Position detection device, valve actuator and valve assembly for air conditioning system

Abstract

The utility model provides a position detection device, a valve actuator and a valve assembly for an air conditioning system. The position detection device is used for the valve actuator, the valve actuator comprises a base plate and an actuating rod penetrating through the base plate, and the position detection device comprises a connecting element used for being fixedly connected with the actuating rod; the stress element can be arranged on the base plate, one end of the stress element is arranged to be a fixed end, and the other end of the stress element is arranged to be a free end; the middle element is arranged between the connecting element and the free end of the stress element; and the strain gauge is arranged on the surface, which is deformed due to the stress of the middle element, of the stress element. The position detection means for the valve actuator is high in cost performance, and the problem that the position of a control valve is not accurate due to the fit clearance between a gear and a potentiometer in position feedback can be solved.

Description

Technical Field

[0001] The present disclosure relates to the position detection of valve actuators and the field of air conditioning systems. Specifically, it relates to a position detection device, a valve actuator, and a valve assembly for an air conditioning system. Background Art

[0002] This section aims to provide background information related to understanding the various technologies described herein. As implied by the title of this section, this is in no way to be construed as an admission that any of the related technologies are necessarily prior art. Therefore, it should be understood that any statement in this section should be read from this perspective and not as an admission of prior art.

[0003] In some embodiments known to the applicant, there are several ways to obtain the opening degree information of the valve. First, by adding a gear drive in the reduction system, the angular position of time is converted into a resistance change of the potentiometer through the mechanical cooperation of the shaft (i.e., the valve stem) and the potentiometer, and then the voltage value is read by the MCU (Microcontroller Unit), thereby obtaining the opening degree information of the valve. The risks that may exist in this technical solution are that there are gaps in the reduction gear of the actuator. The bearing and the shaft need to be installed with clearance fit, and there are also gaps, and there are cumulative errors in the deformation of all force-bearing mechanisms such as gear deformation, resulting in the inability to accurately reflect the current position of the valve. Second, the BLDC (Brushless Direct Current) motor has Hall signals. First, the actuator walks through the entire process of the valve body, records the number of Hall signals, and then obtains the number of Hall signals for controlling the valve position through a linearization equation, thereby realizing the precise control of the valve position. The risks that may exist in this technical solution are that when the actuator is powered on, it does not know the absolute position where the actuator is located. Because after the actuator is powered off or during the first installation, the actuator may be manually debugged for its position. At this time, since the actuator is not powered on, the changing Hall signals will not be recorded by the MCU. Summary of the Utility Model

[0004] The purpose of the present disclosure is to provide a cost-effective position detection means for a valve actuator, which can overcome the problem of inaccurate control of the valve position caused by the clearance between the gear and the potentiometer in position feedback.

[0005] In addition, the present disclosure also aims to solve or at least alleviate one or more technical problems existing in the prior art.

[0006] The present disclosure solves the above problems by providing a position detection device, a valve actuator, and a valve assembly for an air conditioning system. Specifically, according to one aspect of the present disclosure, the following is provided:

[0007] A position detection device for a valve actuator, the valve actuator including a substrate and an actuating rod passing through the substrate, wherein the position detection device includes:

[0008] A connecting element for fixedly connecting with the actuating rod;

[0009] A force-receiving element that can be arranged on the substrate, one end of the force-receiving element being set as a fixed end and the other end being set as a free end;

[0010] An intermediate element arranged between the connecting element and the free end of the force-receiving element; and

[0011] A strain gauge arranged on the surface of the force-receiving element that is deformed by the intermediate element.

[0012] Optionally, according to an embodiment of the present disclosure, the position detection device further includes a strain gauge arranged on the surface of the force-receiving element that is not deformed by force.

[0013] Optionally, according to an embodiment of the present disclosure, the force-receiving element is configured as a cantilever structure or a spring piece.

[0014] Optionally, according to an embodiment of the present disclosure, the intermediate element includes a first spring, one end of the first spring abutting against the connecting element and the other end being supported by the force-receiving element.

[0015] Optionally, according to an embodiment of the present disclosure, the first spring is configured as a conical spring, and a plurality of the force-receiving elements support the other end of the first spring on the substrate with a uniform angular distribution.

[0016] Optionally, according to an embodiment of the present disclosure, the intermediate element includes a transmission mechanism, the transmission mechanism being connected to the connecting element such that a first movement of the connecting element along the movement direction of the actuating rod is converted into a second movement of the transmission mechanism, the direction of the second movement being in a plane perpendicular to the direction of the first movement, and the transmission mechanism directly or indirectly transmits the second movement to the free end of the force-receiving element.

[0017] Optionally, according to an embodiment of the present disclosure, the transmission mechanism and the connecting element are in concave-convex fit.

[0018] Optionally, according to an embodiment of the present disclosure, the connecting element is configured with a groove and a protrusion formed on the groove, and the transmission mechanism is configured with a guide groove that cooperates with the protrusion.

[0019] Optionally, according to an embodiment of the present disclosure, the intermediate element further includes a second spring, and the second spring is disposed between the transmission mechanism and the force-receiving element.

