Thrust actuator explosion-proof test device and thrust actuator explosion-proof test method

Abstract

The invention belongs to the technical field of actuator explosion-proof testing, and particularly relates to a thrust actuator explosion-proof testing device and a thrust actuator explosion-proof testing method. The explosion-proof testing device comprises a carrier and an elastic stop mechanism installed on the carrier, and the surface of the carrier is provided with an installation area used for fixing the thrust actuator. During testing, the front end of the push rod of the thrust actuator is opposite to the elastic stop mechanism, and the elastic stop mechanism can apply elastic acting force to the push rod to prevent the push rod from advancing. The maximum thrust of a push rod of the thrust actuator is adjusted to rated working condition thrust in advance, the thrust actuator is fixed to a carrier and aligned with an elastic stop mechanism, the whole thrust actuator is arranged in an explosion-proof test tank filled with combustible gas, power is supplied to drive the push rod to stretch out and abut against the elastic stop mechanism, and under the synergistic effect of elastic resistance and an internal clutch mechanism of the actuator, the thrust actuator is driven to rotate. And the push rod forms axial wriggling, so that the thrust continuously fluctuates near a rated value, thereby accurately simulating a rated working condition in a limited space, and solving the problem that the limited test space and the real load are considered at the same time.

Description

Technical Field

[0001] This invention belongs to the field of explosion-proof testing technology for actuators, specifically relating to an explosion-proof testing device and method for thrust actuators. Background Technology

[0002] Currently, in home environments in Europe, North America, and other countries and regions, built-in appliances have become a mainstream design trend. These products strive for seamless integration with overall kitchen cabinets, creating a clean and unified visual effect by eliminating exposed door handles. In the domestic market, with the upgrading of consumption and the popularization of smart home concepts, built-in appliances have also become an important development direction for the home appliance industry. More and more families are beginning to choose integrated kitchen and living room appliance designs, and the demand for handle-less doors continues to grow.

[0003] However, this integrated design generally faces a common challenge: users lack a direct point of leverage when opening the door. To address this, automatic door opening functionality was developed, using a drive mechanism to first push the door open a small angle, facilitating subsequent manual opening.

[0004] Existing automatic door opening solutions primarily rely on purely mechanical structures, such as pressing the door to activate a built-in spring-loaded sliding rail mechanism to open the door. While these structures are relatively inexpensive, they have significant limitations, providing limited thrust and resulting in a small initial opening angle and a subpar user experience. With technological advancements, higher-performance electric automatic door opening mechanisms are gradually entering the market. These electric actuators offer greater thrust and wider opening angles, better meeting the needs of modern embedded home appliances, and their application in mid-to-high-end home appliances both domestically and internationally is steadily increasing.

[0005] However, for electric automatic door opening mechanisms to enter the mainstream global market (especially in regions with strict safety standards such as Europe and the United States), they must pass stringent explosion-proof safety certifications. Even in China, with the improvement of home appliance safety standards, explosion-proof performance has become an important assessment indicator for high-end embedded home appliances. This brings new challenges to product development and testing. On the one hand, there are few laboratories in China with qualifications for explosion-proof certification of home appliances, and testing resources are scarce, making it difficult to meet the needs of enterprises for efficient R&D. On the other hand, the existing explosion-proof test tanks are generally small in volume, unable to accommodate the entire home appliance for testing, nor can they accommodate the door mechanism for testing. In addition, traditional testing methods cannot balance safety and the realism of operating condition simulation. If a rigid barrier is used to replace the door, although it can fit the space of the test tank, it cannot truly reproduce the stress state of the actuator under rated operating conditions, resulting in a large deviation between the test results and actual performance.

[0006] Therefore, how to construct a test environment that can both ensure test safety and accurately simulate the actual working load of the actuator within a limited explosion-proof test space has become a technical problem that urgently needs to be solved in the research and development of embedded home appliance electric actuators both domestically and internationally. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides an explosion-proof testing device and method for thrust actuators. It aims to solve the problems that existing explosion-proof testing tanks are limited in volume and cannot accommodate actual doors, and that traditional testing methods cannot balance testing safety with the realism of simulated rated operating conditions of thrust actuators. This invention provides a solution for explosion-proof testing of thrust actuators that is adaptable to limited spaces and can accurately reproduce real working loads.

