Joint torque sensor based on glass film curing process

Abstract

The utility model relates to the technical field of sensors, in particular to a joint torque sensor based on a glass film curing process, which comprises an elastic element comprising an inner ring and an outer ring which are concentrically arranged, a plurality of strain beams which are distributed at equal intervals are connected between the inner ring and the outer ring, a plurality of mounting holes are formed in the outer ring, and a plurality of positioning holes are formed in the inner ring; the strain gauge is fixedly connected to the strain beam; the signal conditioning circuit is fixed on the inner ring and is connected with the strain gauge; the strain gauge is fixedly connected to the strain beam through a glass film. According to the utility model, the strain gauges on the strain beams between the inner ring and the outer ring sense the strain force, then the strain force sensed by the strain gauges is transmitted to the signal conditioning circuit, and the strain gauges are fixedly connected to the elastic elements through the glass film curing technology. The sensor can stably work under harsh environmental conditions (such as high temperature, high humidity and chemical corrosion environments), and the service life of the sensor is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of sensors, in particular to a joint torque sensor based on a glass film curing process. Background Art

[0002] The strain gauge joint torque sensor is a sensor that uses a strain gauge to measure torque. The strain gauge is a thin film made of conductive material, usually attached to the surface of an elastomer (such as metal). When the elastomer is subjected to torque, it will produce a slight deformation, which will cause the resistance of the strain gauge to change. By arranging it into a Wheatstone bridge circuit, the resistance change of the strain gauge can be converted into an electrical signal, thereby accurately measuring the torque. This sensor is widely used in industrial robots, manufacturing, automotive engineering, medical equipment and other fields due to its high precision and high reliability, and can effectively improve the accuracy, safety and performance of equipment operation.

[0003] In the prior art, the connection between the strain gauge and the elastic element is mostly made of organic bonding, such as silicone, epoxy resin glue, polyurethane glue, etc. However, as the working temperature increases, the organic adhesive will become viscoplastic, increasing the sensor hysteresis error and the instability of the output signal, making the temperature application range of the sensor narrower; organic adhesives also have an affinity for liquids, which greatly increases the failure risk of the sensor in the use environment of the harmonic reducer oil and liquid mixture, and to a certain extent reduces the service life and reliability of the sensor; at the same time, a large amount of manual participation is required in the production and assembly process, which, on the one hand, reduces the production efficiency of the sensor, and on the other hand, the interference of human factors increases the instability of the sensor and reduces the consistency of the sensor performance.

[0004] In view of the limitations of the bonding method between the strain gauge and the elastic part in the existing technology, we urgently need a new bonding method to improve the service life and stability of the sensor. Utility Model Content

[0005] In view of at least one of the above technical problems, the utility model provides a joint torque sensor based on a glass film curing process, which improves the bonding method to increase the service life.

[0006] According to a first aspect of the utility model, a joint torque sensor based on a glass film curing process is provided, comprising:

[0007] An elastic element, wherein the elastic element comprises an inner ring and an outer ring which are arranged concentrically, a plurality of strain beams which are equidistantly distributed are connected between the inner ring and the outer ring, a plurality of mounting holes are opened on the outer ring, and a plurality of positioning holes are opened on the inner ring;

[0008] A strain gauge, wherein the strain gauge is fixedly connected to the strain beam;

[0009] a signal conditioning circuit, the signal conditioning circuit being fixed on the inner ring and connected to the strain gauge;

[0010] Wherein, the strain gauge is fixedly connected to the strain beam via a glass film.

[0011] Furthermore, the area of ​​the glass film is greater than or equal to the area of ​​the strain gauge.

[0012] Furthermore, the mounting hole includes a round hole and a waisted round hole connected to the round hole.

[0013] Furthermore, the strain gauge is a silicon strain gauge.

[0014] Furthermore, a deformation seam and a deformation cavity are provided between the inner ring and the outer ring, the strain beam is arranged in the deformation cavity, and the deformation seam is connected between two adjacent deformation cavities.

[0015] Furthermore, the deformation cavity is provided with reinforcing ribs, and the reinforcing ribs are arranged on both sides of the strain beam having the strain gauge end surface.

[0016] Furthermore, the inner circle includes a circuit area at a central position and a positioning area on the periphery of the circuit area, the signal conditioning circuit is fixed on the circuit area, the positioning hole is opened on the positioning area, and a protective band protruding from the surface of the elastic element is provided between the circuit area and the positioning area.