[0020] Optionally, according to an embodiment of the present disclosure, a plurality of the force-receiving elements are symmetrically arranged with respect to the actuating rod.

[0021] Optionally, according to an embodiment of the present disclosure, the position detection device further includes a controller, and the controller has:

[0022] a collection unit for collecting the output value of the strain gauge;

[0023] a processing unit for obtaining the position of the connecting element based on the output value; and

[0024] an output unit for outputting the position of the connecting element.

[0025] According to another aspect of the present disclosure, there is provided a valve actuator, wherein the valve actuator includes any one of the above position detection devices, and the actuating rod is used to adjust the working position of the valve.

[0026] According to still another aspect of the present disclosure, there is provided a valve assembly for an air-conditioning system, wherein the valve assembly includes a damper or a water valve of the air-conditioning system, and the above valve actuator, and the valve actuator is used to adjust the working position of the damper or the water valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] With reference to the accompanying drawings, the above and other features of the present disclosure will become apparent, wherein,

[0028] Figure 1 a perspective schematic diagram of an actuator and its position detection device according to the present disclosure is shown;

[0029] Figure 2 a perspective schematic diagram of another actuator and its position detection device according to the present disclosure is shown;

[0030] Figure 3 a schematic structural diagram of a connecting element according to the present disclosure is shown;

[0031] Figure 4 a schematic structural diagram of a transmission mechanism according to the present disclosure is shown;

[0032] Figure 5 a perspective schematic diagram of still another actuator and its position detection device according to the present disclosure is shown; and

[0033] Figure 6 is shown based on Figure 5 a cross-sectional view at the position detection device area. Detailed implementation manners

[0034] It is easy to understand that, according to the technical solution of the present disclosure, without changing the essence of the present disclosure, those of ordinary skill in the art can propose various interchangeable structural manners and implementation manners. Therefore, the following detailed implementation manners and the accompanying drawings are only exemplary descriptions of the technical solution of the present disclosure, and should not be regarded as all elements of the present disclosure or as a limitation or restriction on the technical solution of the present disclosure.

[0035] The orientation terms such as up, down, left, right, front, back, front side, back side, top element, bottom element, etc. mentioned or possibly mentioned in this specification are defined relative to the structures shown in the respective drawings. They are relative concepts, and thus may change accordingly depending on their different positions and different usage states. Therefore, these or other orientation terms should not be interpreted as restrictive terms. In addition, the terms "first", "second", "third", etc. or similar expressions are only used for descriptive and differentiating purposes, and cannot be understood as indicating or implying the relative importance of the corresponding components.

[0036] Reference Figure 1 , which shows a perspective schematic view of an actuator and its position detection device according to the present disclosure.

[0037] The position detection device 1 is used for a valve actuator 100, and the valve actuator 100 includes a substrate 101 and an actuating rod 102 passing through the substrate 101. Wherein, the position detection device 1 includes:

[0038] A connecting element 11 for fixedly connecting with the actuating rod 102;

[0039] A force-receiving element 12 that can be arranged on the substrate 101, one end of the force-receiving element 12 is set as a fixed end, and the other end is set as a free end;

[0040] An intermediate element 13 arranged between the connecting element 11 and the free end of the force-receiving element 12; and

[0041] A strain gauge arranged on the surface of the force-receiving element 12 that is deformed due to the intermediate element 13.

[0042] It should be understood that the valve actuator is used to control the opening of the valve or the working position of the regulating valve through its actuating rod, including the open position, the closed position or the intermediate position between the two, so as to achieve the flow control of the corresponding fluid. There are many types of valve actuators, for example, composed of a control unit, a three-phase or single-phase motor, and an optional mechanical transmission mechanism 103, the transmission mechanism is used to transmit the output of the motor to the actuating rod, the valve actuator and the valve seat of the valve are connected together through the valve stem, so that the valve stem can be driven by the actuating rod to drive the valve seat to move in the valve body, so as to open or close the fluid flow channel in the valve body, realize the opening control of the valve, and finally realize the flow control of the fluid (such as air or cooling water) through the opening of the valve.

[0043] It is feasible that the transmission mechanism can be composed of a gear set, and one of the gears (e.g., a smaller gear) meshes with the gear on the output shaft of the motor 104 to achieve power transmission, and the larger gear is in transmission connection with the actuating rod, so that the rotational motion of the larger gear can be converted into the linear motion of the actuating rod. At the same time, due to the size difference design of this series of gears, a deceleration effect is achieved. Therefore, this transmission mechanism can also be called a deceleration mechanism. The transmission mechanism is, for example, arranged on one side of the substrate (with Figure 1 For example, the bottom surface of the substrate is shown in FIG. 1 , and the position detection device is arranged on the opposite side of the substrate, for example Figure 1 The top surface of the substrate. Regarding the above-mentioned specific method of converting rotational motion into linear motion, in one embodiment, the inner wall of the larger gear (or the actuating rod sleeve connected to the larger gear in synchronous rotation, which is sleeved on the actuating rod) is configured with an internal thread, and the actuating rod is configured with an external thread, and the thread cooperation between the external thread and the internal thread achieves the above-mentioned motion conversion effect. In this regard, the actuating rod can also be called a screw. It can also be understood that the connecting element is configured with an internal thread so as to form a fixed connection with the external thread of the screw.

