THERMOCOMPRESSION DEVICE FOR THE MANUFACTURE OF MECHANICAL PARTS
The thermocompression device addresses the challenge of complex burrs by introducing a burr zone between the cavity and compression chamber, simplifying deburring and enhancing manufacturing efficiency for mechanical parts.
Patent Information
- Application Number
- FR2023001646
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2023-02-23
- Publication Date
- 2026-02-20
- Estimated Expiration
- 2043-02-23
AI Technical Summary
The existing thermocompression devices for manufacturing mechanical parts, particularly those of aircraft turbomachinery, generate complex and time-consuming burrs that require extensive deburring operations, complicating the manufacturing process.
The thermocompression device is redesigned with an intermediate burr zone between the cavity and compression chamber, allowing for easier deburring by relocating the burrs to be offset from the part's edge, simplifying the manufacturing process and reducing the complexity of removing excess material.
The redesign facilitates easier and more efficient deburring by controlling the burr profile, reducing the need for complex operations and improving the manufacturing efficiency of mechanical parts with complex shapes.
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Abstract
Description
Title of the invention: THERMOCOMPRESSION DEVICE FOR THE MANUFACTURE OF MECHANICAL PARTS Technical field
[0001] The invention relates to the field of manufacturing mechanical parts and, in particular, to a thermocompression device for this manufacturing. Prior art
[0002] It is known to manufacture certain mechanical parts, in particular mechanical parts of aircraft turbomachinery, by a molding process called thermocompression, that is to say a process in which material is put under pressure, at a determined temperature, in a mold (i.e. in a cavity formed in the mold) having the shape of a part to be manufactured in order to obtain in the end said part.
[0003] Figure 1 shows an embodiment of a mold 101 (or thermocompression device) according to the prior art, and Figure 2 shows an enlargement of a portion of this device 101. The thermocompression device 101 comprises a first part 103, also called a punch, and a second part 105, also called a die. The punch 103 and the die 105 are configured to fit together and, once fitted, form within them a cavity 107 having predetermined dimensions corresponding to those of the mechanical part to be manufactured.
[0004] In the example shown, the punch 103 includes a molten polymer injection system 109 in the cavity 107 while the die 105 is configured to receive a fibrous preform 111 for the purpose of manufacturing a mechanical part in composite material.
[0005] In particular, as shown in a simplified way in [Fig.1], during a first manufacturing step of the part (shown in the left part), the molten polymer is injected into the cavity 107. Then, during a second step, (shown in the right part), under the combined effect of a determined temperature to which the device 101 is brought and the pressure generated in the cavity 107 by the fitting of the punch 103 into the die 105, the molten polymer spreads in the cavity and diffuses into the fibrous preform so as to form the mechanical part 117 in composite material.
[0006] In the example shown, the punch 103 is driven into the die 105 in the direction symbolized by the arrows 115 until the required pressure is generated in the cavity 107 to form the mechanical part 117.
[0007] Furthermore, in addition to the elements already described, the thermocompression device 101 also includes compression chambers 113. These are interstitial zones, distinct from the cavity, formed between the punch 103 and the die 105 when they are fitted together and which extend along the direction of penetration of the punch 103 into the die 105.
[0008] Indeed, at the respective walls of the punch 103 and the die 105, which slide along each other when the punch 103 is driven into the die 105, there is an interstitial zone into which material used for manufacturing the part enters or can enter. Thus, each compression chamber 113 is likely, during the manufacturing of the part, to fill, in whole or in part, with the material of the part under the effect of the pressure generated in the device 101.
[0009] The filling of the compression chamber 113 causes a protrusion of the part to form, which is eventually extracted from the device. This protrusion extends along the direction of the compression chamber 113.
[0010] Fig. 3 schematically shows an example of part 117 extracted from a thermocompression device such as the thermocompression device 101 described with reference to Figures 1 and 2. The burrs 301 are defects of part 117 extracted from the thermocompression device which must subsequently be removed to obtain a finished part of the desired dimensions.
[0011] In particular, obtaining the finished part requires a deburring operation, which consists of removing existing burrs. As illustrated in [Fig. 4], such an operation can, for example, be performed by a human operator using a specific tool to remove existing burrs. In any case, given the shape and arrangement of the burrs generated by such a device, deburring is a complex and time-consuming operation. Summary of the invention
[0012] The present invention proposes a solution to these drawbacks.
[0013] Thus, an objective of the invention is to relocate the compression chamber(s) of a thermocompression device, by introducing an intermediate zone between the cavity of the device and the compression chamber, so as to obtain a part that is easier to deburr and, consequently, so as to simplify the manufacture of a finished part.
