Hot isostatic pressing sintering furnace for powder metallurgy blanks

Abstract

The utility model relates to the technical field of metal powder sintering devices, and discloses a powder metallurgy blank hot isostatic pressing sintering furnace which is characterized in that a sintering cylinder body (4) consists of a ceramic cylinder (5) and a graphite cylinder (6), the graphite cylinder (6) is fixedly mounted in the ceramic cylinder (5), and a heating wire (7) is mounted on the inner wall of the graphite cylinder (6); a rotating ball seat (9) is arranged on the inner bottom surface of the sintering cylinder body (4), rotating ball grooves (10) are formed in the rotating ball seat (9) in the circumferential direction, rotating balls (11) are arranged in the rotating ball grooves (10), and a blank frame (8) is arranged on the rotating balls (11) and can rotate; a shaft hole (13) is formed in the middle of a tray (12) at the bottom of the blank frame (8), the shaft hole (13) is connected with a rotating shaft (14), and the rotating shaft (14) penetrates out of the cavity (2) to be connected with a motor (15). According to the utility model, the defects of thermal stress concentration, cracks and the like possibly generated in the sintering process are reduced, and the quality of sintered products is improved.

Description

Technical Field

[0001] This utility model relates to the technical field of metal powder sintering equipment, specifically to a hot isostatic pressing sintering furnace for powder metallurgy billets. Background Technology

[0002] With the development of advanced ceramics and special metal materials, powder metallurgy technology has also made rapid progress. Hot isostatic pressing (HIP) involves placing a powder compact in a sealed container and applying isotropic pressure (usually argon, helium, or nitrogen as the pressure medium, but molten salt solution or molten glass water are also used) while heating at high temperatures. Under the combined effects of high temperature and uniform pressure, the compact is sintered into a dense body. However, existing HIP devices suffer from uneven heating, leading to cracks in powder metallurgy gears during sintering.

[0003] Reference CN104999081A discloses a small hot isostatic pressing furnace device. Its heating system includes a ceramic cylinder and heating wires, with the heating wires wrapped around the inside of the ceramic cylinder. The ceramic cylinder is installed inside the cavity, and ceramic electrodes are set on the upper outer sidewall of the cavity. The ceramic electrodes pass through the sidewall of the cavity and are connected to the heating wires inside the ceramic cylinder. The ceramic cylinder cannot rotate, which prevents uniform heating of the billet and results in relatively low sintering quality of the billet. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a powder metallurgy billet hot isostatic pressing sintering furnace that reduces defects such as thermal stress concentration and cracks that may occur during the sintering process and improves the quality of sintered products.

[0005] To solve the above technical problems, this utility model provides a hot isostatic pressing sintering furnace for powder metallurgy billets, including a water-cooled jacket, a cavity, an insulation layer, and a sintering cylinder. The sintering cylinder is composed of a ceramic cylinder and a graphite cylinder. The graphite cylinder is fixedly installed inside the ceramic cylinder, and heating wires are installed on the inner wall of the graphite cylinder. A billet rack is rotatably arranged inside the sintering cylinder, and a bead seat is provided on the bottom surface of the sintering cylinder. A bead groove is opened circumferentially on the bead seat, and a bead is placed in the bead groove. The billet rack is placed on the bead. A shaft hole is opened in the middle of the bottom tray of the billet rack, and the shaft hole is connected to a rotating shaft. The rotating shaft passes through the cavity and is connected to a motor.

[0006] By adopting the above technical solution, a rotating billet rack is set inside the sintering cylinder. During sintering, the motor drives the billet rack to rotate at a uniform speed, ensuring that the billet is heated evenly at all positions inside the sintering cylinder, reducing defects such as thermal stress concentration and cracks that may occur during the sintering process, and improving the quality of sintered products.

[0007] Preferably, the billet rack is multi-layered, mainly composed of trays and supports, with the trays supported by the supports between each other.

[0008] By adopting the above technical solutions, the multi-layer design makes full use of vertical space, allowing more blanks to be stored in the same area.

[0009] Preferably, the tray has slots for the support to stand upright.

[0010] By adopting the above technical solution, the support column is connected to the tray through the slot, forming a stable support structure. The number of tray layers can be adjusted in a timely manner according to the quantity of sintered billets.