[0044] Furthermore, the linear motion of the actuating rod, or rather the longitudinal motion of the actuating rod along its longitudinal direction of the rod length, drives the connecting element to move, that is, corresponding to the linear motion of the connecting element (also referred to as the first motion hereinafter), and then the linear motion of the connecting element is reflected onto the force-bearing element via the intermediate element. For example, it is manifested as the force-induced deformation of the force-bearing element, and finally the force-induced deformation is sensed by the strain gauge on the force-bearing element. In this regard, one end of the force-bearing element is set as a fixed end, and the other end is set as a free end, and the intermediate element is arranged between the connecting element and the free end of the force-bearing element, so that the intermediate element can transfer the motion of the connecting element to the free end of the force-bearing element. Among them, the fixed end of the force-bearing element is responsible for determining the position of the force-bearing element and providing stable support for the force-bearing element, while the free end of the force-bearing element is responsible for absorbing the force transmitted by the intermediate element and reflecting it in the form of deformation on the free end, thereby providing a basis for the strain sensing of the strain gauge on the force-bearing element. Thus, it can also be understood that the strain gauge can be directly arranged in the free end area of the force-bearing element, or can be arranged on the deformed part of the strain gauge caused by the deformation of the free end. In other words, the strain gauge can be arranged on the surface of the force-bearing element that is deformed due to the intermediate element.

[0045] It should be noted that the intermediate element is arranged between the connecting element and the free end of the force-bearing element, which does not strictly require that the spatial position layout of the intermediate element is between the connecting element and the free end of the force-bearing element, but means that the intermediate element is in a transmission connection between the two. That is, the intermediate element can transfer the first motion of the connecting element to the free end of the force-bearing element in a certain form. For example, Figure 1 the embodiments of Figure 2 and Figure 5 the embodiments of

[0046] In the accompanying drawings of the present disclosure, the above-mentioned transmission process is exemplarily implemented in a mechanical contact manner. In addition, in some other embodiments, it is also possible to consider implementing the transmission of motion in a non-contact manner, such as in a magnetic drive manner. Specifically, one or more magnets (such as permanent magnets or electromagnets) are installed on the connecting element, and these magnets generate a magnetic field. On the force-receiving element, there are installed magnets or induction coils that can respond to this magnetic field. When the connecting element moves, the magnetic field generated by the magnets on it also changes accordingly, thereby generating a corresponding induced stress or electromagnetic force on the force-receiving element, causing the force-receiving element to deform under force. Thus, it can be seen that this technical solution uses the magnetic field as the medium for power transmission to achieve non-contact transmission between two components. The advantages of magnetic drive include no contact, no noise, and high transmission efficiency. In this regard, the intermediate element is the magnet for realizing this magnetic force transmission. After studying various transmission methods of the present disclosure, those skilled in the art can select a suitable transmission method according to actual requirements, such as cost factors, external environmental factors (such as whether there is a non-negligible external magnetic field interference), design space, and layout space factors.

[0047] Since the motion or force relationship among the actuating rod, the connecting element, the intermediate element, and the force-receiving element is determined, the output value of the strain gauge (such as its resistance value or voltage value) can establish a one-to-one mapping relationship with the position of the actuating rod. Thus, the position of the actuating rod can be obtained according to the output value of the strain gauge through the determined mapping relationship, and further the position of the valve seat can be reflected, corresponding to the opening degree of the valve. As for the establishment of the mapping relationship, it can be determined by theoretical means, that is, by analyzing the motion or force of the components involved, or a look-up table regarding the output value of the strain gauge and the position of the connecting element (or the position of the actuating rod, the valve seat, the opening degree of the valve, etc., which are essentially the same thing) can be established in advance. Thus, in the subsequent actual use process, the current output value of the strain gauge is combined with the look-up table to find the corresponding position of the connecting element, and then the current opening degree of the valve can be determined. This method can focus only on the position of the connecting element and the output value of the strain gauge without considering the intermediate links, which is more convenient and effective. It should be noted that this mapping relationship can be a linear relationship or a non-linear relationship. In the case of a linear relationship, the relationship between the position of the connecting element and the resistance value or voltage of the strain gauge can be established with a minimum of only two sets of known data. In the actual use process, for example, the initial position of the connecting element and the corresponding output value of the strain gauge are used as one set of data, and the end position of the connecting element and the corresponding output value of the strain gauge are used as another set of data to calibrate the detection device or the entire valve assembly, establish a linear relationship, or use the intermediate position and output value as supplementary data to fit the corresponding relationship, reducing errors and improving accuracy.

[0048] Due to this design of the actuator (the linear motion of the actuating rod, the rotational motion of the motor and the transmission mechanism), this actuator is sometimes also referred to as a linear stroke actuator or a multi-turn actuator in the industry. In addition, since the strain gauges are arranged on the force-bearing element, the force-bearing element can sometimes also be referred to as a load-bearing element.