[0014] To this end, the invention, according to a first aspect, relates to a thermocompression device for the manufacture of mechanical parts comprising:
[0015] - at least a first part and a second part configured to form, by fitting said first part into said second part in a first direction, a cavity having the shape of a mechanical part to be manufactured; and,
[0016] - at least one first interstitial zone called a compression chamber, distinct from the cavity, formed between the first part and the second part when said first the first part and the second part are nested together, and extending longitudinally along the first direction,
[0017] said thermocompression device being characterized in that it further comprises at least one second interstitial zone called burr zone, formed between the first part and the second part when said first part and said second part are nested, and extending longitudinally between the cavity and the first interstitial zone, in a second direction distinct from the first direction, preferably perpendicular to said first direction.
[0018] Thus, thanks to the fact that the compression chamber is offset from the end of the part by the addition of a small pinch width of material with a final thickness of zero or very little, the invention makes it possible to obtain burrs which extend in the continuation of the shape of the part and which are therefore easier to eliminate by a simple finishing operation or even to completely eliminate the very existence of the burr after thermocompression.
[0019] The thermocompression device according to the invention may comprise one or more of the following features, taken individually or in combination with each other:
[0020] - the mechanical part to be manufactured is a mechanical part of an aircraft turbomachine.
[0021] - the device further comprises a system for injecting a liquefiable material in the cavity, formed in the first part and comprising at least one conduit traversing said first part from an external surface of said first part to the cavity so as to permit the injection of said liquefiable material from outside the thermocompression device into said cavity.
[0022] - at least one burr zone has a substantially constant thickness according to the second direction.
[0023] - at least one burr zone has an increasing thickness, according to the second direction, from the cavity to the compression chamber.
[0024] - at least one burr zone has a decreasing thickness, according to the second direction, from the cavity to the compression chamber.
[0025] - at least one burr zone has a length along the second direction comprising between 0.5mm and 10mm, preferably between 0.5 and 4mm.
[0026] - the thermocompression device comprises a greater number of parts or equal to 4, positioned side by side in a bidirectional matrix, forming cavities between each part when said parts are fitted together, so as to manufacture a grid-shaped mechanical part, preferably a thrust reversal grid for an aircraft nacelle.
[0027] - at least one burr zone is not located at the level of an edge of the cavity.
[0028] - the liquefiable material is a polymer and the second part is configured to receive a fibrous preform so that said thermocompression device makes it possible to manufacture a mechanical part in composite material, for example a part of a propulsion assembly or a grid-type part.
[0029] Furthermore, the invention according to a second aspect relates to a method of using a device according to the first aspect, comprising the steps of: - positioning of a material comprising at least one fibrous structure between the first and second part; - compression of matter by displacement from the first part to the second part; - consolidation of the material by solidification; and, - demolding of the part. Brief description of the drawings
[0030] The present invention will be better understood and other details, features and advantages of the present invention will become more apparent upon reading the following description of a non-limiting example, with reference to the accompanying drawings in which:
[0031] [Fig.1] is a schematic representation of an embodiment of a thermocompression device according to the prior art;
[0032] [Fig.2] is a schematic representation of an embodiment of part of a thermocompression device according to the prior art;
[0033] [Fig.3] is a schematic representation of a mechanical part manufactured by a thermocompression device according to the prior art;
[0034] [Fig.4] is an illustration of the deburring of a mechanical part manufactured by a thermocompression device according to the prior art;
[0035] [Fig.5] is a schematic representation of a first embodiment of a thermocompression device according to the invention;
[0036] [Fig.6a] is a schematic representation of a second embodiment of a thermocompression device according to the invention;
[0037] [Fig.6b] is a schematic representation of a third embodiment of a thermocompression device according to the invention;
[0038] [Fig.7] is a schematic representation of a mechanical part manufactured by a thermocompression device according to the invention;
[0039] Figure 8 is a schematic representation of a fourth embodiment of a thermocompression device according to the invention; and,
[0040] [Fig.9] is a step diagram of an implementation method of using the device according to the invention. Description of the implementation methods
[0041] With reference to [Fig. 5], we will now describe an embodiment of a thermocompression device 501 according to the invention. [Fig. 5] represents only a portion of the device located at the edge of a cavity of the device described below.
[0042] Device 501 is a thermocompression device for manufacturing mechanical parts such as, for example, mechanical parts of aircraft turbomachinery.
[0043] The device 501 comprises a first part 503 and a second part 505 which are configured to form, by fitting the first part 503 into the second part 505 along a first direction X, a cavity 507 having the shape of a mechanical part to be manufactured. In different embodiments of the invention, fitting the two parts of the device together may involve the movement of a movable part towards the other fixed part or the movement of two movable parts towards each other, in all cases along the first direction X.
