Temperature-sensitive trigger type fire fighting device based on liquid crystal elastomer fibers

Abstract

The invention belongs to the technical field of fire fighting equipment, and relates to a liquid crystal elastomer fiber-based temperature-sensitive trigger type fire fighting device, which comprises a support, a first movable arm, an LCEF, a deflector rod, a second movable arm, a fixed arm, a reset component, a firing pin and a fire extinguishing device, the first movable arm is arranged on the support, the left end is rotatably connected with the support, the right end is connected with the lower end of the LCEF, the upper end of the LCEF is connected with the support, and the lower end of the LCEF is connected with the fixed arm; the left end of the second movable arm is rotationally connected to the fixed arm, the right end of the second movable arm extends downwards to form a second hook body and is in hooked connection with the first hook body, the LCEF is heated and contracted to drive the first movable arm to rotate, when the angle exceeds a third threshold value, the driving lever is driven to rotate, and the two hook bodies are disconnected; the reset component drives the second movable arm to reset, and the firing pin impacts the fire extinguishing device switch. According to the invention, the LCEF is applied to the fire-fighting device, so that the problems of separation of detection and execution and response lag in a traditional fire-fighting system are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of fire-fighting equipment and relates to a temperature-sensitive trigger type fire-fighting device based on liquid crystal elastomer fibers. Background Art

[0002] In the field of firefighting equipment, existing temperature-sensitive trigger firefighting devices commonly suffer from issues such as the separation of detection and actuation mechanisms and delayed response. Traditional temperature detectors only provide an alarm function, requiring fire extinguishing devices to rely on additional circuit control, which carries the risk of failure due to circuit malfunction. For example, in traditional firefighting systems, temperature detectors use thermistors or bimetallic strips to detect temperature changes and trigger alarm signals, but the activation of fire sprinklers relies on an independent circuit control module. If the circuit is damaged or short-circuited due to a fire, the fire extinguishing function will be unavailable.

[0003] The thermally actuated materials currently used in the fire protection field (such as shape memory alloys) also have obvious defects: their response temperature is relatively single, and it is difficult to flexibly adjust according to the temperature changes in different fire scenarios; at the same time, the deformation rate of the material is usually less than 10%, which may affect the reliability of the fire protection device due to insufficient power when driving the fire extinguishing device.

[0004] Liquid crystal elastomers (LCEs), as smart materials, have attracted attention in the field of temperature-sensitive actuation in recent years due to their unique thermal response properties and high deformation capacity (deformation rate can reach over 30%). However, existing LCE-based temperature-sensitive trigger devices have limited functionality and have yet to integrate detection and fire extinguishing functions. For example:

[0005] Nanyang Technological University has developed a novel flame-actuated soft actuator based on a multilayer liquid crystal elastomer (LCE) / hydrogel composite (Ind. Eng. Chem. Res. 63, 1432–1441 (2024)). The researchers designed a fire detection module based on the LCE-hydrogel composite actuator. This module consists of a curved LCE-hydrogel composite film (with a conductive copper tape on one end), an LED light, and a circuit. While the module can achieve temperature-sensitive switching and high-temperature alarms through strain mismatch caused by thermal deformation of the LCE, it is not directly integrated with fire extinguishing devices (such as sprinklers or fire extinguishing agent release mechanisms) and still requires external circuitry or mechanical structures to extinguish the fire.

[0006] Research from South China University of Technology (Machine vision-enabled surface temperature mappingbased on thermo-responsive cholesteric liquid crystal elastomerarrays.J.Mater.Chem.A13,3484–3494(2025).) shows that thermoresponsive cholesteric LCE can achieve surface temperature monitoring through machine vision, but its application is still limited to the field of temperature sensing and does not involve the integration of fire extinguishing actuators.

