A pressure detection device and an electric bed

Abstract

The application discloses a pressure detection device and an electric bed. The pressure detection device comprises a hose, a sound emitting device and a microphone. The hose (1) is adapted to be deformed after being pressed in the radial direction. The sound emitting device (2) is connected with the hose (1) and emits sound into the hose (1). The microphone (3) is at least partially located in the hose (1) and is used to receive the sound signal transmitted by the sound emitting device (2) through the hose (1). The pressure detection device of the application judges whether it is pressed by mechanical extrusion, so that it has no requirement on the temperature of foreign matters, has a wider detection range, good reliability, high detection accuracy and is not prone to misjudgment.

Description

TECHNICAL FIELD

[0001] The present application relates to a bed, in particular to a pressure detection device and an electric bed. BACKGROUND

[0002] An electric bed is a bed that can be deformed under the drive of a motor or other driving device. Generally, an electric bed comprises a bed body fixed to the ground and a deformable bed frame connected to the bed body. The bed frame has at least one frame body that can be converted between a flat state and an inclined state, which can be used to support the back of a human body. Some electric beds have multiple frame bodies that can be raised to support the back and legs of a human body respectively, and can be adjusted to more postures.

[0003] During the conversion of the frame body from the inclined state to the horizontal state, the distance between the frame body and the bed body becomes smaller. At this time, if there is a foreign object between the frame body and the bed body, it is easy to cause a safety risk. For example, if a child or a pet is located between the frame body and the base, it may injure the child or the pet. If a hard object is located between the frame body and the bed body, it may damage the object and damage the bed frame, resulting in property loss.

[0004] In the prior art, there is a technical solution of providing an infrared detection sensor on the electric bed, which is used to detect whether there is a foreign object between the frame body and the bed body. When a person or a pet is located between the frame body and the base, it can be detected by the infrared detection sensor because its temperature is higher than the surrounding environment, so as to control the electric bed to stop the action of lowering the frame body, thereby improving the safety.

[0005] However, this solution still has some defects. For example, it cannot detect foreign objects with the same or similar temperature as the surrounding environment, and there is still a risk of property loss. For another example, when some electrical components on the electric bed generate heat, there is a possibility of misjudging the heated electrical components as a heat-sensing foreign object, which affects the normal operation of the electric bed.

[0006] Therefore, it is necessary to improve the prior art to overcome the defects in the prior art. SUMMARY

[0007] The present application aims to provide a pressure detection device and an electric bed. The pressure detection device can conveniently detect extrusion, and the electric bed with the pressure detection device has better safety.

[0008] To achieve the above-mentioned application purposes, on the one hand, the present application provides a pressure detection device, comprising:

[0009] a hose adapted to deform after being radially pressed;

[0010] a sound generating device connected to the hose and generating sound towards the hose; and

[0011] a microphone located at least partially in the hose and receiving the sound signal transmitted by the sound generating device through the hose and converting the sound signal into an electric signal.

[0012] Further, the sound generating device and the microphone are respectively arranged at two ends of the hose.

[0013] Further, the sound generating device is arranged at a first end of the hose, and a second end of the hose is provided with a plug made of sound absorbing material, which plugs the second end of the hose.

[0014] Further, the microphone is connected to the plug or the hose.

[0015] Further, the sound signal generated by the sound generating device propagates in the hose in the form of a plane wave, and the sound signal is a single frequency signal.

[0016] Further, the inner diameter of the hose is greater than or equal to 5 mm and less than or equal to 10 mm, the wall thickness is greater than or equal to 1 mm, and the sound generating device emits a single frequency signal with a frequency greater than or equal to 5 kHz and less than or equal to 10 kHz.

[0017] Further, the hose is made of flexible material and elastically deforms after being pressed in the radial direction, and the acoustic impedance of the hose is greater than or equal to 500 times the acoustic impedance of air.

[0018] Further, the microphone is in communication connection with a controller, and the controller receives the sound signal transmitted by the microphone and determines that the hose is pressed when the target parameter of the sound signal is lower than a preset value.

[0019] In another aspect, the present application provides an electric bed comprising the pressure detection device according to any one of the above.