[0044] The device 501 further comprises an interstitial zone 509, referred to as a compression chamber, which is distinct from the cavity and formed between the first and second parts when they are fitted together. This compression chamber 509 extends longitudinally along the X direction.
[0045] In particular, as can be seen in Fig. 5, the compression chamber 509 is located at the walls of the first part 503 and the second part 505 which move opposite each other and along each other when the two parts 503 and 505 are fitted together.
[0046] The example of compression device 501 shown in [Fig.5] shows only one compression chamber 509, however, those skilled in the art will appreciate that the invention applies, in general, to a thermocompression device comprising a number of compression chambers greater than or equal to 1.
[0047] The thermocompression device 501 further comprises at least one second interstitial zone 511, referred to as the burr zone, which is formed between the first part 503 and the second part 505 when they are nested together. The burr zone extends longitudinally between the cavity 507 and the compression chamber 509 along a second direction Y distinct from the first direction X.
[0048] The Y direction can form an angle with the X direction between 30° and 90°, preferably close to 90°. In the non-limiting example shown, the second Y direction is perpendicular to the first X direction and extends substantially in line with the shape of the cavity 507.
[0049] Thus, in the thermocompression device 501, a liquefiable material (during the manufacture of the part) put under pressure in the cavity 507 can flow into the compression chamber 509 via the burr zone 511.
[0050] In different configurations of use of the device 501, the material used to manufacture the mechanical part can either be positioned beforehand between the first part 503 and the second part 505 before they are fitted together, or injected, in whole or in part, between the two parts, during compression.
[0051] Thus, the thermocompression device 501 may include a system for injecting a liquefiable material into the cavity 507 such as that shown in [Fig.1].
[0052] Such an injection system can be formed in one of the two parts of the device, for example the first part 503, and include at least one conduit passing through this part from an external surface of this part to the cavity so as to allow the injection of the liquefiable material from outside the thermocompression device into the cavity.
[0053] By way of non-limiting example, the liquefiable material injected into the cavity can be a polymer and one of the parts of the device, for example the second part 505, can be configured to receive a fibrous preform so that the thermocompression device makes it possible to manufacture a mechanical part in composite material.
[0054] Fig. 7 shows an example of a mechanical part 701 obtained from the thermocompression device 501. The part 701 has two burrs 703. Each burr 703 has a portion that extends substantially in the continuation of the shape of the part 701 (generated by the flow of the material in the burr area) and a portion that extends substantially perpendicularly to the other (generated by the flow of the material in the compression chamber).
[0055] Advantageously, the profile of the burrs thus obtained simplifies deburring by avoiding the need for complex operations to remove excess material and / or reduces the number of operations required to achieve the final shape of the part.
[0056] In addition, better control of the profile of the burrs (i.e. their shape and location) also simplifies the manufacture of mechanical parts having a complex shape at their ends.
[0057] Typically, each burr zone 511 can have a length along the second direction Y of between 0.5mm and 10mm, for example between 0.5 and 4 mm, for example equal to 1mm to obtain the effect (of simplifying deburring) indicated above without requiring the use of too much space within the thermocompression device.
[0058] Furthermore, the thermocompression device can be configured so that each burr zone 511 is not located at an edge of the cavity 507 (as is the case in the example illustrated in [Fig. 7]), in particular to avoid damaging the part during deburring or making the deburring process too complex. Moreover, as also illustrated in [Fig. 7], the burr being offset of the edge of the part, it does not impact the geometry of the molded part in that area.
[0059] In all cases, a person skilled in the art will know how to adapt the position and dimensions of each burr zone according to the objectives pursued.
[0060] For example, in different embodiments of the invention each burr zone 511 can have either a substantially constant thickness along the second direction Y as shown in [Fig.5], or an increasing thickness, along the second direction Y, from the cavity 507 to the compression chamber 509 as shown in [Fig.6a], or even a decreasing thickness, along the second direction Y, from the cavity 507 to the compression chamber 509 as shown in [Fig.6b].
[0061] Advantageously, a configuration such as that shown in [Fig.6a] allows for the creation of a more pronounced line of weakness (at the junction between the cavity and the burr zone) to further facilitate deburring, while a configuration such as that shown in [Fig.6b] allows for the re-engagement of the material in the cavity.
[0062] Figure 8 illustrates yet another embodiment of a thermocompression device 801 according to the invention. In the example shown, the thermocompression device 801 comprises 4 parts 803, 805, 807 and 809 which are positioned side by side in a so-called bidirectional matrix, that is to say a matrix which has two intersecting directions, which can form, for example, square, rectangular, rhombic, or even triangular elements.
