Bottom heating device of hot isostatic press

Abstract

The invention discloses a bottom heating device of a hot isostatic press. A mounting flange is arranged at the bottom of the hot isostatic press; a mounting base plate is fixedly connected with the mounting flange, and a plurality of mounting grooves which are uniformly formed in a linear array are formed in one surface, far away from the mounting flange, of the mounting base plate; the heating units are uniformly arranged on the mounting substrate in an array; the cover plate is fixedly connected with the mounting substrate, covers all the heating units and tightly presses all the heating units; a stable and firm mechanical connection interface with the mounting flange is provided through the mounting part, the reliability of combination of the whole heating device serving as a rigid module and a furnace body is ensured, and thermal stress and mechanical vibration in the working process can be effectively borne.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hot isostatic pressing equipment, more particularly, it relates to a hot isostatic pressing machine bottom heating device. BACKGROUND

[0002] Hot isostatic pressing technology is an advanced process for processing materials or products under the combined action of high temperature and high hydrostatic pressure; it uses inert gases such as argon as pressure transmission medium, and can apply uniform pressure to the workpiece in all directions, thereby realizing densification of powder metallurgy products, healing of internal defects of castings, diffusion bonding of dissimilar materials, and near-net shaping of complex components; due to its unique process advantages, the technology has been widely used in aerospace, energy equipment, biological medicine and high-end manufacturing, etc. Key fields, and is one of the core technical means for producing high-performance and high-reliability materials and components.

[0003] At present, in order to realize high temperature environment, the heating system of the mainstream hot isostatic pressing equipment usually adopts resistance heaters or induction coils arranged on the side wall of the furnace chamber, and often adds auxiliary heaters on the top to form a pattern of radiation heating from all around and the top to the center. Although this classic heating layout is relatively mature, it has inherent physical defects in the thermal field distribution. Due to the natural convection effect of hot air, the heat conduction and dissipation of the furnace body structure, and the large heat capacity of the furnace bed, tray and other components that need to bear weight at the bottom, the heat transfer efficiency from high temperature zone to low temperature zone is insufficient. Therefore, in the bottom area of the working chamber, there is a "cold zone" where the temperature is significantly lower than the process set value, causing a significant and stable axial temperature gradient in the entire working space.

[0004] The existence of the above-mentioned axial temperature gradient is a serious quality problem for hot isostatic pressing processes that require high uniformity. It directly leads to inconsistent sintering degree, densification rate or diffusion behavior of the upper and lower parts of the same batch or the same workpiece, and further causes product deformation, performance not meeting standards or uneven residual stress distribution. To solve the problem of the cold zone at the bottom, two passive strategies are usually adopted in the prior art: one is to increase the set temperature of the furnace chamber as a whole, trying to compensate for the deficiency of the lower part by "overheating" the upper part; the other is to greatly extend the holding time in the process, hoping that the heat can slowly transfer to the bottom. However, the first method not only greatly increases the energy consumption, but also may cause overheating of the upper part of the workpiece, leading to grain coarsening or abnormal phase change; the second method seriously sacrifices production efficiency; in recent years, a few designs have tried to add simple heating elements to the bottom, but these designs often interfere with the load-bearing structure and gas circulation path, or are difficult to be put into practical use due to their poor heating uniformity and extremely difficult maintenance. SUMMARY

[0005] The application aims to provide a hot isostatic pressing machine bottom heating device to solve the problems in the prior art.

[0006] The above technical objective of the application is achieved by the following technical scheme: a hot isostatic pressing machine bottom heating device, comprising:

[0007] A mounting flange is arranged at the bottom of the isostatic pressing machine;

[0008] A mounting base plate is fixedly connected with the mounting flange, and a plurality of mounting grooves are arranged in a uniform linear array on one side of the mounting base plate away from the mounting flange;

[0009] A plurality of heating units are arranged in a uniform array on the mounting base plate;

[0010] A cover plate is fixedly connected with the mounting base plate and covers and compresses all the heating units.

[0011] The mounting portion provides a stable and firm mechanical connection interface between the mounting flange and the mounting base plate, ensures the reliability of the entire heating device as a rigid module combined with the furnace body, and can effectively withstand thermal stress and mechanical vibration during work.

[0012] The application is further provided with a plurality of mounting portions arranged on both sides of the side of the mounting base plate close to the mounting flange.

[0013] The mounting portion provides a stable and firm mechanical connection interface between the mounting flange and the mounting base plate, ensures the reliability of the entire heating device as a rigid module combined with the furnace body, and can effectively withstand thermal stress and mechanical vibration during work.

[0014] The application is further provided with a plurality of weight-reducing holes arranged between adjacent mounting grooves of the mounting base plate.

