Peristaltic grinding arc temperature field measurement method and system based on semi-artificial thermocouple

Abstract

The application discloses a kind of based on semi-artificial thermocouple peristaltic grinding arc temperature field measurement method and system, comprising: in peristaltic grinding test piece interval arrangement several first thermocouple wires perpendicular to grinding surface and with the peristaltic grinding test piece insulation, and second thermocouple wire is arranged on the peristaltic grinding test piece position away from the first thermocouple wire, wherein, one end of several first thermocouple wire can be contacted with grinding equipment;The other end of several first thermocouple wire and the second thermocouple wire are connected to signal acquisition module respectively;Using the grinding equipment is ground to the peristaltic grinding test piece, when the grinding equipment contacts the first thermocouple wire, heat signal acquisition is carried out using the signal acquisition module.The application can accurately directly measure the internal temperature field of entire grinding arc.

Description

Technical Field

[0001] This invention belongs to the field of peristaltic grinding arc temperature field measurement technology, specifically relating to a peristaltic grinding arc temperature field measurement method and system based on a semi-artificial thermocouple. Background Technology

[0002] As an advanced grinding technology, peristaltic grinding relies heavily on the temperature of the grinding arc to significantly impact the surface integrity and machining quality of the workpiece. Traditional temperature measurement methods suffer from limitations such as using only one measurement point and failing to comprehensively reflect the temperature distribution. Therefore, developing a method capable of accurately measuring the temperature distribution of the grinding arc is of great importance.

[0003] The current research status on the measurement of the internal temperature field of the creep grinding arc can be summarized as follows: I. Development of temperature measurement technology: Traditional temperature measurement methods, such as thermocouples and infrared thermometry, are susceptible to inaccurate results due to their contact nature and the influence of grinding force and heat during the grinding process. In recent years, non-contact temperature measurement technologies have been developed, such as spectral analysis-based methods. These methods estimate the temperature by analyzing the spectral characteristics of the grinding region, allowing for real-time monitoring without affecting the grinding process. II. Establishment of temperature models: To more accurately predict and control grinding temperature, researchers have established various heat source models and heat conduction models. These models are typically based on grinding force, grinding parameters, and the thermophysical properties of the workpiece material, using numerical simulation to predict the temperature distribution during the grinding process. Some studies have also incorporated finite element analysis to simulate the grinding temperature field. This method can provide detailed temperature distribution information, helping to optimize grinding parameters and improve machining quality. However, there is currently no method that can directly measure the internal temperature field of the entire grinding arc; therefore, the method described in this invention is needed to address this issue. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention provides a method and system for measuring the temperature field of a creeping grinding arc based on a semi-artificial thermocouple, which can accurately and directly measure the internal temperature field of the entire grinding arc.

[0005] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution:

[0006] A method for measuring the temperature field of creep grinding arc based on a semi-artificial thermocouple includes:

[0007] A plurality of first thermocouple wires, perpendicular to the grinding surface and insulated from the peristaltic grinding specimen, are arranged at intervals inside the peristaltic grinding specimen, and a second thermocouple wire is arranged on the peristaltic grinding specimen at a position away from the first thermocouple wires. One end of the plurality of first thermocouple wires can contact the grinding equipment.

[0008] The other ends of several first thermocouple wires and second thermocouple wires are respectively connected to the signal acquisition module;

[0009] The peristaltic grinding specimen is ground using the grinding equipment. When the grinding equipment comes into contact with the first thermocouple wire, the thermoelectric signal is acquired using the signal acquisition module.

[0010] Furthermore, several of the first thermocouple wires are arranged at equal intervals, with the spacing between two adjacent first thermocouple wires being 1mm to 2mm.

[0011] Furthermore, the provision of a plurality of first thermocouple wires, perpendicular to the grinding surface and insulated from the peristaltic grinding specimen, arranged at intervals within the peristaltic grinding specimen, specifically includes:

[0012] The peristaltic grinding specimen is obliquely cut into two halves along the grinding direction, and several receiving grooves are opened at intervals on the cut surface of one half. The first thermocouple wire is placed in the receiving groove accordingly, and mica sheet is used to insulate the peristaltic grinding specimen from the first thermocouple wire.

[0013] Furthermore, the thickness of the mica sheet is no greater than 10 μm.

