylinder (304), the second supporting seat (303) and the second lower clamping block are arranged on the second base (301); the middle part of a second lever (302) is hinged with a second supporting seat (303), one end of the second lever (302) is hinged with the output end of a second oil cylinder (304), the other end of the second lever is connected with a second upper clamping block (305), and the second upper clamping block (305) is positioned right above a second lower clamping block (306); a sliding rail (307) is arranged at the lower part of the second base (301), the sliding rail (307) is matched with a sliding assembly arranged on the support (1), and a displacement sensor is arranged on the second base (301); the length of the second upper clamping block (305) is the same as that of the second lower clamping block (306), and the lengths of the second upper clamping block and the second lower clamping block are both larger than the width of the skin to be tensioned;

the stretching mechanism (4) comprises a mounting frame (401) fixed on the support (1) and a third oil cylinder (402) fixed on the mounting frame (401), and the output end of the third oil cylinder (402) is connected with the second base (301) through a pull rod (403);

the hydraulic pump station (5) is respectively connected with the first oil cylinder (204), the second oil cylinder (304) and the third oil cylinder (402) through oil pipes, and the hydraulic pump station (5) is connected with a pressure gauge.

2. A skin tensioning device according to claim 1, wherein: the first clamping mechanism (2) is detachably connected with the support (1).

3. A skin tensioning device according to claim 1 or 2, wherein: the sliding assembly comprises a rolling shaft and a rolling bearing, the rolling shaft is arranged on the support (1), and the rolling bearing is sleeved on the rolling shaft and matched with the sliding rail (307).

4. A skin stretch-draw control system which characterized in that: the skin tensioning device comprises a hoisting device, an upper computer, a data control unit, an image acquisition unit, a display unit and the skin tensioning device as claimed in any one of claims 1 to 3;

the image acquisition unit acquires preset information of the skin to be tensioned and transmits the preset information to the data control unit;

the data control unit receives the preset information and judges whether the skin to be tensioned meets the preset requirement or not; if the skin tensioning device is not matched with the display unit, the skin tensioning device is controlled to execute a preset program, and if the skin tensioning device is not matched with the display unit, the preset program is not executed, and information is displayed through the display unit; the data control unit receives an upper computer instruction, pressure value data of a pressure gauge of the skin tensioning device and displacement data of the displacement sensor, judges the tensioning working condition of the skin tensioning device according to the pressure value data and the displacement data, and controls the hoisting device and the skin tensioning device to work by combining a preset program;

the hoisting device hoists the skin to be tensioned which meets the preset requirement to the skin tensioning device, and after the skin tensioning device completes tensioning and auxiliary welding operation, the tensioned skin is hoisted away;

the skin tensioning device is used for tensioning the skin to be tensioned and assisting in completing welding operation;

the upper computer receives instruction input of an operator and sends the instruction to the data control unit;

the display unit is connected with the data control unit and displays pressure value data, displacement data, tensioning working conditions, preset information and preset programs.

5. A skin tensioning control system according to claim 4, wherein: the device also comprises an alarm unit; when the data control unit judges that the skin to be tensioned does not accord with the preset requirement or the tensioning condition is abnormal, the data control unit sends alarm information to the alarm unit, and the alarm unit sends an alarm prompt.

6. A skin tensioning control method of a skin tensioning control system according to claim 4 or 5, characterized by comprising the following steps:

step 1, collecting preset information of a skin to be tensioned by using an image collecting unit, and sending the preset information to a data control unit; the data control unit judges whether the skin to be tensioned meets preset requirements, if so, the skin tensioning device is controlled to execute a preset program, if not, the preset program is not executed, and information is displayed through the display unit;

step 2, if the skin to be tensioned meets the preset requirements, hoisting the skin to be tensioned to a skin tensioning device by using a hoisting device, clamping the skin to be tensioned between a first clamping mechanism (2) and a second clamping mechanism (3), and moving away the hoisting device;

step 3, tensioning the skin to be tensioned by a skin tensioning device; if the tension value data and the displacement data both meet the preset requirements in the tensioning process, the skin tensioning device continuously works; if any one of the tension value data and the displacement data does not meet the preset requirement, stopping the operation of the skin tensioning device, and checking and adjusting; until the stretching of the skin to be stretched is finished;

step 4, the hoisting device hoists the process support (28) to the skin stretched in the step 3, and the welding trolley (6) completes welding;

and 5, integrally hoisting the process support (28) welded in the step 4 and the skin by using the hoisting device.

