A forming tool for slender parts with non-uniform cross-section

Abstract

The utility model discloses a molding tool for slender parts with non-uniform cross-sections, including a lower core mold installed on a lower mold and an upper core mold detachably connected to an upper mold, a molding opening is provided at the top of the cavity of the lower core mold, and the size of the molding opening away from one end of the cavity is larger than the size close to one end of the cavity; a plurality of stripping modules are provided between the lower mold and the lower core mold, and the length direction of the stripping modules is perpendicular to the length direction of the lower core mold; the male mold of the upper core mold is adapted to the cavity of the lower core mold; and a stripping buckle detachably connected to the two ends of the stripping modules is provided on the upper mold. The straightness of the parts obtained by the molding tool of the present application can meet the requirements, and the lower core mold can be quickly and conveniently removed, which is convenient for demolding the parts and improves the efficiency of parts manufacturing.

Description

Technical Field

[0001] The utility model relates to the technical field of composite material parts processing, in particular to a non-uniform cross-section elongated parts forming tool. Background Art

[0002] At present, slender composite parts with an axial to radial ratio of more than 1:100 are mainly formed by pultrusion. However, the material of the pultruded parts is unidirectional carbon fiber yarn, which can only be used to make products with a constant cross-section and have low lateral strength.

[0003] When making something like Figure 1 As shown in the figure, there is a requirement for lateral strength, the raw material is fabric, and there is a fiber direction requirement. The slender composite parts with a large profile on one end and a small profile on the other end cannot be achieved by pultrusion and can only be formed by other processes such as RTM or molding.

[0004] For such slender composite parts with an axial to radial ratio of more than 1:100, which are required to be able to withstand a certain force in the axial direction and have non-uniform cross-sections, there are two problems in using the molding process to manufacture slender composite parts with non-uniform cross-sections:

[0005] (1) The tooling cavity is too small, the woven prepreg cannot be laid in place and fit perfectly with the cavity. The fibers are easily twisted during molding, causing the part to be twisted after molding and insufficient straightness.

[0006] (2) The efficiency of molded parts is low, the tooling temperature rises and falls, which takes a long time, and the temperature of the hot demolding press is too high, making it inconvenient for employees to operate. Summary of the invention

[0007] The utility model aims to provide a non-uniform cross-section elongated workpiece forming tool to solve the problems of difficulty and low efficiency in the workpiece forming in the prior art.

[0008] In order to achieve the above purpose, the utility model is implemented by adopting the following technical solutions:

[0009] In a first aspect, the present application discloses a non-uniform cross-section elongated workpiece forming tool, comprising:

[0010] A lower core mold installed on the lower mold, wherein the top of the mold cavity of the lower core mold is provided with a molding opening, and the size of the molding opening away from one end of the mold cavity is larger than the size close to one end of the mold cavity; a plurality of stripping modules are provided between the lower mold and the lower core mold, and the length direction of the stripping modules is perpendicular to the length direction of the lower core mold;

[0011] An upper core mold is detachably connected to the upper mold, and the male mold of the upper core mold is adapted to the cavity of the lower core mold; and a demoulding buckle detachably connected to the two ends of the demoulding module is provided on the upper mold.

[0012] Furthermore, the size of the molding opening gradually decreases toward one end of the mold cavity.

[0013] Furthermore, the lower mold is provided with a lower core mold connecting groove, and the lower core mold is clamped in the lower core mold connecting groove;

[0014] The lower core mold comprises a first lower core mold and a second lower core mold with the same structure, and the first lower core mold and the second lower core mold are positioned by at least two positioning pins.

[0015] Furthermore, the lower mold is provided with a plurality of parallel lower core mold connecting grooves so that the lower mold can be connected to a plurality of lower core molds.

[0016] Furthermore, the lower mold is provided with an avoidance groove perpendicular to the lower core mold connecting groove.

[0017] Furthermore, one end of the demoulding buckle is rotatably connected to the upper film through a connecting bolt, a marble bolt is connected to the middle part, and a slot is provided at the other end;

[0018] The upper mold is provided with a connecting groove, and the ball bolt is connected to the connecting groove so that the demoulding buckle is in an unlocked state;

[0019] The demoulding module is provided with a connecting protrusion, the ball bolt releases the connection with the groove, and the slot and the connecting protrusion are engaged to put the demoulding buckle in a locked state.

