Micro-stroke pressure feedback switch and pressing identification method thereof

Abstract

A micro-stroke pressure feedback type switch and a pressing identification method thereof are disclosed, the micro-stroke pressure feedback type switch comprises a base, the base is provided with a housing, and the housing is used for receiving a pressing action of an external user to control on-off of the switch; the deformation unit is used for conducting the pressing force received by the shell to generate deformation; the deformation unit is arranged between the shell and the sensing chip and is used for detecting the pressing force conducted by the deformation unit and sensing the deformation quantity of the micron-order stroke; and the micro-control unit is used for receiving a signal of the sensing chip to control on and off of the switch. The flexible rubber layer is arranged between the shell and the sensing chip, and the sensing chip with high sensitivity is selected, so that millimeter-level and even submillimeter-level micro-stroke displacement recognition can be realized, and the problem that pressure sensing can be realized only by depending on an obvious motion gap in the prior art is effectively solved; and the structure compactness and the feedback response speed are improved.

Description

Technical Field

[0001] This invention relates to a micro-stroke pressure feedback switch and its press recognition method, belonging to the field of automotive switches. Background Technology

[0002] The automotive infrared pressure feedback switch is a new type of interactive device that combines infrared sensing technology with a pressure feedback mechanism. It is mainly used to improve the safety and accuracy of driving operations.

[0003] Existing push-button switches typically use an internal infrared pressure sensor for sensing. The pressed part assembly has a reflective surface, and the infrared pressure sensor is placed on the circuit board directly below the reflective surface, about 4mm away from the reflective surface. It can detect millimeter-level displacement. When the surface of the pressed part is displaced, the pressure sensor compares the infrared reflected light after the press with the infrared reflected light before the press to determine the operation position and pressure value.

[0004] For example, Chinese utility model CN222202459U discloses an infrared pressure sensing automotive steering wheel switch, which includes a steering wheel frame, spokes, and a PCB assembly. The steering wheel frame is located on the outer periphery of the spokes and is connected to each other. The key feature is that the spokes are provided with an operating area, and the inner side of the spokes is provided with a sliding bracket and a sensing plate. The sensing plate is located below the operating area and is connected to the PCB assembly. The sliding bracket is connected to the spokes and is provided with a reflective surface. The PCB assembly is located below the sliding bracket and is provided with an infrared sensor. The infrared sensor is arranged opposite to the reflective surface.

[0005] Existing infrared push-button switches have the following problems:

[0006] 1. Pressure feedback is currently mostly used in scenarios with significant travel (millimeter level). It uses infrared technology and requires a significant suspension structure, i.e., movement clearance, so it cannot meet the requirements of achieving this function under sealed conditions.

[0007] 3. The press point position signal needs to be transmitted to the processor through a touch sensor, which is costly;

[0008] 4. The surface to be pressed cannot be made of conductive electroplated or metal surfaces, resulting in poor durability. Summary of the Invention

[0009] The purpose of this invention is to overcome the shortcomings and deficiencies of the existing technology and to provide a micro-stroke pressure feedback switch and its press recognition method.

[0010] A micro-stroke pressure feedback switch includes a base, on which is provided

[0011] The outer casing is used to receive pressing actions from external users to control the opening and closing of the switch;

[0012] Deformation unit, used to transmit the pressing pressure received by the outer shell to generate deformation;

[0013] The sensing chip, wherein the deformation unit is disposed between the housing and the sensing chip, is used to detect the pressure transmitted by the deformation unit and sense the deformation of the micron-level stroke;

[0014] The microcontroller unit is used to receive signals from the sensing chip to control the opening and closing of the switch.

[0015] This invention, by incorporating a flexible rubber layer between the outer shell and the sensing chip, and employing a high-sensitivity sensing chip, enables the recognition of micro-stroke displacement at the millimeter or even sub-millimeter level. This effectively overcomes the problem in existing technologies that rely on significant movement gaps for pressure sensing, improving structural compactness and feedback response speed. This invention eliminates the reflective structure of traditional infrared sensors and no longer relies on the upper and lower reflection gaps for signal recognition. Instead, it uses a combination of deformation units and the sensing chip, allowing for a fully enclosed design that significantly improves the switch's dustproof and waterproof capabilities, meeting the reliability requirements of harsh environments such as automotive applications. Because this invention does not rely on capacitive sensing and is not limited by shielding interference from metals or conductive materials, the pressing surface can be made of metal, metal plating, or other highly wear-resistant materials on the outer shell, not only enhancing the product's appearance but also significantly extending its service life.