Technical Field

The invention belongs to a device for manufacturing a railway engineering vehicle body, and particularly relates to a skin tensioning device, a control system and a control method.

Background

Railway engineering vehicle is the professional equipment who overhauls the railway contact net, and the car body surface smoothness and the automobile body rigidity requirement of this type of motorcycle type are very high, and in order to satisfy the requirement, the automobile body side wall adopts the high-strength steel board of 2.5mm thick as the skin material, and this makes how to control the plane degree become the difficult point that whole car was made in the side wall manufacturing process. The whole-plate skin manufacturing process is adopted if the quality requirement is met during the manufacturing of the side wall, the splicing welding seams can be reduced, the flatness of the side wall is improved, but when the skin and the side wall frame are assembled and welded, the whole-plate skin is subjected to buckling deformation during continuous welding, and the whole vehicle is protruded outwards or concaved inwards locally, so that the quality of the whole vehicle is influenced. In order to overcome the defects, the side wall is manufactured by adopting a whole plate process and a tensioning process, namely, the side wall is pre-tensioned before skin welding, so that the flatness of the skin and the framework after welding is ensured. The process from skin hoisting to stretching to the required length only needs about twenty minutes, and the stretching equipment must continuously clamp and keep the skin in a stretching state during welding, but the process of welding large-size skins often lasts for several hours, and other operations cannot be carried out by the stretching equipment in the process. The traditional tensioning equipment can not realize closed-loop control on skin tensioning, the mechanical properties of different batches of plates are different, the uncoiling quality of each skin is different, and the tensioning effect is different when the same process parameters are adopted.

Fig. 1 is a schematic structural view of a hydraulic tensioning machine disclosed in a utility model with application number 200820149303.X, which includes a frame 12, and a motor 13, a coupling 11, an oil pump 19 and a hydraulic cylinder 17 which are fixed on the frame 12 and connected in sequence, wherein the oil pump 19 is further connected with a reversing switch 10, and the oil pump 19, the reversing switch 10 and the hydraulic cylinder 17 are connected through an oil pipe 9; the frame 12 is also provided with a spring scale 18, one end of the spring scale 18 is provided with a steel wire rope 16, the other end of the steel wire rope 16 sequentially rounds a movable pulley 15 and a fixed pulley 14 and is then fixed on the frame 12, and the front end of the movable pulley 15 is fixed with a tractor 7; the lower part of the frame 12 is provided with a roller 8 which is convenient to move. When the steel wire straightening machine works, the starting motor 13 drives the oil pump 19 to work, the reversing switch 10 is adjusted to enable oil in the oil pump 19 to enter the hydraulic cylinder 17 through the oil pipe 9, the cylinder body of the hydraulic cylinder 17 extends outwards and simultaneously drives the fixed pulley 14 installed on the hydraulic cylinder 17 to pull the steel wire 16, and the steel wire 16 drives the movable pulley 15 to straighten the steel wire to be pulled. The conventional tensioning machine is only suitable for drawing steel wires and cannot be used for drawing plates. Even if modifications are made for drawing of sheet materials, there are many problems: (1) the whole frame is simple and small in size, and large skins such as side walls cannot be pulled; (2) only one hydraulic cylinder is provided, so that the working tension is small; (3) the clamping of the skin cannot be realized; (3) the measurement of the tension and the elongation is indirectly finished by driving the spring scale by the steel wire rope, and the measurement precision is low.