[0008] A first aspect of the present invention is to provide an explosion-proof testing device for a thrust actuator, comprising a carrier and an elastic stop mechanism mounted on the carrier; the carrier is provided with a mounting mechanism for fixing the thrust actuator; the elastic stop mechanism is used to abut against the front end of the push rod of the thrust actuator during testing and to apply an elastic stop force to the push rod to impede its forward movement.

[0009] As a further optimization, the carrier is flat, and the mounting mechanism includes multiple mounting holes on the carrier, as well as fastening screws that cooperate with the mounting holes to secure the thrust actuator.

[0010] As a further optimization, the mounting holes are arranged in a dense array on the carrier.

[0011] As a further optimization, the carrier is made of aluminum alloy with a thickness of 3-10mm.

[0012] As a further optimization, the elastic stop mechanism includes a fixed block fixed to the carrier and a floating block elastically assembled with the fixed block, the floating block being used to abut the front end of the push rod.

[0013] As a further optimization, the elastic stop mechanism also includes at least one limit screw and a compression spring; the threaded end of the limit screw passes through the floating block and is threadedly connected to the fixed block, so that the floating block can slide along the axis of the limit screw; the compression spring is sleeved on the limit screw, and its two ends abut against the floating block and the fixed block respectively.

[0014] As a further optimization, the elastic stopping mechanism includes a fixing block fixed to the carrier, a blind hole is provided on the side wall of the fixing block, and a compression spring is provided in the blind hole.

[0015] As a further optimization, the inner diameter of the blind hole is slightly smaller than the outer diameter of the compression spring, so that the blind hole and the compression spring form an interference fit.

[0016] As a further optimization, the elastic stop mechanism is positioned such that when the thrust actuator is fixed to the carrier, the axis of its push rod remains coaxial with the axis of the floating block in the elastic stop mechanism.

[0017] A second aspect of the present invention is to provide a method for testing the explosion-proof properties of a thrust actuator, employing the aforementioned explosion-proof testing device for thrust actuators, and comprising the following steps: S1. Thrust actuator pre-processing: Adjust the maximum thrust of the push rod to F1 according to the rated working thrust F1 of the thrust actuator; S2. Device assembly: Fix the pre-treated thrust actuator onto the carrier and make the front end of the push rod opposite the elastic stop mechanism; S3. Test environment setup: Place the assembly obtained in S2 into an explosion-proof test container and fill the container with a flammable gas of a preset concentration. S4. Simulated rated working condition test: Power is supplied to the thrust actuator to drive its push rod to extend and abut against the elastic stop mechanism, so that the push rod forms a back-and-forth creeping state under the combined action of the elastic stop force and the clutch mechanism inside the actuator. S5. Test Termination: After the preset test duration is reached, the power is cut off and the test is terminated.

[0018] As a further optimization, in step S1, the thrust actuator is a push rod actuator with an adjustable clutch torque transmission upper limit. By adjusting the preload of the clutch torque transmission mechanism in its transmission assembly, the maximum thrust of the push rod is adjusted to the rated working condition thrust F1.

[0019] As a further optimization, in step S2, during assembly, the orientation of the thrust actuator is adjusted so that the axis of the push rod is in the same straight line as the direction of the elastic force provided by the elastic stop mechanism.

[0020] As a further optimization scheme, in step S4, the push rod squeezes the elastic stop mechanism during the extension process to generate a reverse force. When the reverse force reaches the rated thrust of the thrust actuator, the clutch mechanism inside the actuator slips, the push rod retracts slightly and then extends again, forming an axial creep state, so that the push rod thrust fluctuates near the rated thrust.

[0021] As a further optimization, in step S4, the power supply process includes timing control: first, power is supplied to the position sensing element of the push rod of the thrust actuator (such as a micro switch, photoelectric sensor, or other sensing element used to monitor the position of the push rod), and then power is supplied to its drive motor after a preset interval; the preset interval for supplying power to the position sensing element of the push rod is preferably 0.2 seconds.