[0049] Based on the above understanding and combined with this technical solution, it realizes the position detection of the valve actuator in a relatively cost-effective manner, such as the position of the connecting element and the determination of the valve opening. And since the entire detection device is arranged based on the substrate and not on the gear, the error caused by the inevitable fitting clearance between the gear and the potentiometer can be avoided, improving the measurement accuracy of the valve opening, which is beneficial to the subsequent valve position control, thus achieving the purpose of this disclosure.

[0050] From Figure 1 it can also be seen that, as mentioned above, the transmission mechanism is arranged on the bottom surface of the substrate, and the force-bearing element of the position detection device is arranged on the top surface of the substrate (it will also be mentioned later that a circuit board can also be arranged on the top surface of the substrate). Therefore, due to this positional relationship, the substrate is sometimes also referred to as the middle plate in the industry. In addition, two relatively large through holes are arranged on the substrate. One through hole is for the actuating rod to pass through, and the other through hole is located in the area where the motor is arranged. The output shaft of the motor passes through this through hole and extends into the bottom side area of the substrate. The small gear connected to the output shaft meshes with the smaller gear of the transmission mechanism to complete the power transmission.

[0051] Regarding the working principle of the strain gauge, it should be known that when it is subjected to mechanical stress, its resistance value or voltage value will change proportionally with the strain of the attached device. There is approximately a linear relationship between this resistance / voltage change and its strain, which can conveniently reflect the deformation amount of the involved components. In addition, the advantages of using strain gauges also include: low cost and diverse implementation methods; strong adaptability to the working environment; large measurement range; small size, light weight; fast measurement speed; high sensitivity and accuracy; convenient for multi-point measurement; and the measurement results are convenient for transmission, recording and processing, etc. Thus, the various technical solutions of this disclosure can inherit the above advantages.

[0052] In some embodiments of this disclosure, the position detection device 1 further includes strain gauges arranged on the non-force-deformed surface of the force-bearing element 12.

[0053] It should be understood that the term "force-bearing element" only represents that a certain part of this element will undergo force deformation, and it does not necessarily mean that all parts have to be force-deformed. For example, in Figure 1 the shown embodiment, the top surface of the force-bearing element is the force-deformed surface, and the side surface is not force-deformed; in Figure 2 、 5In the illustrated embodiment, the top surface of the force-bearing element is not deformed by force, while the side surface is deformed by force. Those skilled in the art can understand the specific references to the side surface and the top surface of the force-bearing element. Among them, the side surface can also be expressed as a surface perpendicular to the top surface of the substrate (the substrate bearing surface), and the top surface can be expressed as a surface parallel to the top surface of the substrate and away from the top surface of the substrate.

[0054] Through the above technical solution, a differential design of the arrangement positions of the strain gauges is carried out. For example, the strain gauges are respectively arranged on the surface of the force-bearing element that is deformed by the action of the intermediate element (such as the top surface) and the surface that is not deformed by force (such as the side surface). Thus, the strain gauge arranged on the top surface is responsible for measuring the deformation caused by the force, while the strain gauge arranged on the side surface is not responsible for deformation measurement but is used for temperature compensation. This is because in some application scenarios, the resistance / voltage change of the strain gauge, that is, the deformation measurement, is sensitive to temperature (this is because when the ambient temperature changes, the expansion coefficient of the strain gauge is different from that of the measured component, resulting in a change in the resistance / voltage of the resistance strain gauge, thereby generating extra strain. This strain caused by temperature change is interference strain). Therefore, this measure can be considered to offset the influence brought by temperature change, so as to improve the measurement accuracy and adapt to a wider range.

[0055] Those skilled in the art should know the working principle of strain gauge temperature compensation. Briefly speaking, the strain gauge arranged on the side surface of the force-bearing element is in the same temperature field as the strain gauge used for measurement. If all the strain gauges are the same (including material and linear expansion coefficient), the influence of temperature output can be eliminated, and complete temperature compensation can be achieved. In this case, the strain gauge for temperature compensation does not generate any deformation, but transfers the temperature change of the force-bearing element to this strain gauge. It can also be understood that, as mentioned above, in Figure 2 and Figure 5 the illustrated embodiment, the side surface of the force-bearing element is the force-bearing surface, while the top surface is the non-force-bearing surface. Therefore, the strain gauge layout idea of the Figure 1 embodiment needs to be analogized in reverse.

[0056] Regarding the specific design of the strain gauge, in some embodiments of the present disclosure, the strain gauge is configured as a bridge-type resistance strain gauge group. The bridge-type resistance strain gauge group includes a plurality of (such as four) bridge-type resistance strain gauges. At least one (such as two) bridge-type resistance strain gauges are arranged on the force-deformed surface of the force-bearing element 12, and at least one (such as two) bridge-type resistance strain gauges are arranged on the surface of the force-bearing element 12 that is not deformed by force

[0057] The bridge-type resistive strain gauge can achieve high measurement accuracy and linearity, has strong anti-interference ability and an expanded output signal range, the measurement results are reliable, and through the above arrangement method, according to the sum and difference rules of the output voltage of the bridge, complete temperature compensation is also achieved. In addition, regarding the "bridge" arrangement method, in one embodiment, the bridge structure is a Wheatstone bridge structure, and the resistors are all strain gauges to ensure the accuracy and compensation of the measurement.