As shown in fig. 2, the tensioning device adopts a horizontal tensioning and under-vehicle welding mode, the skin 21 is clamped between the third clamping mechanism 24 and the first tensioning mechanism 20 and is placed on the platform 23, after the skin 21 is tensioned to a required length, the tensioning device continuously clamps and keeps the skin 21 in a tensioning state, the vehicle body part frame 22 is hung on the skin 21, after the welding of the skin 21 and the frame 22 is completed, the whole body is lifted away, the process allowance reserved for tensioning the skin is cut off, and finally the vehicle body frame 22 is assembled and welded. However, when the skin 21 and the frame 22 are welded, the skin must be continuously clamped by the tensioning equipment, the skin is kept in a tensioning state, the time consumed for welding the skin frame 22 is long, and the effective utilization rate of the tensioning equipment is low, so that the process becomes a bottleneck process, and the batch production line production is not facilitated. In addition, the long-term retention of the clamping and tensioning states also consumes the service life of each part of the equipment, after the side wall frame 22 and the skin are welded, the side wall frame is also required to be vertically lifted and then welded with the underframe, the skin welded with the side wall frame 22 is inconvenient to vertically lift, and a special lifting appliance or a welding lifting lug is also required.

As shown in fig. 3, two sets of vertical tensioning devices 26 are respectively arranged on the underground tracks 25, the integral welding of the body frame 22 is firstly completed, the body frame 22 falls into a welding tire position between the underground tracks 25, two skins 21 are respectively hoisted to the tensioning devices on two sides, the skins 21 are clamped, the skins 21 are placed on the supports 27, the skins 21 are tensioned after the height of the skins 21 is adjusted to a proper position, the driving mechanisms of the tensioning devices are adjusted after the skins 21 are tensioned to a required length, the skins 21 are tightly attached to the body frame 22, the tensioning devices loosen the skins 21 after the welding is completed, and finally, the process allowance is cut off. Although the equipment can simultaneously stretch and weld two skins 21, the essence of the equipment is realized by two sets of stretching equipment, the time consumption for hoisting and position adjustment of the skins 21 before stretching is longer than that of horizontal stretching, the stretching equipment still needs to be occupied during welding, and the effective utilization rate of the equipment is low. There is also the problem that maintaining the clamped and tensioned state for a long time consumes the service life of the components of the equipment. In addition, vertical tensioning is adopted, the movement of the skin 21 in three directions needs to be realized, the structure is complex, a large-tonnage hydraulic cylinder is difficult to provide clamping force and tension force required by tensioning, and the vertical tensioning method is only suitable for the condition that the required tension force is small.

Disclosure of Invention

The invention mainly aims to solve the technical problems that a tensioning machine in the prior art is low in working efficiency, is not beneficial to batch production line production, and consumes all parts of equipment to affect the service life when the clamping and tensioning states are kept for a long time, and provides a skin tensioning device, a control system and a control method.

In order to achieve the purpose, the invention provides the following technical scheme:

a skin tensioning device is characterized by comprising a hydraulic pump station and a support; a first clamping mechanism, a second clamping mechanism and a stretching mechanism are coaxially and sequentially arranged on the support; the first clamping mechanism comprises a first lever, a first base, a first oil cylinder, a first supporting seat and a first lower clamping block, wherein the first oil cylinder, the first supporting seat and the first lower clamping block are arranged on the first base; the middle part of a first lever is hinged with a first supporting seat, one end of the first lever is hinged with the output end of a first oil cylinder, the other end of the first lever is connected with a first upper clamping block, the first upper clamping block is positioned right above a first lower clamping block, and the first upper clamping block and the first lower clamping block are the same in length and are both larger than the width of a skin to be tensioned; the second clamping mechanism comprises a second lever, a second base, a second oil cylinder, a second supporting seat and a second lower clamping block, wherein the second oil cylinder, the second supporting seat and the second lower clamping block are arranged on the second base; the middle part of the second lever is hinged with the second supporting seat, one end of the second lever is hinged with the output end of the second oil cylinder, the other end of the second lever is connected with the second upper clamping block, and the second upper clamping block is positioned right above the second lower clamping block; the lower part of the second base is provided with a slide rail which is matched with a sliding component arranged on the support, the second base is provided with a displacement sensor, and the second upper clamping block and the second lower clamping block have the same length and are both larger than the width of the skin to be tensioned; the stretching mechanism comprises a mounting frame fixed on the support and a third oil cylinder fixed on the mounting frame, and the output end of the third oil cylinder is connected with the second base through a pull rod; the hydraulic pump station is connected with the first oil cylinder, the second oil cylinder and the third oil cylinder through oil pipes respectively, and the hydraulic pump station is connected with a pressure gauge.