[0063] All the parts form cavities in pairs (i.e., one cavity between each pair of parts) when they are fitted together. Furthermore, the cavities are all interconnected and thus form a single overall cavity 811 filled with the liquefiable material when the latter is injected into the pressurized overall cavity 811.
[0064] Such a device, with a number of parts greater than or equal to 4, positioned in this way, makes it possible in particular to manufacture a mechanical part in the shape of a grid, such as for example a thrust reversing grid for an aircraft turbomachine nacelle.
[0065] In addition, as with the embodiments described above, each cavity formed between a pair of parts of the thermocompression device 801 includes at least one compression chamber 813 and a burr zone 815 which allow the generation of burrs whose shape and arrangement facilitate their removal.
[0066] Finally, in a variant of the thermocompression device 501, the parts of the device themselves can be either solid elements that can be broken down into pieces so that they can be easily removed from the part, or liquefiable elements, which are removed from the part after compression (for example by heat to cause them to melt or by dissolution in a liquid).
[0067] With reference to [Fig.9], we will now describe a method 901 of using the device described above.
[0068] Step 903 consists of positioning a material comprising at least one fibrous structure (i.e., a preform) between the first and second parts. The fibrous structure may be pre-impregnated (i.e., it incorporates a quantity of liquefiable material within itself) or dry (without incorporating any liquefiable material).
[0069] Furthermore, as mentioned above with reference to the device, in the different modes of implementation of the process, liquefiable material can be injected directly into the cavity formed between the first part and the second part by means of an injection system after they have been fitted together or all or part of the material can have been positioned between the first and the second part before they are fitted together.
[0070] Step 905 consists of compressing the material by moving the first part towards the second part. It therefore involves fitting the first part into the second part by translating the first part along the X direction.
[0071] Step 907 consists of consolidating the material by solidification. Specifically, the material that coats the fibers (of the fibrous structure) solidifies and thus gives the part its final shape (with possible burrs).
[0072] Step 909 consists of demolding the part. In addition, depending on the final state of the demolded part, a deburring step (simplified thanks to the device and the process) can be carried out to obtain the finished part.
Claims
Demands
1. Thermocompression device (501) for manufacturing mechanical parts comprising: - at least a first part (503) and a second part (505) configured to form, by fitting said first part (503) into said second part (505) along a first direction (X), a cavity (507) having the shape of a mechanical part to be manufactured, said mechanical part to be manufactured being a mechanical part of an aircraft turbomachine, for example a part of a propulsion assembly or a grid-type part; and, - at least a first interstitial zone (509) referred to as a compression chamber, distinct from the cavity (507), formed between the first part (503) and the second part (505) when said first part (503) and said second part (505) are fitted together, and extending longitudinally along the first direction (X),said thermocompression device (501) being characterized in that it further comprises at least one second interstitial zone (511) referred to as the burr zone, formed between the first part (503) and the second part (505) when said first part (503) and said second part (505) are nested, and extending longitudinally between the cavity (507) and the first interstitial zone (509), along a second direction (Y) distinct from the first direction (X), preferably forming an angle between 30° and 90° with respect to said first direction (X), and in that the at least one burr zone (511) has a thickness increasing, along the second direction (Y), from the cavity (507) to the compression chamber (509).
2. Thermocompression device (501) according to claim 1, further comprising a system for injecting a liquefiable material into the cavity (507), formed in the first part (503) and comprising at least one conduit passing through said first part (503) from an external surface of said first part (503) into the cavity (507) so as to permit the injection of said liquefiable material from outside the thermocompression device (501) into said cavity (507).
3. Thermocompression device (501) according to claim 2, wherein the liquefiable material is a polymer and the second part (505) is configured to receive a fibrous preform so that said thermocompression device (501) makes it possible to manufacture a mechanical part of composite material.
4. Thermocompression device (501) according to any one of the preceding claims, wherein at least one burr zone (511) has a length along the second direction (Y) of between 0.5mm and 10mm, preferably between 0.5mm and 4mm.
5. Thermocompression device (501) according to any one of the preceding claims, said thermocompression device (501) comprising a number of parts (803, 805, 807, 809) greater than or equal to 4, positioned side by side in a bidirectional matrix, forming cavities between each part when said parts (803, 805, 807, 809) are nested, so as to manufacture a grid-shaped mechanical part.
6. Thermocompression device (501) according to any one of the preceding claims, wherein at least one burr zone (511) is not located at an edge of the cavity (507).
7. A method (901) of using the compression device (501) according to any one of the preceding claims, said method (901) comprising the steps of: - positioning (903) of a material having at least one fibrous structure between the first and second part; - compression (905) of the material by displacement of the first part towards the second part; - consolidation (907) of the material by solidification; and, - demolding (909) of the part.