[0058] In some embodiments, the force-bearing element 12 is configured as a cantilever structure or a leaf spring. For example, Figure 1 、 Figure 2 in the embodiment of Figure 5 a leaf spring is selected, and in the embodiment of

[0059] a cantilever structure is selected as the force-bearing element. The leaf spring and the cantilever structure can both be made of metal material exemplarily, which can ensure strength, stiffness, wear resistance, corrosion resistance, high elasticity and elastic recovery ability, and stable elastic deformation characteristics.

[0060] As for the technical solution where the force-bearing element is a cantilever structure, in this case, the spring acts on the free end of the cantilever structure. The advantages of the cantilever structure include high strength and easy maintenance. It can bear a large weight and pressure, and the structural design can make the force distribution more uniform, thereby improving the strength of the entire structure. When subjected to an external force, the cantilever structure can maintain good stability and load-bearing capacity. In particular, the deformation amount of the cantilever structure is small, the structure is relatively stable and strong, and it is not easily affected by interference factors.

[0061] It should also be understood that the selection of the leaf spring or the cantilever structure in the embodiments of the present disclosure is exemplary and there is no particular limitation. Those skilled in the art can flexibly select the leaf spring or the cantilever structure according to the above characteristics of the leaf spring and the cantilever structure as needed in different embodiments.

[0062] To achieve a better motion or mechanical transmission effect, exemplarily, the intermediate element 13 includes a first spring 131. One end of the first spring 131 abuts against the connecting element 11, and the other end is supported by the force-receiving element 12. Thus, while the connecting element makes a longitudinal motion, the first spring undergoes a telescopic motion. The spring force generated by this telescopic motion is then transmitted to the force-receiving element and the strain gauge thereon. The advantage of using a spring as the intermediate element is that the force analysis of the spring is relatively easy. Those skilled in the art know that the deformation force FS1 generated by the first spring is FS1 = KS1 * L1, where KS1 is the spring constant of the first spring and L1 is the longitudinal motion distance of the connecting element. It is also known that the deformation force FS1 of the first spring is applied to the force-receiving element. Therefore, it can be obtained that the deformation amount LC at the contact part between the force-receiving element and the first spring is LC = (KS1 * L1) / KC, where KC is the spring constant of the force-receiving element. It is also known that the deformation amount LC is proportional to or at least has a corresponding relationship with the resistance / voltage of the strain gauge. Therefore, finally, the corresponding relationship between the resistance / voltage and the position of the connecting element can be obtained through theoretical analysis. Of course, if the strain gauge for sensing deformation is located at other parts on the top surface of the force-receiving element, then when conducting theoretical analysis, the lever relationship between the contact part and the other part also needs to be considered. In any case, as previously mentioned, since the motion and force relationships of these components are corresponding, it is possible to simply use an experimental method to record the resistance / voltage of the corresponding strain gauge by adjusting the position of the connecting element, and finally establish a comparison table between the two, without the need to conduct theoretical analysis on the intermediate links, and the final position detection effect can also be obtained. The theoretical and experimental analysis methods can be analogized in the embodiments shown in Figure 2 and Figure 5 which will not be elaborated further below.

[0063] It can also be seen in Figure 1 that the first spring 131 is configured as a conical spring (sometimes also referred to as a tapered spring), and a plurality of the force-receiving elements 12 support the other end of the first spring 131 on the substrate 101 with a uniform angular distribution.

[0064] Compared with a straight spring, the design of the tower spring can improve the compactness of the entire position detection device. This is because during the telescopic movement of the tower spring, the thinner end can move within the accommodation space formed by the thicker end, while when a straight spring is compressed to a certain extent, it will be "compressed into a block" and can no longer be compressed. That is to say, the tower spring can be compressed more "flat". Therefore, the tower spring can support a greater degree of expansion and contraction, or has a smaller floor space under the condition of the same degree of expansion and contraction (the same stroke of the actuating rod), improving the compactness of the entire position detection device. In addition, in this technical solution, multiple force-bearing elements are arranged evenly. For example, three force-bearing elements are used and are evenly distributed at an angle of 120° to each other, which can measure the deformation amount more comprehensively, and can improve the reliability of measurement through methods such as averaging, with strong anti-interference ability; it can also maintain the normal operation of the entire position detection device in the case of a failure of one or some strain gauges, improving the redundancy of the device and having high safety. In Figure 2 and Figure 5 In other embodiments, two force-bearing elements are respectively arranged exemplarily, and the above-mentioned dual effects can also be achieved, which will not be elaborated further below.

[0065] Refer to Figure 2 , which shows a three-dimensional schematic diagram of another actuator and its position detection device according to the present disclosure.

[0066] The intermediate element 13 includes a transmission mechanism 132. The transmission mechanism 132 is connected to the connecting element 11, so that the first movement of the connecting element 11 along the movement direction (longitudinal direction) of the actuating rod 102 is converted into the second movement of the transmission mechanism 132. The direction of the second movement is in a plane perpendicular to the direction of the first movement. The transmission mechanism 132 directly or indirectly transmits the second movement to the free end of the force-bearing element 12.

