A mechanical differential temperature fire detection device

Abstract

The present invention belongs to the technical field of fire detection and alarm technology, and specifically relates to a mechanical differential temperature fire detection device. The detection device includes a housing provided with a bellows, with a bellows base and a bellows cover encapsulated at both ends of the bellows. The bellows, the bellows base, and the bellows cover cooperate to form a closed inner cavity. The bellows base is fixed to the housing, and the bellows cover is slidably assembled in the housing. The bellows has a tube wall that enables internal and external heat exchange, and the housing is provided with a communication channel that communicates with the outside of the bellows. The detection device also includes a pull member for stretching the bellows, the pull member being provided on the bellows cover and having a fusible section that disconnects when the temperature reaches a melting point, causing the bellows to contract. The bellows base is provided with an air outlet for connecting to a pressure element. When the rate of increase of the ambient temperature exceeds a set threshold and / or the ambient temperature exceeds the melting point, gas in the inner cavity is ejected from the air outlet to trigger the pressure element.

Description

Technical Field

[0001] The present invention belongs to the technical field of fire detection and alarm, and in particular relates to a mechanical differential temperature fire detection device. Background Art

[0002] Temperature-sensing fire detection devices detect changes in ambient temperature and issue an alarm signal when the temperature around a point or circuit within the warning range is abnormal. Currently, common fire detection devices fall into two categories: electronic and mechanical.

[0003] Electronic temperature-sensing fire detection devices that rely on electrical signals for control, such as photoelectric detection, distributed fiber optic temperature measurement, multi-source composite detection, activation detection, and image monitoring, are all electronic temperature-sensing fire detection devices. For example, Chinese Utility Model Patents with Authorization Publication Numbers CN203276461U and CN201203924Y are both electronic temperature-sensing fire detection devices that rely on electrical signals for control. The detection principle of electronic temperature-sensing fire detection devices is to convert temperature changes into electrical signals and output them. Electronic temperature-sensing fire detection devices are easy to use and widely used. Electronic temperature-sensing fire detection devices are generally divided into fixed-temperature detection devices, differential-temperature detection devices, and fixed-temperature differential detection devices. Fixed-temperature detection devices generate an alarm when the ambient temperature exceeds a set threshold. Differential-temperature detection devices monitor temperature changes over a period of time and generate an alarm if the temperature rise rate exceeds the set threshold. Fixed-temperature differential detection devices integrate the relevant structures of both fixed-temperature and differential-temperature detection devices.

[0004] Mechanical heat-sensing fire detection devices include glass bulb and bimetallic types. Glass bulb detectors use a temperature-sensing glass bulb to sense temperature. When the temperature reaches a certain threshold, the bulb shatters, triggering an alarm. Bimetallic detectors use thermal deformation of a metal plate to generate an alarm. For example, Chinese invention patent application CN112270804A relates to a bimetallic detector. Mechanical heat-sensing fire detection devices convert temperature changes into mechanical action and output the output. They are typically fixed-temperature detectors.

[0005] Both types of fire detection devices in existing technology have drawbacks. Electronic heat-sensing fire detection devices rely on electricity for normal operation. If power is lost, the detection device instantly ceases to function, making them unsuitable for environments with unstable or unreliable power supply. Conventional mechanical heat-sensing fire detection devices typically operate at a constant temperature and are unable to detect rapid temperature changes that do not reach the set temperature. They also react slowly to rapid temperature changes and are unable to detect differential temperatures. Summary of the Invention

[0006] The purpose of the present invention is to provide a mechanical differential temperature fire detection device to solve the technical problems in the prior art that electronic temperature-sensing fire detection devices cannot work after power failure and mechanical fire detection devices have a slow response speed to rapid temperature changes.