[0014] Further, after the first thermocouple wire is correspondingly arranged in the receiving groove and the peristaltic grinding specimen is insulated from the first thermocouple wire using mica sheets, the method further includes:

[0015] The two halves of the specimen and the mica sheet were bonded together using an adhesive.

[0016] Furthermore, the thickness of the adhesive layer formed by the adhesive is no greater than 10 μm.

[0017] Furthermore, after acquiring thermoelectric signals using the signal acquisition module, the method further includes:

[0018] Temperature is calculated using the calibrated thermoelectric signal and its relationship with temperature.

[0019] Furthermore, a compensating wire bundle is used to connect the other ends of several of the first thermocouple wires to the signal acquisition module.

[0020] A creep grinding arc temperature field measurement system based on a semi-artificial thermocouple includes:

[0021] A plurality of first thermocouple wires are arranged at intervals within the peristaltic grinding specimen. The plurality of first thermocouple wires are perpendicular to the grinding surface. The plurality of first thermocouple wires are insulated from the peristaltic grinding specimen. One end of the plurality of first thermocouple wires can contact the grinding equipment.

[0022] The second thermocouple wire is connected to the peristaltic grinding specimen at a position away from the first thermocouple wire;

[0023] A signal acquisition module is connected to the other end of several first thermocouple wires and second thermocouple wires. When the grinding equipment comes into contact with the first thermocouple wires, the signal acquisition module is used to acquire thermoelectric signals.

[0024] Compared with the prior art, the present invention has at least the following beneficial effects:

[0025] This invention provides a method for measuring the temperature field of a creeping grinding arc based on a semi-artificial thermocouple. A first thermocouple wire, perpendicular to the grinding surface and insulated from the creeping grinding specimen, is placed in the creeping grinding specimen 1. A second thermocouple wire is placed on the creeping grinding specimen 1 at a position away from the first thermocouple 2. The other end of the first thermocouple wire 2 and the second thermocouple wire 3 are respectively connected to a signal acquisition module 5. When the grinding equipment performs creeping grinding feed, one end of the first thermocouple wire contacts the grinding equipment, forming a hot junction, which constitutes the hot end of the semi-artificial thermocouple. Because the grinding arc is far from the second thermocouple wire, the temperature at the second thermocouple wire hardly changes, forming the cold end of the semi-artificial thermocouple. This forms a semi-artificial thermocouple device that can stably output a thermoelectric signal. By calibrating the relationship between the electromotive force and temperature of the thermocouple wire, the temperature field of the grinding arc zone can be measured by the voltage difference between the cold and hot ends. This allows for the formation of a stable and non-interfering temperature signal during the creep grinding process, enabling precise and direct measurement of the internal temperature field of the entire grinding arc.

[0026] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the specific embodiments of the present invention, the drawings used in the description of the specific embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the measurement system for the creep grinding arc temperature field measurement method based on a semi-artificial thermocouple in an embodiment of the present invention;

[0029] Figure 2 This is a schematic diagram illustrating the fabrication and structure of a semi-artificial thermocouple in an embodiment of the present invention.

[0030] In the figure: 1-Crawling grinding specimen; 100-First specimen; 101-Second specimen; 2-First thermocouple wire; 3-Second thermocouple wire; 4-Grinding equipment; 5-Signal acquisition module; 6-Mica sheet; 7-Receiving groove; 8-Compensating wire bundle; 9-Clamp; 10-Worktable; 11-Computer Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] like Figure 1 and Figure 2 As shown in the figure, this application provides a method for measuring the temperature field of a creep grinding arc based on a semi-artificial thermocouple, as detailed below:

[0033] 1. Installation of thermocouple wires

[0034] First, the peristaltic grinding specimen 1 is obliquely cut into two halves along the grinding direction. Preferably, the length of the obliquely cut surface along the peristaltic grinding direction should be greater than the length of the grinding arc.

[0035] Then, on one half of the cut surface, several receiving grooves 7 are equally spaced, with a distance of 1mm to 2mm between two adjacent receiving grooves 7, thereby achieving a distance of 1mm to 2mm between two adjacent first thermocouple wires 2. Preferably, the distance between two adjacent first thermocouple wires 2 is 1.5mm.

