CN111055515A

CN111055515A - Fiber preforming line forming and clamping device and method

Info

Publication number: CN111055515A
Application number: CN201911408485.7A
Authority: CN
Inventors: 廖永辉; 林丰; 谢剑林; 陈楠; 陈晖�
Original assignee: Fujian Haiyuan Composite Materials Technology Co ltd
Current assignee: Fujian Haiyuan Composite Materials Technology Co ltd
Priority date: 2019-12-31
Filing date: 2019-12-31
Publication date: 2020-04-24

Abstract

The invention discloses a fiber preforming line forming and clamping device and a fiber preforming line forming and clamping method, wherein the fiber preforming line forming and clamping device comprises a heating table press, a clamping device and a preforming press which are sequentially arranged according to the advancing direction of a fiber to be formed; the clamping device slides on the two parallel clamping hand guide rails and conveys the fiber cloth heated by the heating table press into the preforming press; the clamping device is two gantry clamping hand mechanisms which are arranged in front and back and independently perform linear motion, each gantry clamping hand mechanism comprises two advancing and retreating mechanisms, a lifting mechanism, a cross rod mechanism and a clamping tool, the advancing and retreating mechanisms move along the clamping guide rails respectively, each advancing and retreating mechanism is connected with the lifting mechanism respectively, the cross rod mechanism stretches across the clamping guide rails, and two ends of the cross rod mechanism are connected with the lifting mechanisms respectively; the clamping tool comprises a plurality of clamping units, and each clamping unit is used for carrying out closed-loop or tension closed-loop control on the position of the fiber cloth in the pressing process of the preforming press.

Description

Fiber preforming line forming and clamping device and method

Technical Field

The invention belongs to the field of fiber preforming equipment, and particularly relates to a fiber preforming line forming and clamping device and method.

Background

The fiber preforming technology is a novel and practical fiber preforming body preparation technology developed in the early 90 s of the 20 th century. The principle is that a small amount of special tackifying material, namely tackifier/sizing agent, is coated on the surface of the reinforced fiber or fabric, the laminated fabric or fiber bundle is bonded together by means of solvent volatilization, heating softening or melting (pre-curing), cooling and the like, and the fiber preform with the required shape, size and fiber volume content is prepared under the action of pressure and a shape mold.

In the prior art, a forming clamping device used in fiber preforming production mainly adopts a robot to match with a special clamping hand to meet the feeding and cloth transmission requirements of a fiber cloth from a heating table press to a preforming press, and the mode of matching with the special clamping hand by the robot has the following problems: firstly, fiber cloth materials of different shapes need to be matched with corresponding special clamping hands by a robot, once products are various and frequently replaced, the production efficiency is affected, and the cost of the tool is high; secondly, the required time of the heated fiber cloth from the heating table to the preforming press is as short as possible, but the heated cloth can be conveyed from the heating table press to the preforming press only through multi-shaft linkage matching in the prior art, so that the transmission efficiency is low; thirdly, the clamping hands in the prior art are loosened before the fiber cloth is pressed and shaped, so that the fiber cloth can not be kept under tension in the pressing process, and wrinkles are easy to appear.

Disclosure of Invention

In order to solve the technical problems, the invention provides a fiber preforming line forming and clamping device and a fiber preforming line forming and clamping method.

The technical scheme of the invention is as follows:

a fiber preforming line forming and clamping device comprises a heating table press, a clamping device and a preforming press which are sequentially arranged according to the advancing direction of a fiber to be formed; the clamping device slides on the two parallel clamping hand guide rails and conveys the fiber cloth heated by the heating table press into the preforming press; the clamping device is two gantry clamping hand mechanisms which are arranged in front and back and independently perform linear motion, each gantry clamping hand mechanism comprises two advancing and retreating mechanisms, a lifting mechanism, a cross rod mechanism and a clamping tool, the advancing and retreating mechanisms move along the clamping guide rails respectively, each advancing and retreating mechanism is connected with the lifting mechanism respectively, the cross rod mechanism stretches across the clamping guide rails, and two ends of the cross rod mechanism are connected with the lifting mechanisms respectively; the clamping tool comprises a plurality of clamping units, and each clamping unit is used for carrying out closed-loop or tension closed-loop control on the position of the fiber cloth in the pressing process of the preforming press.