[0016] Preferably, the housing is provided with a pressing surface for receiving the pressing action of an external user to control the opening and closing of the switch, and the deformation unit is a rubber layer.

[0017] By designing a clearly defined pressing surface on the casing, a distinct operating area can be provided for the user, guiding them to perform accurate touch operations; at the same time, in conjunction with the elastic deformation of the rubber layer, the pressing surface can provide obvious pressure feedback, which helps to improve the feel and feedback experience of operation.

[0018] Furthermore, the pressing surface is a conductive surface or an insulating surface.

[0019] Compared to the strict limitations on the material of the pressing surface in traditional capacitive or infrared button structures (such as the requirement for insulating and transparent materials), the structural design of this invention is not affected by the conductivity of the material. Therefore, it supports the use of conductive materials such as metals and electroplated coatings, or insulating materials such as glass and plastics, greatly expanding the design space of the pressing surface. Using conductive materials (such as aluminum alloys and metal electroplating layers) as the pressing surface not only provides excellent mechanical strength and durability but also meets the stringent requirements for scratch resistance and aging resistance in high-frequency use scenarios such as automotive applications. The sensing principle of this invention is based on the deformation of the rubber layer driving the sensing chip for pressure recognition, without relying on the penetration of capacitive or infrared signals. Therefore, even when using a conductive surface, there will be no signal interference or sensitivity reduction issues, avoiding the technical bottleneck of conductive materials obscuring the sensing in traditional infrared / capacitive solutions.

[0020] Preferably, there are multiple sensing chips, and the number of deformation units corresponds to the number of sensing chips. The sensing chips are evenly distributed inside the housing, so that multiple sensing chips form a combination for realizing multi-point pressure detection.

[0021] The chip layout scheme can be flexibly adjusted according to the actual product structure (such as rectangular, circular, irregular, etc. shell shape). Through simulation analysis, it is ensured that every operating area is covered, avoiding the existence of "blind spots", which is particularly suitable for large or multi-area control panels.

[0022] Preferably, the outer shell is provided with a positioning groove for fitting with the deformation unit. The positioning groove covers the outside of the deformation unit so that the deformation of the outer shell under force is transmitted to the deformation unit. The sensing chip is located inside the rubber layer.

[0023] The outer casing features a positioning groove into which a rubber layer is embedded. This design accurately limits and secures the rubber layer, preventing slippage or rotation caused by prolonged use or frequent pressing. This ensures a stable sensing environment where the sensor chip remains in its preset position. The deformation of the outer casing under user pressure is directly transmitted through the positioning groove to the encased rubber layer. The elastic deformation of the rubber layer then drives the internal sensor chip, enabling high-precision, small-displacement pressure detection and effectively improving the overall system response sensitivity and control stability.

[0024] Preferably, a sealing sheet is provided between the base and the outer shell, the sealing sheet and the base form an installation cavity, the base has a sealing surface around the installation cavity for sealing connection with the outer shell, the base is sealed to the outer shell and the sealing sheet by sealant, and the installation cavity is filled with fixing adhesive.

[0025] The mounting cavity formed by the sealing plate and the base, through the structural design with a sealing surface and the filling with sealant, can achieve a tight fit, significantly improving the overall waterproof and dustproof capabilities of the switch assembly, meeting IP rating requirements, and is particularly suitable for harsh environments with high humidity, high dust or drastic temperature differences.

[0026] Furthermore, the base has slots on both sides, and the outer shell has blocks for engaging with the slots.

[0027] The interlocking mechanism of the locking blocks and slots provides additional mechanical locking force on top of the sealant bonding, effectively preventing the outer casing from loosening or misaligning due to external impacts, long-term vibrations, or thermal expansion and contraction, thus improving the overall structural stability. The locking blocks and slots also serve as a self-positioning mechanism during installation, guiding the outer casing and base to align quickly and accurately during assembly, avoiding internal component misalignment caused by human error, and ensuring that critical components such as the sensor chip and rubber layer remain in their designed positions.

