Nickel-titanium memory alloy over-temperature protector and application circuit thereof

Abstract

The invention relates to the technical field of protectors, in particular to a nickel-titanium memory alloy over-temperature protector and an application circuit thereof.A memory alloy wire, metal contact pieces and a temperature sensing layer are contained in an over-temperature protector shell, the metal contact pieces are arranged at the upper end and the lower end of the over-temperature protector shell respectively, and the memory alloy wire is located between the upper metal contact piece and the lower metal contact piece; the bottom end of the memory alloy wire is a fixed end, the upper end of the memory alloy wire is a movable end, the memory alloy wire at the fixed end is always in contact with the metal contact piece below, and the temperature sensing layer is arranged on the periphery of the memory alloy wire. The application circuit of the nickel-titanium memory alloy over-temperature protector comprises a power input end, a protection circuit, a post-stage circuit and a circuit ground wire loop, the power input end, the protection circuit and the post-stage circuit are sequentially connected in series, the protection circuit is connected with the circuit ground wire loop, and the post-stage circuit is connected back to the power input end through the circuit ground wire loop. The over-temperature protection device is high in over-temperature protection response speed, small in size and wide in application.

Description

Technical Field

[0001] The invention relates to the technical field of protectors, and in particular to a nickel-titanium memory alloy over-temperature protector and an application circuit thereof. Background Art

[0002] With the advancement of science and technology and the development of industry, various electronic equipment, mechanical equipment and household appliances play an increasingly important role in daily life and industrial production. However, these devices often generate a lot of heat during operation. If the temperature is not properly controlled, it is very easy to cause the equipment to overheat, which in turn causes serious consequences such as fire, equipment damage and even personal injury. Therefore, as a key component to ensure the safe operation of the equipment, the stability and reliability of the over-temperature protector are particularly important.

[0003] Traditional over-temperature protectors mostly use bimetallic strips, thermistors and other components. Although these components have certain over-temperature protection functions, they have some shortcomings in practical applications. For example, although the bimetallic strip will deform when the temperature changes, its recovery is poor and the deformation range is limited, making it difficult to adapt to complex and changing temperature environments; although thermistors have a fast response speed, their long-term stability and reliability need to be improved, and they are prone to aging and failure in high-temperature environments. Traditional over-temperature protector devices are often difficult to adapt to the needs of high-tech fields such as precision instruments, microelectronic equipment and new energy vehicles due to their large size, slow response speed or insufficient accuracy.

[0004] The traditional over-temperature protection circuit requires a temperature sensor, a PID processor and a switching power supply to achieve the function of circuit over-temperature protection, and the circuit structure is complicated and cumbersome. The over-temperature protection circuit after using the memory alloy over-temperature protector is also in urgent need of improvement. Summary of the invention

[0005] To solve the above problems, the present invention provides a nickel-titanium memory alloy over-temperature protector and its application circuit. The circuit structure is simple. It only needs to add a nickel-titanium memory alloy over-temperature protector at the initial end of the power supply to realize the over-temperature protection function. The nickel-titanium memory alloy over-temperature protector can be reused.

[0006] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a nickel-titanium memory alloy over-temperature protector, including an over-temperature protector shell, characterized in that the over-temperature protector shell contains a memory alloy wire, a metal contact and a temperature-sensitive layer, the metal contacts are respectively arranged at the upper and lower ends of the over-temperature protector shell, the memory alloy wire is located between the upper and lower metal contacts, the bottom end of the memory alloy wire is a fixed end, and the upper end of the memory alloy wire is a movable end, the memory alloy wire at the fixed end is always in contact with the metal contact below, and the temperature-sensitive layer is provided on the periphery of the memory alloy wire.

[0007] Furthermore, the memory alloy wire is a spiral structure.

[0008] Furthermore, the temperature sensing layer material is any one of ceramics, silicone rubber, and polyimide.