[0017] Furthermore, a wire groove is provided between the circuit area and the strain beam.

[0018] Furthermore, the protection belt is provided with an opening corresponding to the position of the wire trough.

[0019] Furthermore, the outer ring is provided with a positioning groove.

[0020] The beneficial effects of the utility model are as follows: the utility model senses the strain force through the strain gauge on the strain beam between the inner ring and the outer ring, and then transmits the strain force sensed by the strain gauge to the signal conditioning circuit, and fixes the strain gauge on the elastic element through the glass film curing process. On the one hand, it provides higher mechanical strength and stability for the strain gauge, reduces the risk of the strain gauge falling off or moving in a high stress environment, ensures the long-term reliable operation of the sensor, and thus improves the measurement accuracy of the sensor; on the other hand, through the application of the glass film curing process, the sensor can work stably under more harsh environmental conditions (such as high temperature, high humidity and chemical corrosion environment), thereby improving the service life of the sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 This is a schematic diagram of the structure of a joint torque sensor based on a glass film curing process in an embodiment of the utility model;

[0023] Figure 2 This is a front view of a joint torque sensor based on a glass film curing process in an embodiment of the utility model;

[0024] Figure 3 In the embodiment of the utility model Figure 1 A schematic diagram of the structure enlargement at the center A;

[0025] Figure 4 This is a schematic diagram of the structure of a joint torque sensor based on a glass film curing process in an embodiment of the utility model;

[0026] Figure 5 It is a schematic diagram of the structure of the strain gauge fixed by solidifying the glass film in the embodiment of the utility model. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0028] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the technical field of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0030] like Figures 1 to 5The joint torque sensor shown in the figure, which is based on the curing process of the glass film 3 , comprises: an elastic element 1 , a strain gauge 2 , a glass film 3 and a signal conditioning circuit 4 .

[0031] The elastic element 1 includes an inner ring 11 and an outer ring 12 arranged concentrically, a plurality of equally spaced strain beams 13 are connected between the inner ring 11 and the outer ring 12, a plurality of mounting holes 12a are provided on the outer ring 12, and a plurality of positioning holes 11a are provided on the inner ring 11; the strain gauge 2 is fixedly connected to the strain beam 13; the signal conditioning circuit 4 is fixedly connected to the inner ring 11 and connected to the strain gauge 2; wherein the strain gauge 2 is fixedly connected to the strain beam 13 through the glass film 3. Figure 1 , Figure 2 As shown, the sensor is fixedly installed through the mounting hole 12a on the outer ring 12 and the positioning hole 11a on the inner ring 11. The opening of the positioning hole 11a and the mounting hole 12a can ensure the accurate positioning of the signal conditioning circuit 4 and the entire inner ring 11 and the outer ring 12 during the assembly process, reduce assembly errors, and improve assembly efficiency and consistency. The strain force is transmitted by the change of the strain beam 13 between the outer ring 12 and the inner ring 11. The strain gauge 2 is fixedly connected to the elastic element 1 through the glass film 3. By utilizing the hydrophobicity of the glass and the use environment where the harmonic reducer oil is mixed, it has high stability and reliability, and can also increase the service life of the sensor. It should be pointed out here that there are many types of strain gauges 2, which can be semiconductor strain gauges 2, nickel-chromium alloy strain gauges 2, aluminum titanate alloy strain gauges 2, or constantan strain gauges 2. It should also be pointed out that the number of strain beams 13 can be one, two, or a multiple of four. It should also be noted that the elastic element 1 can be made of many materials, such as stainless steel, aluminum alloy, titanium alloy, etc., engineering plastics such as polycarbonate, polyamide, polyetheretherketone, etc., and composite materials. It should also be noted that the mounting hole 12a has many forms, such as a round hole, an elongated or elliptical hole, or other shapes that can be locked and fixed.