[0007] In summary, the application of LCE-based temperature-sensitive trigger devices in the fire protection field in the existing technology is still in the laboratory research stage, and has not yet formed a product that integrates fire detection and emergency fire extinguishing functions. Summary of the Invention

[0008] The purpose of the present invention is to solve the deficiencies in the prior art and to provide a temperature-sensitive trigger fire-fighting device based on liquid crystal elastomer fibers.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions:

[0010] A temperature-sensitive trigger fire-fighting device based on liquid crystal elastomer fiber, comprising a bracket, a first movable arm, LCEF (liquid crystal elastomer fiber), a lever, a second movable arm, a fixed arm, a reset component, a striker, and a fire-extinguishing device;

[0011] The first movable arm is horizontally arranged on the bracket, with the left end being rotatably connected to the bracket and the rotation center axis Y1 being parallel to the front-back direction, the right end being connected to the lower end of the LCEF, and the upper end of the LCEF being connected to the bracket;

[0012] The lever is horizontally arranged on the bracket, with the middle portion being rotatably connected to the bracket and the rotation center axis Y2 being parallel to the front-to-back direction. The left end is located above the left side of the first movable arm and extends upward to form a first hook body, and the right end is located directly above the first movable arm and extends downward to form an extension portion.

[0013] The second movable arm is arranged on the fixed arm with its left side lower and its right side higher, and its left end is rotatably connected to the fixed arm with its rotation center axis parallel to the front-back direction. The right end extends downward to form a second hook body, and the second hook body is hooked with the first hook body.

[0014] The LCEF shrinks due to heat, driving the first movable arm to rotate around the central axis Y1. When the rotation angle of the first movable arm is greater than or equal to a third threshold, the first movable arm drives the lever to rotate around the central axis Y2, causing the second hook to disconnect from the first hook.

[0015] The fixed arm is mounted on the bracket;

[0016] The reset component is used to drive the second movable arm to reset when the second hook body is disconnected from the first hook body;

[0017] The striker is arranged obliquely with the left side higher and the right side lower, and the right end is connected to the right end of the second movable arm;

[0018] The installation position of the fire extinguishing device satisfies the following conditions: during the resetting process of the second movable arm, the striker can strike the switch of the fire extinguishing device.

[0019] As the preferred technical solution:

[0020] The temperature-sensitive trigger fire-fighting device based on liquid crystal elastomer fiber as described above also includes an alarm light, a strain gauge and an electromagnetic relay; the alarm light is installed on the bracket; the strain gauge is attached to the first movable arm to detect the strain signal of the first movable arm; the electromagnetic relay is used to control the opening and closing of the fire-extinguishing device.

[0021] The temperature-sensitive trigger fire-fighting device based on liquid crystal elastomer fiber as described above further includes a single-chip microcomputer module;

[0022] The single-chip computer module is connected to the alarm light, strain gauge and electromagnetic relay at the same time. When the strain gauge sends the first strain signal, the alarm light and electromagnetic relay are turned off. When the strain gauge sends the second strain signal, the alarm light is turned on. When the strain gauge sends the third strain signal, the electromagnetic relay is turned on.

[0023] When the strain gauge sends a first strain signal, the rotation angle of the first movable arm is less than a first threshold; when the strain gauge sends a second strain signal, the rotation angle of the first movable arm is greater than or equal to the first threshold and less than a second threshold; when the strain gauge sends a third strain signal, the rotation angle of the first movable arm is greater than or equal to the second threshold and less than a third threshold.

[0024] In the temperature-sensitive trigger fire-fighting device based on liquid crystal elastomer fiber as described above, the first threshold value is 3°, the second threshold value is 10°, and the third threshold value is 30°.

[0025] The aforementioned temperature-sensitive trigger fire-fighting device based on liquid crystal elastomer fiber, wherein the bracket comprises a base bracket, an upper bracket and an intermediate bracket;

[0026] The base bracket and the upper bracket are both arranged horizontally, the upper bracket is located above the base bracket, and the two are connected by an intermediate bracket;

[0027] A shaft a parallel to the front-back direction is fixedly mounted on the base bracket, and the left end of the first movable arm is movably sleeved on the shaft a;

[0028] The upper end of the LCEF is connected to the upper bracket;

[0029] The middle bracket is provided with a first hollow area, in which a shaft b parallel to the front-back direction is fixedly installed. The shift lever passes through the first hollow area, and the middle part is movably sleeved on the shaft b.