[0022] As a further optimization, in step S5, the power supply to the drive motor is first cut off, and the power supply to the position sensing element of the push rod is cut off after the drive motor stops running.

[0023] Beneficial effects Compared with existing technologies, the explosion-proof testing device for thrust actuators provided by this invention can solve the problem of limited volume in explosion-proof test tanks that cannot accommodate actual doors, when used with an adjustable thrust actuator. This device can accurately simulate the load characteristics of a thrust actuator under rated operating conditions. Utilizing the synergistic effect of the elastic stop mechanism and the actuator's clutch mechanism, the push rod maintains a stable creeping state during testing, ensuring that the thrust always fluctuates near the rated value, thus realistically replicating the actual working conditions of the actuator in an explosion-proof environment. This device cleverly utilizes the inherent clutch slippage characteristic within the thrust actuator. Through cooperation with the external elastic stop mechanism, it transforms the continuous rated thrust test, which originally required a large stroke, into the axial creeping of the push rod within a limited space, fundamentally overcoming the limitation of explosion-proof test tank volume on testing feasibility. Furthermore, the device has a simple and compact structure, strong versatility, and significantly improves the accuracy, safety, and efficiency of testing, providing a reliable and convenient solution for the explosion-proof certification of thrust actuators. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the assembly of the explosion-proof testing device and the actuator for the thrust actuator.

[0025] Figure 2 This is a schematic diagram of the explosion-proof testing device for thrust actuators.

[0026] Figure 3 This is a schematic diagram showing the cooperation between the elastic stop mechanism and the front end of the push rod of the thrust actuator.

[0027] Figure 4 This is a schematic diagram showing the cooperation between the elastic stop mechanism and the front end of the thrust actuator push rod in another embodiment.

[0028] Figure 5 This is an assembly diagram of the explosion-proof test device and the actuator for the thrust actuator in another embodiment.

[0029] In the figure, 1 is the base plate; 2 is the elastic stop mechanism; 3 is the mounting hole; 4 is the fastening screw; 21 is the fixing block; 22 is the floating block; 23 is the limit screw; and 24 is the compression spring. Detailed Implementation

[0030] The present invention is further illustrated below with specific embodiments. These embodiments are exemplary and intended to illustrate the problem and explain the present invention, and are not intended to be limiting. Example

[0031] The explosion-proof testing device for thrust actuators disclosed in this embodiment aims to solve the problems of existing explosion-proof testing tanks being small in size, unable to accommodate actual doors, and difficult to simulate the rated operating conditions of thrust actuators. For example... Figure 1 , Figure 2 , Figure 3As shown, the explosion-proof test device for the thrust actuator mainly includes a base plate 1 as a carrier and an elastic stop mechanism 2 mounted on the base plate 1.

[0032] The substrate 1 is preferably made of aluminum alloy with a thickness of 3-10mm to meet the requirements of lightweight and sufficient strength. The substrate 1 has a thrust actuator fixing area, and a mounting mechanism is provided within or around this area to fix the thrust actuator to the substrate 1. In this embodiment, the mounting mechanism includes multiple mounting holes 3 on the substrate 1 and fastening screws 4 that can form a threaded connection with the mounting holes 3. The positions of these mounting holes 3 are specifically designed according to the structural characteristics of the thrust actuator to adapt to its shape. The fastening screws 4 pass through mounting ears on the thrust actuator housing to fix the thrust actuator to the substrate 1. In other embodiments, the mounting holes 3 can also be arranged in a dense array on the substrate 1 to accommodate different models and specifications of thrust actuators, improving the versatility of the device.

[0033] The elastic stop mechanism 2 is mounted on the base plate 1, and the position of the elastic stop mechanism 2 is opposite to the front end of the push rod of the thrust actuator. When the push rod extends forward and abuts against the elastic stop mechanism 2, the elastic stop mechanism 2 can apply an elastic stop force to the push rod to prevent it from continuing to move forward.