Further, the clamping units are fixed on the cross rod mechanism, and each clamping unit comprises a servo electric cylinder and a clamping hand connected with the servo electric cylinder.

Further, the advancing and retreating mechanism comprises a machine frame which is connected to the clamping hand rail in a sliding mode; a forward and backward servo motor is fixedly arranged in the rack, and a first gear is sleeved on an output shaft of the forward and backward servo motor; the first gear is meshed with a first rack arranged in parallel with the hand clamping guide rail, and then the bearing driving and reversing mechanism is driven to move along the first rack and the hand clamping guide rail.

Furthermore, the lifting mechanism is in sliding connection with the driving and reversing mechanism through an adapter piece fixed on the side wall of the rack; the lifting mechanism comprises a lifting servo motor and a second gear sleeved on an output shaft of the lifting servo motor; the adapter comprises a first connecting plate vertically fixed on the side wall of the rack, a sliding assembly fixed on the first connecting plate and a second rack; the sliding assembly comprises a sliding rail fixed on the first connecting plate and a sliding block matched with the sliding rail to slide, and the sliding block is fixed on a second connecting plate which supports the lifting servo motor and is arranged in parallel with the first connecting plate; the second gear is meshed with the second rack.

Furthermore, the first connecting plate is fixedly connected with the top of the rack through a supporting rib plate.

Further, the cross bar mechanism comprises a main bar and an auxiliary bar fixed at the bottom of the main bar; the main rod is fixed on the second connecting plate, and the auxiliary rod is provided with a plurality of mounting holes; the servo electric cylinder of the clamping tool is fixed on the auxiliary rod; the main rod is also provided with a fine adjustment device for adjusting the height of the cross rod mechanism; the clamping hand is a pneumatic finger, and tooth-shaped clamping plates which are symmetrical up and down are arranged at the opening and closing position at the front end of the clamping hand, which is used for clamping fiber cloth.

Furthermore, the heating platform press spans across the two parallel clamping guide rails, and two ends of the heating platform press are positioned outside the clamping guide rails and fixedly connected with a support for supporting the clamping guide rails; the preforming press spans the two parallel clamping guide rails, and two ends of the preforming press are located on the outer sides of the clamping guide rails and fixedly connected with the support for supporting the clamping guide rails.

Further, the heating platform press comprises a heating machine and a steel wire lifting device which is arranged in the heating machine and can move up and down to lift the fiber cloth; the steel wire lifting device comprises a main body frame, a plurality of steel wire ropes fixed on the main body frame in parallel and at least one lifting cylinder connected to the lower surface of the main body frame; two ends of each steel wire rope are connected with the main body frame through a rope tensioning device; the lifting cylinders are all fixed on different vertical rod side walls of a working table top used for heating in the supporting and heating machine.

Furthermore, the steel wire lifting device is at least provided with a guide mechanism; the guide mechanism is fixed on the lower surface of the main body frame and comprises a limiting block and a limiting groove; the limiting groove is fixed on the side wall of the vertical rod, and the limiting block is fixed on the main body frame.

A fiber preformed line forming and clamping method comprises the following specific steps:

s1, the fiber cloth after being heated on the heating table press is lifted by starting the steel wire lifting device;

s2, starting the gantry clamping hand mechanisms to enable the two symmetrical gantry clamping hand mechanisms to move to the two sides of the fiber cloth on the steel wire lifting device along the clamping hand guide rails to be clamped and move to the position of the preforming press;

s3, the two gantry clamping hand mechanisms always keep a state of clamping the fiber cloth, the lifting mechanism of the gantry clamping hand mechanisms is used for jacking the fiber cloth to enable the fiber cloth to be in contact with an upper die of the preforming press, the fiber cloth descends together with the upper die after being in contact with the upper die, and meanwhile, the fiber cloth keeps synchronous with the descending speed of the upper die under the driving of the lifting mechanism of the clamping device;

s4, in the process that the fiber cloth descends under pressure in the preforming press, the clamping device keeps the position still, the clamping hand in one gantry clamping hand mechanism is driven by the servo electric cylinder to send the fiber cloth to the direction of the die of the preforming press at a constant speed, the position is kept closed, the clamping hand in the other gantry clamping hand mechanism is driven by the servo electric cylinder to pull in the opposite direction, the tension is kept closed, and therefore the fiber cloth is always in a tensioning state in the pressing and shaping process;

and S5, when the fiber cloth descends to determine the position, two rows of clamping hands of the clamping device are loosened, and the fiber cloth enters a pressure maintaining and shaping stage.