[0030] The fixed arm and the warning light are mounted on the base bracket.

[0031] In the temperature-sensitive trigger fire-fighting device based on liquid crystal elastomer fiber as described above, the fixed arm is horizontally mounted on the base bracket; the left end of the second movable arm is rotatably connected to the left end of the fixed arm.

[0032] As described above, in a temperature-sensitive trigger fire-fighting device based on liquid crystal elastomer fiber, a second hollow area is provided at the left end of the fixed arm, and an axis c parallel to the front-to-back direction is fixedly installed in the second hollow area. The left end of the second movable arm is located in the second hollow area and is movably sleeved on the axis c.

[0033] In the temperature-sensitive trigger fire-fighting device based on liquid crystal elastomer fiber as described above, the reset component is a torsion spring, and the torsion spring is connected to the second movable arm and the fixed arm at the same time.

[0034] As described above, a temperature-sensitive triggered fire-fighting device based on liquid crystal elastomer fiber has a phase transition temperature of LCEF of 64±5°C and an initial thermal decomposition temperature of 330±10°C. This material has unique thermal response characteristics, can undergo significant shape changes within a specific temperature range, and has good stability and repeatability, providing a strong guarantee for the reliable operation of the fire-fighting device.

[0035] Beneficial effects

[0036] This invention integrates liquid crystal elastomer fibers into firefighting devices, leveraging their thermally responsive deformation to directly drive fire extinguishing devices. This not only solves the problems of detection and execution separation and response lag in traditional firefighting systems, but also overcomes the limitations of materials such as shape memory alloys. Specific advantages are as follows:

[0037] Passive triggering: Leveraging the natural thermal sensitivity of liquid crystal elastomer fibers, this technology enables mechanical emergency activation without the need for an external power source. In the event of a fire, even if external circuits are damaged by high temperatures, the firefighting device automatically activates thanks to the temperature response of the liquid crystal elastomer fibers, significantly improving system reliability in emergency situations.

[0038] Multi-level response: A four-level temperature warning system provides a progressive response to varying degrees of temperature rise—from initial temperature warning to alarm, and then to activation of fire extinguishing devices, gradually increasing the intensity of the response. This design improves system adaptability and enables more precise response to fires of varying sizes.

[0039] Safe structure: The pure mechanical linkage structure replaces the traditional complex circuit control, completely avoiding the risk of device failure due to circuit short circuit, burning and other faults, ensuring stable operation in harsh environments such as high temperature and smoke.

[0040] Environmentally friendly: Liquid crystal elastomer fiber has programmable response function and can be customized according to actual needs to adapt to various firefighting scenarios; at the same time, it has good natural degradation performance, is not easy to produce harmful substances in the natural environment, and has a low impact on the ecological environment.

[0041] Figures in the specification

[0042] Figure 1 Schematic diagram of the side structure of the fire-fighting device of the present invention (when the first movable arm is rotated to a certain angle);

[0043] Figure 2 Schematic diagram of the three-dimensional structure of the fire-fighting device of the present invention (when the first movable arm is rotated to a certain angle);

[0044] Figure 3 、 Figure 4 It is a structural schematic diagram of the fixed arm and the second movable arm of the fire-fighting device of the present invention;

[0045] Figure 5 Schematic diagram of the operation logic of the fire-fighting device of the present invention, in which T is the ambient temperature, and S1, S2, S3, and S4 correspond to different working conditions respectively;

[0046] Figure 6 is the rotation angle of the first movable arm of the fire-fighting device of the present invention at a specific temperature;

[0047] Figure 7 The DSC image of the liquid crystal elastomer fiber used in the present invention shows the thermal effect changes of the liquid crystal elastomer fiber during heating and cooling;

[0048] Figure 8 A physical diagram of the fire-fighting device of the present invention;