[0007] To achieve the above-mentioned objectives, the technical solution of the mechanical differential temperature fire detection device provided by the present invention is as follows: a mechanical differential temperature fire detection device includes a housing, a bellows is provided in the housing, a bellows base and a bellows cover are encapsulated at both ends of the bellows, the bellows, the bellows base and the bellows cover cooperate to form a closed inner cavity; the bellows base is fixedly mounted on the housing, the bellows cover is slidably assembled in the housing, the bellows has a tube wall for realizing internal and external heat exchange, and the housing is provided with a connecting channel connected to the outside of the bellows; the detection device also includes a pulling member disposed on the housing and stretching the bellows, the pulling member is disposed on the bellows cover, the pulling member is provided with a fusible section, the fusible section is made of a fusible material and disconnects when the temperature reaches the melting temperature to allow the bellows to contract; the bellows base is provided with an air outlet for connecting to a pressure element, when the rate of increase of the ambient temperature exceeds a set threshold and / or the ambient temperature is higher than the melting temperature, the gas in the inner cavity is ejected from the air outlet to trigger the pressure element.

[0008] Beneficial effects: The present invention utilizes the corrugated tube wall of the bellows to achieve rapid heat exchange inside and outside the bellows; at the same time, the fusible section automatically melts when the melting temperature threshold is set, so that the bellows can shrink. When the rate of increase of the ambient temperature is higher than the set threshold but the ambient temperature is not higher than the melting temperature, the temperature inside the bellows rises rapidly. Since the fusible section has not melted, the space in the inner cavity of the bellows remains unchanged. Due to the rapid rise in temperature, the gas pressure in the bellows rises rapidly, and the dynamic pressure of the gas in the bellows is large. Eventually, the gas is ejected from the air outlet and triggers the pressure element. When the rate of increase of the ambient temperature is lower than the set threshold but the ambient temperature has reached the melting temperature, the fusible section is melted, the bellows shrinks, the space in the inner cavity of the bellows shrinks rapidly, the gas is compressed, and the kinetic energy is large. Eventually, the gas is ejected from the air outlet and triggers the pressure element. The detection device of the present invention converts temperature changes into pressure signals and outputs them externally. It can be used normally without power supply. In addition, it utilizes the characteristics of rapid heat exchange inside and outside the bellows and rapid contraction of the bellows after the fusible section melts, and is more sensitive to the temperature change rate and the absolute value of the temperature.

[0009] Preferably, the detection device further includes an elastic member, which is used to drive the bellows to contract and deform after the fusible section melts and disconnects. With the elastic member, after the fusible section melts, the bellows can contract not only by its own elastic force but also by being driven by the elastic member. This results in a faster contraction speed, a faster reduction in the bellows' internal cavity, and a higher gas pressure, ensuring that the pressure element is triggered. The provision of the elastic member improves the reliability of the detection device.

[0010] Preferably, the elastic member presses against the side of the bellows cover facing away from the bellows base, and is used to be compressed when the pulling member stretches the bellows. The elastic member is arranged outside the bellows, and no processing operation is required inside the bellows, which makes assembly more convenient.

[0011] Preferably, a support body is provided in the housing, the pulling member passes through the support body, and the elastic member is elastically pressed between the bellows cover and the support body. The support body is provided in the housing to support the elastic member, and the support body is closer to the bellows cover, so that the overall size of the elastic member can be smaller.

[0012] Preferably, the elastic member is a spring, and the bellows cover is provided with a positioning boss for the corresponding end of the spring to be fitted. The positioning boss can position the spring to prevent the spring from being skewed or other undesirable conditions.

[0013] Preferably, the pulling member is arranged at the center of the bellows cover, and the spring is sleeved on the outside of the pulling member.

[0014] Preferably, the pull member includes a first support rod fixed to the bellows cover and a second support rod fixed to the housing, with the fusible section connecting the first and second support rods. Since only a portion of the pull member comprises the fusible section, only the fusible section needs to be replaced for repeated use, eliminating the need to replace the first and second support rods, resulting in lower costs.

[0015] Preferably, both ends of the fusible section are provided with hook holes, and the first support rod and the second support rod are hooked in the corresponding hook holes. The first support rod and the second support rod are connected to the fusible section by hooking, and the connection method is relatively simple.

