Food temperature measuring probe and cooking equipment

Abstract

The utility model relates to a food temperature measuring probe and cooking equipment, the food temperature measuring probe comprises a probe part and a radio frequency part which are connected, the probe part is internally provided with at least one sensor, the sensor comprises a piezoelectric substrate, an interdigital transducer and a reflecting grating, the interdigital transducer and the reflecting grating are both connected to the piezoelectric substrate and are arranged at intervals, and the radio frequency part is connected with the piezoelectric substrate. The radio frequency part is located at the tail end of the probe part, an antenna is arranged in the radio frequency part, and the sensor is electrically connected with the antenna. According to the scheme, the probe and other parts do not need to be connected through wires, parts such as a power supply do not need to be arranged in the probe, wireless and passive effects are achieved, and therefore the problems that in the prior art, probe wires are inconvenient to connect, and internal electronic elements cannot tolerate the high-temperature environment are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of kitchen appliances, in particular to a food temperature probe and a cooking device. BACKGROUND

[0002] When cooking food, precise control of the internal temperature of the food is an important link to ensure the cooking effect and food safety. The existing steam oven usually monitors the food temperature in real time through a temperature probe inserted into the food to achieve precise control of the cooking process. However, the existing temperature probe technology is mainly divided into wired and wireless active types, both of which have certain technical defects, limiting their widespread use in practical applications.

[0003] Firstly, the existing wired food probe relies on a wire connected to the control unit of the steam oven for power supply and temperature signal transmission. However, this design has the following problems: 1. The connection and arrangement of the wire are relatively complex, especially in a high-temperature environment, the wire is prone to unstable connection due to bending or stretching; 2. When in a high-temperature environment for a long time, the insulation layer of the wire may accelerate aging, thereby causing safety hazards such as short circuit or electric shock; 3. The steam oven is usually a sealed cavity, and the design of the sealed connector of the wire is difficult, which is prone to cause steam or liquid to seep in due to poor sealing, further affecting the reliability of the probe.

[0004] Secondly, the existing wireless active food probe is powered by an internal battery or capacitor and transmits temperature data using wireless signals. However, the internal electronic components of this probe are prone to performance degradation or even damage in a high-temperature environment, which prevents the probe from working normally, thereby limiting its application in high-temperature cooking scenarios.

[0005] In summary, the existing steam oven temperature probe technology has obvious deficiencies in wire connection and high-temperature resistance. Therefore, there is an urgent need for an innovative solution that can avoid wire connection problems and withstand high-temperature environments. INNOVATION CONTENT

[0006] Therefore, it is necessary to provide a food temperature probe and a cooking device to solve the problems of inconvenient wire connection of the temperature probe and the inability of the internal electronic components to withstand high-temperature environments in the existing cooking device.

[0007] A food temperature probe, the food temperature probe comprises a probe head and a radio frequency part connected together, at least one sensor is built-in the probe head, the sensor comprises a piezoelectric substrate, an interdigital transducer and a reflective grating, the interdigital transducer and the reflective grating are both connected to the piezoelectric substrate and are arranged at intervals, the radio frequency part is located at the tail end of the probe head and the radio frequency part is built-in an antenna, the sensor is electrically connected with the antenna.

[0008] In one of the embodiments, the probe part comprises a plurality of sensors, the plurality of sensors are distributed along the axial direction of the probe part and are arranged at intervals, the plurality of sensors are electrically connected to the same antenna, and the signals of the plurality of sensors occupy different intervals of the corresponding frequency band of the antenna respectively.

[0009] In one of the embodiments, the signals of the sensors occupy different intervals of the corresponding frequency band of the antenna in sequence according to the distance between the sensors and the radio frequency part.

[0010] In one of the embodiments, each of the sensors comprises two reflection gratings, and the two reflection gratings are symmetrically distributed on both sides of the interdigital transducer.