Furthermore, first clamping mechanism and support be for dismantling the connection, are convenient for remove first clamping mechanism's position according to operating mode needs.

Furthermore, the sliding assembly comprises a rolling shaft and a rolling bearing, the rolling shaft is mounted on the support, and the rolling bearing is sleeved on the rolling shaft and matched with the sliding rail.

A skin tensioning control system is characterized by comprising a hoisting device, an upper computer, a data control unit, an image acquisition unit, a display unit and the skin tensioning device;

the image acquisition unit acquires preset information of the skin to be tensioned and transmits the preset information to the data control unit;

the data control unit receives the preset information and judges whether the skin to be tensioned meets the preset requirement or not; if the skin tensioning device is not matched with the display unit, the skin tensioning device is controlled to execute a preset program, and if the skin tensioning device is not matched with the display unit, the preset program is not executed, and information is displayed through the display unit; the data control unit receives an upper computer instruction, pressure value data of a pressure gauge and displacement data of a displacement sensor, judges the stretching working condition of the skin stretching device according to the pressure value data and the displacement data, and controls the hoisting device and the skin stretching device to work by combining a preset program;

the hoisting device hoists a skin to be tensioned which meets the preset requirement to the skin tensioning device, and the skin tensioning device hoists away the tensioned skin after tensioning and auxiliary welding operations are completed;

the skin tensioning device is used for tensioning the skin to be tensioned and assisting in completing welding operation;

the upper computer receives instruction input of an operator and sends the instruction to the data control unit;

the display unit is connected with the data control unit and displays pressure value data, displacement data, tensioning working conditions, preset information and preset programs.

Further, the device also comprises an alarm unit; when the data control unit judges that the skin to be tensioned does not accord with the preset requirement or the tensioning condition is abnormal, the data control unit sends alarm information to the alarm unit, and the alarm unit sends an alarm prompt.

The skin tensioning control method of the skin tensioning system is characterized by comprising the following steps of:

step 1, collecting preset information of a skin to be tensioned by using an image collecting unit, and sending the preset information to a data control unit; the data control unit judges whether the skin to be tensioned meets preset requirements, if so, the skin tensioning device is controlled to execute a preset program, if not, the preset program is not executed, and information is displayed through the display unit;

step 2, if the skin to be tensioned meets the preset requirements, hoisting the skin to be tensioned to a skin tensioning device by using a hoisting device, clamping the skin to be tensioned between a first clamping mechanism and a second clamping mechanism, and moving away the hoisting device;

step 3, tensioning the skin to be tensioned by a skin tensioning device; if the tension value data and the displacement data both meet the preset requirements in the tensioning process, the skin tensioning device continuously works; if any one of the tension value data and the displacement data does not meet the preset requirement, stopping the operation of the skin tensioning device, and manually checking; until the stretching of the skin to be stretched is finished;

step 4, the hoisting device hoists the process support to the skin stretched in the step 3, and the welding trolley completes welding;

and 5, hoisting the process support and the integral skin welded in the step 4 by using the hoisting device.

Compared with the prior art, the invention has the beneficial effects that:

1. the skin tensioning device is large in size, can be used for tensioning large skin workpieces, is provided with the hydraulic pump station, is large in tensioning tonnage, and can effectively stretch the skin to plastic deformation; the assembled pressure gauge can display the pressure condition of the hydraulic pump station in real time, and the displacement sensor can monitor the tensioning effect of the skin in real time; the tensioning device is compact in structure, suitable for tensioning skins with various parameters and has a real-time monitoring function. The upper clamping block and the lower clamping block of the clamping mechanism form a pincer shape, so that the skin cannot slide relatively under high tension and can deviate, and the safety is further ensured.

2. The first clamping mechanism is detachably connected with the support, so that the first clamping mechanism can be conveniently moved and adjusted according to the processing condition; the U-shaped plate is more favorable for the position adjustment of the first clamping mechanism, and is simple to connect and convenient to disassemble.