[0009] The present invention also provides a nickel-titanium memory alloy over-temperature protector application circuit, comprising a power input end, a protection circuit, a post-stage circuit, and a circuit ground loop, wherein the power input end, the protection circuit and the post-stage circuit are connected in series in sequence, the protection circuit is connected to the circuit ground loop, and the post-stage circuit is connected back to the power input end via the circuit ground loop; the protection circuit comprises a first resistor, a capacitor, a second resistor and a field effect transistor, the first resistor, the capacitor and the field effect transistor are connected in parallel in sequence and then connected in series with the second resistor and the nickel-titanium memory alloy over-temperature protector, in a normal temperature state, the power output from the power input end passes through the first resistor and the capacitor to the second resistor and the nickel-titanium memory alloy over-temperature protector, so that the connection end of the field effect tube and the second resistor is at a low level, the field effect tube is in a pass state, and the post-stage circuit obtains power; in an over-temperature state, the power output from the power input end passes through the first resistor and the capacitor to the second resistor and the nickel-titanium memory alloy over-temperature protector, so that the connection end of the field effect tube and the second resistor is at a high level, the field effect tube is in a circuit state, and the post-stage circuit disconnects the power supply.

[0010] Furthermore, the nickel-titanium memory alloy over-temperature protector includes an over-temperature protector shell, in which a memory alloy wire, a metal contact and a temperature-sensitive layer are arranged, the metal contacts are respectively arranged at the upper and lower ends of the over-temperature protector shell, the memory alloy wire is located between the upper and lower metal contacts, the bottom end of the memory alloy wire is a fixed end, and the upper end of the memory alloy wire is a movable end, the memory alloy wire at the fixed end is always in contact with the metal contact below, and the temperature-sensitive layer is arranged on the periphery of the memory alloy wire. When the nickel-titanium memory alloy over-temperature protector is connected to the protection circuit, it is directly connected to the wire in the protection circuit through the metal contact, and when the memory alloy wire undergoes a phase change, the power transmission in the protection circuit is turned on and off by turning on and off the metal contact.

[0011] The technical solution of the present invention has the following advantages:

[0012] 1. The connection between the memory alloy wire in the nickel-titanium memory alloy over-temperature protector of the present invention and the circuit does not require other auxiliary components, external leads, etc., and only relies on its own characteristics, namely phase change expansion and contraction, to achieve regulation of the circuit on and off. The traditional over-temperature protection circuit also needs to use a temperature sensor to detect the temperature and then use the processor to process the control signal to turn off the power supply. The response is not timely and fast enough, and signal errors are prone to occur during the process. If the processor is damaged or there is no processor installed in the circuit, the over-temperature protection circuit cannot be used. Nickel-titanium memory alloy is a special metal material that can restore its original shape under specific temperature conditions. It has excellent shape memory function, high elasticity and good corrosion resistance. Therefore, it has broad application prospects in the field of over-temperature protection.

[0013] 2. The protection circuit in the application circuit of the present invention has a simple structure and does not affect the overall arrangement of the subsequent circuit, namely the device working circuit. The protection circuit itself can be directly applied to the working circuits of various devices.

[0014] It should be appreciated that all combinations of the foregoing concepts, as well as additional concepts described in greater detail below, may be considered to be part of the inventive subject matter of the present disclosure, provided such concepts are not mutually inconsistent.

[0015] The foregoing and other aspects, embodiments and features of the present invention can be more fully understood from the following description in conjunction with the accompanying drawings. Other additional aspects of the present invention, such as the features and / or beneficial effects of the exemplary embodiments, will be apparent from the following description or learned from the practice of the specific embodiments according to the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings are not drawn to scale according to actual reference objects. In the accompanying drawings, each identical or nearly identical component shown in various figures may be represented by the same reference numeral. For the sake of clarity, not every component is labeled in each figure. Now, embodiments of various aspects of the present invention will be described by way of example and with reference to the accompanying drawings, in which:

[0017] Figure 1 It is a schematic diagram of the structure of the nickel-titanium memory alloy over-temperature protector of the present invention at room temperature.

[0018] Figure 2 It is a schematic structural diagram of the nickel-titanium memory alloy over-temperature protector of the present invention in an over-temperature state.

[0019] Figure 3 This is a circuit diagram of the nickel-titanium memory alloy over-temperature protector of the present invention.

[0020] Figure 4 This is a circuit diagram of the nickel-titanium memory alloy over-temperature protector of the present invention.

[0021] Description of Figure Numbers:

[0022] 1-metal contact; 2-memory alloy wire; 3-temperature sensing layer; 100-nickel-titanium memory alloy over-temperature protector; R1-first resistor; R2-second resistor; C1-capacitor; Q1-field effect tube. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein should be the common meaning understood by people with general skills in the field to which the present invention belongs.