[0016] Preferably, the housing is provided with a flange surface, and the bellows base is a flange plate, which is fixed to the housing by bolts. The bellows base is mounted on the housing by flange connection, which is simple to install and easy to replace.

[0017] Preferably, the air outlet hole is a threaded hole, and the threaded hole is used to be connected to the air outlet pipeline. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1This is a schematic diagram of the mechanical differential temperature fire detection device provided by the present invention when the fusible material is not melted;

[0019] Figure 2 for Figure 1 Schematic diagram of the AA section;

[0020] Figure 3 This is a schematic diagram of the mechanical differential temperature fire detection device provided by the present invention after the fusible material has melted;

[0021] Figure 4 for Figure 3 Schematic diagram of the BB section.

[0022] Description of reference numerals:

[0023] 1. Shell; 2. Bellows; 3. Bellows base; 4. Bellows cover; 5. Spring; 6. Fusible material; 7. Pulling piece; 8. Support body; 9. First support rod; 10. Second support rod; 11. Mounting ear plate; 12. Air vent; 13. Connecting hole; 14. Grid post; 15. Disc. DETAILED DESCRIPTION

[0024] In order to make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present invention and are not intended to limit the present invention. That is, the embodiments described herein are only some embodiments of the present invention, not all embodiments. Generally, the components of the embodiments of the present invention described and illustrated in the drawings herein may be arranged and designed in various different configurations.

[0025] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but is merely intended to represent selected embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative work are within the scope of protection of the present invention.

[0026] It should be noted that relational terms such as "first" and "second" that may appear are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, terms such as "include", "comprise" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, elements defined by the phrase "including a..." do not exclude processes or methods that include the elements.

[0027] In the description of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0028] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "provided with" and "provided with" should be understood in a broad sense. For example, the object "provided with" may be a part of the main body, or may be arranged separately from the main body and connected to the main body. The connection may be detachable or non-detachable. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0029] The present invention is described in further detail below with reference to the examples.

[0030] Specific embodiment 1 of the mechanical differential temperature fire detection device provided by the present invention:

[0031] Mechanical differential temperature fire detection devices utilize the corrugated structure of the bellows wall to accelerate temperature transfer between the inside and outside of the bellows. A pull element containing fusible material maintains the bellows in a stretched state. When the ambient temperature rises rapidly but does not reach the melting point of the fusible material, the temperature of the gas inside the bellows rises rapidly. The internal volume of the bellows remains unchanged, causing the pressure inside the bellows to rise rapidly. The gas in the bellows is rapidly ejected through the vents, creating a high dynamic pressure that impacts pressure components (such as pneumatic valves and pressure detectors). The pressure components control the alarm and trigger an alarm. When the ambient temperature rises slowly but does not reach the melting point of the fusible material, the gas in the bellows rises slowly and does not trigger the pressure component. When the ambient temperature rises to the melting point of the fusible material, the fusible material melts, and the bellows contracts and deforms under its own contraction and the action of the spring. The internal volume of the bellows rapidly decreases, causing the pressure inside the cavity to rise rapidly. The gas in the bellows is rapidly ejected through the vents, creating a high dynamic pressure that impacts the pressure component. The mechanical differential and constant temperature fire detection device of the present invention can convert temperature changes into pressure signal outputs, can work without power supply, and can meet the detection needs of differential temperature and constant temperature.

[0032] like Figures 1 to 4 As shown, the mechanical differential temperature fire detection device (hereinafter referred to as the detection device) includes a housing 1 with three mounting lugs 11 fixed to the exterior of the housing 1. These lugs 11 secure the housing 1 to a fixed object. A bellows 2 is housed within the housing 1. A bellows base 3 and bellows cover 4 are secured to each end of the bellows 2 by welding. The bellows base 3, bellows cover 4, and bellows 2 form a closed inner cavity. For ease of description, the bellows 2 is defined as extending vertically, with the bellows base 3 located at the upper end and the bellows cover 4 located at the lower end. The bellows base 3 is fixedly mounted to the housing 1. Specifically, the housing 1 has a flange surface, and the bellows base 3 is actually a flange plate. The two are secured together by bolts. The bellows base 3 has an air outlet 12, which communicates with the inner cavity. The air outlet 12 is threaded. During use, the air outlet 12 is connected to an air outlet line, which in turn is connected to a pressure element.