[0011] In one of the embodiments, the probe part is internally provided with mounting cavities, the sensors are arranged in the mounting cavities one by one, and when the number of the mounting cavities is plural, the adjacent mounting cavities are arranged at intervals.

[0012] In one of the embodiments, the radio frequency part is provided with a placing cavity, and the antenna is located in the placing cavity.

[0013] In one of the embodiments, the food temperature probe further comprises a coaxial cable, and two ends of the coaxial cable are connected to the sensor and the antenna respectively, so that the sensor and the antenna are electrically connected.

[0014] In one of the embodiments, when the number of the sensors is plural, the sensors are connected to the coaxial cable in sequence.

[0015] In one of the embodiments, the probe part is of a tubular structure, and the probe part is internally filled with a heat-conducting material.

[0016] A cooking device comprises the food temperature probe according to any one of the above embodiments.

[0017] The food temperature probe provided in the above scheme can detect the change of temperature by arranging sensors in the probe part and arranging antennas capable of signal transmission with the sensors in the radio frequency part, using the principle that the propagation of acoustic surface waves in the sensors is affected by environmental factors, and the time delay or resonance frequency of the return signal changes due to the performance of the piezoelectric substrate, so that the change of temperature can be obtained by detecting the time delay or frequency change of the return signal, and the temperature detection is realized. The temperature change is obtained by the frequency change of the signal emitted by the receiving antenna, which does not need to connect the probe and other components through wires, nor needs to internally embed power supply and other components, realizes wireless and passive, and thus solves the problems of inconvenient connection of probe wires and inability of internal electronic elements to withstand high temperature environment in the prior art. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 Fig. 1 is a schematic view of a cross-sectional structure of a food temperature probe according to an embodiment of the present application.

[0019] Figure 2 Fig. 2 is a schematic view of a cross-sectional structure of a food temperature probe according to another embodiment of the present application. Figure 1 Fig. 3 is a schematic view of a principle of a sensor according to an embodiment of the present application. Figure 1

[0020] Figure 3 Fig. 4 is a schematic view of a principle of a sensor according to another embodiment of the present application. Figure 1 Figure 2

[0021] Figure 4 Fig. 5 is a schematic view of a frequency signal of a food temperature probe according to an embodiment of the present application. Figure 1

[0022] BRIEF DESCRIPTION OF DRAWINGS

[0023] 100, food temperature probe; 110, probe portion; 111, mounting cavity; 120, radio frequency portion; 121, placement cavity; 130, sensor; 130a, first sensor; 130b, second sensor; 130c, third sensor; 131, piezoelectric substrate; 132, interdigital transducer; 132a, input interdigital transducer; 132b, output interdigital transducer; 133, reflective grid; 134, sound absorbing member; 140, antenna; 150, coaxial cable; 160, processor. DETAILED DESCRIPTION

[0024] In order to make the above objectives, features and advantages of the present application more clear and comprehensible, specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced in a number of different ways from those described herein without departing from the scope of the present application, and it is understood that similar improvements can be made by those skilled in the art without departing from the spirit of the present application, and therefore the present application is not limited to the specific embodiments disclosed below.

[0025] In the description of the present application, it should be understood that if there are terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0026] ​​​​In addition, if there are these terms "first", "second", these terms are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second" can be explicitly or implicitly included at least one of the features. In the description of the present application, if there are the terms "a plurality of", the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise explicitly specified and limited.

[0027] In the present application, unless otherwise explicitly specified and limited, if there are the terms "mounting", "connecting", "connecting", "fixing" and the like, these terms should be understood in a broad sense. For example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0028] In the present application, unless otherwise explicitly specified and limited, if there are similar descriptions such as "first feature on" or "second feature", the meaning can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature "above", "above" and "above" of the second feature can be the first feature directly above or obliquely above the second feature, or only indicates that the first feature is higher than the second feature in horizontal height. The first feature "below", "below" and "below" of the second feature can be the first feature directly below or obliquely below the second feature, or only indicates that the first feature is lower than the second feature in horizontal height.