[0015] The weight-reducing holes form a flow channel for high-pressure inert gas, ensure that the pressure medium can uniformly penetrate the bottom of the device, and are key structures for realizing a global "isostatic pressure" environment; at the same time, the design reduces the self-weight of the device under the premise of ensuring the structural strength.

[0016] The application is further provided with a plurality of heating units, each comprising a box body, a plurality of heating bridges arranged in parallel and uniformly spaced in the box body, and an electrode tube penetrating through one side wall of the box body and vertically penetrating through the plurality of heating bridges after penetrating through the box body, and the two electrode tubes are bridged by the heating bridges.

[0017] The structure makes the heating bridge and the electrode tube form a stable parallel circuit, current is uniformly distributed, so that a single heating unit becomes a surface heat source; the sealing box body cooperates with the internal structure to effectively protect the heating body, and improve the durability and safety of the heating body in a high pressure and high temperature environment.

[0018] The application further provides that a wire harness seat is further arranged at the side edge of the mounting substrate, and a plurality of wire harness connectors are arranged on the wire harness seat, each of the wire harness connectors being capable of connecting a column of the heating units in series or in parallel.

[0019] Through the integration and standardization of the electrical connection of all the heating units, the circuit (series / parallel) can be flexibly configured through the wire harness connectors, temperature control in different zones is facilitated, the centralized wiring mode simplifies external connection, improves installation efficiency and maintenance convenience, and is beneficial to ensuring the sealing of the furnace body.

[0020] In summary, the application has the following beneficial effects:

[0021] Through the bottom active heating and the array type surface heat source design, the bottom heat loss in the traditional structure is directly and uniformly compensated, the axial temperature gradient of the working chamber is effectively eliminated, and the process consistency and product quality are greatly improved.

[0022] The device adopts a hierarchical module design of "substrate-unit array-cover plate". The heating unit is an independent detachable standard part, and once damaged, it can be replaced individually by only disassembling the cover plate, greatly reducing the maintenance complexity, cost and equipment downtime.

[0023] The device integrates bearing, heating, heat equalization, heat insulation and electrical interface in one, and has a compact structure. The weight reduction hole design ensures the circulation of the core process gas, and the sealed heating unit and the integrated wire harness seat ensure the long-term operation stability and safety under high pressure and high temperature conditions.

[0024] The modular heating unit array combined with the integrated electrical connection provides a hardware basis for zoned temperature control, enabling more accurate closed-loop temperature control, avoiding energy waste caused by excessive heating to compensate for cold areas, and achieving the purpose of energy saving and efficiency improvement. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a perspective view in the embodiment of the application;

[0026] Figure 2 is a first exploded view in the embodiment of the application;

[0027] Figure 3 is a second exploded view in the embodiment of the application;

[0028] Figure 4 is a sectional view in the embodiment of the application.

[0029] In the picture:

[0030] 1. Install the flange;

[0031] 2. Mounting base; 21. Mounting part; 22. Mounting groove; 23. Fixing hole;

[0032] 3. Heating unit; 31. Weight reduction hole; 32. Heating bridge; 33. Electrode tube; 34. Housing;

[0033] 4. Cover plate; 41. Protective layer; 42. Insulation layer; 43. Heat equalization layer; 44. Countersunk bolts;

[0034] 5. Ribbon cable socket; 51. Ribbon cable plug. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0036] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0037] It should be noted that, unless otherwise specified, the embodiments and features described in this invention can be combined with each other.

[0038] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0039] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only used for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. In addition, the terms "first," "second," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0040] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0041] The following is in conjunction with the appendix Figures 1-4 The present invention will be described in further detail below, but the scope of protection of the present invention is not limited to the following description.

[0042] Example

[0043] This embodiment provides a bottom heating device for a hot isostatic press, including: a mounting flange 1, a mounting base plate, a heating unit 3, and a cover plate 4.

[0044] Mounting flange 1 is located at the bottom of the static press; it is bolted to the bottom of the lower furnace body of the hot isostatic press.

[0045] The mounting base plate is fixedly connected to the mounting flange 1. The mounting base plate has a number of uniformly linearly arranged mounting grooves 22 on the side away from the mounting flange 1.

[0046] The heating units 3 are arranged in a uniform array on the mounting base plate;

[0047] The cover plate 4 is fixedly connected to the mounting base plate and covers all the heating units 3 and presses all the heating units 3 tightly.

[0048] Several mounting portions 21 are provided on both sides of the mounting base plate near the mounting flange 1.

[0049] Weight reduction holes 31 are provided between adjacent mounting slots 22 of the mounting substrate. These holes are key to ensuring the flow of high-pressure process gas.

[0050] The heating unit 3 includes a housing 34, which contains several parallel and evenly spaced heating bridges 32. An electrode tube 33 passes through one side wall of the housing 34 and then vertically through the heating bridges 32. Two electrode tubes 33 are connected by the heating bridges 32. Each housing 34 contains two electrode tubes 33 that pass through the side wall of the housing 34. The housing is filled with magnesium oxide or aluminum nitride powder. During installation, each heating unit 3 is precisely embedded in a mounting slot 22.