[0028] Furthermore, it also includes a circuit board, with the sensing chip disposed between the circuit board and the deformation unit. The circuit board is electrically connected to the sensing chip and is used to support the sensing chip and transmit electrical signals. The circuit board is disposed in the mounting cavity, and the base is provided with a support part, which is correspondingly disposed at the mounting position of the sensing chip and abuts against the bottom surface of the circuit board.

[0029] By incorporating a support unit in the base that directly abuts against the bottom surface of the circuit board, a robust support is formed in the sensor chip mounting area. This prevents board warping or displacement when the chip is subjected to pressure and deformation, thereby ensuring the stability and repeatability of the sensed data. In addition to supporting the sensor chip's position, the support unit also serves to limit and clamp the circuit board, preventing it from wobbling or vibrating within the mounting cavity, thus improving operational reliability in dynamic environments such as automotive and industrial control systems.

[0030] Preferably, the base is provided with a mounting part, and the circuit board is fixedly connected to the mounting part; the bottom of the base is provided with a connecting part, and the connecting part is provided with a connecting hole communicating with the mounting cavity for electrical connection between the circuit board and external equipment.

[0031] By setting up a mounting section and fixing it to the circuit board, the circuit board can be effectively ensured to remain in its designed position throughout its entire service life, unaffected by external environmental factors such as vibration, drops, and temperature changes, thereby improving the stability and reliability of the entire device. The sensing chip is typically mounted on the circuit board, and its detection accuracy highly depends on the circuit board's fixed state. Fixing it to the base mounting section reduces micro-movements and deformation of the circuit board, ensuring consistent and high-precision sensing data response. The connection holes establish stable electrical connection channels between the circuit board and external control systems, power systems, etc., ensuring that the signals acquired by the sensing chip can be quickly and efficiently transmitted to the host computer or execution module. The connection holes are located at the bottom, allowing for concealed wiring and preventing wiring from affecting the force transmission and structural integrity of the upper sensing area, making the entire device more integrated and lightweight while maintaining functionality.

[0032] The present invention also provides a press recognition method for a micro-stroke pressure feedback switch, implemented using any of the above-mentioned micro-stroke pressure feedback switches, comprising the following steps:

[0033] (1) Signal acquisition: The deformation detected by the multiple sensing chips is output as a corresponding electrical signal, and converted into a digital ADC value by the built-in ADC module; the ADC value is sent to the microcontroller unit via the IIC bus protocol;

[0034] (2) Area division and calibration: The outer shell surface is divided into n pressure detection areas, and each area is calibrated using standard force values ​​a (N) and b (N); during the application of the above different pressures, the ADC output values ​​of the three pressure chips under pressures a (N) and b (N) are recorded to determine the ADC response relationship and reference value corresponding to the force in each area;

[0035] (3) ADC value classification: The pressure data is divided into n levels from high to low according to the ADC value to represent stress response of different intensities. Force values ​​exceeding the upper limit are calibrated as n-1 level and above, and those below the effective recognition range are calibrated as 1 level or below.

[0036] (4) Pressing state determination: The pressing and releasing states of the micro-stroke pressure feedback switch are distinguished according to the combination of the gear positions of each sensor chip.

[0037] The beneficial effects of this invention are as follows: By setting a flexible rubber layer between the outer shell and the sensing chip, and using a high-sensitivity sensing chip, this invention can achieve micro-stroke displacement recognition at the millimeter or even sub-millimeter level, thereby effectively overcoming the problem in existing technologies that require a significant movement gap to achieve pressure sensing, and improving structural compactness and feedback response speed. This invention eliminates the reflection structure of traditional infrared sensors and no longer relies on the upper and lower reflection distance for signal recognition. Instead, it uses a combination of deformation units and sensing chips, enabling a fully enclosed design for the entire structure. This greatly improves the switch's dustproof and waterproof capabilities, meeting the reliability requirements of harsh environments such as automotive applications. Since this invention does not rely on capacitive sensing and is not limited by shielding interference from metals or conductive materials, the pressing surface can be made of metal, metal plating, or other highly wear-resistant materials on the outer shell surface, not only improving the product's appearance and texture but also significantly extending its service life. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, obtaining other drawings based on these drawings without creative effort still falls within the scope of the present invention.