[0020] Further, the electric bed further comprises:

[0021] a swingable frame, the pressure detection device being connected to the bottom of the frame;

[0022] a driving device for driving the frame to swing; and

[0023] a controller in communication connection with the driving device and the microphone of the pressure detection device, and when the target parameter of the sound signal received by the microphone is lower than a preset value, the controller controls the frame to stop descending through the driving device.

[0024] Further, the electric bed comprises three pressure detection devices, and the three pressure detection devices are arranged in a U shape.

[0025] The hose is at least partially in a U shape.

[0026] Further, the frame body comprises a hard support member arranged correspondingly to the hose, and the hose is connected to the support member; and the target parameter is sound pressure or sound wave transmittance of the sound signal.

[0027] Compared with the prior art, the pressure detection device has the following beneficial effects: the pressure detection device comprises a hose, a sound generating device and a microphone, the microphone receives the sound signal transmitted by the sound generating device through the hose, and when the sound signal is abnormal, it can be judged whether the hose is under pressure, since whether the hose is under pressure can be judged by mechanical extrusion, the temperature of foreign matters has no requirement, the detection range is wider, and the device has good reliability and high detection accuracy and is not prone to misjudgment. In addition, the hose can be bent into various shapes, so as to better cover the area to be detected, and the arrangement is convenient. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a structure diagram of a pressure detection device according to an embodiment of the present application.

[0029] Figure 2 is a structure diagram of a pressure detection device according to an embodiment of the present application. Figure 1 is a sectional view of the pressure detection device shown in the figure.

[0030] Figure 3 is a sectional view of a pressure detection device according to an embodiment of the present application, and the microphone is connected to the plug.

[0031] Figure 4 is a sectional view of a pressure detection device according to an embodiment of the present application, and the plug is arranged at both ends of the pipe body.

[0032] Figure 5 is a graph of the relationship between the sound wave transmittance and the deformation of the pipe diameter of a pressure detection device according to an embodiment of the present application.

[0033] Figure 6 is a structure diagram of an electric bed according to an embodiment of the present application.

[0034] Figure 7 is a layout diagram of a pressure detection device according to an embodiment of the present application on an electric bed, and the number of the pressure detection devices is three and the pressure detection devices are arranged in a U shape.

[0035] Figure 8 is a layout diagram of a pressure detection device according to an embodiment of the present application on an electric bed, and the hose of the pressure detection device is in a U shape.

[0036] Figure 9 Fig. 1 is a schematic view of an arrangement of a pressure detecting device in an electric bed according to an embodiment of the present application, in which the hose of the pressure detecting device has multiple turns.

[0037] Figure 10 Fig. 2 is a schematic view of the positions of three pressure detecting devices and a hard support shown in Fig. 1. Figure 7 DETAILED DESCRIPTION

[0038] In order to make the above objectives, features and advantages of the present application more clear and comprehensible, the specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. It can be understood that the specific embodiments described herein are only used to explain the present application, but not to limit the present application. In addition, it should be noted that, for the purpose of description, only the parts related to the present application are shown in the drawings, rather than all the structures. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0039] The terms "comprising" and "having" and any variations thereof in the present application are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units is not limited to the listed steps or units, but optionally further includes steps or units not listed, or optionally further includes other steps or units inherent to the process, method, product or device.

[0040] In the present text, the expression "embodiment" means that the specific features, structures or properties described in connection with the embodiment can be included in at least one embodiment of the present application. The appearance of this phrase at various places in the specification does not necessarily all refer to the same embodiment, nor is it mutually exclusive or alternative to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0041] As shown in Figs. 1 and 2, the present application provides a pressure detecting device, which comprises a hose 1, a sound generating device 2 and a microphone 3. Figure 1 Figure 2 As shown in Figs. 1 and 2, the present application provides a pressure detecting device, which comprises a hose 1, a sound generating device 2 and a microphone 3.

[0042] The hose 1 is made of flexible material, such as plastic, rubber or silicone, etc., which can be elastically deformed after being subjected to radial pressure, so that the cross-sectional area of the pressure receiving part is reduced, and can return to the original state after losing the pressure.

