Novel hot knife

Abstract

A novel heat knife comprises a shell and a base. The base is fixedly connected to the bottom of the shell; the device further comprises a wire and a silicon nitride hot knife. The silicon nitride hot knife is arranged in the shell; the top of the shell is fixedly connected with a shroud ring, the silicon nitride hot knife is arranged in the shroud ring in a penetrating manner, and the silicon nitride hot knife extends out of the shroud ring; the middle part of the silicon nitride hot knife is embedded in the shell; and one end of the wire passes through the base, and the other end is connected with the silicon nitride hot knife. The resistance wire is placed in the silicon nitride ceramic powder, pressed, sintered and machined, the direct heat conduction path of resistance heating is shortened, and the heating efficiency and the heat bearing capacity are improved. The joint of the wire and the rod body is protected through the protection ring, and it is ensured that the wire cannot fall off due to vibration in use. The highest heating temperature of the silicon nitride hot knife is 1100 DEG C, the silicon nitride hot knife can be lightened for a long time, and the service life is longer than or The heat knife is supplied with power through a double-circuit power supply, normal heating of the heat knife is ensured, and faults are avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of unlocking control of spacecraft solar arrays, and particularly to a new type of thermal knife. Background Art

[0002] With the continuous development of space technology, the application scale of spacecraft (such as artificial satellites, etc.) is also constantly expanding. Locking and unlocking are key technologies for spacecraft in-orbit flight, which are used to achieve key actions such as solar wing deployment, antenna deployment, payload release, etc., and this technology needs to be realized based on a cutter.

[0003] Traditional cutters mostly use pyrotechnic cutters, whose technology is relatively mature and stable, but there are obvious defects such as large device weight, large impact load, and serious explosion pollution. With the development of technology, hot-melt cutters have gradually emerged, which achieve the purpose of unlocking and releasing the upper components of the spacecraft by heating the thermal knife to fuse the rope. However, in the existing hot-melt cutters, that is, thermal knives, there is stress between the cutter and the fuse wire, which is likely to cause damage to the thermal knife; in the existing technology, most hot-melt cutters are clamped at both ends and energized at both ends, and the rope is wound around the middle of the fixed hot-melt cutter at both ends. The stress exerted by the rope on the thermal knife can only improve the stress resistance of the thermal knife by enlarging the diameter of the thermal knife; however, this runs counter to the original design intention of reducing the device weight. Therefore, there is an urgent need for a structure that can improve the stress resistance of the thermal knife without enlarging the diameter of the thermal knife. Summary of the Utility Model

[0004] The utility model provides a new type of thermal knife, aiming to solve the technical problem that the thermal knife in the existing technology has a risk of being damaged by the stress of the fuse wire.

[0005] The utility model provides a new type of thermal knife, including a housing and a base; the base is fixedly connected to the bottom of the housing; it also includes a wire and a silicon nitride thermal knife; one end of the silicon nitride thermal knife is arranged inside the housing; a hoop is fixedly connected to the top of the housing, and the silicon nitride thermal knife passes through the hoop and extends out of the hoop; the middle part of the silicon nitride thermal knife is buried inside the housing; one end of the wire passes through the base and the other end is connected to the silicon nitride thermal knife; a heating wire is arranged inside the silicon nitride thermal knife; both ends of the heating wire are connected to the wire; the heating wire and the silicon nitride thermal knife are integrally hot-pressed.

[0006] Further, the space between the housing and the silicon nitride thermal knife is filled with a filler; the filler is an insulating and heat-insulating filler.

[0007] Further, there are two limiting through holes between the base and the silicon nitride thermal knife inside the filler; the wire passes through the limiting through holes.

[0008] Further, the heating wire is wound and stacked outside the housing to form a heating mandrel; the heating wire passes through the silicon nitride hot knife inside the housing and is connected to a wire; the wire is wound at the connection with the heating wire to form a protective ring.

[0009] Further, an electrical connector is provided at the bottom of the base; the electrical connector is connected to a dual-power supply, and the dual-power supply is a backup circuit for each other; the electrical connector has two positive electrodes and two negative electrodes; the wires are respectively electrically connected to the two positive electrodes and the two negative electrodes.

[0010] Advantages of the present utility model:

[0011] The present utility model provides a novel hot knife. The resistance wire is placed in silicon nitride ceramic powder, compacted and then sintered, and machined after sintering. Compared with the prior art that requires a heat conduction path through multiple protective layers or heat conduction layers, the present utility model shortens the direct heat conduction path of resistance heating, improves the heating efficiency and heat-bearing capacity; the hot knife is processed by integral hot pressing to reduce the influence of stress on the hot knife; the anti-shear stress ability is further improved through structures such as a hoop, a limiting through hole and a protective ring.

[0012] The present utility model provides a novel hot knife. The connection between the wire and the heating wire is protected by a protective ring to ensure that the wire and the heating wire will not fall off due to vibration during use.