[0020] Furthermore, the upper core mold is connected to the upper mold via bolts.

[0021] Furthermore, both ends of the top surface of the stripping module are provided with hanging rings.

[0022] According to the above technical solution, the beneficial effects of the utility model are:

[0023] The molding tool of the present application is provided with a molding opening at the top of the cavity of the lower core mold. When in use, the prefabricated preform can be placed on the molding opening first. When the mold is closed, the male mold protruding from the upper core mold can be smoothly embedded in the middle of the preform, and the prepreg will not be bent and pressed to the bottom, which will not cause the bottom thickness of the workpiece to be too thick and the tooling to be unable to close the mold in place. The straightness of the workpiece obtained by using this tooling can meet the requirements;

[0024] The molding tooling of the present application is provided with a demolding module between the lower mold and the lower core mold, and a demolding buckle detachably connected to the two ends of the demolding module is provided on the upper mold. When demolding, the demolding buckle and the demolding module are first connected, and the upper mold can drive the lower core mold to follow the demolding module to separate from the lower mold, so the lower core mold can be quickly and conveniently removed, which is convenient for demolding of the workpiece and improves the workpiece manufacturing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1It is a schematic diagram of a non-uniform cross-section workpiece in the background technology;

[0026] Figure 2 Schematic diagram of the cross section of the component and the installation of prepreg on the component;

[0027] Figure 3 It is a cross-sectional schematic diagram of the lower core mold in the utility model;

[0028] Figure 4 It is a schematic diagram of the zigzag paving tooling in the utility model;

[0029] Figure 5 It is a schematic diagram of the connection arrangement between the V-shaped preform and the core mold in the utility model;

[0030] Figure 6 It is a structural schematic diagram of the molding tool of the utility model;

[0031] Figure 7 It is a partial cross-sectional view of the molding tool of the utility model;

[0032] Figure 8 It is a schematic diagram of different tooling states of the clamping buckle;

[0033] Fig. 9 This is a schematic diagram of the structure of a ball bolt.

[0034] Among them: 1. upper mold; 2. upper core mold; 3. lower core mold; 31. first lower core mold; 32. second lower core mold; 33. cavity; 34. molding opening; 4. stripping module; 5. lower mold; 51. avoidance groove; 6. locking buckle; 61. connecting bolt; 62. ball bolt; 63. connecting protrusion; 64. slot; 65. connecting groove; 7. serrated paving tooling; 00. V-shaped preform; 01. local filling yarn. DETAILED DESCRIPTION

[0035] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further described below in conjunction with specific implementation methods.

[0036] It should be noted that in the description of the present invention, the directions or positional relationships indicated by the terms "front", "rear", "left", "right", "up", "down", "inside", "outside", etc. are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention rather than requiring that the present invention must be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. The terms "front", "rear", "left", "right", "up", and "down" used in the description of the present invention refer to the directions in the accompanying drawings, and the terms "inside" and "outside" refer to the directions toward or away from the geometric center of a specific component, respectively.

[0037] In view of the problems of the molding process mentioned in the background technology, this application optimizes the technology of this type of parts in the following ways:

[0038] It was found that this process would cause the following problems before optimization:

[0039] Question 1: The prepreg is thicker before curing than after curing, e.g. Figure 2 As shown in the figure, the opening space at the top of the part is only 4.5mm. When the fluffy prepreg is laid, the actual opening space is only 2-3mm, and the edge of the material droops toward the middle. When the mold is closed, the protruding male mold of the upper mold cannot completely support the prepreg from the middle, and the material is easily bent and pressed to the bottom, resulting in a thicker bottom part and the tooling cannot be closed in place.

[0040] The optimization measures of this application are: Figure 3 As shown, margins are left on both sides of the lower core mold 3 to form a V shape, so that the V-shaped opening of the lower core mold 3 is larger, and when the mold is pressed and closed, the protruding male mold of the upper mold can be smoothly embedded in the middle of the material.

