Liquid level detection device and method

[0028] In order to help those skilled in the art to accurately understand the subject matter claimed by the present invention, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0029] Terms of spatial position or terms of spatial relationship, such as "vertical", "longitudinal", etc., are used herein for the convenience of description to describe the relationship between one element or feature and another element or feature as shown in the figure. . It will be appreciated that in addition to the directions depicted in the figures, the terms of spatial relationship are intended to encompass different orientations of devices, components, or structures in use or operation. In this text, "vertical" and "longitudinal" refer to the directions shown in the drawings, and also along the direction of the liquid level.

[0030] See figure 1 , Is the principle diagram of the liquid level detection device involved in the present invention. The liquid level detection device at least includes a light-emitting device 11, a plurality of optical fibers 12, a checking fixture 13 and a housing 14. The light emitting device 11 has a plurality of light sources 111, and each light source 111 generates a directional light beam 112. An optical fiber 12 is arranged on the opposite side of the light-emitting device 11. One end of each optical fiber 12 is a receiving end 121 for receiving the light beam signal generated by the opposite light source 111, and the other end is an output end 122 for transmitting the light beam signal For observation. The gauge 13 is set in the object 9 to be tested, that is, the liquid to be tested, and is positioned to block at least a part of the light beam 112, so that part of the optical fiber 12 cannot receive the corresponding light beam signal, so that the corresponding liquid level information is on the optical fiber 12. The output terminal 122 outputs. The light emitting device 11 and the receiving end 121 of the optical fiber 12 are arranged on the housing 14.

[0031] Using the above-mentioned device, the inspection tool 13 is immersed in the tested object 9, that is, the liquid to be tested. Under the action of buoyancy, the inspection tool 13 is positioned in the liquid to be tested. For the light emitting device 11 and the optical fiber 12, a part of the light beam signal can reach the receiving end 121 of the optical fiber 12, while the other part of the light beam signal cannot be received by the corresponding optical fiber 12 because of the shielding of the gage 13. Therefore, the optical fiber 12 can transmit different signals to characterize different liquid levels.

[0032] Optical fiber is a transparent glass fiber filament with a diameter of about 1-100μm. It is composed of two layers of inner core and outer jacket. The refractive index of the inner core is greater than that of the outer jacket. Light enters from one end at the interface between the inner core and the outer jacket. After multiple total reflections, it shoots out from the other end. Optical fiber has the advantages of bandwidth, low loss, strong anti-interference ability, reliable working performance and low cost.

[0033] See figure 2 , Is a schematic structural diagram of an embodiment of the liquid level detection device related to the present invention. The liquid level detection device includes a light emitting device 11, an optical fiber 12, a checking fixture 13 and a housing 14. The working principle of light-emitting device 11 and optical fiber 12 is figure 1 The content of the introduction is similar. The housing 14 has at least a main body 141 and a column 142 extending from the bottom of the main body 141.

[0034] A number of light sources 111 and a number of optical fibers 12 in the longitudinal direction as shown in the figure are respectively arranged on opposite sides of the body 141. The number of the light source 111 and the optical fiber 12 are equal, and their positions correspond one-to-one. That is, one of the light sources emits light beams, and the corresponding fiber on the opposite side is responsible for receiving light beam signals. In a limited space, the number of light sources 111 also depends on the required detection accuracy. The denser the light sources 111 are arranged in the longitudinal direction, the higher the detection accuracy. In addition, those skilled in the art can imagine that the light source 111 may also be arranged in multiple rows in the housing 14 to cooperate with a certain control method to improve the accuracy of the detection result. The optical fiber 12 is flexible, so it can be arranged in a desired path without restriction, and the light beam signal is transmitted to the fiber output end 122 without loss, and finally converted into information that is convenient for the observer to read. Therefore, the output terminal 122 may be arranged near a position visible to the observer. The layout of the output terminal and the circuit layout of the entire liquid level detection device will be introduced below.