[0043] ​​The sound emitting device 2 is connected to the hose 1, and emits sound into the hose 1. Since the acoustic impedance of the hose 1 is much greater than that of air, the sound signal emitted by the sound emitting device 2 can propagate along the hose 1. As a preferred embodiment, the acoustic impedance of the hose 1 is greater than or equal to 500 times the acoustic impedance of air, so that the sound signal can reliably propagate in the hose 1 with small attenuation.

[0044] The microphone 3 is at least partially located in the hose 1, and is configured to receive the sound signal transmitted by the sound emitting device 2 through the hose 1, and convert the sound signal into a corresponding electrical signal.

[0045] When the hose 1 is not compressed, the sound signal emitted by the sound emitting device 2 can reliably reach the microphone 3 with small loss. When the portion of the hose 1 between the sound emitting device 2 and the microphone 3 is compressed, the cross-sectional area of the hose 1 becomes smaller, and the sound signal will be abnormal. At this time, it can be determined that the hose 1 is compressed. Specifically, after the hose 1 is compressed, the attenuation of the sound signal is intensified, and at this time, the amplitude (i.e. sound pressure) and other parameters of the sound signal received by the microphone 3 will decrease significantly. By selecting a target parameter (for example, the amplitude of the sound signal is selected as the target parameter), whether the hose 1 is compressed can be determined according to the change of the target parameter.

[0046] The compression detection device can further include a controller or be connected to an external controller. The controller is in communication connection with the microphone 3 and the sound emitting device 2, for example, through a signal line, and can control the sound emitting device 2 to emit a preset sound signal, and receive the electrical signal of the sound signal converted by the microphone 3. The controller can process the sound signal transmitted by the microphone 3 and extract the target parameter for comparison with a preset value. When the target parameter is lower than the preset value (for example, the amplitude of the received sound signal is lower than 60% of the amplitude of the emitted sound signal), it is determined that the hose 1 is compressed. At this time, a control signal can be sent to the outside (for example, to control the electric bed to stop moving), or the external personnel can be prompted by sound, light or other forms that the hose 1 is compressed. As a preferred embodiment, the controller includes a signal processing circuit and a processor. The signal processing circuit can perform analog-to-digital conversion, signal amplification, noise reduction and other processes, and the processor can be a single-chip microcomputer.

[0047] As a preferred embodiment, the target parameter is the transmittance of the sound wave, which refers to the ratio of the amplitude (sound pressure) of the sound signal received by the microphone 3 to the amplitude (sound pressure) of the sound signal received by the microphone 3 when the hose 1 is not deformed.

[0048] As a preferred embodiment, the sound emitting device 2 and the microphone 3 are respectively arranged at two ends of the hose 1, so that the length of the part between the sound emitting device 2 and the microphone 3 is relatively longer when the total length of the hose 1 is unchanged, and the area that can be detected under pressure is also longer, which is beneficial to improve the comprehensiveness of detection. For example, when the pressure detection device is arranged on an electric bed, the detectable part can cover a larger area, thereby improving the detection effect.

[0049] The two ends of the hose 1 are respectively the first end and the second end, and as a preferred embodiment, the sound emitting device 2 is arranged at the first end of the hose 1, and the second end of the hose 1 is provided with a plug 4 made of sound-absorbing material, which blocks the second end of the hose. In this way, the sound signal emitted by the sound emitting device 2 is absorbed by the plug 4 when transmitted to the second end, and will not be transmitted to the outside world, which has little effect on the outside world. The plug 4 can be made of porous materials such as sound-absorbing cotton, and the thickness is preferably greater than or equal to 9 mm, which has good sound-absorbing effect. The plug 4 with a thickness of 9 mm can basically achieve a sound absorption coefficient >0.9 above 6 kHz, and when the sound emitting device 2 emits a 10 kHz single-frequency signal, it can be considered to have an approximate full absorption effect. Generally speaking, the thicker the plug 4, the better the sound-absorbing effect.

[0050] In order to further reduce the leakage of sound, the sound emitting device 2 can block the first end (see Figure 2 and Figure 3 ), or plugs 4 are arranged at both ends of the hose 1 (see Figure 4 ), and the sound emitting device 2 is arranged in the area between the two plugs 4 and completely located in the hose 1. In addition, a sleeve made of sound-absorbing material can be wrapped outside the hose 1 to prevent sound from being transmitted outward through the vibration of the hose 1.