[0041] When paving, use Figure 4 The zigzag laying tool 7 shown directly lays the preform into a V shape, and the vacuum bagging and heating pre-pressing can make the preform keep the fibers smooth and straight without twisting, and present a harder V shape.

[0042] like Figure 5 As shown, the bottom is partially filled with yarn (the part is not of uniform thickness and follows the shape, there is a profile inside, and there is more material at the two corners. A small amount of yarn is filled first to avoid that the two sharp corners of the shape cannot be pressed out), and then the V-shaped preform 00 is placed in the cavity 33 of the lower core mold of the molding tool, and pressure is slowly and evenly applied by relying on the protruding male mold of the upper core mold 2, so that the fibers are evenly stressed and remain smooth and straight without twisting. In this way, the part will not be twisted and deformed due to the internal stress generated by the twisted fibers, resulting in poor straightness.

[0043] There is another problem with this process: the molding process takes a long time to solidify because the tooling needs to be heated. The parts also need to be disassembled and demolded after the tooling is cooled. The efficiency is far less than that of the pultrusion production line. The solidification time is determined by the performance of the material itself and cannot be changed. The only way is to optimize the tooling structure to achieve fast demolding and fast loading to shorten the manufacturing cycle.

[0044] In view of the above two problems, the present application designs a molding tool for non-uniform cross-section slender parts, including a lower core mold 3 installed on the lower mold 5 and an upper core mold 2 detachably connected to the upper mold 1, a molding opening 34 is provided at the top of the cavity 33 of the lower core mold 3, and the size of the molding opening 34 away from the end of the cavity 33 is larger than the size close to the end of the cavity 33; a plurality of stripping modules 4 are provided between the lower mold 5 and the lower core mold 3, and the length direction of the stripping modules 4 is perpendicular to the length direction of the lower core mold 3; the male mold of the upper core mold 2 is adapted to the cavity 33 of the lower core mold 3; the upper mold 1 is provided with a stripping buckle 6 detachably connected to the two ends of the stripping module 4.

[0045] The molding tool of the present application is provided with a molding opening 34 at the top of the cavity of the lower core mold. When in use, the prefabricated preform can be placed on the molding opening 33 first. When closing the mold, the male mold protruding from the upper core mold 2 can be smoothly embedded in the middle of the preform, and the prepreg will not be bent and pressed to the bottom, and the bottom thickness of the workpiece will not be too thick, and the tooling cannot be closed in place. The straightness of the workpiece obtained by using this tooling can meet the requirements. A stripping module 4 is provided between the lower mold 5 and the lower core mold 3. The length direction of the stripping module 4 is perpendicular to the length direction of the lower core mold 3, which is convenient for separating the lower core mold from the lower mold 5. A stripping buckle detachably connected to the two ends of the stripping module is provided on the upper mold. When demolding, the stripping buckle is first connected to the stripping module. The upper mold can drive the lower core mold to follow the stripping module to separate from the lower mold, and the lower core mold can be quickly and conveniently removed, which is convenient for demolding the workpiece and improves the efficiency of the workpiece.

[0046] The forming tooling of the present application is described below through a specific embodiment.

[0047] Molding tooling structure such as Figure 6 As shown, it is mainly composed of an upper mold 1, an upper core mold 2, a lower mold 5, a lower core mold 3, a stripping mold 4, a locking buckle 5 and several standard parts. The tooling of the present application has one mold and four cavities, and can mold four parts at a time. In other embodiments, the number of tooling cavities can be appropriately increased or decreased.

[0048] like Figure 7 As shown, the upper core mold 2 is positioned on the upper mold 1 by its own shape, and the back is locked by bolts. The upper core mold is made into 2 sets at a time, that is, 8 pieces, of which 4 are used as interchangeable finished spare parts; this structure allows the upper core mold to be replaced with a spare upper core mold when it is worn, scratched, etc. after being used many times, saving the time for repairing the tooling upper mold. The present application connects the upper core mold 2 and the upper mold 1 by bolts, which facilitates the replacement of the upper core mold 2.