The invention has the following beneficial effects:

1. the invention is provided with a clamping tool consisting of a servo electric cylinder and a clamping hand, wherein the clamping tool can enter force closed-loop control in the fiber cloth pressing process, and the clamping hand in a gantry clamping hand mechanism is driven by the servo electric cylinder to convey the fiber cloth to the mold direction of a preforming press at a constant speed so as to keep position closed-loop; the clamping hand in the other gantry clamping hand mechanism is driven by the servo electric cylinder to pull in the opposite direction, so that a tension closed loop is maintained, the fiber cloth is always in a tensioning state in the pressing and shaping process, the preset optimal fiber cloth tension is always maintained, and the fiber cloth is prevented from being wrinkled, so that the finished product rate and the surface quality of a product are improved.

2. The invention adopts the moving mode of matching the clamping guide rail and the sliding block, can shorten the running conveying track of the fiber cloth, improves the transmission efficiency and the production efficiency from the heating table press to the preforming press, avoids more heat loss in the conveying process after the fiber cloth is heated, and is beneficial to optimizing the setting property of the heated fiber cloth.

3. The clamping device provided by the invention can overcome the problem that different fiber cloth materials need to be clamped by different clamping hands in the prior art, and the clamping device formed by two symmetrical gantry clamping hand mechanisms can meet the clamping of the fiber cloth materials with various shapes, so that the cost is saved, and the production efficiency is improved.

4. The two gantry clamping hand mechanisms forming the clamping device can respectively carry out independent movement on the clamping hand guide rails to complement each other; simultaneously, the advancing and retreating mechanism and the lifting mechanism of the same gantry clamping hand mechanism move independently in the horizontal direction and in the vertical direction, and do not influence each other, so that the arrangement is favorable for respectively adjusting the positions of the fiber cloth according to the actual production requirement, and the transmission and the positioning of the fiber cloth are more accurate.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic view of the structure of the gripper rail according to the present invention;

FIG. 3 is a schematic structural view of a clamping device according to the present invention;

FIG. 4 is an enlarged schematic view at A in FIG. 3;

FIG. 5 is a schematic view showing a connection structure of the advancing/retreating mechanism and the elevating mechanism according to the present invention;

fig. 6 is a schematic view of the connection between the cross bar mechanism and the clamping tool of the present invention.

FIG. 7 is a schematic view of a heating platen press according to the present invention;

fig. 8 is a schematic structural view of a wire lifting mechanism according to the present invention.

In the drawings, the reference numbers denote:

1. a heating table press; 11. a heater; 110. a hydraulic system; 111. heating plates; 12. a steel wire lifting device; 13. a main body frame; 14. a wire rope; 141. a rope tensioning device; 15. a lifting cylinder; 16. a work table; 17. a vertical rod; 18. a guide mechanism; 181. a limiting block; 182. a limiting groove; 2. a clamping device; 21. a gantry clamping mechanism; 3. a preforming press; 4. a gripper guide rail; 41. a support; 5. an advancing and retreating mechanism; 51. a frame; 52. a forward and backward servo motor; 53. a first gear; 54. a first rack; 55. a frame moving block; 6. a lifting mechanism; 61. an adapter; 62. a lifting servo motor; 63. a second gear; 64. a first connecting plate; 65. a second rack; 66. a slide rail; 67. a slider; 68. a second connecting plate; 69. a support rib plate; 7. a cross bar mechanism; 71. a main rod; 72. an auxiliary rod; 73. mounting holes; 74. a fine adjustment device; 8. clamping a tool; 81. a servo electric cylinder; 82. clamping a hand; 83. a tooth-shaped splint.

Detailed Description

The invention will be further described with reference to preferred embodiments and the accompanying drawings.