[0033] Bellows cover 4 slides vertically within housing 1. Housing 1 defines a communication channel connecting the interior and exterior of housing 1. This communication channel comprises a plurality of communication holes 13 evenly distributed throughout housing 1. The exterior of bellows 2 is connected to the environment via the communication channel, ensuring that the temperature outside bellows 2 is consistent with the ambient temperature. In other embodiments, the communication channel may be a slotted hole, for example.

[0034] A pulling member 7 is connected between the bellows cover 4 and the inner wall of the lower end of the shell 1. The pulling member 7 pulls the bellows cover 4 so that the bellows 2 is in a stretched state. The pulling member 7 is located at the center of the bellows cover 4. Specifically, the shell 1 includes a disc 15 connected by four circumferentially spaced grid posts 14. The pulling member 7 includes a first support rod 9 connected to the bottom of the bellows cover 4, a second support rod 10 connected to the disc 15, and a fusible material 6 connecting the first support rod 9 and the second support rod 10. The fusible material 6 in this embodiment is a fusible alloy, such as a bismuth alloy. In other embodiments, the fusible material 6 can also be other materials, such as wax. It should be noted that in fact, many materials can be melted. The fusible material 6 here refers to a material that can melt by itself when the ambient temperature rises to an alarm value (set threshold value). The alarm value is set manually. When the ambient temperature rises to a set threshold (either rapidly or slowly), the fusible material 6 melts, the pull member 7 disconnects, and the upward contraction of the bellows 2 is no longer restricted. Specifically, the fusible material 6 is a disk with hook holes at both the top and bottom ends. The lower end of the first support rod 9 and the upper end of the second support rod 10 are hooked onto the fusible material 6, respectively. In actual use, different types and materials of fusible material 6 are selected according to different alarm values.

[0035] When the fusible material 6 is melted, the contraction of the bellows 2 is no longer restricted. To drive the bellows 2 to contract, a spring 5 is provided below the bellows 2. Specifically, a support body 8 is fixed in the housing 1. The spring 5 here is a compression spring, with the lower end of the spring 5 supported on the support body 8 and the upper end pressing against the bellows cover 4. The first support rod 9 in the pulling member 7 passes through the spring 5 and the support body 8 and is connected to the bellows cover 4. When the fusible material 6 is not melted, the pulling member 7 pulls the bellows cover 4 downward and compresses the spring 5. When the fusible material 6 is melted, the spring 5 presses the bellows cover 4 upward, causing the bellows 2 to contract.

[0036] In order to position the spring 5 , the middle position of the bottom of the bellows cover 4 is protruded downward to form a positioning boss, and the spring 5 is sleeved on the positioning boss.

[0037] The use process of the present invention is as follows: Figure 1 and Figure 2 As shown, when the ambient temperature rises rapidly within a short period of time, the gas within the inner cavity of bellows 2 expands due to the heat. The inner cavity space of bellows 2 remains unchanged, causing the pressure within the cavity to rise rapidly. The gas is ejected through outlet 12. After the pressure is amplified by the pressure amplification mechanism, it triggers the pressure element to complete the fire alarm and activate the fire fighting mechanism. The pressure element can be a pressure collector that collects pressure change signals; or it can be a pneumatic valve that opens when the pressure reaches the opening pressure.

[0038] like Figure 3 and Figure 4 As shown, when the ambient temperature rises slowly over time and reaches the set threshold (related to the fusible material and the alarm temperature), the fusible material 6 melts, the spring 5 returns to its initial state from the compressed state, and the bellows 2 returns to its initial state from the stretched state, causing the gas in the bellows 2 to be rapidly compressed. The inner cavity space of the bellows 2 becomes smaller, causing the pressure in the cavity to rise rapidly, and the gas is ejected through the outlet hole 12.