[0013] The present utility model provides a novel hot knife. The maximum heating temperature of the silicon nitride hot knife is 1100 °C, it can be lit for a long time, and the service life ≥ 5000 h.

[0014] The present utility model provides a novel hot knife. The hot knife is powered by a dual-power supply to ensure that the hot knife can be heated normally and avoid failures. Description of the drawings

[0015] Figure 1 is a schematic structural diagram of a novel hot knife described in the present utility model;

[0016] Figure 2 is a cross-sectional view of a novel hot knife described in the present utility model;

[0017] Figure 3 is a circuit diagram of a novel hot knife described in the present utility model;

[0018] Figure 4 is an assembly diagram of a novel hot knife described in the present utility model and the satellite end;

[0019] Among them, 1 - housing, 2 - base, 3 - wire, 4 - silicon nitride hot knife, 5 - heating wire, 6 - limiting through hole, 7 - protective ring, 8 - hoop, 9 - electrical connector, 10 - filler, 11 - heating mandrel. Detailed implementation manners

[0020] The utility model provides a novel hot knife, which comprises a housing 1, a base 2, a wire 3 and a silicon nitride hot knife 4. The housing 1 is fixedly connected to the base 2. The middle part of the silicon nitride hot knife 4 is fixedly connected inside the housing 1. An insulating filler 10 is filled between the silicon nitride hot knife 4 and the housing 1. A heating wire 5 is arranged inside the silicon nitride hot knife 4. The tungsten wire is used as the heating wire 5, and the tungsten wire is buried in the silicon nitride hot knife 4 and formed into an integral body through a hot pressing sintering process to form a heating element. The silicon nitride ceramic rod is an atomic crystal, which has high hardness, lubricity and wear resistance by itself; it has oxidation resistance at high temperature and can resist thermal shock; and the silicon nitride hot knife has certain self-lubricity after hot pressing molding, ensuring that after the fuse is melted, residues are not easily retained, and further reducing the risk of damage caused by the residues pulling the hot knife. The wire 3 is connected to both ends of the heating wire 5. The heating wire 5 is wound and stacked into a heating mandrel outside the housing 1. The heating wire 5 passes through the silicon nitride hot knife 4 inside the housing 1 and is connected to the wire 3. The wire 3 is wound to form a protective ring 7 at the connection with the heating wire 5. A hoop 8 is connected to the top of the housing 1 by threads. The silicon nitride hot knife 4 passes through the hoop 8 and extends out of the housing 1. Two limiting through holes 6 are arranged on the base 2, and the wire 3 is arranged in the limiting through holes 6. An electrical connector 9 is fixedly connected to the bottom of the base 2. The electrical connector 9 is connected to the dual power supply at the satellite end. The dual power supply is a backup circuit for each other. There are two positive electrodes and two negative electrodes on the hot knife socket 9. The wire 3 is electrically connected to the two positive electrodes and the two negative electrodes on the electrical connector.

Claims

1. A novel hot knife, comprising a housing (1) and a base (2); the base (2) is fixedly connected to the bottom of the housing (1); characterized in that: It also includes a wire (3) and a silicon nitride hot knife (4); one end of the silicon nitride hot knife (4) is arranged in the shell (1); a hoop (8) is fixedly connected to the top of the shell (1), the silicon nitride hot knife (4) is inserted into the hoop (8), and the silicon nitride hot knife (4) extends from the hoop (8); the middle part of the silicon nitride hot knife (4) is buried in the shell (1); one end of the wire (3) passes through the base (2), and the other end is connected to the silicon nitride hot knife (4); a heating wire (5) is arranged in the silicon nitride hot knife (4); both ends of the heating wire (5) are connected to the wire (3); the heating wire (5) and the silicon nitride hot knife (4) are integrally hot-pressed.

2. A new type of hot knife according to claim 1, characterized in that: A filler (10) is provided between the shell (1) and the silicon nitride hot knife (4); the filler (10) is an insulating and heat-insulating filler.

3. A new type of hot knife according to claim 2, characterized in that: Two limiting through holes (6) are provided in the filler (10) between the base (2) and the silicon nitride hot knife (4); the limiting through holes (6) and the filler (10) are integrally formed; and the wire (3) is passed through the limiting through holes (6).

4. A new type of hot knife according to claim 1, characterized in that: The heating wire (5) is wound and stacked outside the outer shell (1) to form a heating core rod (11); the heating wire (5) passes through the silicon nitride hot knife (4) inside the outer shell (1) and is connected to the wire (3); the wire (3) is wound at the connection with the heating wire (5) to form a protective ring (7).

5. A new type of hot knife according to claim 1, characterized in that: An electrical connector (9) is provided at the bottom of the base (2); the electrical connector (9) is connected to a dual-circuit power supply, and the dual-circuit power supplies serve as backup circuits for each other; the electrical connector (9) is provided with two positive poles and two negative poles; and the wire (3) is electrically connected to the two positive poles and the two negative poles, respectively.

Images