Referring to fig. 1, a fiber preforming line forming and clamping device includes a heating table press 1, a clamping device 2 and a preforming press 3 which are sequentially arranged according to the advancing direction of a fiber to be formed; the clamping device 1 slides on two parallel clamping hand guide rails 4, and the fiber cloth heated by the heating table press 1 is conveyed into the preforming press 3; the heating table press 1 spans the two parallel clamping guide rails 4, and two ends of the heating table press are positioned outside the clamping guide rails 4 and fixedly connected with a bracket 41 for supporting the clamping guide rails 4; the preforming press 3 spans the two parallel gripper guide rails 4, and two ends of the preforming press are positioned outside the gripper guide rails 4 and fixedly connected with the bracket 1 for supporting the gripper guide rails 4; so that the smooth sliding of the clamping device on the clamping guide rail 4 is not influenced by the heating table press 1 and the pre-pressing forming machine 3; the clamping device 2 is provided with two gantry clamping mechanisms 21 which are arranged in the front and back and independently perform linear motion, when the fiber cloth needs to be clamped, one gantry clamping mechanism 21 close to the heating table press 1 independently moves to one side of the fiber cloth along the clamping guide rail 4, the other gantry clamping mechanism 21 is positioned at the opposite side of the fiber cloth, the two gantry clamping mechanisms 21 are close to each other along the linear direction of the clamping guide rail 4 after the position is determined, the fiber cloth is clamped from the front end and the rear end together according to the conveying direction of the fiber cloth, and then the gantry clamping mechanisms move on the clamping guide rail 4 in the same direction to convey the fiber cloth to the preforming press 3; the gantry clamping hand mechanism 21 comprises two advancing and retreating mechanisms 5, a lifting mechanism 6, a cross bar mechanism 7 and a clamping tool 8 which respectively move along the clamping hand guide rail 4, each advancing and retreating mechanism 5 is respectively connected with the lifting mechanism 6, and the advancing and retreating mechanisms 5 and the lifting mechanism 6 can independently move; the cross rod mechanism 7 stretches across the gripper guide rail 4, two ends of the cross rod mechanism 7 are respectively connected with the lifting mechanism 6, and the lifting mechanism 6 realizes the up-and-down movement of the cross rod mechanism 7; the clamping tool 8 is fixed on the cross bar mechanism 7 and used for clamping fiber cloth; the clamping tool 8 comprises a plurality of clamping units, and each clamping unit is used for carrying out closed-loop or tension closed-loop control on the position of the fiber cloth in the pressing process of the preforming press 4.

Referring to fig. 3 to 5, the clamping units are fixed on the cross bar mechanism 7, and each clamping unit includes a servo electric cylinder 81 and a clamping hand 82 connected with the servo electric cylinder 81; the gripper 82 can adjust the tension on the fiber cloth in the horizontal direction under the driving of the servo electric cylinder 81, so as to keep the tension closed-loop control and maintain the tension state of the fiber cloth.

Referring to fig. 3-5, the advancing-retreating mechanism 5 comprises a frame 51 slidably connected to the gripper rail 4; a forward and backward servo motor 52 is fixedly installed in the frame 51, and a first gear 53 is sleeved on an output shaft of the forward and backward servo motor 52; the first gear 53 is meshed with a first rack 54 arranged in parallel with the gripper guide rail 4, so as to drive the bearing advancing and retreating mechanism 5 to move along the first rack 54 and the gripper guide rail 4; the bottom of the rack 51 is further provided with a rack moving block 55 with a downward groove, the gripper guide rail 4 is embedded into the groove of the rack moving block 55, and the rack 51 slides on the gripper guide rail 4 under the matching transmission of the first gear 53 and the first rack 54, so that the moving position of the rack 51 is limited, the rack 51 is ensured not to be separated from the gripper guide rail 4 in the moving process, and the advancing and retreating mechanism 5 is enabled to stably move.