[0039] In this embodiment, the spring 5 constitutes an elastic member that drives the bellows 2 to contract, and the location of the fusible material 6 constitutes a fusible section of the pulling member 7 .

[0040] Specific embodiment 2 of the mechanical differential temperature fire detection device provided by the present invention:

[0041] The difference from Example 1 lies in the type of air outlet 12. In Example 1, air outlet 12 is a threaded hole connected to an air outlet pipeline, which in turn is connected to a pressure element. In this embodiment, the air outlet can be a plain hole to connect to the air outlet pipeline. A quick connector is welded to the air outlet hole and connected to the air outlet pipeline via the quick connector.

[0042] Specific embodiment 3 of the mechanical differential temperature fire detection device provided by the present invention:

[0043] The difference from Example 1 lies in the assembly method of the housing 1 and the bellows base 3. In Example 1, the housing 1 has a flange surface, and the bellows base 3 is a flange plate, and the housing 1 and the bellows base 3 are connected together by bolts. In this embodiment, the bellows base has external threads on the outside, and the inner wall of the housing has internal threads, and the bellows base is threadedly assembled to the housing. It should be noted that when using this assembly method, the bellows base and bellows must be installed first, and then the pull member is installed.

[0044] Specific embodiment 4 of the mechanical differential temperature fire detection device provided by the present invention:

[0045] The difference from Example 1 lies in the assembly method of the fusible section, the first support rod 9, and the second support rod 10. In Example 1, the first support rod 9 and the second support rod 10 are both hooked on the fusible section. In this embodiment, the first support rod and the second support rod can be welded to the fusible section. Specifically, the first support rod and the second support rod are inserted into the fusible section when the fusible section is in a molten state, and then assembled after cooling.

[0046] Specific embodiment 5 of the mechanical differential temperature fire detection device provided by the present invention:

[0047] The difference from Example 1 lies in the structure of the pull member 7. In Example 1, the pull member 7 includes a first support rod 9, a second support rod 10, and a fusible section. In this embodiment, the pull member is entirely a fusible section, the upper end of which is connected to the bellows cover and the lower end is connected to the housing.

[0048] Specific embodiment 6 of the mechanical differential temperature fire detection device provided by the present invention:

[0049] The difference from Example 1 lies in the number and arrangement of springs 5 ​​and pull members 7. In Example 1, the pull member 7 is located at the center of the bellows cover 4, and there is a single spring 5 that is sheathed around the pull member 7. In this embodiment, the pull member is located at the center of the bellows cover, and the spring is arranged around the pull member; in this case, multiple positioning bosses are provided on the bottom of the bellows cover. In other embodiments, there are multiple pull members, and the springs are sheathed around the pull members or staggered with the springs.

[0050] Specific embodiment 7 of the mechanical differential temperature fire detection device provided by the present invention:

[0051] The difference from Example 1 lies in the type of elastic member and how it cooperates with the bellows cover 4. In Example 1, the elastic member is a spring 5, and the bellows cover 4 has a positioning boss that cooperates with the spring 5. In this embodiment, the elastic member is a rubber block, and the pulling member extends through the rubber block. In this embodiment, the bellows cover no longer has a positioning boss.

[0052] Specific embodiment 8 of the mechanical differential temperature fire detection device provided by the present invention:

[0053] The difference from Example 1 lies in the arrangement of the elastic member. In Example 1, a support body is provided within the housing 1, and the elastic member is elastically press-fitted between the bellows cover 4 and the support body. In this embodiment, the support body is eliminated, and the lower end of the elastic member is supported on the housing, and the upper end is supported on the bellows cover.

