CN107379383B

CN107379383B - Composite material hot-press forming die

Info

Publication number: CN107379383B
Application number: CN201710770544.XA
Authority: CN
Inventors: 安鲁陵; 韩宁; 赵一鸣; 周来水; 卫炜
Original assignee: Nanjing University of Aeronautics and Astronautics
Current assignee: Nanjing University of Aeronautics and Astronautics
Priority date: 2017-08-31
Filing date: 2017-08-31
Publication date: 2020-02-04
Anticipated expiration: 2037-08-31
Also published as: CN107379383A

Abstract

The invention relates to a composite material hot-press forming die, which mainly comprises an upper die holder, a lower die holder and an intermediate forming core die, wherein the core die comprises an upper core die and a lower core die, the bottom of the upper die holder is provided with a first U-shaped groove penetrating through the upper die holder, the upper die holder is detachably and fixedly connected with the upper core die embedded in the first U-shaped groove, the top of the lower die holder is provided with a second U-shaped groove penetrating through the lower die holder, the lower die holder is detachably and fixedly connected with the lower core die embedded in the second U-shaped groove, the upper core die corresponds to the lower core die in position, and a die cavity provided with a forming surface of a formed product is formed between the upper core die and the lower core die after the upper die holder and the; the upper die base and the lower die base are both provided with a plurality of oil through pipes, and each oil through pipe is provided with a valve. The mold can reduce production cost and improve the temperature consistency of the forming surface of the core mold cavity.

Description

Composite material hot-press forming die

Technical Field

The invention relates to a composite material hot-press forming die, and belongs to the technical field of die forming.

Background

The advanced composite material has the remarkable advantages of high specific strength-specific modulus, strong designability, good fatigue resistance and the like, and is widely applied to the field of aviation. The composite material is cured and formed in a process of heating, heat preservation and cooling, the temperature of a die is taken as one of the most important composite material curing process parameters, the appearance quality and the mechanical property of a product are directly influenced, and the production efficiency and the production cost of hot press forming processing are determined to a great extent. Therefore, reasonable mold temperature control has important significance for the hot-press forming process.

Thermoforming molds are typically heated by convection heating, i.e., by heat exchange between a high temperature fluid (gas or liquid) and the mold, so that the high temperature fluid can flow through the mold interior heating conduits to indirectly heat the mold cavity surfaces. Traditional thermoforming mould mostly is special mould, and the die cavity setting is between last mandrel and lower mandrel, guarantees the appearance quality and the mechanical properties of product through rationally setting up heating/cooling pipeline's size and position. But the disadvantages of the special mould are: 1) the core mold can not be used repeatedly (not used universally), and because the surface temperature uniformity of the cavity of the core mold requires that the position shape of an oil pipe in the upper mold base and the lower mold base is consistent with the shape of the cavity of the core mold, each product needs the unique upper mold base and the lower mold base and the core mold corresponding to the product, the manufacturing cost is high, and the price of the product is high; 2) the heating/cooling pipelines arranged in the upper die base and the lower die base are usually in a coil pipe shape and only have one oil inlet and one oil outlet, when the heating/cooling pipelines are subjected to hot press forming, the thickness and the shape of parts are different, the distance between each pipeline and the cavity surface of the core model is different, and the temperature consistency of the cavity surface of the core model is difficult to guarantee.

Disclosure of Invention

The invention aims to solve the technical problems that: the composite material hot press forming die can reduce production cost, can be reused and can improve the temperature consistency of the cavity surface.

In order to solve the technical problems, the technical scheme provided by the invention is as follows: a temperature-adjustable composite material hot-press forming die comprises an upper die holder and a lower die holder, wherein a first U-shaped groove penetrating through the upper die holder is formed in the bottom of the upper die holder, an upper core die embedded in the first U-shaped groove is detachably and fixedly connected with the upper die holder, a second U-shaped groove penetrating through the lower die holder is formed in the top of the lower die holder, a lower core die embedded in the second U-shaped groove is detachably and fixedly connected with the lower die holder, the upper core die corresponds to the lower core die in position, and a cavity provided with a forming surface of a formed product is formed between the upper core die and the lower core die after the upper die holder and the lower die holder are assembled; the upper die base and the lower die base are both provided with a plurality of oil through pipes, and each oil through pipe is provided with a valve.