[0034] In this embodiment, the elastic stop mechanism 2 includes a fixed block 21 fixed to the base plate 1, and a floating block 22 is assembled on one side of the fixed block 21. A set of limit screws 23, with their threaded ends passing through the floating block 22, are threadedly connected to threaded holes on the side wall of the fixed block 21, allowing the floating block 22 to slide along the axis of the limit screws 23 within a preset axial length range. Each limit screw 23 is fitted with a compression spring 24, one end of which abuts against the floating block 22, and the other end abuts against the fixed block 21, thereby applying a spring force away from the fixed block 21 to the floating block 22. The floating block 22 is used to abut against the front end of the thrust actuator push rod during testing.

[0035] In other embodiments, such as Figure 4 and Figure 5 As shown, the elastic stop mechanism 2 can also be simply constructed from a fixed block 21 and a compression spring 24. The fixed block 21 is also fixed to the base plate 1, and a horizontally arranged blind hole is provided on the side wall of the fixed block 21 for inserting the compression spring 24. The inner diameter of the blind hole is set to be slightly smaller than the outer diameter of the compression spring 24, which can not only keep the compression spring 24 stably in the blind hole and prevent it from falling out, but also facilitate the replacement of compression springs 24 with different spring force specifications to adapt to the explosion-proof testing requirements of more types of thrust actuators.

[0036] The following describes the explosion-proof testing method for thrust actuators based on the explosion-proof testing device for thrust actuators. This testing method is applicable to thrust actuators with adjustable maximum thrust of the push rod. Such thrust actuators have wide applications in the prior art, such as in smart refrigerators and built-in ovens, used to drive automatic door opening. Taking a modular push rod actuator with electrical components disclosed in patent CN218324474U as an example, the core structure of this push rod actuator includes a power unit, a transmission assembly, and a clutch mechanism. The power unit consists of a reduction gearbox and a drive motor. The transmission assembly includes a drive shaft, a driven shaft, a connecting rod, a spring, and an adjusting nut. The clutch mechanism transmits torque through the wavy clutch teeth on the mating surfaces of the drive shaft and the driven shaft. A microswitch is connected to the PCB circuit board of the electrical components. The push rod has a first trigger part and a second trigger part corresponding to the microswitch. The microswitch can determine the extension or retraction state of the push rod by sensing the touch of the trigger part, providing a position signal for the actuator's operation control. The adjustment of the maximum thrust of the actuator depends on the adjusting nut. Rotating the adjusting nut changes the clamping force of the spring on the connecting rod, thereby adjusting the upper limit of torque transmission on the clutch tooth surface between the drive shaft and the driven shaft, ultimately achieving control over the maximum thrust of the actuator. The explosion-proof testing method for the thrust actuator of this invention fully utilizes the structural features of this type of thrust actuator by combining it with the testing device.

[0037] Before testing, the thrust actuator needs to be pre-processed. The maximum thrust of the push rod in such actuators is usually greater than the rated thrust under operating conditions, requiring adjustment to bring it to the rated thrust. First, obtain the standard push rod thrust F1 under rated operating conditions when driving a load from the product technical documentation of the actuator under test. Then, based on the obtained standard push rod thrust F1, adjust the maximum thrust of the thrust actuator's push rod to F1. Taking a modular push rod actuator with electrical components disclosed in patent CN218324474U as an example, clockwise rotation of the adjusting nut increases the spring clamping force on the connecting rod, enhancing the torque transmission capability between the drive shaft and the driven shaft, thus increasing the maximum push rod thrust. Counterclockwise rotation decreases the spring clamping force, reducing the maximum push rod thrust. By adjusting the upper limit of torque transmission on the clutch teeth between the drive shaft and the driven shaft by turning the adjusting nut, the maximum push rod thrust is adjusted to the rated thrust under operating conditions.