[0035] The body 141 and the cylinder 142 of the housing 14 can be filled with the liquid to be measured. The housing 14 has a structure for positioning the measuring tool 13 so that when the measuring tool 13 contacts the bottom surface of the liquid to be tested, the measuring tool 13 is positioned relative to the liquid in the vertical direction of the liquid. Specifically, the column 142 has a certain length in the longitudinal direction, and the inspection tool 13 can move longitudinally in the column 142 relative to the column 142. The inspection tool 13 may adopt a float having a cross-sectional shape similar to that of the column 142. The top of the float may be provided with an expansion part having a surface 131 for measurement. The surface 131 is kept parallel to the transmission direction of the signal (or the surface of the liquid to be measured), thereby improving the accuracy of detection. The bottom of the float has a contact surface 132 that contacts the bottom surface of the liquid to be measured. After the float touches the bottom surface of the liquid to be measured, the float is positioned in the vertical direction. However, it can be known that the shape of the inspection tool 13 or the column 142 is not limited to the embodiment shown in the figure, and other alternative designs can be made according to the actual measurement environment.

[0036] In the liquid to be measured, the float floats up due to the buoyancy effect, thereby blocking the corresponding light beam, so that the corresponding optical fiber 12 cannot receive light. Light can be transmitted almost non-destructively from the fiber receiving end 121 to the output end 122, and then to the observer’s eyes. One way of characterization is that the brightness of the output end 122 of the optical fiber 12 can be used as the observer’s judgment of the liquid level. in accordance with. This method will be introduced in detail below.

[0037] image 3 An embodiment of the circuit diagram of the liquid level detection device of the present invention is shown, and the circuit connection mode of the light-emitting device is shown. 31 is the light source (ie figure 1 , 2 In the light source 111), 32 is a switch, 33 is a power source, and 34 is a wire. The multiple light sources 31 are connected in parallel in the circuit.

[0038] Figure 4 It is a schematic diagram of an embodiment of the observation end surface of the liquid level detection device according to the present invention. In the figure, 41 is the optical fiber observation end, 42 is the power switch, and 43 is the reference label. The optical fiber observation end 41 may be directly connected to the output end of the optical fiber, which is composed of a plurality of output holes arranged vertically, and light is transmitted to the observer's eyes through each output hole. The power switch indicator 42 may be a physical image of the switch 32. The reference label 43 is used as a judgment reference for judging the liquid level, which can let the observer know the current liquid level information more intuitively. For example, the label may indicate the liquid level with "upper limit 431", "center 432", "lower limit 433", etc. In this way, the observer can know whether it is necessary to replenish the liquid in time. For different detection objects, the liquid level detection device can be used by correctly calibrating the fiducial label without changing the liquid level detection device itself, so that the present invention has good applicability.

[0039] See Figure 5 , 6 It is an embodiment of the liquid level detection device of the present invention applied to the liquid level detection of a gearbox. in Figure 5 An oil level detection hole 61 is provided on the housing 62 of the automatic gearbox shown. Image 6 Shown is a cross-sectional view of the detection hole 61 on the housing 62. In the internal structure of the detection hole 61, the detection hole 61 is made in the housing 62 of the gearbox. The detection hole 61 has a certain depth. The inspected object 9 is filled with oil, and at least has a space for accommodating the housing of the liquid level detecting device extending into the oil. The observation window together with the output end of the optical fiber can be arranged at any desired position in the front compartment of the vehicle. The liquid level detection device is inserted into the detection hole 61 so that the bottom of the inspection tool is in contact with the bottom 611 of the detection hole, so that the inspection tool is positioned in the direction of the height of the liquid level. On the other end away from the detection hole, the observer can immediately get the relevant liquid level information. It can be seen that the present invention can be provided without changing the main structure of the front compartment of the vehicle. Therefore, the present invention can be applied to various vehicles/car front compartments with complicated layout, and the oil level detection is very convenient.

[0040] Although the specific embodiments of the present invention have been shown and described in detail to illustrate the principles of the present invention, it should be understood that the present invention can be implemented in other ways without departing from such principles.