[0054] Specific embodiment 9 of the mechanical differential temperature fire detection device provided by the present invention:

[0055] The difference from Example 1 lies in the placement of the elastic member. In Example 1, the elastic member is located on the side of the bellows cover 4 facing away from the bellows base 3. In this embodiment, the elastic member is located inside the bellows, with one end of the elastic member connected to the bellows base and the other end connected to the bellows cover. In this embodiment, the elastic member is a tension spring or an elastic strap.

[0056] Specific embodiment 10 of the mechanical differential temperature fire detection device provided by the present invention:

[0057] The difference from Example 1 lies in the driving force for the contraction and deformation of the bellows 2. In Example 1, the detection device includes an elastic member. When the pull member 7 is melted, the elastic member drives the bellows 2 to contract, and the bellows 2 itself also contracts. In this embodiment, the elastic member is eliminated. When the pull member is melted, the bellows contracts by its own elastic force.

[0058] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments without inventive effort, or replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A mechanical differential temperature fire detection device, characterized in that: The invention comprises a shell (1), wherein a bellows (2) is provided in the shell (1), and a bellows base (3) and a bellows cover (4) are encapsulated at both ends of the bellows (2), and the bellows (2), the bellows base (3) and the bellows cover (4) cooperate to form a closed inner cavity; the bellows base (3) is fixed on the shell (1), and the bellows cover (4) is slidably assembled in the shell (1); the bellows (2) has a tube wall for realizing internal and external heat exchange, and the shell (1) is provided with a communication channel communicating with the outside of the bellows (2); the detection device also comprises a tube provided on the shell ( 1) and a pulling piece (7) for stretching the bellows (2), the pulling piece (7) being arranged on the bellows cover (4), the pulling piece (7) being provided with a fusible section, the fusible section being made of a fusible material (6) and being disconnected when the temperature reaches a melting temperature to allow the bellows (2) to contract; an air outlet (12) for connecting to a pressure element is provided on the bellows base (3), when the rate of increase of the ambient temperature is higher than a set threshold value and / or the ambient temperature is higher than the melting temperature, the gas in the inner cavity is ejected from the air outlet (12) to trigger the pressure element.

2. The mechanical differential temperature fire detection device according to claim 1, characterized in that: The detection device also includes an elastic member, which is used to drive the bellows (2) to contract and deform after the fusible section melts and disconnects.

3. The mechanical differential temperature fire detection device according to claim 2, characterized in that: The elastic member presses against the side of the bellows cover (4) facing away from the bellows base (3), and the elastic member is used to be compressed when the pulling member (7) stretches the bellows (2).

4. The mechanical differential temperature fire detection device according to claim 3, characterized in that: A support body (8) is provided in the housing (1), the pulling member (7) passes through the support body (8), and the elastic member is elastically pressed between the bellows cover (4) and the support body (8).

5. The mechanical differential temperature fire detection device according to claim 3 or 4, characterized in that: The elastic member is a spring (5), and the bellows cover (4) is provided with a positioning boss for the corresponding end of the spring (5) to be fitted.

6. The mechanical differential temperature fire detection device according to claim 5, characterized in that: The pulling member (7) is arranged at the center of the bellows cover (4), and the spring (5) is sleeved on the outside of the pulling member (7).

7. The mechanical differential temperature fire detection device according to any one of claims 1 to 4, characterized in that: The pulling member (7) comprises a first support rod (9) fixed on the bellows cover (4) and a second support rod (10) fixed on the housing (1); the fusible section connects the first support rod (9) and the second support rod (10).

8. The mechanical differential temperature fire detection device according to claim 7, characterized in that: Both ends of the fusible section are provided with hook holes, and the first support rod (9) and the second support rod (10) are correspondingly hooked in the corresponding hook holes.

9. The mechanical differential temperature fire detection device according to any one of claims 1 to 4, characterized in that: The housing (1) is provided with a flange surface, and the bellows base (3) is a flange plate, which is fixed to the housing (1) by bolts.

10. The mechanical differential temperature fire detection device according to any one of claims 1 to 4, characterized in that: The air outlet hole (12) is a threaded hole, and the threaded hole is used to be connected to the air outlet pipeline.

Images