[0024] The words "first", "second" and similar words used in the patent application specification and claims of the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, unless the context clearly indicates otherwise, the singular forms of "a", "an" or "the" and other similar words do not indicate a quantitative limitation, but indicate the existence of at least one. Words such as "include" or "comprise" mean that the elements or objects appearing before "include" or "comprise" cover the features, wholes, steps, operations, elements and / or components listed after "include" or "comprise", and do not exclude the existence or addition of one or more other features, wholes, steps, operations, elements, components and / or their collections. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0025] The traditional over-temperature protection circuit requires a temperature sensor, a PID processor and a switching power supply to achieve the function of circuit over-temperature protection, and the circuit structure is complicated and cumbersome. The over-temperature protection circuit after using the memory alloy over-temperature protector is also in urgent need of improvement.

[0026] Based on the above problems, an embodiment of the present invention provides a nickel-titanium memory alloy over-temperature protector and an application circuit thereof.

[0027] See also Figure 1 and Figure 2As shown, a nickel-titanium memory alloy over-temperature protector 100 includes an over-temperature protector shell, in which a memory alloy wire 2, a metal contact 1 and a temperature sensing layer 3 are arranged, the metal contact 1 is respectively arranged at the upper and lower ends of the over-temperature protector shell, the memory alloy wire 2 is located between the upper and lower metal contacts 1, the bottom end of the memory alloy wire 2 is a fixed end, and the upper end of the memory alloy wire 2 is a movable end, the memory alloy wire 2 at the fixed end is always in contact with the metal contact 1 below, and the temperature sensing layer 3 is arranged on the periphery of the memory alloy wire 2.

[0028] In some embodiments of the present invention, the memory alloy wire 2 is a spiral structure. Designing the memory alloy wire 2 into a spiral structure further increases the overall deformation degree, which is more conducive to the contraction and expansion of the memory alloy wire 2, ensuring timely circuit breaking and smooth power-on each time, and improving the response speed of the nickel-titanium memory alloy over-temperature protector 100.

[0029] In some embodiments of the present invention, the material of the temperature-sensitive layer 3 is any one of ceramic, silicone rubber, and polyimide. The memory alloy wire 2 itself can sense temperature changes, and the temperature-sensitive layer 3 is added on this basis to further improve the temperature sensing speed of the memory alloy wire 2, and further improve the reaction speed of the nickel-titanium memory alloy over-temperature protector 100 to turn on and off the power, thereby improving the reliability and safety of the circuit in the use of the over-temperature circuit.

[0030] The present invention also provides an application circuit of a nickel-titanium memory alloy over-temperature protector 100, comprising a power input terminal, a protection circuit, a subsequent circuit, and a circuit ground loop. The power input terminal, the protection circuit, and the subsequent circuit are connected in series in sequence, the protection circuit is connected to the circuit ground loop, and the subsequent circuit is connected back to the power input terminal via the circuit ground loop; the protection circuit comprises a first resistor R1, a capacitor C1, a second resistor R2, and a field effect transistor Q1, the first resistor R1, the capacitor C1, and the field effect transistor Q1 are connected in parallel in sequence, and then connected in series with the second resistor R2 and the nickel-titanium memory alloy over-temperature protector 100. In the normal temperature state, the power output from the power input end passes through the first resistor R1 and the capacitor C1 to the second resistor R2 and the nickel-titanium memory alloy over-temperature protector 100, so that the connection end of the field effect tube Q1 and the second resistor R2 is at a low level, the field effect tube Q1 is in a pass state, and the subsequent circuit obtains power; in the over-temperature state, the power output from the power input end passes through the first resistor R1 and the capacitor C1 to the second resistor R2 and the nickel-titanium memory alloy over-temperature protector 100, so that the connection end of the field effect tube Q1 and the second resistor R2 is at a high level, the field effect tube Q1 is in an open circuit state, and the subsequent circuit disconnects the power.

[0031] Furthermore, the nickel-titanium memory alloy over-temperature protector 100 includes an over-temperature protector shell, in which a memory alloy wire 2, a metal contact 1 and a temperature-sensitive layer 3 are arranged, the metal contact 1 is respectively arranged at the upper and lower ends of the over-temperature protector shell, the memory alloy wire 2 is located between the upper and lower metal contacts 1, the bottom end of the memory alloy wire 2 is a fixed end, and the upper end of the memory alloy wire 2 is a movable end, the memory alloy wire 2 at the fixed end is always in contact with the metal contact 1 below, and the temperature-sensitive layer 3 is arranged on the periphery of the memory alloy wire 2. When the nickel-titanium memory alloy over-temperature protector 100 is connected to the protection circuit, it is directly connected to the wire in the protection circuit through the metal contact 1, and when the memory alloy wire 2 undergoes a phase change, the power transmission in the protection circuit is turned on and off by turning on and off the metal contact 1.