[0032] like Figure 5As shown, in the specific production process, firstly, glass powder is placed on the strain beam 13 of the elastic element 1, and the glass powder is melted into liquid glass through high temperature, and cooled until the liquid glass becomes a glass film 3, and the strain gauge 2 is placed on the glass film 3, and the glass film 3 is heated again to melt, so that the strain gauge 2 partially sinks into the glass film 3, and cooled until the glass solidifies, at which time the glass film 3 fixes the strain gauge 2 on the strain beam 13. By fixing the strain gauge 2 and the elastic element 1 through the curing process of the glass film 3, automated production equipment can be introduced to improve the efficiency and consistency of the sensor manufacturing process, reduce the impact of human factors on the performance of the joint torque sensor, and minimize the gas release of the glass film 3 in a high temperature and low pressure environment, thereby reducing the hysteresis and repeatability errors of the joint torque sensor, and can expand the operating temperature range of the joint torque sensor.

[0033] The utility model senses the strain force through the strain gauge 2 on the strain beam 13 between the inner ring 11 and the outer ring 12, and then transmits the strain force sensed by the strain gauge 2 to the signal conditioning circuit 4, and fixes the strain gauge 2 on the elastic element 1 through the glass film 3 curing process. On the one hand, it provides higher mechanical strength and stability for the strain gauge 2, reduces the risk of the strain gauge falling off or moving in a high stress environment, ensures the long-term reliable operation of the sensor, and thus improves the measurement accuracy of the sensor; on the other hand, through the application of the glass film 3 curing process, the sensor can work stably under more harsh environmental conditions (such as high temperature, high humidity and chemical corrosion environment), thereby improving the service life of the sensor.

[0034] like Figure 1 , Figure 3 As shown, the area of ​​the glass film 3 is greater than or equal to the area of ​​the strain gauge 2. When the glass powder is melted into the glass film 3, in order to make the fixation of the strain gauge 2 more firmly, the area of ​​the glass film 3 is greater than or equal to the area of ​​the strain gauge 2. When the strain gauge 2 settles, it can completely settle inside the glass film 3, which can distribute the stress more evenly, reduce the local stress concentration phenomenon of the strain gauge 2, and improve the accuracy and reliability of the measurement. At the same time, the glass film 3 and the base material of the strain gauge 2 usually have similar thermal expansion coefficients, which can reduce the thermal stress and thermal drift caused by temperature changes and improve temperature stability.

[0035] like Figure 2 , Figure 4 As shown, the mounting hole 12a includes a round hole and a waist round hole connected to the round hole. During the installation process, the connecting piece to be fixed is inserted into the mounting hole 12a, and the elastic element 1 is rotated so that the connecting piece is inserted into the waist round hole. On the one hand, the design of the round hole can make the joint torque sensor fine-tuned within a certain range, and on the other hand, it can be locked through the waist round hole.

[0036] In some embodiments of the utility model, the strain gauge 2 is a silicon strain gauge 2. The silicon strain gauge 2 adopts epitaxial growth technology to improve the uniformity of the thickness of the epitaxial layer in the radial direction and the consistency of the resistivity, thereby ensuring that the zero-point output of the sensor bridge is at a lower value, which is beneficial to the subsequent temperature signal processing and compensation, and can also provide a strong guarantee for the mass production and process consistency of the sensor; at the same time, the silicon strain gauge 2 has good chemical stability and can work stably for a long time in various industrial environments.

[0037] like Figure 2 , Figure 4 As shown, there is a deformation seam 14 and a deformation cavity 15 between the inner ring 11 and the outer ring 12, the strain beam 13 is arranged in the deformation cavity 15, and the deformation seam 14 is connected between two adjacent deformation cavities 15. Through the arrangement of the deformation seam 14 and the deformation cavity 15, the inner ring 11 and the outer ring 12 are connected only through the strain beam 13, which reduces the interference between the inner ring 11 and the outer ring 12 on the one hand, and provides an installation position for the installation of the inner ring 11 and the outer ring 12 on the other hand.

[0038] Continue to refer Figure 2 , Figure 4 As shown, the deformation cavity 15 also has a reinforcing rib 16, which is arranged on both sides of the end surface of the strain beam 13 having the strain gauge 2. The reinforcing rib 16 is arranged on both sides of the end surface of the strain beam 13, which helps to balance and disperse the stress distribution during torque loading, increase the rigidity of the sensor, and improve the anti-eccentric load capability, thereby extending the service life of the strain beam 13.