[0049] The lower core mold 3 is a combined type, divided into two parts, specifically including a first lower core mold 31 and a second lower core mold 32, and the first lower core mold 31 and the second lower core mold 32 are positioned by two positioning pins. Specifically, the first lower core mold 31 and the second lower core mold 32 are provided with pin holes in the width direction to facilitate the connection of the positioning pins. After the connection, the left and right ends of the first lower core mold 31 and the second lower core mold 32 are flush, the bottom is flush, and the top surface forms a cavity 33. The lower core mold 3 is positioned on the lower mold 5 using the overall shape after the two parts are combined. The split-petal structure makes it more convenient to clean the corners of the tooling cavity, and the workpiece can be more easily removed from the lower core mold 3.

[0050] The top of the cavity 33 of the lower core mold 3 is provided with a molding opening 34, and the size of the molding opening 34 at one end away from the cavity 33 is larger than the size at one end close to the cavity 33. Further, the shape of the molding opening 34 can be an inverted eight-shaped shape, an arc shape, a V shape, etc., and the molding opening 34 is used to place the V-shaped preform 00, so the shape of the V-shaped preform 00 is adapted to the shape of the molding opening 34.

[0051] Furthermore, if Figure 3-5 As shown, the molding opening 34 is preferably V-shaped. With this design, on the one hand, during the molding process, the V-shaped preform 00 is more easily pressed into the mold cavity 33 along the inclined surface of the molding opening 34, and on the other hand, compared with preforms of other shapes, the V-shaped preform 00 is easier to produce.

[0052] like Figure 4 As shown, the present application provides a sawtooth paving tool for forming a V-shaped preform 00, which has a plurality of V-shaped molding cavities on a main body plate, and the V-shaped molding cavity includes two symmetrical inclined surfaces, and the bottom ends of the two inclined surfaces are connected by an arc groove. The sawtooth paving tool 7 designed in the present application can form multiple V-shaped preforms 00 at one time.

[0053] The molding tool of the present application is provided with a molding opening at the top of the cavity of the lower core mold. When in use, the prefabricated V-shaped preform 00 can be placed on the molding opening first. When closing the mold, the male mold protruding from the upper core mold can be smoothly embedded in the middle of the V-shaped preform 00, and the prepreg will not be bent and pressed to the bottom, which will not cause the bottom thickness of the product to be too thick and the tooling to be unable to close the mold in place. The straightness of the product obtained by using this tooling can meet the requirements;

[0054] The molding tooling of the present application is provided with a demolding module between the lower mold and the lower core mold, and a demolding buckle detachably connected to the two ends of the demolding module is provided on the upper mold. When demolding, the demolding buckle and the demolding module are first connected, and the upper mold can drive the lower core mold to follow the demolding module to separate from the lower mold, so the lower core mold can be quickly and conveniently removed, which is convenient for demolding of the workpiece and improves the workpiece manufacturing efficiency.

[0055] The stripping module 4 is assembled with the lower die 5 as a whole. There are 4 stripping modules in one set of tooling. Both ends of each stripping module are provided with bolt mounting holes matching with the clamping buckle 6. The mounting position of the clamping buckle 6 on the tooling is as follows: Figure 8 As shown, the locking buckle 6 is connected to the upper mold 1 by connecting bolts 61 of the same height, and the locking buckle 6 can rotate around the connecting bolts 61 of the same height.

[0056] The upper mold 1 is provided with a spherical connection groove 65 near the installation hole of the connection bolt 61 at the same height. The ball of the spherical ball bolt 62 will be pressed into the connection groove 65 under the action of force, so the locking buckle 6 will be stuck with the connection groove 65 with the help of the ball bolt 62. When the locking buckle 6 is in the horizontal open position, the spherical connection groove 65 will clamp the ball of the ball bolt 62, so that the locking buckle will not slide down due to its own weight. When demoulding is required, a little force can be applied to put it in a vertical working state. In this state, the slot 64 on the locking buckle 6 is engaged with the connection protrusion 63 on the demoulding module. At this time, if the press is opened, since the upper mold is fixed to the upper pressure plate of the press by bolts / pressure plate, the 4 sets of lower core molds 3 will be pulled by the stripping module 4 and the locking buckle 6 and follow the upper mold 1 to separate from the lower mold 5. When the bottom of the stripping module is at a predetermined distance from the lower mold mating surface, an insulating fiberglass plate can be inserted, and the locking buckle 6 is loosened, so that the stripping module 4 and the lower core mold 3 fall on the fiberglass plate and can be lifted out as a whole.