3. The sliding assembly adopts the rolling bearing, moves smoothly in the tensioning process, and is more accurate in operation.

4. The skin tensioning control system is provided with the upper computer capable of inputting instructions and the data control unit capable of receiving and processing data and controlling the skin tensioning device and the hoisting device, so that automatic control of skin tensioning and subsequent welding is realized, the tensioning process is more accurate, the controllability is stronger, and centralized control of skin hoisting, skin tensioning and welding is also realized.

5. The skin tensioning system is provided with the alarm unit, so that an operator can be prompted to check in time when an abnormity occurs, and the production safety and the production progress are ensured.

6. According to the skin tensioning control method, the preset information of the skin is identified in advance by the image acquisition unit, whether the skin meets the production requirements or not can be identified in time, manual operation is reduced, and waste of subsequent processes is avoided; firstly, welding the process support 28 and the skin qualified for tensioning, wherein the welding quantity is far smaller than that of the skin and the frame, the utilization rate of a tensioning device is improved, the quantity of the skin capable of being tensioned in unit time is increased, one piece of tensioning equipment can meet the requirements of 2-3 frame welding stations, and the production efficiency is improved; in addition, the process support is convenient for welding, the welding quality is improved, and the labor intensity of workers is reduced; meanwhile, as the welding efficiency is improved, the skin is prevented from being kept in a clamping and stretching state for a long time, and the service life is prolonged; moreover, the tensioning working condition is judged in real time in the tensioning process, so that an operator can find out tensioning abnormity in time, and the processing efficiency and the processing yield are further improved.

Drawings

FIG. 1 is a schematic structural diagram of a tensioning device in the background art;

FIG. 2 is a schematic structural diagram of a horizontal tensioning device in the prior art;

FIG. 3 is a schematic structural diagram of a vertical tensioning device in the prior art;

FIG. 4 is a schematic structural diagram of a skin tensioning device according to an embodiment of the present invention;

FIG. 5 is a schematic structural view of a first clamping mechanism in an embodiment of the present invention;

FIG. 6 is a schematic structural view of a second clamping mechanism in an embodiment of the present invention;

FIG. 7 is a schematic structural diagram of a stretching mechanism in an embodiment of the present invention;

FIG. 8 is a schematic diagram of the composition of the skin tensioning control system of the present invention;

fig. 9 is a schematic view of the auxiliary welding working state of the skin tensioning device.

Wherein, 1-support, 2-first clamping mechanism, 201-first base, 202-first lever, 203-first support seat, 204-first oil cylinder, 205-first upper clamping block, 206-first lower clamping block, 3-second clamping mechanism, 301-second base, 302-second lever, 303-second support seat, 304-second oil cylinder, 305-second upper clamping block, 306-second lower clamping block, 307-slide rail, 4-stretching mechanism, 401-mounting rack, 402-third oil cylinder, 403-pull rod, 5-hydraulic pump station, 6-welding trolley, 7-tractor, 8-roller, 9-oil pipe, 10-reversing switch, 11-coupler, 12-frame, 13-motor, 14-fixed pulley, 15-movable pulley, 16-steel wire rope, 17-hydraulic cylinder, 18-spring balance, 19-oil pump, 20-first stretching mechanism, 21-skin, 22-frame, 23-platform, 24-third clamping mechanism, 25-geographical track, 26-vertical tensioning equipment, 27-bracket and 28-process support.

Detailed Description

The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention and the accompanying drawings, and it is obvious that the described embodiments do not limit the present invention.