[0039] Figure 1 This is a structural diagram of the main body of the present invention;

[0040] Figure 2 This is a schematic diagram of the structure of the present invention with the outer shell removed;

[0041] Figure 3 This is a schematic diagram of the structure of the present invention with the sealing sheet removed;

[0042] Figure 4 This is a schematic diagram of the structure of the present invention with the circuit board removed;

[0043] Figure 5 This is a schematic diagram of the outer shell structure;

[0044] Figure 6 This is a cross-sectional view of the present invention;

[0045] In the diagram, 1. Base; 11. Mounting cavity; 12. Sealing surface; 13. Slot; 14. Support part; 15. Mounting part; 16. Connecting part; 17. Connecting hole; 2. Outer shell; 21. Pressing surface; 22. Positioning groove; 23. Locking block; 3. Rubber layer; 4. Sensing chip; 5. Circuit board; 6. Sealing sheet. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings.

[0047] It should be noted that all uses of "first" and "second" in the embodiments of the present invention are for the purpose of distinguishing two entities or parameters with the same name but different names. It is clear that "first" and "second" are only for the convenience of expression and should not be construed as limiting the embodiments of the present invention. Subsequent embodiments will not explain this in detail.

[0048] The directional and positional terms used in this invention, such as "up," "down," "front," "back," "left," "right," "inner," "outer," "top," "bottom," and "side," are merely for reference to the accompanying drawings. Therefore, the directional and positional terms used are for illustrating and understanding this invention, and not for limiting the scope of protection of this invention.

[0049] like Figure 1-6 As shown, this is an embodiment of a micro-stroke pressure feedback switch according to the present invention, including a base 1, on which is provided...

[0050] Housing 2 is used to receive the pressing action of an external user to control the opening and closing of the switch;

[0051] Deformation unit, used to transmit the pressing pressure received by the outer shell 2 to generate deformation;

[0052] The sensing chip 4, wherein the deformation unit is disposed between the housing 2 and the sensing chip 4, is used to detect the pressing force transmitted by the deformation unit and to sense the deformation of the micron-level stroke;

[0053] The microcontroller unit is used to receive signals from the sensing chip 4 to control the opening and closing of the switch.

[0054] This invention, by setting a flexible rubber layer 3 between the outer shell 2 and the sensing chip 4, and selecting a high-sensitivity sensing chip 4, can achieve micro-stroke displacement recognition at the millimeter or even sub-millimeter level. This effectively overcomes the problem in existing technologies that require a significant movement gap to achieve pressure sensing, improving structural compactness and feedback response speed. This invention eliminates the reflection structure of traditional infrared sensors and no longer relies on the upper and lower reflection distance for signal recognition. Instead, it uses a combination of deformation units and the sensing chip 4, enabling a fully enclosed design that greatly improves the switch's dustproof and waterproof capabilities, meeting the reliability requirements of harsh environments such as automotive applications. Because this invention does not rely on capacitive sensing and is not limited by shielding interference from metals or conductive materials, the pressing surface 21 can be made of metal, metal plating, or other highly wear-resistant materials on the surface of the outer shell 2, not only improving the product's appearance but also significantly extending its service life.

[0055] The outer casing 2 is provided with a pressing surface 21 for receiving the pressing action of an external user to control the opening and closing of the switch, and the deformation unit is a rubber layer 3.

[0056] By setting a clear pressing surface 21 on the outer shell 2, a clear operating area can be provided for the user, guiding the user to perform accurate touch operations; at the same time, in conjunction with the elastic deformation of the rubber layer 3, the pressing surface 21 can provide obvious pressure feedback, which helps to improve the feel and feedback experience of operation.