Referring to fig. 3-5, the lifting mechanism 6 is slidably connected to the advancing and retreating mechanism 5 through an adapter 61 fixed on the side wall of the frame 51; the lifting mechanism 6 comprises a lifting servo motor 62 and a second gear 63 sleeved on an output shaft of the lifting servo motor 62; the adaptor 61 comprises a first connecting plate 64 vertically fixed on the side wall of the frame 51, a sliding assembly fixed on the first connecting plate 64 and a second rack 65; the sliding assembly comprises a sliding rail 66 fixed on the first connecting plate 64 and a sliding block 67 matched with the sliding rail 66 to slide, and the sliding block 67 is fixed on a second connecting plate 68 which supports the lifting servo motor 62 and is arranged in parallel with the first connecting plate 64; the second gear 63 is engaged with the second rack 65; the lifting servo motor 62 is started, an output shaft of the lifting servo motor 62 rotates to drive the second gear 63 to rotate, the second gear 63 is meshed with the second rack 65, the lifting servo motor 62 and the second connecting plate 68 are driven to move up and down along the second rack 65, meanwhile, a sliding block 67 arranged on the second connecting plate 68 moves along a sliding rail 66 fixed on the first connecting plate 64, the moving position of the second connecting plate 68 is limited, and linear motion is guaranteed; the up-and-down movement of the second connecting plate 68 can drive the cross rod mechanism 7 to move up and down; the first connecting plate 64 is fixedly connected with the top of the frame 51 through a supporting rib plate 69, and the supporting rib plate 69 can stably connect the frame 51 and the first connecting plate 64.

Referring to fig. 6, the cross bar mechanism 7 includes a main bar 71 and a sub-bar 72 fixed to the bottom of the main bar 71; the main rod 71 is fixed on the second connecting plate 68, and the auxiliary rod 72 is provided with a plurality of mounting holes 73; the servo electric cylinder 81 of the clamping tool 8 is fixed on the auxiliary rod 72, the servo electric cylinder 81 can pass through the mounting hole 73 through a bolt to be fixedly connected with the auxiliary rod 72, and meanwhile, the positions of the servo electric cylinder 81 and the clamping hand 82 are adjustable; the main rod 71 is also provided with a fine adjustment device 74 for adjusting the height of the cross rod mechanism 7; the clamping hand 82 is a pneumatic finger, and tooth-shaped clamping plates 83 which are symmetrical up and down are arranged at the opening and closing part at the front end of the clamping hand 82 for clamping fiber cloth.

Referring to fig. 7-8, the heating platen press 1 includes a heater 11 and a wire lifting device 12 disposed inside the heater 11 and capable of moving up and down to lift the fiber cloth; a hydraulic system 34 is fixed on an upper shelf of the heater 11, a working table 16 is fixed on a lower shelf, the working table 16 is heated by electricity, the hydraulic system 34 drives a heating plate 35 positioned above the hydraulic system to move up and down by mutually connecting a hydraulic pump station and a hydraulic cylinder, and the heating plate and the working table 16 are closed to heat fiber cloth; the steel wire lifting device 12 comprises a main body frame 13, a plurality of steel wire ropes 14 fixed on the main body frame 13 in parallel and at least one lifting cylinder 15 connected to the lower surface of the main body frame 13; both ends of each wire rope 14 are connected to the main body frame 13 through rope tensioners 141; the lifting cylinders 15 are all fixed on the side walls of different vertical rods 17 supporting a working table surface 16 in the heating machine 11; the telescopic rod of the lifting cylinder 15 is fixedly connected with the main body frame 13, and the lifting cylinder 15 drives the main body frame 13 to move up and down; the wire lifting device 12 is at least provided with a guide mechanism 18; the guide mechanism 18 is fixed on the lower surface of the main body frame 13 and comprises a limit block 181 and a limit groove 182; the limiting groove 182 is fixed on the side wall of the vertical rod 17, and the limiting block 181 is fixed on the main body frame 13.

s1, the fiber cloth after being heated on the heating table press 1 is lifted by starting the steel wire lifting device 12;

s2, starting the gantry clamping hand mechanisms 21, so that the two symmetrical gantry clamping hand mechanisms 21 move to the two sides of the fiber cloth arranged at the steel wire lifting device 12 along the clamping hand guide rails 4 to be clamped and move to the position of the preforming press 3;

s3, the two gantry gripper mechanisms 21 always keep a state of clamping the fiber cloth, the fiber cloth is jacked by the lifting mechanisms 6 in the gantry gripper mechanisms 21 to be in contact with the upper die of the preforming press 3, the fiber cloth descends together with the upper die after being in contact with the upper die, and meanwhile, the fiber cloth keeps synchronous with the descending speed of the upper die under the driving of the lifting mechanisms 6 of the clamping device 2;