[0038] After adjusting the actuator thrust, assemble the test device and the actuator. Place the pre-treated thrust actuator in the thrust actuator fixing area of ​​the base plate 1, adjust the actuator position so that the axis of the push rod is coaxial with the axis of the floating block 22 in the elastic stop mechanism 2, and then fix the thrust actuator to the base plate 1 through the mounting mechanism. For example, take the fastening screw 4, pass it through the mounting lug on the actuator housing and thread it into the corresponding mounting hole 3 on the base plate 1, and tighten the fastening screw 4 gradually with uniform force until the actuator housing and the base plate 1 are tightly fitted and there is no sign of looseness. After assembly, manually push the push rod to make a short reciprocating motion and observe whether the floating block 22 can slide smoothly along the axis of the limit screw 23 to ensure that the compression spring 24 of the elastic stop mechanism 2 can be compressed and reset normally.

[0039] After assembly, the entire assembly of the test device and actuator is moved into the explosion-proof test chamber to create an environment that meets the requirements for explosion-proof testing. First, clean the inside of the explosion-proof test chamber to ensure that there are no foreign objects inside. Place the device stably inside the chamber, and fill the explosion-proof test chamber with a flammable gas (a mixture of propane and air) of a preset concentration according to the IEC60079 series standards, and then seal it. Use sealed terminals to establish an electrical connection between the external power supply and the electrical components of the actuator.

[0040] The power supply system is activated to provide operating power to the actuator to simulate rated operating conditions. The power supply process follows a preset timing sequence. First, power is supplied to the microswitch of the actuator to maintain a preset operating current (e.g., 200mA). 0.2s after the microswitch is powered on, power is supplied to the drive motor of the actuator, causing the motor to drive the reduction gearbox to rotate. The reduction gearbox drives the drive shaft and driven shaft to rotate through the transmission assembly, thereby driving the push rod to extend forward axially. As the push rod continues to extend, its front end gradually approaches and abuts against the floating block 22 of the elastic stop mechanism 2. The floating block 22 slides along the axis of the limit screw 23 towards the fixed block 21 under the action of the thrust, compressing the compression spring 24. The compression spring 24 generates a reverse elastic stop force. At this time, the push rod will be in a creeping state within a short distance range limited by the limit screw 23. This state is achieved through the cooperation of the elastic stop mechanism 2 of the testing device and the clutch mechanism of the actuator. As the push rod moves forward and compresses the elastic stop mechanism 2, the force applied by the elastic stop mechanism 2 to the push rod continuously increases. The clutch teeth of the drive shaft and the driven shaft slip due to the transmitted torque exceeding the upper limit. The push rod loses driving force and briefly retracts. During slippage, the torque transmission between the drive shaft and the driven shaft is interrupted. The compression spring 24 pushes the push rod to move slightly in the opposite direction. The driven shaft re-engages with the clutch teeth of the drive shaft, and the push rod regains driving force and extends forward. This cycle forms a creeping motion. At this time, the push rod thrust fluctuates slightly around the rated thrust F1, accurately simulating the rated operating condition of the actuator.

[0041] The test is terminated after the preset duration (e.g., 5 minutes or 1 hour of motor power-on). First, the power supply to the drive motor is cut off. After the motor has completely stopped running, the power supply to the microswitch is cut off after a 0.2-second interval. Then, the exhaust valve of the explosion-proof test tank is opened to release flammable gas. Finally, the explosion-proof test tank is opened, and the test device and actuator are removed. Data is collected during the test according to the test standard and used as the basis for explosion-proof certification.

[0042] In summary, this invention, through the cooperation of an elastic stop mechanism and the actuator's built-in clutch mechanism, induces axial creep in the push rod, causing its output thrust to fluctuate continuously around the rated value. This, in a mechanical sense, highly realistically simulates the rated load condition of pushing open a real door. It is precisely this dynamic force balance and simulation achieved within a limited stroke that eliminates the need for actual large-scale door opening during the entire testing process, minimizing the space required for testing and fundamentally solving the limitation of explosion-proof test tank volume on explosion-proof certification of large household appliance actuators. Therefore, this invention provides a solution for explosion-proof testing of thrust actuators that combines high-fidelity simulation with high space efficiency.