The invention has the following beneficial effects: 1) the invention sets replaceable core moulds (upper core mould and lower core mould) on the hot-press forming mould, and sets the forming surface of the cavity between the upper core mould and the lower core mould, so that parts with different shapes can be processed by replacing the core moulds, and the rest parts of the mould can be reused while ensuring that the temperature rise difference of the whole core mould cavity surface meets the use requirement, thereby greatly reducing the production cost. 2) The invention heats/cools the forming surface of the cavity by a plurality of oil pipes, and can obtain more consistent heating/cooling temperature on the surface of the cavity of the whole core die compared with the prior art when producing parts with different shapes by controlling the on-off and oil flow rate of the oil pipes, thereby ensuring the quality of formed products.

In the actual use process, the shape and the thickness of the product are changeable, in order to ensure that the shape surface of the cavity of the core mold can obtain more uniform heating/cooling temperature consistency, the invention improves the technical scheme by adjusting the distance between the oil pipe and the shape surface of the cavity, so that the mold is provided with shape-following heating/cooling pipelines, namely, the distances between all the heating/cooling pipelines and the surface of the cavity are uniform, and therefore, the invention provides two improved technical schemes.

One of the improvement schemes is as follows: waist-shaped through holes which are in one-to-one correspondence with the oil through pipes are vertically arranged on the upper die base and the lower die base, supporting plates which can slide along the side surfaces are arranged on two side surfaces of each waist-shaped through hole, a plurality of springs are arranged between the two supporting plates, and two ends of each spring are fixedly connected with the two supporting plates respectively; two ends of the supporting plate respectively extend outwards along the axial direction of the waist-shaped through hole and are respectively bent outwards at two ends of the waist-shaped through hole to form bent parts, so that the supporting plate can move in the waist-shaped through hole; a flat plate used for supporting an oil pipe is laid above the two supporting plates, the waist-shaped through hole is filled with heat conduction materials, and the heat conduction coefficient of the heat conduction materials is larger than or equal to that of the upper die base and the lower die base. The oil pipe can be supported by the friction force between the support plate and the side wall of the waist-shaped through hole, the friction force is increased by the spring, and the bending part of the support plate can enable the support plate to play a role in guiding in the up-and-down sliding process. In order to accurately position the oil pipe, vertical scale marks are arranged at the positions, located on the two sides of the waist-shaped through hole, of the upper die base and the lower die base.

In order to improve the reliability of supporting the oil through pipe, a further improvement of one of the improvement schemes is that: the bending part of the supporting plate is provided with a pin hole, and the upper die base and the lower die base are vertically provided with a plurality of limiting holes matched with the pin holes and limiting pin shafts capable of being inserted into the limiting holes and the pin holes. Therefore, after the supporting plate slides up and down, the oil pipe is further positioned through the pin shaft, and the oil pipe is prevented from sliding down in the using process to influence the temperature consistency of the forming surface of the cavity.

And the second improvement scheme is as follows: waist-shaped through holes which are in one-to-one correspondence with the oil through pipes are vertically formed in the upper die base and the lower die base, supporting blocks which are inserted into the waist-shaped through holes and can be replaced are arranged in the waist-shaped through holes, the width of each supporting block is consistent with that of each waist-shaped through hole, the supporting blocks extend upwards from the bottoms of the waist-shaped through holes, and grooves for supporting the oil through pipes are formed in the tops of the supporting blocks; when in use, the height of the oil through pipe can be adjusted by replacing the supporting blocks with different heights.

In order to further improve the temperature uniformity of the surface of the cavity, the temperature is regulated and controlled by adjusting the distance between the oil pipes, and the technical scheme is further improved as follows: the oil pipe is internally sleeved with a detachable and replaceable delivery pipe, and the delivery pipe is tightly attached to the oil pipe; when in use, the distance between the oil through pipes can be adjusted by replacing the conveying pipes with different thicknesses. Thus, the temperature of the surface of the cavity can be finely adjusted by replacing the conveying pipes with different thicknesses.

It should be noted that the main object of the present invention is to provide a temperature-adjustable thermoforming mold which can ensure temperature consistency of the cavity shape of the core mold for different complicated and variable products and can reuse the upper and lower die holders, so that the present invention adjusts the position of the oil through pipe and the distance between the oil through pipes for specific products, and the specific adjustment range can be realized by experience or experiment simulation.

Drawings

The invention will be further explained with reference to the drawings.