[0039] Continue to refer Figure 2 , Figure 4 As shown, the inner ring 11 includes a circuit area 11c at the center and a positioning area 11d on the periphery of the circuit area 11c, the signal conditioning circuit 4 is fixed on the circuit area 11c, the positioning hole 11a is provided on the positioning area 11d, and a protective band 11e protruding from the surface of the elastic element 1 is provided between the circuit area 11c and the positioning area 11d. The protective band 11e is located between the circuit area 11c and the positioning area 11d, and can effectively protect the signal conditioning circuit 4 in the circuit area 11c from physical damage or pollution from the external environment, such as dust, water vapor, etc., thereby improving the reliability and stability of the circuit; at the same time, the provision of the protective band 11e can reduce mechanical damage caused by external impact or vibration, and extend the service life of the inner ring 11 and the circuit area 11c.

[0040] In some embodiments of the present invention, Figure 4As shown, a wire groove 11b is also provided between the circuit area 11c and the strain beam 13. The strain gauge 2 and the signal conditioning circuit 4 are connected through the circuit passing through the wire groove 11b. The wire groove 11b provides an orderly channel for arranging and managing the circuit connection wires, making the wiring more neat and controllable. The wire groove 11b can effectively protect the circuit line from mechanical damage or wear in the external environment, thereby extending the service life of the circuit.

[0041] In some embodiments of the present invention, continue to refer to Figure 4 As shown, the protective strip 11e is provided with an opening 11e1 opposite to the wire groove 11b. The wires between the strain gauge 2 and the signal conditioning circuit pass through the wire groove 11b for connection. To facilitate the connection process, the protective strip 11e is provided with an opening 11e1 opposite to the wire groove 11b. The wires pass through the opening 11e1 and the wire groove 11b to connect the strain gauge 2 and the signal conditioning circuit.

[0042] like Figure 2 , Figure 4 As shown, the outer ring 12 also has a positioning groove 12b. The positioning groove 12b can provide an accurate position reference to ensure that the outer ring 12 can be accurately aligned with other components during the assembly process, reduce assembly errors, and improve assembly efficiency and consistency.

[0043] Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and the description are only for explaining the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which are within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A joint torque sensor based on glass film curing technology, characterized in that: include: An elastic element, wherein the elastic element comprises an inner ring and an outer ring which are arranged concentrically, a plurality of strain beams which are equidistantly distributed are connected between the inner ring and the outer ring, a plurality of mounting holes are provided on the outer ring, and a plurality of positioning holes are provided on the inner ring; A strain gauge, wherein the strain gauge is fixedly connected to the strain beam; a signal conditioning circuit, the signal conditioning circuit being fixed on the inner ring and connected to the strain gauge; Wherein, the strain gauge is fixedly connected to the strain beam via a glass film.

2. The joint torque sensor based on glass film curing process according to claim 1 is characterized in that: The area of ​​the glass film is greater than or equal to the area of ​​the strain gauge.

3. The joint torque sensor based on glass film curing process according to claim 1 is characterized in that: The mounting hole comprises a round hole and a waist-round hole connected to the round hole.

4. The joint torque sensor based on glass film curing process according to claim 1 is characterized in that: The strain gauge is a silicon strain gauge.

5. The joint torque sensor based on glass film curing process according to claim 1 is characterized in that: A deformation seam and a deformation cavity are provided between the inner ring and the outer ring, the strain beam is arranged in the deformation cavity, and the deformation seam is connected between two adjacent deformation cavities.

6. The joint torque sensor based on glass film curing process according to claim 5 is characterized in that: The deformation cavity is further provided with reinforcing ribs, and the reinforcing ribs are arranged on both sides of the strain beam having the strain gauge end surface.

7. The joint torque sensor based on glass film curing process according to claim 1 is characterized in that: The inner circle includes a circuit area at the center and a positioning area on the periphery of the circuit area. The signal conditioning circuit is fixed on the circuit area. The positioning hole is opened on the positioning area. A protective band protruding from the surface of the elastic element is provided between the circuit area and the positioning area.

8. The joint torque sensor based on glass film curing process according to claim 7 is characterized in that: A wire groove is also provided between the circuit area and the strain beam.

9. The joint torque sensor based on glass film curing process according to claim 8 is characterized in that: The protection belt is provided with an opening which is opposite to the position of the wire slot.

10. The joint torque sensor based on glass film curing process according to claim 1, characterized in that: The outer ring is also provided with a positioning groove.

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