[0049] Among them, 1-base bracket, 2-upper bracket, 3-first movable arm, 4-LCEF, 5-lever, 6-alarm light, 7-striker, 8-second movable arm, 9-fixed arm, 12-microcontroller module, 13-strain gauge, 14-torsion spring. DETAILED DESCRIPTION

[0050] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0051] A temperature-sensitive trigger fire-fighting device based on liquid crystal elastomer fiber, such as Figures 1 to 4 、 Figure 8 As shown, it includes a bracket, a first movable arm 3, an LCEF 4, a lever 5, a second movable arm 8, a fixed arm 9, a reset component, a striker 7, a fire extinguishing device, an alarm light 6, a strain gauge 13, an electromagnetic relay (for controlling the opening and closing of the fire extinguishing device) and a single-chip computer module 12;

[0052] like Figure 1 、 Figure 2 As shown, the bracket consists of a base bracket 1, an upper bracket 2 and an intermediate bracket;

[0053] The base bracket 1 and the upper bracket 2 are both arranged horizontally, the upper bracket 2 is located above the base bracket 1, and the two are connected by an intermediate bracket;

[0054] An axis a parallel to the front-to-back direction is fixedly mounted on the base bracket 1; a first hollow area is provided on the intermediate bracket, and an axis b parallel to the front-to-back direction is fixedly mounted in the first hollow area; a fixed arm 9 is horizontally mounted on the base bracket 1, and a second hollow area is provided at its left end, and an axis c parallel to the front-to-back direction is fixedly mounted in the second hollow area;

[0055] like Figure 1 、 Figure 2 As shown, the first movable arm 3 is arranged horizontally, with its left end movably sleeved on the shaft a, and its right end connected to the lower end of the LCEF 4, and the upper end of the LCEF 4 is connected to the upper bracket 2;

[0056] The lever 5 passes horizontally through the first hollow area, with the middle portion movably sleeved on the shaft b. The left end is located above the left side of the first movable arm 3 and extends upward to form a first hook body, and the right end is located directly above the first movable arm 3 and extends downward to form an extension portion.

[0057] The second movable arm 8 is arranged obliquely with the left side lower and the right side higher, the left end of which is located in the second hollow area and is movably sleeved on the shaft c, and the right end of which extends downward to form a second hook body, which is hooked with the first hook body;

[0058] The striker 7 is arranged obliquely with the left side higher and the right side lower, and the right end is connected to the right end of the second movable arm 8;

[0059] like Figure 1 As shown, the warning light 6 is mounted on the base bracket 1;

[0060] The phase transition temperature of LCEF 4 is 64±5°C, and the initial thermal decomposition temperature is 330±10°C. It can be prepared by referring to the method in the prior art. The DSC image of LCEF used in the present invention is as follows: Figure 7 As shown;

[0061] The LCEF 4 contracts due to heat, driving the first movable arm 3 to rotate about the central axis Y1 (axis a). When the rotation angle of the first movable arm 3 is greater than or equal to a third threshold, the first movable arm 3 drives the lever 5 to rotate about the central axis Y2 (axis b), causing the second hook to disconnect from the first hook.

[0062] like Figure 3 、 Figure 4 As shown, the reset component is a torsion spring 14, which is connected to the second movable arm 8 and the fixed arm 9 at the same time, and is used to drive the second movable arm 8 to reset when the second hook body is disconnected from the first hook body;

[0063] The installation position of the fire extinguishing device satisfies the following conditions: during the resetting process of the second movable arm 8, the striker 7 can strike the switch of the fire extinguishing device;

[0064] like Figure 2 As shown, the strain gauge 13 is attached to the first movable arm 3 and is used to detect the strain signal of the first movable arm 3; any common strain gauge on the market can be used, and the present invention uses the RK10 strain gauge produced by Shenzhen Luojia Technology Co., Ltd.;

[0065] The single-chip computer module 12 is connected to the alarm light 6, the strain gauge 13, and the electromagnetic relay at the same time. When the strain gauge 13 sends a first strain signal, the alarm light 6 and the electromagnetic relay are turned off. When the strain gauge 13 sends a second strain signal, the alarm light 6 is turned on. When the strain gauge 13 sends a third strain signal, the electromagnetic relay is turned on.