s4, in the process that the fiber cloth descends under pressure in the preforming press 3, the clamping device 2 keeps the position still, the clamping hand 82 in one gantry clamping hand mechanism 21 is driven by the servo electric cylinder 81 to send the fiber cloth to the mold direction of the preforming press 3 at a constant speed, the position is kept closed, the clamping hand 82 in the other gantry clamping hand mechanism 21 is driven by the servo electric cylinder 81 to pull in the opposite direction, the tension is kept closed, and therefore the fiber cloth is always in a tensioning state in the pressing and shaping process; the preforming press 4 is a hydraulic press which is controlled by a programmable controller and integrates machine, electricity and liquid, and can automatically complete the process actions of fast descending, slow descending, pressure maintaining, mold opening, slow ascending, fast ascending and the like in the pressing process;

and S5, when the fiber cloth descends to a certain position, two rows of clamping hands 82 of the clamping device 2 are loosened, and the fiber cloth enters a pressure maintaining and shaping stage.

The above-mentioned embodiments only express the preferred embodiments of the present invention, and the description is specific and detailed, but not understood as the limitation of the patent scope of the present invention, it should be noted that, for those skilled in the art, many variations, modifications and substitutions can be made without departing from the concept of the present invention, and these all fall into the protection scope of the present invention, therefore, the protection scope of the present invention should be subject to the appended claims.

Claims

1. A fiber preforming line forming and clamping device is characterized in that: comprises a heating table press (1), a clamping device (2) and a preforming press (3) which are arranged in sequence according to the advancing direction of the fiber to be formed; the clamping device (2) slides on two parallel clamping hand guide rails (4) and conveys the fiber cloth heated by the heating table press (1) into the preforming press (3); the clamping device (2) is provided with two gantry clamping hand mechanisms (21) which are arranged in front and back and independently perform linear motion, each gantry clamping hand mechanism (21) comprises two advancing and retreating mechanisms (5) which respectively move along a clamping hand guide rail (4), a lifting mechanism (6), a cross rod mechanism (7) and a clamping tool (8), each advancing and retreating mechanism (5) is respectively connected with the lifting mechanism (6), the cross rod mechanism (7) stretches across the clamping hand guide rail (4), and two ends of each cross rod mechanism (4) are respectively connected with the lifting mechanisms (6); the clamping tool (8) is fixed on the cross bar mechanism (4) and used for clamping fiber cloth; the clamping tool (8) comprises a plurality of clamping units, and each clamping unit is used for carrying out closed-loop or tension closed-loop control on the position of the fiber cloth in the pressing process of the preforming press (3).

2. A fiber preform line forming and retaining apparatus as claimed in claim 1, wherein: the clamping units are fixed on the cross rod mechanism (4), and each clamping unit comprises a servo electric cylinder (81) and a clamping hand (82) connected with the servo electric cylinder (81).

3. A fiber preform line forming and retaining apparatus as claimed in claim 2, wherein: the advancing and retreating mechanism (5) comprises a rack (51) which is connected to the clamping hand rail (4) in a sliding way; a forward and backward servo motor (52) is fixedly installed in the rack (51), and a first gear (53) is sleeved on an output shaft of the forward and backward servo motor (52); the first gear (53) is meshed with a first rack (54) arranged in parallel with the gripper guide rail (4), and then the bearing advancing and retreating mechanism (5) is driven to move along the first rack (54) and the gripper guide rail (4).

4. A fiber preform line forming and retaining apparatus as claimed in claim 3, wherein: the lifting mechanism (6) is in sliding connection with the advancing and retreating mechanism (5) through an adapter piece (61) fixed on the side wall of the rack (51); the lifting mechanism (6) comprises a lifting servo motor (62) and a second gear (63) sleeved on an output shaft of the lifting servo motor (62); the adaptor (61) comprises a first connecting plate (64) vertically fixed on the side wall of the rack (51), a sliding assembly fixed on the first connecting plate (64) and a second rack (65); the sliding assembly comprises a sliding rail (66) fixed on the first connecting plate (64) and a sliding block (67) matched with the sliding rail (66) to slide, and the sliding block (67) is fixed on a second connecting plate (68) which supports the lifting servo motor (62) and is arranged in parallel with the first connecting plate (64); the second gear (63) is meshed with the second rack (65).