[0029] It should be noted that if an element is referred to as "fixed to" or "provided to" another element, it can be directly on another element or there can be a middle element. If an element is considered to be "connected" to another element, it can be directly connected to another element or there can be a middle element. If there is, the terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used in the present application are only for the purpose of illustration, and do not represent the only implementation.

[0030] An embodiment of the present application provides a cooking device, which can be a steam oven, a steam oven, an oven, or any other device with cooking function. The cooking device includes a food temperature probe 100 as described in any of the following embodiments, which is used to detect the temperature of the food to realize the regulation of the cooking process.

[0031] Referring to Figure 1 , Figure 1A cross-sectional structure diagram of the food temperature probe 100 in an embodiment of the present application is shown. The food temperature probe 100 provided by the embodiment of the present application can be applied to the cooking device described above, and can also be applied to other fields.

[0032] As shown in Figure 1 , the food temperature probe 100 includes a probe part 110 and a radio frequency part 120 connected together, as shown in Figure 1 , the end of the probe part 110 away from the radio frequency part 120 is a tapered tip with a reduced diameter, so as to facilitate insertion into the interior of the food material.

[0033] As shown in Figure 1 , the probe part 110 is internally provided with at least one sensor 130. The number of sensors 130 can be one or multiple. When the number of sensors 130 is multiple, the temperature at different positions of the food temperature probe 100 can be detected simultaneously. For example, when the number of sensors 130 is three, after the food temperature probe 100 is inserted into the food, three temperatures corresponding to different positions of the food detected by the three sensors 130 can be obtained. Correspondingly, when the number of sensors 130 is other numbers, the temperatures of the corresponding number of different positions can also be obtained.

[0034] As shown in Figure 2 and Figure 3 , the sensor 130 includes a piezoelectric substrate 131, an interdigital transducer 132 and a reflective grating 133. The interdigital transducer 132 and the reflective grating 133 are both connected to the piezoelectric substrate 131 and are arranged at intervals. The interdigital transducer 132 is composed of a comb-shaped metal electrode and is divided into an input interdigital transducer 132a and an output interdigital transducer 132b. Each sensor 130 includes an input interdigital transducer 132a and an output interdigital transducer 132b, respectively, for receiving signals and outputting signals.

[0035] When receiving the alternating voltage signal on the input interdigital transducer 132a, the piezoelectric substrate 131 will mechanically deform under the action of the electric field, generating sound waves, and its surface will produce mechanical vibrations with the same frequency as the applied signal, forming a surface acoustic wave. The generated surface acoustic wave propagates along the surface of the piezoelectric substrate 131. The propagation speed of the surface acoustic wave is slow, which makes it possible to propagate multiple wavelengths in a small device. The surface acoustic wave will be affected by the physical properties of the substrate material (such as elastic modulus, density, etc.) and the surrounding environmental factors (such as temperature, humidity, etc.) during propagation. When the surface acoustic wave propagates to the reflection grating 133, part of it is reflected back to the interdigital transducer 132, and when the surface acoustic wave propagates to the output interdigital transducer 132b, due to the inverse effect of the piezoelectric effect, the mechanical vibration will be converted back to an electrical signal. The output interdigital transducer 132b converts the received surface acoustic wave into an alternating electrical signal output. The time delay or resonant frequency of the return signal changes due to the performance of the piezoelectric substrate 131, so by detecting the time delay or frequency change of the return signal, the change in temperature can be obtained, and temperature detection can be achieved.

[0036] As shown in Figure 2 , the radio frequency part 120 is located at the tail end of the probe part 110, and the radio frequency part 120 is built-in with an antenna 140, and the sensor 130 is electrically connected with the antenna 140, and the antenna 140 is used for receiving, transmitting and transmitting signals, so as to transmit and transmit the electrical signal output by the output interdigital transducer 132b in the sensor 130, and obtain a radio frequency signal diagram as shown in Figure 4 .