[0032] The working principle of the over-temperature protection circuit in the present invention is: the power input end transmits power to the field effect tube Q1Q1, and at this time, the nickel-titanium memory alloy over-temperature protector 100 at room temperature is in a normal state of conduction, that is, at this time, the memory alloy wires 2 in the nickel-titanium memory alloy over-temperature protector 100 are in direct contact with the metal contact sheet 1, and the metal contact sheet 1 is directly connected to the wire in the protection circuit, so at this time, the nickel-titanium memory alloy over-temperature protector 100 is energized, so that the field effect tube Q1 is also in a conduction state, and the subsequent circuit obtains the power from the power supply through the field effect tube Q1, and realizes the working state through the circuit ground loop.

[0033] When the ambient temperature exceeds the protection temperature, the memory alloy wire 2 in the nickel-titanium memory alloy over-temperature protector 100 will immediately undergo a phase change and then shrink, and the upper end of the memory alloy wire 2 will be disconnected from the metal contact 1 above. Since the metal contact 1 is directly connected to the wire in the protection circuit, the nickel-titanium memory alloy over-temperature protector 100 directly changes from a passage state to an open circuit state. At this time, the field effect tube QI is in an open circuit state through the first resistor R1 and the capacitor C1. The subsequent circuit connected to the rear end of the field effect tube Q1 cannot obtain power and thus stops working. The first resistor R1 and the capacitor C1 serve as the pull-up resistor and the capacitor C1 of the field effect tube Q1, ensuring that the field effect tube Q1 is disconnected when the nickel-titanium memory alloy over-temperature protector 100 is open circuited.

[0034] When the ambient temperature returns to normal, the memory alloy wire 2 in the nickel-titanium memory alloy over-temperature protector 100 also undergoes a phase change and expands back to a normal state. The upper end of the memory alloy wire 2 re-contacts the upper metal contact 1, connecting the wire in the protection circuit, and the nickel-titanium memory alloy over-temperature protector 100 returns to the on state. The field effect tube Q1 switches back to the on state through the nickel-titanium memory alloy over-temperature protector 100 and the first resistor R1 and capacitor C1, and the power transmitted by the subsequent circuit through the field effect tube Q1 also starts working again.

[0035] The normal temperature state described in the present invention is the temperature state within the normal ambient temperature range required for the corresponding subsequent circuit to work, and the over-temperature state is the temperature state when the ambient temperature exceeds the normal ambient temperature required for the subsequent circuit to work. The phase change temperature range of the memory alloy wire can be selected and adapted according to the normal ambient temperature range required for different subsequent circuits to work.

[0036] During the entire process of power on and off, the connection between the memory alloy wire 2 in the nickel-titanium memory alloy over-temperature protector 100 and the circuit does not require other auxiliary components, external leads, etc., and only relies on its own characteristics, namely phase change expansion and contraction, to achieve the regulation of circuit on and off. The traditional over-temperature protection circuit also needs to detect the temperature with the help of a temperature sensor and then process the control signal through the processor to turn off the power supply. The response is not timely and fast enough, and signal errors are prone to occur during the process. If the processor is damaged or there is no processor installed in the circuit, the over-temperature protection circuit cannot be used. Nickel-titanium memory alloy is a special metal material that can restore its original shape under specific temperature conditions. It has excellent shape memory function, high elasticity and good corrosion resistance, so it has broad application prospects in the field of over-temperature protection.

[0037] The nickel-titanium memory alloy over-temperature protector 100 of the present invention utilizes this characteristic of the nickel-titanium memory alloy and realizes automatic cutting off of the subsequent circuit when the device is overheated by precisely controlling the phase change temperature of the memory alloy, thereby effectively avoiding device damage and safety accidents.

[0038] There are still some technical bottlenecks in the design and application of memory alloy over-temperature protectors on the current market. The present invention optimizes the structural design of the memory alloy over-temperature protector, making it lower in cost and more widely used. The metal contact 1 is directly connected to the wire, so that the memory alloy over-temperature protector can be directly used by fixing it in any over-temperature protection circuit.