[0057] The shape of the pressing surface 21 can be designed as concave, convex, or arc-shaped depending on the different operating areas. A concave pressing surface 21 helps to concentrate the user's finger pressure, improving the sense of positioning; a convex design enhances tactile feedback; and an arc-shaped transition surface can be used in multi-finger contact areas to improve multi-point sensing sensitivity. The surface of the pressing surface 21 can be coated with a conductive coating, electroplating layer, or flexible insulating film to meet different functional and wear-resistant requirements.

[0058] When the pressing surface 21 deforms under pressure, the force is concentrated at the center of the sensing chip 4 through the reinforcing block, forming a linkage response. The sensing chip 4 is preferably a capacitive, piezoelectric, or strain gauge chip, which can be embedded on the circuit board 5 or connected through an intermediate pressure pad to achieve high-sensitivity micro-displacement sensing.

[0059] The pressing surface 21 is a conductive surface or an insulating surface.

[0060] Compared to the strict limitations on the material of the pressing surface 21 in traditional capacitive or infrared button structures (such as the requirement for an insulating and transparent material), the structural design of this invention is not affected by the conductivity of the material. Therefore, it supports the use of conductive materials such as metals and electroplated coatings, or insulating materials such as glass and plastics, greatly expanding the design space of the pressing surface 21 of the outer shell 2. Using conductive materials (such as aluminum alloys or metal electroplated layers) as the pressing surface 21 not only provides excellent mechanical strength and durability but also meets the stringent requirements for scratch resistance and aging resistance in high-frequency use scenarios such as automotive applications. The sensing principle of this invention is based on the deformation of the rubber layer 3 driving the sensing chip 4 for pressure recognition. It does not rely on the penetration of capacitive or infrared signals, so even when using a conductive surface, there will be no signal interference or sensitivity reduction issues, avoiding the technical bottleneck of conductive materials obscuring the sensing in traditional infrared / capacitive solutions.

[0061] The pressing surface 21 has a structure consisting of a substrate layer and a surface coating. The substrate can be made of injection-molded PC (polycarbonate), ABS engineering plastic, or polyurethane material, possessing good mechanical strength and molding precision. If the pressing surface 21 is a conductive surface, its outer layer is preferably a PVD (physical vapor deposition) electroplated metal film, such as chromium, titanium, or aluminum alloy, which possesses good electrical conductivity, wear resistance, and reflective properties. If it is an electroplated chromium layer, the surface can be treated with hydrophobic and oleophobic coatings to improve the handling feel and anti-fouling performance.

[0062] When the pressing surface 21 is an insulating surface, an insulating coating can be formed by spraying an insulating coating, laminating, or injection molding. The thickness of the insulating layer can be set to 5–20 μm, and the material can be an epoxy resin coating, a silane-modified polyurethane coating, or a nano-ceramic composite film, possessing high dielectric strength and chemical resistance. A flexible buffer layer (such as a TPU film or foam adhesive layer) can be provided under the coating to alleviate fatigue cracks caused by point pressure and improve durability.

[0063] The number of the sensing chips 4 is multiple, and the number of the deformation units is set in correspondence with the number of sensing chips 4. The sensing chips 4 are evenly distributed in the outer shell 2, so that multiple sensing chips 4 form a combination for realizing multi-point pressure detection.

[0064] The combination of multi-point pressure detection can be arranged through computer simulation. Computer simulation can analyze the stress transmission path between the rubber layer 3 and the outer shell 2 for pressure of different strengths and directions, thereby optimizing the distribution density and layout of the sensing chips 4. This ensures that each chip can accurately sense the target input while effectively filtering out surrounding disturbances, improving overall stability. The chip layout scheme can be flexibly adjusted according to the actual product structure (such as rectangular, circular, irregular, or other shell shapes 2). Simulation analysis ensures that every operating area is covered, avoiding "blind spots," making it particularly suitable for large or multi-area control panels.

[0065] The outer shell 2 is provided with a positioning groove 22 for fitting with the deformation unit. The positioning groove 22 covers the outside of the deformation unit so that the deformation of the outer shell 2 under force is transmitted to the deformation unit. The sensing chip 4 is located inside the rubber layer 3.