[0051] In some embodiments, as shown in Figure 1 and Figure 2 , the microphone 3 is connected to the hose 1 and radially penetrates the hose 1, and the head for picking up sound is located in the hose 1 to pick up the sound signal in the hose 1. In other embodiments, as shown in Figure 3 , the microphone 3 is connected to the plug 4 and axially penetrates the plug 4, and the head for picking up sound is located in the hose 1 to pick up the sound signal in the hose 1.

[0052] As a preferred embodiment, the sound wave (i.e. sound signal) propagates in the tube 1 in a plane wave mode so as to measure and evaluate the transmission of the sound wave in the tube. Since the sound field of the plane wave mode is uniform, the microphone 3 placed at any position of the transmission end (i.e. the second end) will give substantially consistent results; while the sound field of the higher mode is not uniform, the microphone 3 placed at different positions will give results with large deviations, thus the measurement results will be inaccurate. In addition, the tube 1 can be bent in the case of the sound wave propagating in the plane wave mode, and the transmission rate will not be affected in the case of the cross section being consistent, while the higher mode will be affected by the bending of the tube 1.

[0053] In order to make the sound wave propagate in the tube 1 in a plane wave mode, the cross-sectional dimension of the tube 1 and the wavelength of the sound wave are set to satisfy the following relationship:

[0054] For a circular tube:

[0055]

[0056] where f is the frequency of the sound wave, c0is the speed of sound in air, and r is the inner diameter of the tube 1.

[0057] For a rectangular tube:

[0058]

[0059] where f is the frequency of the sound wave, c0is the speed of sound in air, L X is the length of the short side of the inner hole of the tube 1, and if the inner hole of the tube 1 is square, L X is the length of the side of the inner hole.

[0060] As a preferred embodiment, the sound signal emitted by the sound emitting device 2 is a single frequency signal. For sound waves of different frequencies, the transmission rate may vary with the change of the pressure deformation rate of the tube diameter, so the wide frequency signal will be more complex, the medium and high frequency sound wave is more easily absorbed by the plug 4, the reflected wave has little effect, and the low frequency sound wave may not be absorbed enough, and there will be reflected signal interference in the measurement. Therefore, using a single frequency signal is beneficial to improve the accuracy of the measurement.

[0061] It is further preferred that the sound signal emitted by the sound emitting device 2 has a frequency greater than or equal to 5 kHz, and more preferably, the sound signal is a mid-high frequency signal with a frequency of 5-10 kHz (inclusive), and is a single frequency signal, which is more sensitive to the pressure deformation of the hose 1, and the hose 1 is more likely to reflect the change of the sound signal after being pressed, and the human ear is also less sensitive to high frequency signals, so even if the sound leaks, it will not cause much disturbance. In the case where the frequency of the sound signal is 5-10 kHz, the inner diameter of the hose 1 is preferably greater than or equal to 5 mm and less than or equal to 10 mm. If the pipe diameter is too small, the air viscosity layer near the pipe wall will have a too high proportion, which will bring strong absorption, and the sound wave will gradually attenuate in the pipe. By selecting the inner diameter of the pipe to be 5-10 mm, the sound wave can be reliably transmitted in the pipe as a plane wave.

[0062] The wall thickness of the hose 1 is preferably greater than or equal to 1 mm, and more preferably greater than or equal to 2 mm.

[0063] In a specific size example, the hose 1 is a circular pipe with an inner diameter of 12 mm and a wall thickness of 2 mm, and the material is rubber. The acoustic impedance of the rubber is about 5000 times that of air. The sound signal emitted by the sound emitting device 2 is a 10 kHz single frequency signal. Due to the small pipe diameter, the 10 kHz signal can maintain a plane wave in the pipe. The 10 kHz signal has a high frequency and a short wavelength, so the change in sound wave caused by the deformation of the hose 1 is more obvious, and the human ear is not sensitive to high frequency sound waves, so even if the sound leaks, it will not cause much disturbance.