[0066] When the strain gauge 13 sends a first strain signal, the rotation angle of the first movable arm 3 is less than a first threshold value; when the strain gauge 13 sends a second strain signal, the rotation angle of the first movable arm 3 is greater than or equal to the first threshold value and less than a second threshold value; when the strain gauge 13 sends a third strain signal, the rotation angle of the first movable arm 3 is greater than or equal to the second threshold value and less than a third threshold value;

[0067] The first threshold is 3°, the second threshold is 10°, and the third threshold is 30°;

[0068] like Figure 5 、 Figure 6As shown, when the ambient temperature is T<50°C, the rotation angle of the first movable arm 3 is in the range of 0° to 3° (excluding 3°). After the strain gauge 13 detects the strain, it sends a first strain signal to the single-chip computer module 12. After receiving the first strain signal, the single-chip computer module 12 determines that the ambient temperature is normal and does not perform additional operations.

[0069] When the ambient temperature is 50°C ≤ T < 80°C, the rotation angle of the first movable arm 3 is in the range of 3° to 10° (excluding 10°). After the strain gauge 13 detects the strain, it sends a second strain signal to the single-chip computer module 12. After receiving the second strain signal, the single-chip computer module 12 determines that the ambient temperature is abnormal and sends an alarm signal to prompt the user to check for abnormal conditions.

[0070] When the ambient temperature is 80°C ≤ T < 110°C, and the rotation angle of the first movable arm 3 reaches 10° to 30° (excluding 30°), the strain gauge 13 detects the strain and sends a third strain signal to the single-chip computer module 12. After receiving the third strain signal, the single-chip computer module 12 determines that the ambient temperature is abnormal. In addition to the alarm, the system will also activate the fire extinguishing device.

[0071] When the ambient temperature is 110℃≤T, the rotation angle of the first movable arm 3 exceeds 30°, and the fire extinguishing device is directly forced to open. The specific action process is: the first movable arm 3 drives the lever 5 to rotate, the lever 5 releases the second movable arm 8, and the second movable arm 8 immediately drives the striker 7 to rotate. The striker 7 hits the fire extinguishing device switch and mechanically opens the fire extinguishing device. This forced opening mechanism can ensure that the fire is extinguished quickly when the fire is large, and effectively avoid the problem of the fire extinguishing device failing to start due to circuit failure.

[0072] After the fire extinguishing operation is completed or the fault is eliminated, the striker 7 and the lever 5 can be manually reset to restore the fire fighting device to its initial state for subsequent reuse.

Claims

1. A temperature-sensitive trigger fire-fighting device based on liquid crystal elastomer fiber, characterized in that: It comprises a bracket, a first movable arm (3), an LCEF (4), a lever (5), a second movable arm (8), a fixed arm (9), a reset component, a striker (7) and a fire extinguishing device; The first movable arm (3) is horizontally arranged on the bracket, the left end of which is rotatably connected to the bracket and the rotation center axis Y1 is parallel to the front-back direction, the right end of which is connected to the lower end of the LCEF (4), and the upper end of the LCEF (4) is connected to the bracket; The lever (5) is horizontally arranged on the bracket, the middle portion is rotatably connected to the bracket and the rotation center axis Y2 is parallel to the front-back direction, the left end is located above the left side of the first movable arm (3) and extends upward to form a first hook body, and the right end is located directly above the first movable arm (3) and extends downward to form an extension portion; The second movable arm (8) is arranged on the fixed arm (9) with its left side lower and its right side higher, and is tilted. The left end is rotatably connected to the fixed arm (9) and the rotation center axis is parallel to the front-back direction. The right end extends downward to form a second hook body, and the second hook body is hooked with the first hook body. The LCEF (4) contracts due to heat, driving the first movable arm (3) to rotate around the rotation center axis Y1. When the rotation angle of the first movable arm (3) is greater than or equal to a third threshold value, the first movable arm (3) drives the shifting rod (5) to rotate around the rotation center axis Y2, so that the second hook body is disconnected from the first hook body. The fixed arm (9) is mounted on the bracket; The reset component is used to drive the second movable arm (8) to reset when the second hook body is disconnected from the first hook body; The striker (7) is arranged obliquely with the left side higher and the right side lower, and the right end is connected to the right end of the second movable arm (8); The installation position of the fire extinguishing device satisfies the following conditions: during the resetting process of the second movable arm (8), the striker (7) can strike the switch of the fire extinguishing device.