[0066] The outer casing 2 is provided with a positioning groove 22, in which the rubber layer 3 is embedded. This allows for accurate positioning and secure coverage of the rubber layer 3, preventing slippage, rotation, or other structural displacements caused by prolonged use or frequent pressing. This ensures a stable sensing environment where the sensor chip 4 remains in a preset position. The deformation of the outer casing 2 under user pressure is directly transmitted to the covered rubber layer 3 via the positioning groove 22. The elastic deformation of the rubber layer 3 further drives the internal sensor chip 4, achieving high-precision, small-displacement pressure detection and effectively improving the overall system response sensitivity and control stability.

[0067] In the embodiments of this application, unlike the above embodiments, a sealing sheet 6 is provided between the base 1 and the outer shell 2. The sealing sheet 6 and the base 1 form an installation cavity 11. The base 1 is provided with a sealing surface 12 around the installation cavity 11 for sealing connection with the outer shell 2. The base 1 is sealed to the outer shell 2 and the sealing sheet 6 by sealant. The installation cavity 11 is filled with fixing adhesive.

[0068] The mounting cavity 11 formed by the sealing plate 6 and the base 1, through its structural design with a sealing surface 12 and supplemented by sealant filling, achieves a tight fit, significantly improving the overall waterproof and dustproof capabilities of the switch assembly, meeting IP rating requirements, and is particularly suitable for harsh environments with high humidity, high dust, or drastic temperature differences. The sealant is VHB double-sided adhesive, and the fixing adhesive is AB glue. After curing, these materials have high bonding strength and excellent dimensional stability, which can firmly fix the circuit board 5 and the sensor chip 4 module position, avoiding positional displacement caused by vibration or thermal expansion and contraction.

[0069] The base 1 has slots 13 on both sides, and the outer shell 2 has a locking block 23 for engaging with the slots 13.

[0070] The interlocking mechanism between the locking block 23 and the slot 13 provides additional mechanical locking force on top of the sealant bonding, effectively preventing the outer shell 2 from loosening or misaligning due to external impacts, long-term vibration, or thermal expansion and contraction, thus improving the overall structural stability. The locking block 23 and slot 13 also function as a self-positioning mechanism during installation, guiding the outer shell 2 and base 1 to align quickly and accurately during assembly, avoiding internal component misalignment caused by human error, and ensuring that key components such as the sensor chip 4 and rubber layer 3 remain in their designed positions.

[0071] It also includes a circuit board 5, the sensing chip 4 is disposed between the circuit board 5 and the deformation unit, the circuit board 5 is electrically connected to the sensing chip 4, and is used to support the sensing chip 4 and transmit electrical signals; the circuit board 5 is disposed in the mounting cavity 11, and the base 1 is provided with a support part 14, which is disposed at the mounting position of the sensing chip 4 and abuts against the bottom surface of the circuit board 5.

[0072] In this embodiment, unlike the previous embodiment, a support portion 14 is provided on the base 1 and directly abuts against the bottom surface of the circuit board 5. This forms a solid support in the mounting area of ​​the sensing chip 4, preventing board warping or displacement when the chip is deformed under pressure, thereby ensuring the stability and repeatability of the sensing data. In addition to supporting the position of the sensing chip 4, the support portion 14 also serves to limit and clamp the circuit board 5, preventing it from wobbling or vibrating locally inside the mounting cavity 11, thus improving operational reliability in dynamic environments such as automotive and industrial control systems.

[0073] The base 1 is provided with a mounting part 15, the circuit board 5 is fixedly connected to the mounting part 15, the bottom of the base 1 is provided with a connecting part 16, the connecting part 16 is provided with a connecting hole 17 communicating with the mounting cavity 11, for the circuit board 5 to be electrically connected to external equipment.

[0074] By setting the mounting part 15 and fixing it to the circuit board 5, it can be effectively ensured that the circuit board 5 remains in its designed position throughout its service life, unaffected by external environmental factors such as vibration, drops, and temperature changes, thereby improving the stability and reliability of the entire machine. The sensing chip 4 is usually mounted on the circuit board 5, and its detection accuracy is highly dependent on the fixed state of the circuit board 5. By fixing it to the mounting part 15 of the base 1, the micro-movements and deformations of the circuit board 5 can be reduced, ensuring consistent and high-precision sensing data response.