[0064] Figure 5 A graph showing the relationship between the pipe diameter deformation and the sound wave transmittance of the hose 1 in the above specific size example is shown in FIG. 3. Figure 5 When a foreign object touches the hose 1 and causes the hose 1 to deform, the transmitted sound wave received by the microphone 3 will start to change. When the hose 1 is not deformed much, the transmittance is less affected. As the hose 1 deforms gradually, the sound wave transmittance gradually decreases. Until the hose 1 is flattened and blocked, the transmittance decreases to 0. In some embodiments, when the sound pressure is detected to drop to 0.9 times the original (i.e. the sound wave transmittance decreases to 0.9, at this time the cross-sectional area change of the hose 1 is about 40%), it means that there is obvious foreign object extrusion, and a pressure signal can be sent out, for example, the electric bed can be controlled to stop lowering.

[0065] It can be understood that the hose 1 can be in the form of a straight strip, or can be curved into other shapes, such as L-shaped, U-shaped, S-shaped, spiral-shaped, etc., to cover a larger area.

[0066] The present application also provides an electric bed comprising the pressure detection device as described above.

[0067] As Figure 6As shown, the electric bed further comprises a base 7, a frame 5 movably connected with the base 7, a driving device 6 connected with the frame 5, and a controller.

[0068] The base 7 is used to be fixedly connected with a bed body (not shown) of the electric bed, and the bed body is placed on the ground and is fixed relative to the ground, so the base 7 is fixed. The frame 5 is connected at an end of the base 7 and can swing relative to the base 7, and a connection between the frame 5 and the base 7 can be, for example, a connection through a rotating shaft or a connection through a linkage mechanism, and the frame 5 can be switched between a horizontal state and an inclined state. The driving device 6 is used to drive the frame 5 to swing, so as to realize a position change of the frame 5 between the horizontal state and the inclined state.

[0069] As a preferred embodiment, the driving device 6 is an electric cylinder or an electric push rod, which is connected between the base 7 and the frame 5. When a driving rod of the driving device 6 is extended, the frame 5 is raised, and when the driving rod of the driving device 6 is retracted, the frame 5 is moved downward to be flat.

[0070] The controller is in communication connection with the driving device 6 and the microphone 3 of the pressure detection device. When a target parameter of a sound signal received by the microphone 3 is lower than a preset value, the microphone 3 sends a control instruction to the driving device 6, and the frame 5 is stopped from descending by the driving device 6, for example, the driving device 6 is controlled to stop working, so that the frame 5 is kept at a current position, or the driving device 6 is controlled to work reversely, so that the frame 5 is raised upward.

[0071] The pressure detection device is connected at a bottom of the frame 5 (a side facing the bed body). When the frame 5 is lowered, a distance between the frame 5 and the bed body is gradually reduced, and at this time, if there is a foreign object between the frame 5 and the bed body, the hose 1 will be deformed under pressure. As described above, when the target parameter is lower than the preset value, it indicates that the hose 1 is under pressure, that is, at this time, there is a foreign object between the frame 5 and the bed body, and therefore, the frame 5 is stopped from descending, which can reliably prevent the frame 5 from injuring the foreign object, and good safety protection is achieved. Since the hose 1 is a soft object, even if the foreign object is pressed, the foreign object will not be damaged, and if a living being (for example, a person or a pet) is contacted, not only the living being will not be pressed, but also the living being can be warned to quickly leave the dangerous area. The detection of whether there is a foreign object by judging whether the hose 1 is under pressure can be applied to all foreign objects, and is not limited by the temperature of the foreign object, and the application range is wider.

[0072] The target parameter can be, for example, a sound wave transmittance of a sound signal received by the microphone 3, and the preset value is preferably 0.9. The target parameter can also be, for example, a sound pressure of a sound signal received by the microphone 3.

[0073] In some embodiments, the electric bed comprises three pressure detection devices, for example, as shown in FIG. 2. Figure 7As shown, the three pressure detection devices are arranged in a U-shape. Specifically, a pressure detection device is installed at the outer end of the frame 1 (the end away from the base 7) along the width direction of the electric bed, and a pressure detection device is installed on each side of this pressure detection device along the length direction of the electric bed. This arrangement allows the pressure detection devices to cover a larger area under the frame 1, and provides better detection of foreign objects near the outer side of the frame 1.