[0043] The above embodiments are exemplary and are intended to illustrate the technical concept and features of the present invention, so that those skilled in the art can understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made according to the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A thrust executor explosion-proof testing device, characterized in that, The device comprises a carrier and an elastic stop mechanism (2) mounted on the carrier; the carrier is provided with a mounting mechanism for fixing a thrust actuator; the elastic stop mechanism (2) is used to abut against the front end of the push rod of the thrust actuator and apply an elastic stop force to the push rod to prevent the push rod from advancing during testing.

2. The thrust executor explosion proof testing device of claim 1, wherein, The elastic stop mechanism (2) comprises a fixed block (21) fixed to the carrier and a floating block (22) elastically assembled with the fixed block (21), and the floating block (22) is used to abut against the front end of the push rod.

3. The thrust executor explosion proof testing device of claim 2, wherein, The elastic stop mechanism (2) further comprises at least one limiting screw (23) and a compression spring (24); the threaded end of the limiting screw (23) is screwed into the fixed block (21) after passing through the floating block (22), so that the floating block (22) can slide along the axis of the limiting screw (23); the compression spring (24) is sleeved on the limiting screw (23), and the two ends of the compression spring (24) abut against the floating block (22) and the fixed block (21), respectively.

4. The burst test device of claim 1, wherein, The elastic stop mechanism (2) comprises a fixed block (21) fixed to the carrier, a blind hole is formed in the side wall of the fixed block (21), and a compression spring (24) is arranged in the blind hole; the inner diameter of the blind hole is slightly smaller than the outer diameter of the compression spring (24), so that an interference fit is formed between the blind hole and the compression spring (24).

5. A method of explosion-proof testing of a thrust actuator, characterized in that The device comprises a carrier and an elastic stop mechanism (2) mounted on the carrier; the carrier is provided with a mounting mechanism for fixing a thrust actuator; the elastic stop mechanism (2) is used to abut against the front end of the push rod of the thrust actuator and apply an elastic stop force to the push rod to prevent the push rod from advancing during testing. S1, thrust actuator pretreatment: according to the rated working thrust F1 of the thrust actuator, the maximum thrust of the push rod is adjusted to F1; S2, device assembly: the pretreated thrust actuator is fixed on the carrier, and the front end of the push rod is opposite to the elastic stop mechanism (2); S3, test environment building: the assembly obtained in S2 is placed in an explosion-proof test tank, and a combustible gas with a predetermined concentration is filled into the tank; S4, simulation of rated working condition test: power is supplied to the thrust actuator to drive the push rod to extend and abut against the elastic stop mechanism (2), so that the push rod forms a forward and backward peristaltic state under the combined action of the elastic stop force and the internal clutch mechanism of the actuator; S5, test termination: after the predetermined test time is reached, the power is cut off, and the test is terminated.

6. The method of burst testing a thrust executor of claim 5, wherein, In step S1, the thrust actuator is a push rod actuator with adjustable upper limit of clutch torque transmission, and by adjusting the pretightening force of the clutch torque transmission mechanism in the transmission assembly, the maximum thrust of the push rod is adjusted to the rated working thrust F1.

7. The method of burst testing a thrust executor of claim 5, wherein, In step S2, the orientation of the thrust actuator is adjusted during assembly, so that the axis of the push rod is in the same straight line as the direction of the elastic force provided by the elastic stop mechanism (2).

8. The method of burst testing a thrust executor of claim 5, wherein, In step S4, the push rod squeezes the elastic stop mechanism (2) to generate a reverse force during extension, and when the reverse force reaches the rated thrust of the thrust actuator, the internal clutch mechanism of the actuator slips, the push rod retracts slightly and then extends again, forming an axial peristaltic state, so that the thrust of the push rod fluctuates around the rated thrust.

9. The method of burst testing a thrust executor of claim 5, wherein, In step S4, the power supply process comprises time sequence control: first power is supplied to the position sensing element of the push rod of the thrust actuator, and after a preset time interval, power is supplied to the driving motor.

10. The method of burst testing a thrust executor of claim 9, wherein, In step S5, the power supply to the driving motor is first cut off, and after the driving motor stops running, the power supply to the position sensing element of the push rod is cut off.

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