[0051] A ribbon cable holder 5 is also provided on the side edge of the mounting base. The ribbon cable holder 5 is provided with several ribbon cable connectors. Each ribbon cable connector can connect a row of heating units 3 in series or in parallel. The ribbon cable holder 5 combines multiple rows of circuits and connects to an external power supply through a main interface to realize power supply and control.

[0052] Fixing holes 23 are provided at the four corners of the mounting substrate. The fixing holes 23 can be blind holes or through holes.

[0053] The cover plate 4 is composed of multiple layers, including a protective layer 41, a heat insulation layer 42, and a heat equalization layer 43. The heat equalization layer 43 evenly abuts against each heating unit 3, and through holes are provided at the four corners of the heat equalization layer 43 corresponding to the fixing holes 23. Countersunk bolts 44 are provided at the four corners of the heat insulation layer 42 corresponding to the fixing holes 23, passing through the heat insulation layer 42. The countersunk bolts 44 are connected to the mounting base after passing through the heat equalization layer 43. The protective layer 41 is attached to the side of the heat insulation layer 42 that is in contact with the heat equalization layer 43 using a high-temperature resistant adhesive. The powder medium inside not only plays a role in uniform heat conduction, but also forms a buffer protection for the heating bridge 32, preventing the heating bridge 32 from breaking due to high-pressure gas impact or vibration. At the same time, magnesium oxide or aluminum nitride powder has good insulation properties, preventing short circuits between the electrode tube 33 and the heating bridge 32, and improving the service life of the heating unit 3.

[0054] The cover plate 4 is a rigid plate, the heat spreader 43 is a molybdenum plate or high-strength graphite plate with a thickness of at least 3 mm and its lower surface is precision ground, the heat insulation layer 42 is a hard ceramic fiber board or foamed alumina brick with a thickness of 30-50 mm, and thermocouple wire holes can be opened if necessary, and the protective layer 41 is a flexible graphite felt with a thickness of 0.5-1 mm. The three-layer composite structure has its own function. The heat spreader 43 realizes the rapid and uniform diffusion of heat, so that the temperature difference of the bottom hot surface is ≤3℃; the heat insulation layer 42 effectively blocks heat loss and reduces energy consumption by more than 30%; the protective layer 41 enhances the impact resistance and corrosion resistance of the cover plate 4 and extends the maintenance cycle of the overall device.

[0055] The temperature measuring end of the armored thermocouple is embedded or closely attached to different positions on the upper surface of the heat-spreading layer 43 (such as the center and the edge), and its signal line is connected to the cable tray 5 to realize real-time zoned monitoring of the bottom temperature.

[0056] Working principle: During operation, the external power supply supplies power to each heating unit 3 through the cable connector 5. The heating bridge 32 generates heat, which is conducted to the entire box 34 through the powder medium and then diffused through the heat spreader 43 to form a uniform heat surface. The control system dynamically adjusts the output power according to the temperature data fed back by the thermocouple, and accurately compensates for the heat loss at the bottom, so that the temperature field in the entire working chamber reaches a high degree of uniformity.

[0057] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A bottom heating device for a hot isostatic press, characterized in that... ,include: Mounting flange (1) is located at the bottom of the static pressure machine; The mounting base plate is fixedly connected to the mounting flange (1), and a plurality of uniformly linearly arrayed mounting grooves (22) are provided on the side of the mounting base plate away from the mounting flange (1). The heating units (3) are arranged in a uniform array on the mounting base plate; The cover plate (4) is fixedly connected to the mounting base plate and covers all the heating units (3) and presses all the heating units (3) together.

2. The bottom heating device for a hot isostatic press according to claim 1, characterized in that: Several mounting portions (21) are provided on both sides of the mounting base plate near the mounting flange (1).

3. The bottom heating device for a hot isostatic press according to claim 1, characterized in that: Weight reduction holes (31) are provided between adjacent mounting slots (22) of the mounting substrate.

4. The bottom heating device for a hot isostatic press according to claim 1, characterized in that: The heating unit (3) includes a box (34), and a plurality of parallel and evenly spaced heating bridges (32) are provided inside the box (34). An electrode tube (33) is also provided inside the box (34) and passes through one side wall. The electrode tube (33) passes through the box (34) and then passes vertically through the plurality of heating bridges (32). Two electrode tubes (33) are connected by heating bridges (32).

5. The bottom heating device for a hot isostatic press according to claim 4, characterized in that: The mounting base is also provided with a cable tray (5) at the side edge. The cable tray (5) is provided with a number of cable connectors. Each cable connector can connect a row of heating units (3) in series or in parallel.

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