2. A temperature-sensitive trigger fire-fighting device based on liquid crystal elastomer fiber according to claim 1, characterized in that: It also includes an alarm light (6), a strain gauge (13) and an electromagnetic relay; the alarm light (6) is mounted on the bracket; the strain gauge (13) is attached to the first movable arm (3) and is used to detect the strain signal of the first movable arm (3); and the electromagnetic relay is used to control the opening and closing of the fire extinguishing device.

3. The temperature-sensitive trigger fire-fighting device based on liquid crystal elastomer fiber according to claim 2, characterized in that: Also includes a single chip microcomputer module (12); The single chip computer module (12) is connected to the alarm light (6), the strain gauge (13) and the electromagnetic relay at the same time. When the strain gauge (13) sends a first strain signal, the alarm light (6) and the electromagnetic relay are turned off. When the strain gauge (13) sends a second strain signal, the alarm light (6) is turned on. When the strain gauge (13) sends a third strain signal, the electromagnetic relay is turned on. When the strain gauge (13) sends a first strain signal, the rotation angle of the first movable arm (3) is less than a first threshold value; when the strain gauge (13) sends a second strain signal, the rotation angle of the first movable arm (3) is greater than or equal to the first threshold value and less than a second threshold value; when the strain gauge (13) sends a third strain signal, the rotation angle of the first movable arm (3) is greater than or equal to the second threshold value and less than a third threshold value.

4. The temperature-sensitive trigger fire-fighting device based on liquid crystal elastomer fiber according to claim 3, characterized in that: The first threshold is 3°, the second threshold is 10°, and the third threshold is 30°.

5. The temperature-sensitive trigger fire-fighting device based on liquid crystal elastomer fiber according to claim 2, characterized in that: The bracket is composed of a base bracket (1), an upper bracket (2) and an intermediate bracket; The base support (1) and the upper support (2) are both arranged horizontally, the upper support (2) is located above the base support (1), and the two are connected via an intermediate support; A shaft a parallel to the front-back direction is fixedly mounted on the base bracket (1), and the left end of the first movable arm (3) is movably sleeved on the shaft a; The upper end of the LCEF (4) is connected to the upper bracket (2); A first hollow area is provided on the middle bracket, and a shaft b parallel to the front-back direction is fixedly installed in the first hollow area. The shift rod (5) passes through the first hollow area, and the middle part is movably sleeved on the shaft b. The fixed arm (9) and the warning light (6) are both mounted on the base bracket (1).

6. The temperature-sensitive trigger fire-fighting device based on liquid crystal elastomer fiber according to claim 5, characterized in that: The fixed arm (9) is horizontally mounted on the base bracket (1); the left end of the second movable arm (8) is rotatably connected to the left end of the fixed arm (9).

7. The temperature-sensitive trigger fire-fighting device based on liquid crystal elastomer fiber according to claim 6, characterized in that: The left end of the fixed arm (9) is provided with a second hollow area, in which a shaft c parallel to the front-back direction is fixedly installed. The left end of the second movable arm (8) is located in the second hollow area and is movably sleeved on the shaft c.

8. The temperature-sensitive trigger fire-fighting device based on liquid crystal elastomer fiber according to claim 1, characterized in that: The reset component is a torsion spring (14), and the torsion spring (14) is connected to the second movable arm (8) and the fixed arm (9) at the same time.

9. The temperature-sensitive trigger fire-fighting device based on liquid crystal elastomer fiber according to claim 1, characterized in that: The phase transition temperature of LCEF(4) is 64±5℃, and the onset thermal decomposition temperature is 330±10℃.

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