Fig. 1 is a schematic structural diagram of a first embodiment of the present invention.

Fig. 2 is a front view of fig. 1.

Fig. 3 is one of the structural schematic diagrams of the support device of the oil pipe.

Fig. 4 is a second structural schematic diagram of the support device of the oil pipe.

FIG. 5 is a schematic structural diagram of a support block in the second embodiment of the present invention.

Fig. 6 is a schematic structural view of another cavity in the first embodiment of the invention.

Detailed Description

Example one

The composite material hot press forming die of the embodiment, as shown in fig. 1-3, includes an upper die holder 1 and a lower die holder 2; the bottom of the upper die holder 1 is provided with a first U-shaped groove penetrating through the upper die holder, the upper die holder 1 is detachably and fixedly connected with an upper core die 3 embedded in the first U-shaped groove, the top of the lower die holder 2 is provided with a second U-shaped groove penetrating through the lower die holder, the lower die holder 2 is detachably and fixedly connected with a lower core die 4 embedded in the second U-shaped groove, the upper core die 3 corresponds to the lower core die 4, and a cavity 5 provided with a forming surface of a formed product is formed between the upper core die 3 and the lower core die 4 after the upper die holder 1 and the lower die holder 2 are assembled; the upper die base and the lower die base are both provided with a plurality of oil through pipes 6, and each oil through pipe 6 is provided with a valve.

In the embodiment, waist-shaped through holes 7 corresponding to the oil through pipes 6 one by one are vertically formed in the upper die holder 1 and the lower die holder 2, the oil through pipes 6 are positioned through oil through pipe supporting devices, as shown in fig. 3, two side surfaces of each waist-shaped through hole 7 are respectively provided with a supporting plate 9 capable of sliding along the side surface, a plurality of springs 8 are arranged between the two supporting plates 9, and two ends of each spring 8 are fixedly connected with the two supporting plates 9 respectively; two ends of the supporting plate 9 respectively extend outwards along the axial direction of the waist-shaped through hole 7 and are respectively bent outwards at two ends of the waist-shaped through hole 7 to form bent parts; the flat plate 15 is laid above the two supporting plates 9, the flat plate 15 can be directly placed right above the two supporting plates 9 to support the oil through pipe 6, and the flat plate 15 can also be clamped with the supporting plates 9 through a clamping structure to be limited.

Of course, the oil pipe 6 can also be positioned by the oil pipe supporting device shown in fig. 4, the supporting plate 9 can be divided into two sections which are respectively positioned at two ends of the waist-shaped through hole 7, a part of the middle of the supporting plate 9 between the two bent parts is cut off, that is, the supporting plate 9 between the two bent parts is cut into three sections on average, only one section in the middle is cut off, so that the supporting plate is divided into four, the flat plate 15 is laid above the four supporting plates 9, and thus, the material can be saved, and the production cost can be reduced.

The waist-shaped through hole 7 is filled with heat conduction materials (not shown in the figure) with the same heat conduction coefficients as the upper die holder 1 and the lower die holder 2, and certainly, the heat conduction materials with the higher heat conduction coefficients than the upper die holder 1 and the lower die holder 2 can also be selected. The friction force between the support plate and the waist-shaped through hole 7 is increased by the force exerted on the support plate through the spring 8, and meanwhile, the heat conduction material filled in the waist-shaped through hole 7 is assisted, so that the oil pipe 6 can be firmly supported when the support plate 9 is moved to adjust the position, and the temperature control is accurate.

The heat conduction material can be particles made of the same material as the upper die holder 1 and the lower die holder 2, the particles are filled in the bag made of the flexible heat conduction material, and then the flexible bag is placed in the kidney-shaped through hole 7; of course, other embodiments are also possible, such as sheets made of the same material as the upper die holder 1 and the lower die holder 2, which are inserted into the kidney-shaped through hole 7 in a superposed manner.

The embodiment is particularly suitable for the condition that the thickness difference of the cavity 5 shown in fig. 6 is large, and the temperature consistency of the forming surface can be ensured on the premise of only replacing the upper core mold and the lower core mold by pre-adjusting the position, the on-off state and the oil passing speed of the oil passing pipe 6, so that the production cost is greatly reduced compared with the prior art.