[0067] In this technical solution, it should be noted that through the design of the transmission mechanism, the first movement (longitudinal movement or vertical movement) of the connecting element is converted into the second movement (lateral movement or horizontal movement) of the transmission mechanism. Since the longitudinal movement of the connecting element corresponds to the longitudinal movement of the actuating rod, the stroke is usually larger, while the lateral movement of the transmission mechanism can be made to have a smaller stroke according to different embodiments. Therefore, this technical solution provides a possibility, that is, converting a large-stroke movement into a small-stroke movement, and then the strain gauge on the force-bearing element is used to detect the deformation amount caused by the small-stroke movement, improving the convenience of position measurement. At the same time, since these two stroke movements also have a definite and corresponding movement relationship, the measurement accuracy is maintained. Examples of specific conversion means will be further explained below.

[0068] As slightly mentioned before, for example, in Figure 2(and in the embodiments to be further described hereinafter Figure 5 ), a plurality of the force - receiving elements 12 are symmetrically arranged with respect to the actuating rod 102. Thus, the output values of the strain gauges on each force - receiving element can be averaged as the output value of the overall device, improving the redundancy of the entire position - detecting device and also enhancing the overall reliability. Even in the case where one or several strain gauges fail, the normal operation of the device can be maintained. In this regard, it can be understood that the intermediate elements (such as the transmission mechanism and the second spring to be mentioned hereinafter) can also be symmetrically arranged in a matching manner.

[0069] In addition, regarding the specific implementation forms of symmetry, for example, as shown in Figure 2 and Figure 5 , a plurality of force - receiving elements are arranged in rotational symmetry with respect to the longitudinal direction of the actuating rod (such as the vertical direction), or can be arranged in translational symmetry with respect to the plane where the axis of the actuating rod is located and parallel to the long side of the actuator housing. Other symmetry methods can also include mirror symmetry, or a combination form of these symmetry methods, etc. Those skilled in the art can flexibly adjust the number and layout of components such as force - receiving elements according to the actual available accommodation space provided by the actuator, and can understand and select the symmetry method with respect to the actuating rod.

[0070] It can also be understood that in the case where a plurality of transmission mechanisms are provided, although the directions of the second motions of each transmission mechanism are still all in the plane perpendicular to the direction of the first motion, the directions of the second motions have different orientations in this plane, so as to perform force transmission with the second springs or force - receiving elements in different positions respectively.

[0071] Combined with Figure 3 and Figure 4 , wherein, Figure 3 shows a schematic structural view of a connecting element according to the present disclosure; and Figure 4 shows a schematic structural view of a transmission mechanism according to the present disclosure.

[0072] The transmission mechanism 132 and the connecting element 11 are in male - female fit. Exemplarily, the outer peripheral surface of the connecting element is provided with protrusions, and the corresponding side of the transmission mechanism is provided with recesses, and the two cooperate with each other to support the movement guidance of the transmission mechanism and the connecting element. Thus, the male - female fit realizes the stability, smoothness and durability during movement through an accurate and firm connection method.

[0073] Specifically, in some embodiments, the connecting element 11 is configured with a groove 111 and a protrusion 112 formed on the groove 111, and the transmission mechanism 132 is configured with a guide groove 1321 that cooperates with the protrusion 112. Among them, the groove can be a dovetail groove, which can enhance the stability of motion transmission, increase the load-bearing capacity, improve the overall operating efficiency and smoothness of motion, and at the same time has the effect of beautifying the appearance. It is a multi-functional structure or connection technology. According to different shapes, it can be subdivided into multiple types such as "V-shaped dovetail groove", "semicircular dovetail groove", "square dovetail groove", etc. Several sides of the transmission mechanism that cooperate with the groove can be joined to the bottom and side walls of the groove to achieve mutual engagement. Similarly, the protrusion and the guide groove can be shape-mated to better achieve mutual interaction and motion guidance, achieving high stability, smoothness, precision, anti-offset, and simplified structure. Combined with the previous engagement design of the groove, the stability and robustness of the motion are improved, as well as the limiting and guiding of the transmission mechanism during lateral motion. It can also be understood that a guide groove can be designed at the connecting element, and a groove and a protrusion can be designed at the transmission mechanism, and the same comparable technical effects can be achieved.

[0074] In addition, in Figure 2 it can also be seen that the guide groove is inclined. Specifically, relative to the longitudinal direction of the actuating rod, the distance from the actuating rod gradually increases in the direction facing the front of the substrate from top to bottom. In short, the inclination direction of the guide groove forms a certain angle with the longitudinal direction of the actuating rod, so as to support the conversion of the longitudinal motion of the connecting element into the lateral motion of the transmission mechanism. Specifically, when the connecting element moves upward, the transmission mechanism moves away from the actuating rod, and when the connecting element moves downward, the transmission mechanism moves towards the actuating rod. This angle can be a small acute angle, which can improve the overall compactness and better conform to the design concept from a large stroke to a small stroke.

[0075] In Figure 2 embodiments, two sets of intermediate elements and force-bearing elements are designed in total to improve the detection accuracy and redundancy of the entire device. When necessary, the number of sets can be adjusted according to actual requirements. Similarly, in order to support the lateral movement of the transmission mechanism on the substrate, the two can also adopt a concave-convex matching method. For example, one is provided with a groove (such as a dovetail groove), and the other is provided with a convex part to achieve motion guidance and limitation.