[0037] In this embodiment, the sensor 130 is made of high-temperature-resistant material, and the antenna 140 is also made of high-temperature-resistant material, so that the food temperature probe 100 can be applied to the high-temperature environment such as the above-mentioned cooking equipment.

[0038] As shown in Figure 2 and Figure 3 , the food temperature probe 100 further comprises a processor 160, which is used for receiving the electrical signal output by the output interdigital transducer 132b, and inversely deducing the performance of the piezoelectric substrate 131 and the ambient temperature of the piezoelectric substrate 131 according to the electrical signal, so as to realize temperature detection of the corresponding position of the food material.

[0039] As shown in Figure 1 and Figure 4As shown, in one of the embodiments, the probe part 110 comprises a plurality of sensors 130, which are distributed and spaced along the axial direction of the probe part 110, and the sensors 130 are electrically connected to the same antenna 140, so as to avoid multiple antennas 140 and increase the size of the food temperature probe 100, so that the overall size of the food temperature probe 100 is smaller and more practical. And the signals of the plurality of sensors 130 respectively occupy different intervals of the corresponding frequency band of the antenna 140, and a frequency division multiple access mode is adopted to realize multi-section temperature measurement.

[0040] As shown in Figure 1 and Figure 4 shown, in this embodiment, the number of sensors 130 is three, which is illustrated and described, but not as a limitation, the number of sensors 130 can be set according to actual needs. In order to distinguish, the three sensors 130 are named as first sensor 130a, second sensor 130b and third sensor 130c in turn, and the first sensor 130a, the second sensor 130b and the third sensor 130c are all connected to the antenna 140 as shown in Figure 1 and emit their own electrical signals in the signal frequency of the antenna 140.

[0041] As shown in Figure 4 , the corresponding frequency band of the antenna 140 is P, the signal of the first sensor 130a occupies the interval p1 of the corresponding frequency band of the antenna 140, the signal of the second sensor 130b occupies the interval p2 of the corresponding frequency band of the antenna 140, and the signal of the third sensor 130c occupies the interval p3 of the corresponding frequency band of the antenna 140. Wherein, the frequency width of the corresponding frequency band P of the antenna 140 is greater than the sum of the corresponding frequency width of the interval p1 of the corresponding frequency band of the antenna 140 occupied by the signal of the first sensor 130a, the corresponding frequency width of the interval p2 of the corresponding frequency band of the antenna 140 occupied by the signal of the second sensor 130b and the corresponding frequency width of the interval p3 of the corresponding frequency band of the antenna 140 occupied by the signal of the third sensor 130c, that is, the frequency width of P > the sum of the corresponding frequency width of p1, the corresponding frequency width of p2 and the corresponding frequency width of p3.

[0042] It should be noted that in actual use, the sensors 130 and the antenna 140 need to be set in combination with the limit temperature of the application environment of the food temperature probe 100, the available electrical signal use power and the frequency width requirement. Exemplarily, the food temperature probe is applied to an oven with a limit temperature of-20℃ and a high temperature of 250℃. At the limit temperature, the frequency width of the corresponding frequency band of the antenna 140 should not exceed the specified frequency width, and at this time, the corresponding frequency band intervals of the plurality of sensors 130 should be set without overlapping.

[0043] As shown in Figure 1 and Figure 4As shown, in one embodiment, the signals of the sensors 130 sequentially occupy different intervals of the corresponding frequency band of the antenna 140 according to the distance between the sensors 130 and the radio frequency part 120. In combination with Figure 1 and Figure 4 Taking three sensors 130 as an example, the first sensor 130a, the second sensor 130b and the third sensor 130c are sequentially arranged according to the distance from the radio frequency part 120, and accordingly, as shown, Figure 4 the signal of the first sensor 130a occupies the interval p1 of the corresponding frequency band of the antenna 140, the signal of the second sensor 130b occupies the interval p2 of the corresponding frequency band of the antenna 140, and the signal of the third sensor 130c occupies the interval p3 of the corresponding frequency band of the antenna 140. They are sequentially arranged and respectively occupy the first, middle and last intervals of the corresponding frequency band of the antenna 140. When the number of sensors 130 is other than three, the sensors 130 are sequentially arranged according to the positions of the sensors 130.