[0075] The base 1 is fixedly connected to the circuit board 5 through bolt connection, guide post and guide groove structure and other fixed connection structures.

[0076] By setting a connecting part 16 and opening a connecting hole 17 at the bottom of the base 1, a stable electrical connection channel can be established between the circuit board 5 and external control systems, power systems, etc., ensuring that the signals acquired by the sensing chip 4 can be transmitted to the host computer or execution module quickly and efficiently. The connecting hole 17 is located at the bottom, which can realize the concealed wiring and avoid the wiring from affecting the force transmission and structural integrity of the upper sensing area, making the whole device more integrated and thinner while ensuring functionality.

[0077] The present invention also provides a press recognition method for a micro-stroke pressure feedback switch, implemented using any of the above-mentioned micro-stroke pressure feedback switches, comprising the following steps:

[0078] (1) Signal acquisition: The deformation sensed by the multiple sensing chips 4 is output as a corresponding electrical signal, and converted into a digital ADC value by the built-in ADC module; the ADC value is sent to the microcontroller unit through the IIC bus protocol;

[0079] (2) Area division and calibration: The surface of the outer shell 2 is divided into n pressure detection areas, and each area is calibrated using standard force values ​​a (N) and b (N); during the application of the above different pressures, the ADC output values ​​of the three pressure chips under pressures a (N) and b (N) are recorded to determine the ADC response relationship and reference value corresponding to the force in each area;

[0080] (3) ADC value classification: The pressure data is divided into n levels from high to low according to the ADC value to represent stress response of different intensities. Force values ​​exceeding the upper limit are calibrated as n-1 level and above, and those below the effective recognition range are calibrated as 1 level or below.

[0081] (4) Pressing state determination: The pressing and releasing states of the micro-stroke pressure feedback switch are distinguished according to the gear combination of each sensor chip 4.

[0082] In this embodiment, the surface of the micro-limit switch housing is divided into five pressure detection areas, from the first to the fifth, and three sensing chips are arranged below these areas accordingly. Calibration is performed by applying standard pressures of 10N and 15N to each detection area, and the ADC output values ​​of the three sensing chips are recorded under each pressure. Based on this, the ADC data is divided into five levels, and the threshold range for each level is determined.

[0083] Since the effective range is 5N-10N, all data from a 10N press should be recognized as a button press, and data from a 15N press should be recognized as a button release. At the same time, when the force is too small, it needs to be judged as a button release. Therefore, the data from the three sensors are divided into five levels for combined judgment.

[0084] 1. The leftmost point, since it is above the left-hand sensor chip, should have its calibration data set to level 3 for 10N and level 4 for 15N. In addition, the sensor chip should be set to level 1 or below.

[0085] 2. For the left and middle positions, since it is between the two left and middle sensing chips, the data calibrated for 10N should all be set to level 2, and the data calibrated for 15N should be set to level 3+2. Since the data shows that the data variation in the middle position is greater, the middle sensing chip is set to level 3, the left sensing chip is set to level 2, and the right sensing chip is set to level 1 or below.

[0086] 3. For the intermediate point, since it is above the intermediate sensing chip, the calibration data for 10N should be set to level 3, the calibration data for 15N should be set to level 4, and the calibration data for other sensing chips should be set to level 1 or below.

[0087] 4. The same applies to the two points on the right.

[0088] 5. According to the above punctuation definition, the press judgment logic is as follows: 1) If any 4th gear exists, it is judged to be out of range and a release signal is sent; 2) If any 3rd gear exists, and if a 2nd gear signal exists, it is judged to be out of range and a release signal is sent; if there is no 2nd gear signal, it is judged to be pressed and a press signal is sent; 3) If there is a 2nd gear + 1st gear or more, it is judged to be pressed and a press signal is sent; 4) Other cases are judged as release.

[0089] In the microcontroller unit, the IIC bus interacts with data according to a standard protocol frame format, sequentially sending a start signal, device address, and read / write bits. It then reads the ADC data transmitted from the three chips and finally sends a stop signal to terminate communication. This standard IIC communication method ensures the stability and reliability of data transmission, enabling the microcontroller unit to accurately acquire pressure information from each detection area and perform corresponding pressure recognition.