The embodiment can be further modified as follows: 1) as shown in fig. 3 and 4, the bent portion of the supporting plate 9 is provided with a pin hole 10, and the upper die holder 1 and the lower die holder 2 are vertically provided with a plurality of limiting holes matched with the pin hole 10 and a limiting pin shaft capable of being inserted into the limiting holes and the pin hole 10. Therefore, after the supporting plate 9 slides up and down, the oil through pipe 6 is further positioned through the pin shaft, and the phenomenon that the oil through pipe 6 slides down to influence the temperature consistency of the forming surface of the cavity in the use process is prevented.

2) A detachable and replaceable delivery pipe is sleeved in the oil pipe 6, and the delivery pipe is tightly attached to the oil pipe 6; when in use, the distance between the oil through pipes can be adjusted by replacing the conveying pipes with different thicknesses.

3) In order to accurately position the oil pipe 6, vertical scale marks are arranged at the positions of the upper die holder 1 and the lower die holder, which are positioned at the two sides of the waist-shaped through hole.

Example two

The difference between the present embodiment and the first embodiment is that the supporting plate 9, the spring 8, etc. are omitted in the present embodiment, and as shown in fig. 5, a supporting block 11 is arranged at the bottom of the kidney-shaped through hole 7, that is, a supporting block 11 which is inserted into the kidney-shaped through hole 7 and can be replaced is arranged in the kidney-shaped through hole 7, the width of the supporting block 11 is the same as the width of the kidney-shaped through hole 7, the supporting block 11 extends upwards from the bottom of the kidney-shaped through hole 7, and the top of the supporting block 11 is provided with a groove 12 for supporting the oil pipe; in use, the height of the oil gallery 6, i.e. the distance of the oil gallery 6 from the forming surface, can be adjusted by replacing the support blocks 11 of different heights. The supporting block 11 is shown in fig. 5, and the material thereof is preferably the same as the material of the upper die holder 1 and the lower die holder 2 or a material with a higher thermal conductivity so as to ensure the thermal conductivity.

In order to accurately position the supporting block in the kidney-shaped through hole, the bottom of the supporting block 11 is provided with a limiting convex strip 13, and the bottom of the kidney-shaped through hole is provided with a limiting groove (not shown in the figure) matched with the limiting convex strip 13. When the device is used, the supporting block loaded with the oil through pipe is pushed into the waist-shaped through hole from one side of the waist-shaped through hole, so that the limiting convex strip 13 is positioned after being sunk into the limiting groove, and the supporting block 11 is prevented from moving horizontally; after the use is finished, the supporting block can be drawn out only by lifting the supporting block 11 to make the limiting convex strip 13 separate from the limiting groove.

The present invention is not limited to the specific technical solutions of the above embodiments, and other embodiments of the present invention are possible in addition to the above embodiments. All technical solutions formed by equivalent substitutions fall within the scope of the claims of the present invention.

Claims

1. A composite material hot-press forming die comprises an upper die base and a lower die base; the method is characterized in that: the bottom of the upper die holder is provided with a first U-shaped groove penetrating through the upper die holder, the upper die holder is detachably and fixedly connected with an upper core die embedded in the first U-shaped groove, the top of the lower die holder is provided with a second U-shaped groove penetrating through the lower die holder, the lower die holder is detachably and fixedly connected with a lower core die embedded in the second U-shaped groove, the upper core die corresponds to the lower core die in position, and a cavity provided with a forming surface of a product to be formed is formed between the upper core die and the lower core die after the upper die holder and the lower die holder are assembled; the upper die base and the lower die base are both provided with a plurality of oil through pipes, and each oil through pipe is provided with a valve; waist-shaped through holes which are in one-to-one correspondence with the oil through pipes are vertically formed in the upper die base and the lower die base, supporting blocks which are inserted into the waist-shaped through holes and can be replaced are arranged in the waist-shaped through holes, the width of each supporting block is consistent with that of each waist-shaped through hole, the supporting blocks extend upwards from the bottoms of the waist-shaped through holes, and grooves for supporting the oil through pipes are formed in the tops of the supporting blocks; when in use, the height of the oil through pipe can be adjusted by replacing the supporting blocks with different heights.

2. The composite material thermoforming mold of claim 1, wherein: the oil pipe is internally sleeved with a detachable and replaceable delivery pipe, and the delivery pipe is tightly attached to the oil pipe; when in use, the distance between the oil through pipes can be adjusted by replacing the conveying pipes with different thicknesses.