[0011] Preferably, the tray has through holes.

[0012] By adopting the above technical solution, the presence of through holes increases the contact area between the tray and the gas in the furnace, improves the heat exchange efficiency, and allows heat to be transferred to the sintering material more quickly, thus accelerating the sintering process.

[0013] Preferably, the shaft hole and the rotating shaft are connected by a key.

[0014] By adopting the above technical solution, the key connection method is simple and convenient, which can make the shaft hole and the rotating shaft fit together more tightly, avoid relative sliding and wear, and thus improve transmission efficiency.

[0015] Preferably, the sintering cylinder and the rotating shaft are sealed by a graphite bearing I.

[0016] By adopting the above technical solution, a tight fit can be formed between the sealing surface of graphite bearing I and the rotating shaft, reducing the possibility of gas and heat leakage in the sintering cylinder. This is especially important for sintering processes that require maintaining a high-pressure, high-temperature environment.

[0017] Preferably, the cavity and the rotating shaft are sealed by a graphite bearing II.

[0018] By adopting the above technical solution, graphite can resist the erosion of corrosive substances such as acids, alkalis, and salts. Even if there is a corrosive medium between the shaft and the cavity, the graphite bearing II can maintain its sealing performance and extend the service life of the device.

[0019] Preferably, the water-cooling jacket and the rotating shaft are sealed by a graphite bearing III.

[0020] By adopting the above technical solution, the graphite bearing III has excellent wear resistance and corrosion resistance, thus its service life is relatively long, reducing equipment downtime and maintenance costs caused by seal failure.

[0021] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0022] 1. This utility model features a rotating billet rack inside the sintering cylinder. During sintering, the motor drives the billet rack to rotate at a uniform speed, ensuring that the billet is heated evenly at all positions inside the sintering cylinder. This reduces potential defects such as thermal stress concentration and cracks that may occur during the sintering process, thereby improving the quality of the sintered products.

[0023] 2. The design of installing rotating balls in the rotating ball holder of this utility model changes the surface contact between the sintering cylinder and the billet rack to point contact, which significantly reduces the friction between the two, reduces the driving force required during the sintering process, reduces energy consumption, and improves overall energy efficiency.

[0024] 3. The tray of this utility model has slots for the support pillars to stand upright. The support pillars are connected to the tray through the slots, forming a stable support structure. The number of tray layers can be adjusted in a timely manner according to the quantity of sintered billets. Attached Figure Description

[0025] Figure 1 This is a perspective view of the present utility model.

[0026] Figure 2 This is a cross-sectional view of the present invention.

[0027] Figure 3 This is a schematic diagram of the sintering cylinder of this utility model.

[0028] Figure 4 This is a schematic diagram of the bead-rotating seat of this utility model.

[0029] Figure 5 This is a schematic diagram of the blank holder of this utility model.

[0030] Figure 6 This is a schematic diagram showing the slots on the tray of this utility model.

[0031] Figure 7 This is a schematic diagram of a through hole on the tray of this utility model.

[0032] Drawing numbers: 1. Water cooling jacket, 2. Cavity, 3. Insulation layer, 4. Sintering cylinder, 5. Ceramic cylinder, 6. Graphite cylinder, 7. Heating wire, 8. Blank rack, 9. Ball bearing seat, 10. Ball bearing groove, 11. Ball bearing, 12. Tray, 13. Shaft hole, 14. Shaft, 15. Motor, 16. Support column, 17. Through hole, 18. Graphite bearing I, 19. Graphite bearing II, 20. Graphite bearing III, 21. Slot, 22. Alumina insulation cover, 23. Ceramic electrode, 24. Inlet pipe, 25. Outlet pipe, 26. End cap. Detailed Implementation

[0033] like Figure 1As shown, the powder metallurgy billet hot isostatic pressing sintering furnace includes a water-cooled jacket 1, a cavity 2, an insulation layer 3, and a sintering cylinder 4. The insulation layer 3 is installed inside the cavity 2, and the sintering cylinder 4 is installed inside the insulation layer 3. An end cap 26 is sealed on the top surface of the cavity 2. The insulation layer 3 is an alumina insulation layer. Two ceramic electrodes 23 are installed on the upper outer wall of the cavity 2. The ceramic electrodes 23 pass through the side wall of the sintering cylinder 4 and are connected to the heating wire 7. The heating wire 7 inside the sintering cylinder 4 is heated by energizing the ceramic electrodes 23. An air inlet pipe 24 is also installed on the upper outer wall of the cavity 2, passing through the cavity 2 and communicating with the interior of the cavity 2. An air outlet pipe 25 is provided on the end cap 26. The air outlet pipe 25 passes through the end cap 26 and communicates with the interior of the cavity 2.