[0057] In some further embodiments, the lower mold 5 is provided with a plurality of parallel lower core mold connecting grooves, and the lower core mold and the lower core mold connecting grooves can be connected in a transition fit manner. Figure 6 As shown, the lower mold 5 is provided with an avoidance groove 51, which is arranged along the width direction of the lower mold and is perpendicular to the lower core mold connection groove, so that the hand has a gripping point when taking out a single set of core molds each time. The stripping module designed in this application can take out multiple sets of lower core molds 3 at the same time, and the design of the avoidance groove 51 facilitates the removal of a single set of lower core molds.

[0058] Furthermore, both ends of the top surface of the demolding module 4 are provided with hanging rings, through which pulling force can be applied to the demolding module to facilitate demoulding.

[0059] Based on the molding tool of the present application, the present application also discloses a molding method, which comprises the following steps:

[0060] Step 1: Connect the upper mold 1 to the upper plate of the press, and the lower mold 5 to the lower plate of the press. This process is the process of connecting the upper mold 1 and the lower mold 5. A guide device is set during installation to ensure accurate position when closing the film. In this step, the upper core mold 2 has been connected to the upper mold, and the lower core mold 3 has been connected to the lower mold 5.

[0061] Step 2: Fill the two corners of the cavity of the lower core mold 3 with yarn, place the preform on the molding opening 34 of the lower core mold 3, and fill the local yarn 01 as shown in FIG. Figure 5 shown.

[0062] Step 3, start the press to close the upper film 1 and the lower mold 5, heat and pressurize to solidify and form the product.

[0063] Step 4, connect the demoulding buckle 6 and the demoulding module 4. In this step, the connection can be achieved by operating the ball bolt 62 and engaging the clamping groove 64 on the locking buckle 6 with the connecting protrusion 63 on the demoulding module.

[0064] Step 5, the press opens the mold, the stripper module 6 and the lower core mold 3 follow the upper mold 1 to move away from the lower mold 5, the connection between the stripper buckle 6 and the stripper module 4 is released, and the lower core mold 3 and the stripper module 6 are separated from the upper mold 1 under the action of gravity.

[0065] Step 6: Take out the workpiece from the lower core mold.

[0066] In step 2, the preform is a V-shaped preform 00, and the method for obtaining the V-shaped preform 00 includes: laying the composite material in the V-shaped molding cavity of the sawtooth laying tool 7; vacuum bagging, heating and pre-pressing to obtain a V-shaped preform with a certain hardness.

[0067] In step 6, taking out the product from the lower core mold includes: separating the lower core mold 3 and the stripping mold 4; separating the first lower core mold 31 and the second lower core mold 32 of the lower core mold 3, and the product automatically separates from the lower core mold 3.

[0068] The above steps can be as follows: fix the upper mold on the upper plate of the press by bolts / pressing plates, fix the lower mold on the lower plate of the press, open the locking buckle, and open the press. Remove the V-shaped preform from the zigzag paving mold, fill the two corners of the core mold cavity with yarn, and then press the V-shaped preform. Figure 5 The pattern is placed on the lower core mold, the mold is closed, and the V-shaped preform is pressed into the cavity of the lower core mold under the action of the raised surface of the upper mold, and heated and pressurized to solidify and form. After the part is solidified and formed, break off the locking buckle (only 4 of the 8 symmetrically distributed ones can be broken off, that is, only 2 demolding modules are needed for demolding) to hook the connecting protrusions on the demolding module. The press opens the mold, the lower core mold is separated from the lower mold, and the fiberglass insulation board is placed. The locking buckle is loosened, and the lower core mold is separated from the upper mold under the action of gravity, falls on the fiberglass board, and is dragged out as a whole. Break open the lower core mold, take out the part, and quickly clean the core mold for the next round of part solidification and molding. Or make 2 sets of lower core molds, one set is removed from the press and cooled at room temperature, and the other set is directly placed on it with the part. After the removed one is cooled, break open the core mold to demold, clean it and prepare for the next wave of replacement.