[0076] As described above, the correspondence between the position of the connecting element and the resistance / voltage of the strain gauge can be found by experimentally establishing a look-up table or a mapping table. If a theoretical method is adopted, for example, assuming the longitudinal movement distance of the connecting element is L1, then the lateral movement distance L2 of the transmission mechanism is L2 = tanα * L1, where α is the angle between the inclination direction of the guide groove and the longitudinal direction of the actuating rod. Further, the deformation amount L3 of the force-bearing element is L3 = L2. Since it is known that there is a definite correspondence between the resistance / voltage of the strain gauge and the strain or deformation, the resistance / voltage output finally has a definite correspondence with the movement distance or position of the connecting element. Also as described above, if the strain gauge for sensing deformation is located at other positions on the side of the force-bearing element, the lever relationship between the contact part and the other part needs to be considered in the theoretical analysis.

[0077] Reference Figure 5 and Figure 6 , wherein, Figure 5 shows a perspective schematic view of another actuator and its position detection device according to the present disclosure; and Figure 6 shows a cross-sectional view based on Figure 5 at the position detection device area.

[0078] The intermediate element 13 further includes a second spring 133, and the second spring 133 is arranged between the transmission mechanism 132 and the force-bearing element 12.

[0079] It can be seen that in this technical solution, the intermediate element is at least divided into two elements, namely a transmission mechanism and a second spring, and the force is transmitted to the force-receiving element and its strain gauge through the second spring. The force analysis of the second spring is relatively simple, and it provides a certain buffer for the force-receiving element. Specifically, the longitudinal movement distance of the connecting element is L1, and the lateral movement distance L2 of the transmission mechanism is L2 = tanα * L1, where α is the angle between the inclination direction of the guide groove and the longitudinal direction of the actuating rod. Further, the deformation amount LS2 of the second spring is LS2 = L2, and the deformation force FS2 generated by the second spring is FS2 = KS2 * LS2, where KS2 is the spring constant of the second spring. The deformation force FS2 of the spring is applied to the force-receiving element, and it can be obtained that the deformation amount LC of the contact part of the force-receiving element in contact with the second spring is LC = (KS2 * L1 * tanα) / KC, where KC is the spring constant of the force-receiving element. It is also known that there is a definite corresponding relationship between the resistance / voltage of the strain gauge and the strain or deformation, so the output resistance / voltage finally has a definite corresponding relationship with the movement distance or position of the connecting element. Also as described above, if the strain gauge for sensing deformation is located at other parts on the side of the force-receiving element, then in theoretical analysis, the lever relationship between the contact part and this other part needs to be considered. Of course, as described above, the corresponding relationship between the two can be established by means of experiments, by inputting at least two sets of relationships between the position of the connecting element and the resistance / voltage of the strain gauge, which is equivalent to obtaining the corresponding relationship between the resistance / voltage of the strain gauge and the position of the screw (or valve opening). For the adjustment of the spring constant of the second spring, it can be adjusted through the material, quantity, series / parallel connection method, size, shape, etc. of the spring, so that the deformation amount of the force-receiving element meets the range of the strain gauge. The design of the spring constant of the first spring can also be considered similarly.

[0080] And Figure 2 Similarly, Figure 5 the embodiments of... have designed two sets of intermediate elements and force-receiving elements in total to improve the detection accuracy and redundancy of the whole device. When necessary, the number of sets can be adjusted according to actual requirements, and even the parts of the detection devices of various different implementation manners can be mixed.

[0081] For the data acquisition and processing of the strain gauge, exemplarily, the position detection device 1 further includes a controller, and the controller has: a collection part for collecting the output value of the strain gauge; a processing part for obtaining the position of the connecting element 11 based on the output value; and an output part for outputting the position of the connecting element 11.

[0082] Among them, the controller can be a microcontroller MCU, sometimes also called the master controller. For example, the controller is the master controller in a valve actuator. Therefore, this solution can be implemented without the need to additionally add new components, improving the compatibility of this solution. In this regard, it can also be understood that the controller is arranged on a circuit board, the circuit board is arranged on a substrate (such as the top surface of the substrate), and the controller is communicatively connected to the strain gauge. For example, the controller and the strain gauge are communicatively connected through a circuit (that is, the two are in the same circuit), so as to realize the acquisition of the resistance / voltage of the strain gauge, which is convenient for subsequent processing and output.

[0083] When the strain gauge is a single strain gauge, its output value can be resistance or voltage. When there are multiple strain gauges (for example, the strain gauges are a bridge resistance strain gauge group), the output value of the strain gauges can select the resistance or voltage value of one of the strain gauges used to measure deformation as the output value, or the output voltage of the entire bridge can be selected as the output value of the strain gauges. By measuring this voltage output, it can also correspond to the strain of the material, so as to establish a unique corresponding relationship with the position of the connecting element. Regarding the specific operation mode of the processing unit, on the one hand, as described above, by establishing a look-up table in advance and storing it in the controller, the processing unit obtains the position of the connecting element corresponding to the output value by calling the look-up table according to the actual output value of the strain gauge, and then obtains the valve stem position, valve seat position or valve opening degree, and outputs it to the user terminal or other devices that need this information; on the other hand, the relationship between the position of the connecting element and the output value of the strain gauge is stored in the controller through theoretical analysis. Thus, the processing unit calculates the position of the connecting element according to the actual output value of the strain gauge by calling this theoretical relationship, and then obtains the valve stem position, valve seat position or valve opening degree, and outputs it to the user terminal or other devices that need this information.