[0034] like Figure 2 As shown, the top surface of the sintering cylinder 4 is covered with an alumina insulation cover 22. A water-cooling jacket 1 is fitted onto the outer wall of the cavity 2.

[0035] The shaft 14 and the sintering cylinder 4 are sealed by a graphite bearing I 18. The sealing surface of the graphite bearing I 18 and the shaft 14 can form a tight fit, reducing the possibility of gas and heat leakage in the sintering cylinder 4. This is especially important for sintering processes that require maintaining a high-pressure, high-temperature environment.

[0036] The shaft 14 and cavity 2 are sealed by a graphite bearing II 19. Graphite material can withstand friction and wear under high-temperature conditions, allowing the graphite bearing II 19 to maintain a stable seal during high-temperature sintering. Graphite resists corrosion from acids, alkalis, salts, and other corrosive substances. Even in the presence of corrosive media between the shaft 14 and cavity 2, the graphite bearing II 19 can maintain its sealing performance, extending the service life of the device.

[0037] The shaft 14 and the water-cooled jacket 1 are sealed by a graphite bearing III 20. The graphite bearing III 20 has excellent wear resistance and corrosion resistance, so its service life is relatively long, reducing the downtime and maintenance costs caused by seal failure.

[0038] like Figure 3 As shown, the sintering cylinder 4 consists of a ceramic cylinder 5 and a graphite cylinder 6. The graphite cylinder 6 is fixedly installed inside the ceramic cylinder 5 to improve the mechanical properties of the ceramic cylinder 5, enhance the overall strength of the sintering cylinder 4, and make the sintering cylinder 4 more durable and reliable. Heating wire 7 surrounds the inner wall of the graphite cylinder 6. A billet rack 8 is rotatably installed inside the sintering cylinder 4, and a ball bearing seat 9 is installed on the bottom surface of the sintering cylinder 4.

[0039] like Figure 4 As shown, a bead-rotating seat 9 has a bead-rotating groove 10 circumferentially opened, and a bead-rotating ball 11 is arranged in the bead-rotating groove 10. The billet rack 8 is placed on the bead-rotating ball 11. The bead-rotating ball 11 can roll smoothly in the bead-rotating groove 10, so that the billet rack 8 can rotate easily in the sintering cylinder 4.

[0040] A shaft hole 13 is formed in the middle of the bottom tray 12 of the billet rack 8, and the shaft hole 13 is connected to the rotating shaft 14. In this embodiment, the rotating shaft 14 passes through the sintering cylinder 4, the cavity 2, and the water cooling jacket 1 and is connected to the motor 15. The motor 15 can be fixedly mounted on the bottom surface of the water cooling jacket 1 with bolts using a mounting bracket. The motor 15 is controlled to rotate at a uniform speed by a PLC controller.

[0041] like Figure 5 As shown, the billet rack 8 is multi-layered, mainly composed of trays 12 and supports 16. Each pair of trays 12 is supported by a support 16. The bottom tray 12 has a shaft hole 13 in its center. This multi-layered design makes full use of vertical space, allowing more billets to be stored within the same area. The shaft hole 13 and the rotating shaft 14 are connected by a key. This key connection is simple and convenient, allowing the shaft hole 13 and the rotating shaft 14 to fit together more tightly, avoiding relative sliding and wear, thereby improving transmission efficiency.

[0042] The lower end face of the top tray 12 has a slot 21 for the support column 16 to stand upright. Both the upper and lower end faces of the middle tray 12 have slots 21 for the support column 16 to stand upright, such as... Figure 6 As shown. The upper surface of the bottom tray 12 has slots 21 for the support pillars 16 to stand on. The support pillars 16 are connected to the tray 12 through the slots 21, forming a stable support structure. The number of layers of the tray 12 can be adjusted in time according to the amount of sintered billets.