[0074] In some embodiments, the hose 1 is at least partially U-shaped, for example, referring to Figure 8 , Figure 8 The hose 1 shown is generally U-shaped, with the sound-generating device 2 and microphone 3 located at both ends of the hose 1. This embodiment reduces the number of pressure detection devices required, thus lowering costs. For example, see Reference... Figure 9 , Figure 9 The hose 1 shown has multiple U-shaped sections, resulting in multiple folds. The sound-generating device 2 and the microphone 3 are also located at both ends of the hose 1. In this case, the hose 1 can cover more area below the frame 1, thereby improving the comprehensiveness of the detection area.

[0075] In order to ensure that hose 1 can reliably withstand pressure deformation, such as Figure 10 As shown, the frame 5 also includes a rigid support 8 corresponding to the hose 1. The rigid support 8 is located above the hose 1 and connected to it. When the hose 1 comes into contact with a foreign object below, it is clamped between the foreign object and the rigid support 8, allowing for more reliable deformation. The material of the rigid support 8 is not limited; for example, it can be hard plastic, aluminum alloy, or stainless steel. The rigid support 8 can have the same shape as the hose 1 or be a single plate covering the bottom of the frame 5, making it easier to install the hose 1.

[0076] The above are merely specific embodiments of the present invention, and any improvements made based on the concept of the present invention shall be considered within the scope of protection of the present invention.

Claims

1. A pressure detection device, characterized in that, include: The hose (1) is adapted to deform under radial pressure; A sound-generating device (2) is connected to the flexible tube (1) and emits sound into the flexible tube (1). The sound signal emitted by the sound-generating device (2) propagates within the flexible tube (1) as a plane wave. The inner diameter of the flexible tube (1) is greater than or equal to 5 mm and less than or equal to 10 mm, and the wall thickness is greater than or equal to 1 mm. The sound-generating device (2) emits a single-frequency signal with a frequency greater than or equal to 5 kHz and less than or equal to 10 kHz. A microphone (3), at least partially located inside the hose (1), is used to receive sound signals transmitted by the sound-generating device (2) through the hose (1) and convert the sound signals into electrical signals.

2. The pressure detection device as described in claim 1, characterized in that, The sound-generating device (2) and the microphone (3) are respectively located at both ends of the flexible tube (1).

3. The pressure detection device as described in claim 1, characterized in that, The sound-generating device (2) is located at the first end of the hose (1), and the second end of the hose (1) is provided with a plug (4) made of sound-absorbing material, which blocks the second end of the hose (1).

4. The pressure detection device as described in claim 3, characterized in that, The microphone (3) is connected to the plug (4) or the hose (1).

5. The pressure detection device according to any one of claims 1 to 4, characterized in that, The hose (1) is made of a flexible material that undergoes elastic deformation after being compressed radially. The acoustic impedance of the hose (1) is greater than or equal to 500 times the acoustic impedance of air.

6. The pressure detection device according to any one of claims 1 to 4, characterized in that, The microphone (3) is connected to the controller for communication. The controller receives the electrical signal of the sound signal transmitted by the microphone (3) and determines that the hose (1) is under pressure when the target parameter of the sound signal is lower than the preset value.

7. An electric bed, characterized in that, Includes the pressure detection device as described in any one of claims 1 to 6.

8. The electric bed as described in claim 7, characterized in that, The electric bed also includes: A swingable frame (5), wherein the pressure detection device is connected to the bottom of the frame (5); Drive unit (6) for driving the frame (5) to swing; and, The controller is communicatively connected to the microphone (3) of the drive device (6) and the pressure detection device. When the target parameter of the sound signal received by the microphone (3) is lower than the preset value, the controller controls the frame (5) to stop descending through the drive device (6).

9. The electric bed as described in claim 8, characterized in that, It includes three pressure detection devices, which are arranged in a U-shape; or, The hose (1) is at least partially U-shaped.

10. The electric bed as described in claim 8 or 9, characterized in that, The frame (5) includes a rigid support (8) corresponding to the hose (1), and the hose (1) is connected to the support (8); the target parameter is the sound pressure of the sound signal or the sound wave transmittance.

Images