A skin tensioning device as shown in fig. 4, 5, 6 and 7 comprises a hydraulic pump station 5 and a support 1; the support 1 is coaxially and sequentially provided with a first clamping mechanism 2, a second clamping mechanism 3 and a stretching mechanism 4; the first clamping mechanism 2 comprises a first lever 202, a first base 201, a first oil cylinder 204 fixed on the first base 201, a first supporting seat 203 and a first lower clamping block 206; the middle part of the first lever 202 is hinged with the first supporting seat 203, one end of the first lever 202 is hinged with the output end of the first oil cylinder 204, the other end of the first lever is connected with the first upper clamping block 205, and the first upper clamping block 205 is positioned right above the first lower clamping block 206; the second clamping mechanism 3 comprises a second lever 302, a second base 301, a second oil cylinder 304 fixed on the second base 301, a second supporting seat 303 and a second lower clamping block 306; the middle part of the second lever 302 is hinged with the second support base 303, one end of the second lever 302 is hinged with the output end of the second oil cylinder 304, the other end of the second lever 302 is connected with a second upper clamping block 305, and the second upper clamping block 305 is positioned right above a second lower clamping block 306; a sliding rail 307 is arranged at the lower part of the second base 301, the sliding rail 307 is matched with a sliding component arranged on the support 1, and a displacement sensor is arranged on the second base 301; the stretching mechanism 4 comprises a mounting frame 401 fixed on the support 1 and a third oil cylinder 402 fixed on the mounting frame 401, and the output end of the third oil cylinder 402 is connected with the second base 301 through a pull rod 403; the hydraulic pump station 5 is connected with the first oil cylinder 204, the second oil cylinder 304 and the third oil cylinder 402 through oil pipes respectively, and the hydraulic pump station 5 is connected with a pressure gauge.

In order to ensure that the skin is tensioned uniformly, the lengths of the first upper clamping block 205 and the first lower clamping block 206 are the same and are both larger than the width of the skin to be tensioned; the second upper clamping block 305 and the second lower clamping block 306 have the same length and are both larger than the width of the skin to be tensioned, and each clamping block completely clamps the skin in the width direction of the skin during tensioning.

In order to be able to be used in more situations in actual processing, the first clamping mechanism 2 and the support 1 are designed to be detachably connected.

The sliding component comprises a rolling shaft and a rolling bearing, the rolling shaft is mounted on the support 1, and the rolling bearing is sleeved on the rolling shaft and matched with the sliding rail 307. Other sliding structures capable of cooperating with the sliding rail 307 may also be used to ensure that the second clamping mechanism 3 moves smoothly with the stretching of the skin 21 during the stretching process.

Furthermore, in order that the skin 21 does not slip or shift due to excessive tension in the tensioning process to cause potential safety hazards, the first upper clamping block 205 and the first lower clamping block 206 form a pincer shape; the second upper clamping block 305 and the second lower clamping block 306 also form a clamp shape, and even the clamp shape can be designed according to the actual processing situation.

The working process of the skin tensioning device is as follows: the skin 21 is hoisted to the skin tensioning device by a hoist, one end of the skin is dropped onto the first lower clamping block 206, the other end of the skin is dropped onto the second lower clamping block 306, and the hoist is removed; pressurizing the first oil cylinder 204 and the second oil cylinder 304 through the hydraulic pump station 5, respectively lifting the first lever 202 and the second lever 302, driving the first upper clamping block 205 and the second upper clamping block 305 to fall down, and further clamping two ends of the skin 21; gradually pressurizing the third oil cylinder 402, driving the second clamping mechanism 3 to move along the sliding rail 307 by the stretching mechanism 4 until the skin 21 is stretched to a required length, keeping the pressure, manually checking the stretching quality of the skin 21, and welding the process frame and the skin 21 after ensuring that the skin is tight and has no wrinkles; after welding, the pressure of the third oil cylinder 402 of the stretching mechanism 4 is reset to zero, and then the first clamping mechanism 2 and the second clamping mechanism 3 are loosened; the whole of the process frame and the skin 21 is lifted off by a hanger. The manometer can show hydraulic power unit's pressurization condition, and displacement sensor can monitor the stretch-draw effect of covering 21.

Based on foretell covering tensioning equipment, the cooperation of other relevant devices and the control unit provides a covering tensioning control system, adopts closed-loop control system, and real time monitoring takes notes covering 21's the stretch-draw volume, hydraulic power unit 5's pressure condition and covering 21's stretch-draw operating mode, specifically includes hoist device, host computer, data control unit, alarm unit, image acquisition unit and display element and as above covering tensioning equipment:

the image acquisition unit acquires preset information of the skin to be tensioned and transmits the preset information to the data control unit.