5. A fiber preform line forming and retaining apparatus as claimed in claim 4, wherein: the first connecting plate (64) is fixedly connected with the top of the rack (51) through a supporting rib plate (69).

6. A fiber preform line forming and retaining apparatus as claimed in claim 4, wherein: the transverse rod mechanism (7) comprises a main rod (71) and an auxiliary rod (72) fixed at the bottom of the main rod (71); the main rod (71) is fixed on the second connecting plate (68), and the auxiliary rod (72) is provided with a plurality of mounting holes (73); a servo electric cylinder (81) of the clamping tool (8) is fixed on the auxiliary rod (72); the main rod (71) is also provided with a fine adjustment device (74) for adjusting the height of the cross rod mechanism (7); the clamping hands (82) are pneumatic fingers, and tooth-shaped clamping plates (83) which are symmetrical up and down are arranged at the opening and closing positions of the front ends of the clamping hands (82) for clamping fiber cloth.

7. A fiber preform thread forming and holding apparatus as claimed in any one of claims 5 or 6, wherein: the heating table press (1) spans the two parallel clamping guide rails (4), and two ends of the heating table press are positioned outside the clamping guide rails (4) and fixedly connected with a bracket (41) for supporting the clamping guide rails (4); the preforming press (3) spans the two parallel gripper guide rails (4), and two ends of the preforming press are located on the outer sides of the gripper guide rails (4) and fixedly connected with a support (41) for supporting the gripper guide rails (4).

8. A fiber preform line forming and retaining apparatus as claimed in claim 7, wherein: the heating table press (1) comprises a heating machine (11) and a steel wire lifting device (12) which is arranged in the heating machine (11) and can move up and down to lift the fiber cloth; the steel wire lifting device (12) comprises a main body frame (13), a plurality of steel wire ropes (14) which are fixed on the main body frame (13) in parallel and at least one lifting cylinder (15) connected to the lower surface of the main body frame (13); the two ends of each steel wire rope (14) are connected with the main body frame (13) through a rope tensioning device (141); the lifting cylinders (15) are all fixed on the side walls of different vertical rods (17) of a working table top (16) for heating in the supporting and heating machine (11); and the telescopic rod of the lifting cylinder (15) is fixedly connected with the main body frame (13).

9. A fiber preform line forming and retaining apparatus as claimed in claim 8, wherein: the steel wire lifting device (12) is at least provided with a guide mechanism (18); the guide mechanism (18) is fixed on the lower surface of the main body frame (13) and comprises a limiting block (181) and a limiting groove (182); the limiting groove (182) is fixed on the side wall of the vertical rod (17), and the limiting block (181) is fixed on the main body frame (13).

10. A method of clamping a preform fiber strand as in any of claims 8 or 9, comprising the steps of:

s1, the fiber cloth after being heated on the heating table press (1) is lifted by starting the steel wire lifting device (12);

s2, starting the gantry clamping hand mechanisms (21) to enable the two symmetrical gantry clamping hand mechanisms (21) to move to the two sides of the fiber cloth on the steel wire lifting device (12) along the clamping hand guide rails (4) to clamp and move to the position of the preforming press (3);

s3, the two gantry clamping hand mechanisms (21) always keep a state of clamping the fiber cloth, the fiber cloth is lifted by the lifting mechanisms (6) of the gantry clamping hand mechanisms (21) to be in contact with the upper die of the preforming press (3), the fiber cloth descends together with the upper die after being in contact with the upper die, and meanwhile, the fiber cloth keeps synchronous with the descending speed of the upper die under the driving of the lifting mechanisms (6) of the clamping device;

s4, in the process that the fiber cloth descends under pressure in the preforming press (3), the clamping device (2) keeps the position still, a clamping hand (82) in one gantry clamping hand mechanism (21) is driven by a servo electric cylinder (81) to send the fiber cloth to the mold direction of the preforming press (3) at a constant speed, the position is kept closed, a clamping hand (82) in the other gantry clamping hand mechanism (21) is driven by the servo electric cylinder (81) to pull in the opposite direction, the tension closed loop is kept, and therefore the fiber cloth is always in a tensioning state in the pressing and shaping process;

s5, when the fiber cloth descends to the determined position, two rows of clamping hands (82) of the clamping device (2) are loosened, and the fiber cloth enters a pressure maintaining and shaping stage.