[0039] The patent document with patent number ZL202222114950.X discloses a secondary over-temperature protection circuit and a battery over-temperature protector. The disclosed secondary over-temperature protection circuit can only be applied to battery circuits and cannot be applied to conventional circuits. If the temperature sensing device in the circuit is damaged, the entire circuit cannot be used. However, if the nickel-titanium memory alloy over-temperature protector 100 in the present invention is damaged, it will not affect the normal use of the circuit. If the nickel-titanium memory alloy over-temperature protector 100 in the present invention is damaged, the memory alloy wire 2 loses its phase change characteristics, and the change in ambient temperature cannot cause the memory alloy wire 2 to deform. The memory alloy wire 2 is always in its normal original form, that is, at this time, the upper end of the memory alloy wire 2 is always connected to the upper metal contact 1. At this time, the nickel-titanium memory alloy over-temperature protector 100 is equivalent to an energized wire in the protection circuit, so the field effect tube Q1 is always energized to transmit electricity to the subsequent circuit, and the subsequent circuit can continue to work, avoiding the situation where the nickel-titanium memory alloy over-temperature protector 100 is damaged at normal ambient temperature and the subsequent circuit cannot work.

[0040] In summary, the nickel-titanium memory alloy over-temperature protector of the present invention has the advantages of high sensitivity, rapid response, precise temperature control, miniaturization and intelligence. Its application circuit can meet the working circuit of any equipment requiring over-temperature protection, and can meet the urgent needs of modern industry for efficient, safe and reliable protection technology.

[0041] Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. A person with ordinary knowledge in the technical field to which the present invention belongs may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the definition of the claims.

Claims

1. A nickel-titanium memory alloy over-temperature protector, comprising an over-temperature protector housing, characterized in that: The over-temperature protector shell contains a memory alloy wire, a metal contact and a temperature-sensitive layer. The metal contacts are respectively arranged at the upper and lower ends of the over-temperature protector shell. The memory alloy wire is located between the upper and lower metal contacts. The bottom end of the memory alloy wire is a fixed end, and the upper end of the memory alloy wire is a movable end. The memory alloy wire at the fixed end is always in contact with the metal contact below, and the temperature-sensitive layer is arranged on the periphery of the memory alloy wire.

2. The nickel-titanium memory alloy over-temperature protector according to claim 1, characterized in that: The memory alloy wire is a spiral structure.

3. The nickel-titanium memory alloy over-temperature protector according to claim 1, characterized in that: The temperature sensing layer is made of any one of ceramics, silicone rubber and polyimide.

4. A nickel-titanium memory alloy over-temperature protector application circuit, characterized in that: It includes a power input end, a protection circuit, a post-stage circuit, and a circuit ground loop. The power input end, the protection circuit and the post-stage circuit are connected in series in sequence. The protection circuit is connected to the circuit ground loop, and the post-stage circuit is connected back to the power input end through the circuit ground loop; the protection circuit includes a first resistor, a capacitor, a second resistor and a field effect transistor. The first resistor, the capacitor and the field effect transistor are connected in parallel in sequence and then connected in series with the second resistor and the nickel-titanium memory alloy over-temperature protector. Under normal temperature conditions, the power output from the power input end passes through the first resistor and the capacitor to the second resistor and the nickel-titanium memory alloy over-temperature protector, so that the connection end of the field effect tube and the second resistor is at a low level, the field effect tube is in a pass state, and the post-stage circuit obtains power; under over-temperature conditions, the power output from the power input end passes through the first resistor and the capacitor to the second resistor and the nickel-titanium memory alloy over-temperature protector, so that the connection end of the field effect tube and the second resistor is at a high level, the field effect tube is in a circuit state, and the post-stage circuit disconnects the power supply.

5. The nickel-titanium memory alloy over-temperature protector application circuit according to claim 4, characterized in that: The nickel-titanium memory alloy over-temperature protector includes an over-temperature protector shell, in which a memory alloy wire, a metal contact and a temperature-sensitive layer are arranged, the metal contact pieces are respectively arranged at the upper and lower ends of the over-temperature protector shell, the memory alloy wire is located between the upper and lower metal contacts, the bottom end of the memory alloy wire is a fixed end, the upper end of the memory alloy wire is a movable end, the memory alloy wire at the fixed end is always in contact with the metal contact piece below, the temperature-sensitive layer is arranged on the periphery of the memory alloy wire, and when the nickel-titanium memory alloy over-temperature protector is connected to the protection circuit, it is directly connected to the wire in the protection circuit through the metal contact piece, and when the memory alloy wire undergoes a phase change, the power transmission in the protection circuit is turned on and off by turning on and off with the metal contact piece.

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