[0044] As shown, Figure 2 the sensor 130 can be a delay type surface acoustic wave sensor 130. Due to temperature changes, the speed and wavelength of the sound wave change, which will cause the time returned by the reflection grating 133 to change or the waveform phase to change, and the time delay of the electrical signal corresponding to the feedback interdigital transducer 132 changes. By collecting the time delay signal of the sound wave, the temperature of the corresponding position of the food material is obtained.

[0045] In some embodiments, the sensor 130 further comprises a sound absorbing member 134 as shown, Figure 2 The sound absorbing member 134 is located on the side of the reflection grating 133 away from the interdigital transducer 132, and is used to absorb the surface acoustic wave not reflected by the reflection grating 133 back to the interdigital transducer 132. In this embodiment, the sound absorbing member 134 is formed by coating a sound absorbing material on the surface of the piezoelectric substrate 131, but is not limited thereto.

[0046] As shown, Figure 3 the sensor 130 can also be a resonance type surface acoustic wave sensor 130. In one embodiment, each sensor 130 comprises two reflection gratings 133, which are symmetrically distributed on both sides of the interdigital transducer 132. The reflection gratings 133 on both sides form a surface acoustic wave resonance cavity, and the interdigital transducer 132 converts the surface acoustic wave and the electrical signal. When an external signal is loaded on the input interdigital transducer 132a, the interdigital transducer 132 converts the electrical signal into a surface acoustic wave, which propagates along the surface of the piezoelectric substrate 131 to both sides, is reflected and superimposed by the reflection gratings 133 on both sides, and is output through the output interdigital transducer 132b. The emitted radio frequency converted sound wave resonates with the reflected sound wave. When the temperature changes, the resonance frequency changes, and the host computer judges the temperature change according to the frequency. By collecting the frequency signal of the resonance point of the sound wave, the change of the temperature is perceived through the change of the resonance frequency.

[0047] Optionally, since the quality factor of the delayed surface acoustic wave sensor 130 is much smaller than that of the resonant surface acoustic wave sensor 130, its volume is generally larger than that of the resonant surface acoustic wave sensor 130. Placing multiple delayed surface acoustic wave sensors 130 would result in an excessively large diameter or length of the food temperature probe 100. Therefore, in this embodiment, the resonant surface acoustic wave sensor 130 is preferred as the sensor 130.

[0048] like Figure 1 As shown, in one embodiment, the probe portion 110 is provided with a mounting cavity 111, and the sensors 130 are respectively disposed in the mounting cavity 111. When there are multiple mounting cavities 111, adjacent mounting cavities 111 are separated to avoid adjacent sensors 130 being too close and interfering with each other.

[0049] like Figure 1 As shown, in one embodiment, the radio frequency unit 120 has a placement cavity 121, and the antenna 140 is located inside the placement cavity 121 to avoid damage to the antenna 140 during operation.

[0050] like Figure 1 As shown, in one embodiment, the food temperature probe 100 further includes a coaxial cable 150 for transmitting analog and digital signals. The two ends of the coaxial cable 150 are connected to a sensor 130 and an antenna 140, respectively, to electrically connect the sensor 130 and the antenna 140, thereby enabling electrical signal transmission between the sensor 130 and the antenna 140.

[0051] like Figure 1 As shown, in one embodiment, when there are multiple sensors 130, the sensors 130 are sequentially connected to the coaxial cable 150 so that each sensor 130 is electrically connected to the antenna 140, thereby enabling electrical signal transmission with the antenna 140.