[0084] According to another aspect of the present disclosure, the present disclosure also relates to: a valve actuator 100, wherein the valve actuator 100 includes any one of the above-mentioned position detection devices 1, and the actuating rod 102 is used to adjust the working position of the valve; a valve assembly for an air-conditioning system, wherein the valve assembly includes a damper or a water valve of the air-conditioning system, and the valve actuator 100, and the valve actuator 100 is used to adjust the working position of the damper or the water valve.

[0085] Accordingly, various embodiments of the valve actuator and valve assembly and the corresponding technical effects are integrated with the embodiments and effects of the position detection device, which will not be elaborated here. Among them, the air conditioning system may be a heating, ventilation, and air conditioning (HVAC) system applied in a building automation system. In this application scenario, the valve is a damper (for regulating air flow) in the air conditioning system or a water valve for controlling water temperature in a water heating system (for example, installed in a cooling water circuit to regulate the flow of inlet or return water), and is controlled by an electric actuator, and ultimately the purpose of temperature control is achieved through flow control.

[0086] It should be understood that all of the above preferred embodiments are exemplary rather than restrictive, and all modifications or deformations made by those skilled in the art to the specific embodiments described above under the concept of the present disclosure should be within the scope of legal protection of the present disclosure.

Claims

1. A position detection device (1) for a valve actuator (100), the valve actuator (100) comprising a substrate (101) and an actuating rod (102) disposed through the substrate (101), characterized in that: The position detection device (1) comprises: A connecting element (11) used for fixedly connecting to the actuating rod (102); A force-bearing element (12) can be arranged on the substrate (101), one end of the force-bearing element (12) being set as a fixed end and the other end being set as a free end; an intermediate element (13) disposed between the connecting element (11) and the free end of the force-bearing element (12); and The strain gauge is arranged on the surface of the force-bearing element (12) that is deformed by the force due to the intermediate element (13).

2. The position detection device (1) according to claim 1, characterized in that: The position detection device (1) further comprises a strain gauge arranged on a surface of the force-bearing element (12) that is not subjected to force deformation.

3. The position detection device (1) according to claim 1, characterized in that: The force-bearing element (12) is configured as a cantilever structure or a spring sheet.

4. The position detection device (1) according to claim 1, characterized in that: The intermediate element (13) comprises a first spring (131), one end of the first spring (131) is in contact with the connecting element (11), and the other end of the first spring (131) is supported by the force-bearing element (12).

5. The position detection device (1) according to claim 4, characterized in that: The first spring (131) is configured as a tower spring, and a plurality of force-bearing elements (12) support the other end of the first spring (131) at evenly distributed angles on the substrate (101).

6. The position detection device (1) according to claim 1, characterized in that: The intermediate element (13) includes a transmission mechanism (132), which is connected to the connecting element (11) so that the first movement of the connecting element (11) along the movement direction of the actuating rod (102) is converted into the second movement of the transmission mechanism (132), and the direction of the second movement is in a plane perpendicular to the direction of the first movement. The transmission mechanism (132) directly or indirectly transmits the second movement to the free end of the force-bearing element (12).

7. The position detection device (1) according to claim 6, characterized in that: The transmission mechanism (132) and the connecting element (11) are matched in a concave-convex manner.

8. The position detection device (1) according to claim 7, characterized in that: The connecting element (11) is configured with a groove (111) and a protrusion (112) configured on the groove (111), and the transmission mechanism (132) is configured with a guide groove (1321) cooperating with the protrusion (112).

9. The position detection device (1) according to claim 6, characterized in that: The intermediate element (13) further comprises a second spring (133), wherein the second spring (133) is arranged between the transmission mechanism (132) and the force-bearing element (12).

10. The position detection device (1) according to claim 6, characterized in that: The plurality of force-bearing elements (12) are symmetrically arranged relative to the actuating rod (102).

11. The position detection device (1) according to any one of claims 1 to 10, characterized in that: The position detection device (1) further comprises a controller, wherein the controller comprises: A collection unit, used for collecting the output value of the strain gauge; A processing unit, used for obtaining the position of the connecting element (11) based on the output value; as well as An output part is used to output the position of the connecting element (11).

12. A valve actuator (100), characterized in that: The valve actuator (100) comprises a position detection device (1) according to any one of claims 1 to 11, wherein the actuating rod (102) is used to adjust a working position of a valve.

13. A valve assembly for an air conditioning system, characterized in that: The valve assembly comprises an air valve or a water valve of the air conditioning system, and a valve actuator (100) according to claim 12, wherein the valve actuator (100) is used to adjust the working position of the air valve or the water valve.

Images