[0043] This application incorporates a rotating billet rack within the sintering cylinder 4. During sintering, the motor 15 drives the billet rack 8 to rotate at a uniform speed, ensuring that the billet is heated evenly at all positions within the sintering cylinder 4. This reduces potential defects such as thermal stress concentration and cracks during sintering, thereby improving the quality of the sintered product. The design of installing rotating balls 11 in the ball bearing seat 9 changes the contact between the sintering cylinder 4 and the billet rack 8 from surface contact to point contact, significantly reducing friction between them, lowering the driving force required during sintering, reducing energy consumption, and improving overall energy efficiency.

[0044] like Figure 7 As shown, in another embodiment, a through hole 17 is formed on the tray 12. The presence of the through hole 17 increases the contact area between the tray 12 and the gas inside the furnace, improves the heat exchange efficiency, and allows heat to be transferred to the sintering material more quickly, thus accelerating the sintering process.

[0045] During sintering, the bottom tray 12 is first mounted onto the rotating shaft 14. Then, powder metallurgy gear blanks are placed one by one on the tray 12, and support pillars 16 are inserted into the slots 21 of the tray 12. The top of the support pillar 16 is inserted into the slots 21 on the lower end face of the second tray 12, and the blank is placed on the second tray 12. The trays 12 are installed in sequence, and the blanks are placed on them. Finally, the alumina insulation cover 22 and the end cover 26 are covered. The heating wire 7 is energized to heat the material, and the motor 15 drives the blank holder 8 to rotate at a uniform speed, thus beginning the sintering of the powder metallurgy gear blanks.

[0046] Those skilled in the art should understand that the embodiments of the present invention described above and shown in the accompanying drawings are merely examples and do not limit the present invention. The purpose of the present invention has been fully and effectively achieved. The functions and structural principles of the present invention have been shown and explained in the embodiments. Without departing from the stated principles, the implementation of the present invention may have any variations or modifications.

Claims

1. Powder metallurgy blank hot isostatic pressing sintering furnace, comprising a water cooling jacket (1), a cavity (2), a heat preservation layer (3) and a sintering cylinder (4), characterized in that: The sintering cylinder (4) is composed of a ceramic cylinder (5) and a graphite cylinder (6), the graphite cylinder (6) is fixedly installed in the ceramic cylinder (5), and a heating wire (7) is installed on the inner wall of the graphite cylinder (6); a blank holder (8) is rotatably arranged in the sintering cylinder (4), a rotating ball seat (9) is arranged on the bottom surface of the sintering cylinder (4), a rotating ball groove (10) is circumferentially formed on the rotating ball seat (9), a rotating ball (11) is arranged in the rotating ball groove (10), and the blank holder (8) is arranged on the rotating ball (11); an axle hole (13) is formed in the middle of a tray (12) at the bottom of the blank holder (8), the axle hole (13) is connected with a rotating shaft (14), and the rotating shaft (14) penetrates out of the cavity (2) and is connected with a motor (15).

2. Powder metallurgical billet hot isostatic pressing sintering furnace according to claim 1, characterized in that: The blank holder (8) is multi-layered and mainly composed of the tray (12) and a support column (16), and the support column (16) is arranged between two trays (12) to support the two trays (12).

3. Powder metallurgical billet hot isostatic pressing sintering furnace according to claim 2, characterized in that: The tray (12) is provided with a slot hole (21) for standing the support column (16).

4. Powder metallurgical billet hot isostatic pressing sintering furnace according to claim 3, characterized in that: A through hole (17) is formed in the tray (12).

5. Powder metallurgy billet hot isostatic pressing sintering furnace according to claim 1, characterized in that: The axle hole (13) and the rotating shaft (14) are connected through a key.

6. Powder metallurgy billet hot isostatic pressing sintering furnace according to claim 1, characterized in that: The sintering cylinder (4) and the rotating shaft (14) are sealed through a graphite bearing I (18).

7. Powder metallurgy billet hot isostatic pressing sintering furnace according to claim 1, characterized in that: The cavity (2) and the rotating shaft (14) are sealed through a graphite bearing II (19).

8. Powder metallurgy billet hot isostatic pressing sintering furnace according to claim 1, characterized in that: The water cooling jacket (1) and the rotating shaft (14) are sealed through a graphite bearing III (20).

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