The data control unit receives the preset information and judges whether the skin to be tensioned meets the preset requirement or not; if the skin tensioning device is not matched with the display unit, the skin tensioning device is controlled to execute a preset program, and if the skin tensioning device is not matched with the display unit, the preset program is not executed, and information is displayed through the display unit; the data control unit receives an upper computer instruction, pressure value data of a pressure gauge of the skin tensioning device and displacement data of the displacement sensor, judges the tensioning working condition of the skin tensioning device according to the pressure value data and the displacement data, and controls the hoisting device and the skin tensioning device to work by combining a preset program;

the judgment of the tensioning working condition specifically means that when the pressure value data and the displacement data both meet the preset requirements, the tensioning working condition is normal, and tensioning is finished; when the displacement data reaches the maximum range, but the pressure data does not reach the minimum requirement, the data is abnormal and needs manual inspection; when the pressure value data reaches the set maximum range, but the displacement data does not reach the requirement, the data is abnormal and needs manual inspection.

The hoisting device hoists the skin to be tensioned which meets the preset requirements to the skin tensioning device, and the skin tensioning device hoists away the tensioned skin after tensioning and auxiliary welding operations are completed.

The skin tensioning device is used for tensioning the skin to be tensioned and assisting in completing welding operation.

The upper computer receives instruction input of an operator and sends the instruction to the data control unit.

The display unit is connected with the data control unit and displays pressure value data, displacement data, tensioning working conditions, preset information and preset programs.

And when the data control unit judges that the skin to be stretched does not meet the preset requirement or the stretching working condition is abnormal, the data control unit sends alarm information to the alarm unit, and the alarm unit sends an alarm prompt.

The control method based on the skin tensioning system specifically comprises the following steps:

step 1, shooting a skin to be stretched placed at a skin storage station by using an image acquisition unit, acquiring preset information of the skin to be stretched, sending the preset information to a data control unit, and obtaining related data of the skin to be stretched through image processing and coding identification; the data control unit judges whether the skin to be tensioned meets preset requirements, if so, the skin tensioning device is controlled to execute a preset program, if not, the preset program is not executed, and information is displayed through the display unit;

step 2, if the skin to be tensioned meets the preset requirements, hoisting the skin to be tensioned to a skin tensioning device by using a hoisting device, clamping the skin to be tensioned between a first clamping mechanism 2 and a second clamping mechanism 3, and moving away the hoisting device;

step 3, tensioning the skin to be tensioned by a skin tensioning device, wherein tensioning parameters can be preset in the skin tensioning device and selected; if the tension value data and the displacement data both meet the preset requirements in the tensioning process, the skin tensioning device continuously works; if any one of the tension value data and the displacement data does not meet the preset requirement, stopping the operation of the skin tensioning device, and manually checking; until the stretching of the skin to be stretched is finished; the specific stretching process is the same as the working process of the skin stretching device;

step 4, as shown in fig. 9, the hoisting device hoists the process support 28 to the skin stretched in the step 3, the hoisting device is moved after the process support is placed stably, the welding trolleys 6 are installed at two ends of the process support 28, the process support 28 and the skin are welded until the welding is finished, and the welding trolleys 6 are moved;

step 5, the hoisting device hoists away the process support 28 welded in the step 4 and the skin integrally, and if the skin frame assembly welding station is close to the tensioning station, the lifting lugs on the side surface of the process support 28 can be directly and vertically hoisted to the welding station for welding; if the welding station is remote, the process support 28 is transferred to the transport equipment using the top lifting lug. At this point, the skin tensioning equipment may be reset in preparation for the next operation.

Firstly, the process support 28 is welded with the skin which is qualified in tensioning, the welding amount is far smaller than that of the skin and the frame, the utilization rate of skin tensioning equipment is improved, and the production efficiency is improved; the real-time recording pressure value data and displacement data are convenient for optimizing process parameters or finding problems in the later period, and can also find abnormal working conditions in time and give an alarm, so that the waste can be reduced to a certain extent, and the safety is improved.

The above description is only an embodiment of the present invention, and is not intended to limit the scope of the present invention, and all equivalent structural changes made by using the contents of the present specification and the drawings, or applied directly or indirectly to other related technical fields, are included in the scope of the present invention.