[0052] like Figure 1 As shown, in one embodiment, the probe portion 110 is a tubular structure, and the interior of the probe portion 110 is filled with a thermally conductive material. In this embodiment, the interior of the probe portion 110 is filled with thermally conductive silicone. The fluidity of the thermally conductive silicone allows heat from the outside of the probe portion 110 to be transferred to the sensor 130 via the flow of the thermally conductive silicone, thereby enabling the sensor 130 to measure the temperature. However, this is not a limitation; in other embodiments, the interior of the probe portion 110 may also be filled with other thermally conductive materials.

[0053] The food temperature probe 100 provided in the above scheme can realize temperature detection by setting the sensor 130 on the probe part 110 and the antenna 140 capable of signal transmission with the sensor 130 on the radio frequency part 120, using the principle that the sound surface wave propagation in the sensor 130 is affected by environmental factors, and the time delay or resonance frequency of the return signal changes due to the performance of the piezoelectric substrate 131, and by detecting the time delay or frequency change of the return signal, the change of temperature can be obtained, and the temperature detection is realized. The temperature change is obtained by the frequency change of the signal emitted by the receiving antenna 140. The probe does not need to be connected with other components through a wire, and does not need to be internally provided with a power supply and other components, and is wireless and passive, thereby solving the problems of inconvenient connection of the probe wire and the inability of internal electronic elements to withstand high temperature environment in the prior art.

[0054] The technical features of the above-described embodiments can be combined in any manner. For the sake of brevity, not all possible combinations of the technical features in the above-described embodiments are described, but it should be understood that any combination of the technical features is within the scope of the present disclosure as long as the combination does not result in contradictions.

[0055] The above-described embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the patent scope of the present application. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present application, and these are within the protection scope of the present application. Therefore, the patent protection scope of the present application should be subject to the appended claims.

Claims

1. A food temperature probe, characterized by, The food temperature probe comprises a probe part and a radio frequency part connected together, the probe part is internally provided with at least one sensor, the sensor comprises a piezoelectric substrate, an interdigital transducer and a reflective grating, the interdigital transducer and the reflective grating are both connected to the piezoelectric substrate and are arranged at intervals, the radio frequency part is located at the tail end of the probe part and is internally provided with an antenna, and the sensor and the antenna are electrically connected.

2. The food temperature probe of claim 1, wherein, The probe part comprises a plurality of sensors, the plurality of sensors are distributed along the axial direction of the probe part and are arranged at intervals, the plurality of sensors are electrically connected to the same antenna, and the signals of the plurality of sensors respectively occupy different intervals of the corresponding frequency band of the antenna.

3. The food temperature probe of claim 2, wherein, The signals of the sensors sequentially occupy different intervals of the corresponding frequency band of the antenna according to the distance between the sensors and the radio frequency part.

4. The food temperature probe according to claim 1 or 2, characterized in that, Each of the sensors comprises two reflective gratings, and the two reflective gratings are symmetrically distributed on both sides of the interdigital transducer.

5. The food temperature probe of claim 1, wherein, The probe part is internally provided with mounting cavities, the sensors are one-to-one correspondingly arranged in the mounting cavities, and when the number of the mounting cavities is plural, the adjacent mounting cavities are arranged at intervals.

6. The food temperature probe of claim 1, wherein, The radio frequency part is provided with a placing cavity, and the antenna is located in the placing cavity.

7. The food temperature probe of claim 1, wherein, The food temperature probe further comprises a coaxial cable, and the two ends of the coaxial cable are respectively connected to the sensor and the antenna, so that the sensor and the antenna are electrically connected.

8. The food temperature probe of claim 7, wherein, When the sensor is plural, the sensors are sequentially connected to the coaxial cable.

9. The food temperature probe of claim 1, wherein, The probe part is in a tubular structure, and the probe part is internally filled with a heat-conducting material.

10. A cooking apparatus, characterized by, The food temperature probe comprises the food temperature probe according to any one of claims 1-9.

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