[0069] In summary, this application has the following advantages:

[0070] (1) The above process methods and tooling can help solve the problems of difficult laying, material pressing, fiber distortion, and difficult operation that occur during the molding process of slender composite parts.

[0071] (2) The press opens to automatically demould, and the glass fiber insulation board drags out the hot demolding module and core module, avoiding the risk of employees being burned by high-temperature core mold removal, making the operation more convenient and safer.

[0072] (3) After the core mold is removed from the demolding module with heat-insulating gloves, the workpiece can be demolded by gently bending it. The lower core mold can be quickly cleaned and used for the next round of workpiece curing and molding; or two sets of lower core molds can be made. After one set is removed from the press, the other set is directly placed on it with the workpiece. The removed set is cooled at room temperature. After cooling, the workpiece is demolded and cleaned before being replaced with the next round. This approach is efficient, saves the time of continuous heating and cooling of the press, and also improves the power consumption rate.

[0073] (4) The V-shaped preform and core mold structure make loading more convenient and quick.

[0074] It is known from common technical knowledge that the present invention can be implemented by other embodiments that do not deviate from its spirit or essential features. Therefore, the embodiments disclosed above are only illustrative in all respects and are not exclusive. All changes within the scope of the present invention or within the scope equivalent to the present invention are included in the present invention.

Claims

1. A tooling for forming slender parts with non-uniform cross-sections, characterized in that: include: A lower core mold installed on the lower mold, wherein the top of the mold cavity of the lower core mold is provided with a molding opening, and the size of the molding opening away from one end of the mold cavity is larger than the size close to one end of the mold cavity; a plurality of stripping modules are provided between the lower mold and the lower core mold, and the length direction of the stripping modules is perpendicular to the length direction of the lower core mold; An upper core mold is detachably connected to the upper mold, and the male mold of the upper core mold is adapted to the cavity of the lower core mold; and a demoulding buckle detachably connected to the two ends of the demoulding module is provided on the upper mold.

2. The non-uniform cross-section elongated workpiece forming tool according to claim 1, characterized in that: The size of the molding opening gradually decreases toward one end of the mold cavity.

3. The non-uniform cross-section elongated workpiece forming tool according to claim 1, characterized in that: The lower mold is provided with a lower core mold connecting groove, and the lower core mold is clamped in the lower core mold connecting groove; The lower core mold comprises a first lower core mold and a second lower core mold with the same structure, and the first lower core mold and the second lower core mold are positioned by at least two positioning pins.

4. The non-uniform cross-section elongated workpiece forming tool according to claim 1, characterized in that: The lower mold is provided with a plurality of parallel lower core mold connecting grooves so that the lower mold can be connected to a plurality of lower core molds.

5. The non-uniform cross-section elongated workpiece forming tool according to claim 4, characterized in that: The lower mold is provided with an avoidance groove which is perpendicular to the lower core mold connecting groove.

6. The non-uniform cross-section elongated workpiece forming tool according to claim 1, characterized in that: One end of the demoulding buckle is rotatably connected to the upper film through a connecting bolt, a marble bolt is connected to the middle part, and a slot is provided at the other end; The upper mold is provided with a connecting groove, and the ball bolt is connected to the connecting groove so that the demoulding buckle is in an unlocked state; The demoulding module is provided with a connecting protrusion, the ball bolt releases the connection with the groove, and the slot and the connecting protrusion are engaged to put the demoulding buckle in a locked state.

7. The non-uniform cross-section elongated workpiece forming tool according to claim 1, characterized in that: The upper core mold is connected to the upper mold through bolts.

8. The non-uniform cross-section elongated workpiece forming tool according to claim 1, characterized in that: Both ends of the top surface of the stripping module are also provided with hanging rings.

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