[0090] The above description discloses only preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

[0091] While the invention has been described with reference to several specific embodiments, it should be understood that the invention is not limited to the disclosed specific embodiments. The invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. A micro-stroke pressure feedback switch, characterized in that: Includes a base, on which a housing is provided for receiving pressing actions from external users to control the opening and closing of the switch; Deformation unit, used to transmit the pressing pressure received by the outer shell to generate deformation; The sensing chip, wherein the deformation unit is disposed between the housing and the sensing chip, is used to detect the pressure transmitted by the deformation unit and sense the deformation of the micron-level stroke; The microcontroller unit is used to receive signals from the sensing chip to control the opening and closing of the switch.

2. The micro-stroke pressure feedback switch as described in claim 1, characterized in that: The outer casing is provided with a pressing surface for receiving the pressing action of an external user to control the opening and closing of the switch, and the deformation unit is a rubber layer.

3. The micro-stroke pressure feedback switch as described in claim 2, characterized in that: The pressing surface is a conductive surface or an insulating surface.

4. The micro-stroke pressure feedback switch as described in claim 1, characterized in that: The number of the sensing chips is multiple, and the number of the deformation units is set in correspondence with the number of sensing chips. The sensing chips are evenly distributed inside the housing, so that multiple sensing chips form a combination for realizing multi-point pressure detection.

5. The micro-stroke pressure feedback switch as described in claim 1, characterized in that: The outer shell is provided with a positioning groove for fitting with the deformation unit. The positioning groove covers the outside of the deformation unit so that the deformation of the outer shell under force is transmitted to the deformation unit. The sensing chip is located inside the rubber layer.

6. The micro-stroke pressure feedback switch as described in claim 1, characterized in that: A sealing sheet is provided between the base and the outer shell, and the sealing sheet and the base form an installation cavity. The base has a sealing surface around the installation cavity for sealing connection with the outer shell. The base is sealed to the outer shell and the sealing sheet by sealant. Fixing adhesive is poured into the installation cavity.

7. The micro-stroke pressure feedback switch as described in claim 1 or 6, characterized in that: The base has slots on both sides, and the outer shell has blocks for engaging with the slots.

8. The micro-stroke pressure feedback switch as described in claim 6, characterized in that: It also includes a circuit board, the sensing chip is disposed between the circuit board and the deformation unit, the circuit board is electrically connected to the sensing chip, and is used to support the sensing chip and transmit electrical signals; the circuit board is disposed in the mounting cavity, and the base is provided with a support part, which is correspondingly disposed at the mounting position of the sensing chip and abuts against the bottom surface of the circuit board.

9. The micro-stroke pressure feedback switch as described in claim 6, characterized in that: The base is provided with a mounting part, and the circuit board is fixedly connected to the mounting part; the bottom of the base is provided with a connecting part, and the connecting part is provided with a connecting hole communicating with the mounting cavity for electrical connection between the circuit board and external equipment.

10. A method for recognizing a press in a micro-stroke pressure feedback switch, characterized in that: The implementation using any of the micro-stroke pressure feedback switches described in claims 1-9 includes the following steps: (1) Signal acquisition: The deformation detected by the multiple sensing chips is output as a corresponding electrical signal, and converted into a digital ADC value by the built-in ADC module; the ADC value is sent to the microcontroller unit via the IIC bus protocol; (2) Area division and calibration: The outer shell surface is divided into n pressure detection areas, and each area is calibrated using standard force values ​​a (N) and b (N); during the application of the above different pressures, the ADC output values ​​of the three pressure chips under pressures a (N) and b (N) are recorded to determine the ADC response relationship and reference value corresponding to the force in each area; (3) ADC value classification: The pressure data is divided into n levels from high to low according to the ADC value to represent stress response of different intensities. Force values ​​exceeding the upper limit are calibrated as n-1 level and above, and those below the effective recognition range are calibrated as 1 level or below. (4) Pressing state determination: The pressing and releasing states of the micro-stroke pressure feedback switch are distinguished according to the combination of the gear positions of each sensor chip.

Images