[0036] Next, the first thermocouple wire 2 is placed in the receiving groove 7, ensuring that the first thermocouple wire 2 is perpendicular to the grinding surface and insulated from the peristaltic grinding specimen 1. To achieve insulation, a mica sheet 6 with a thickness of no more than 10 μm is used for isolation, and the length and width of the mica sheet are equal to the length and width of the cut surface of the peristaltic grinding specimen.

[0037] Preferably, the length l0 of the first thermocouple wire clamped into the specimen should be equal to the height h of the specimen plus 5mm. The added length is used as a compensating wire for the measurement end. The diameter d of the first thermocouple wire is selected as 0.2mm.

[0038] Next, a second thermocouple wire 3 is placed at a position away from the first thermocouple wire 2 on the peristaltic grinding specimen 1. It should be noted that the second thermocouple wire 3 should be as close as possible to the lower part of the peristaltic grinding specimen, and all the first thermocouple wires 2 share one second thermocouple wire 3.

[0039] Finally, the two halves of the specimen and the mica sheet 6 are bonded together using an adhesive (such as epoxy resin), ensuring that the thickness of the adhesive layer is no more than 10 μm.

[0040] 2. Connection of the signal acquisition module

[0041] The other ends of several first thermocouple wires 2 and second thermocouple wires 3 are respectively connected to the signal acquisition module 5. To enhance the stability of the connection and the accuracy of signal transmission, a compensating wire bundle 8 can be used for connection.

[0042] 3. Grinding process and signal acquisition

[0043] The peristaltic grinding specimen 1 is ground using grinding equipment 4. When grinding equipment 4 comes into contact with the first thermocouple wire 2, the first thermocouple wire 2 will generate a thermoelectric signal. The signal acquisition module 5 acquires the thermoelectric signal in real time and transmits it to the data processing unit for further analysis and calculation.

[0044] 4. Temperature Calculation

[0045] By utilizing the pre-calibrated relationship between thermoelectric signals and temperature, the collected thermoelectric signals are converted into corresponding temperature values.

[0046] In one embodiment, combined with Figure 1 and Figure 2 As shown, a method for measuring the temperature field of a creep grinding arc based on a semi-artificial thermocouple is provided. First, the creep grinding specimen 1 is obliquely cut to form a first specimen 100 and a second specimen 101. Then, a semi-circular groove (accommodating groove 7) with a radius of r is engraved on the cut surface of the first specimen 100. The spacing l between adjacent grooves is controlled between 1 and 2 mm to ensure that the temperature signals between two adjacent constantan wires (thermocouple wires) do not interfere, while also ensuring a denser distribution to collect more temperature data from the grinding arc. The cut surfaces of the first specimen 100 and the second specimen 101 are polished to facilitate subsequent bonding. The constantan wires are sequentially placed into the semi-circular groove of the first specimen 100 as hot-end constantan wires. To insulate the constantan wires from the creep grinding specimen, two mica sheets are placed between the grinding specimen and the constantan wire bundle. Subsequently, bisphenol A epoxy resin was used to bond the first specimen 100, the second specimen 101, two mica sheets, and the constantan wire bundle together to form a semi-artificial thermocouple. The epoxy resin layer thickness was controlled within 10 μm to ensure good thermal conductivity of the workpiece under test. The fabricated semi-artificial thermocouple device was clamped with fixture 9 and fixed on the worktable 10 for peristaltic grinding. An insulated compensating wire bundle 8 was used as the hot-end signal bundle to output the thermoelectric signal generated by the hot-end constantan wire bundle. The measuring ends of the compensating wire and the hot-end constantan wire bundle should be insulated with polytetrafluoroethylene (PTFE).

[0047] During peristaltic grinding, when the grinding wheel (grinding equipment 4) contacts the hot-end constantan wire, the workpiece and the constantan wire overlap, forming a thermal junction, and the circuit is connected. Since the temperature inside the grinding arc is much higher than the temperature at the bottom of the workpiece, a temperature difference exists between the hot-end and cold-end constantan wires (second thermocouple wire 3). The semi-artificial thermocouple device converts this temperature difference into a voltage difference signal, which is input to the NI-9202 acquisition module of the Compact RIO acquisition system (including the NI-9202 acquisition module and the FPGA module) through the compensating wire bundle 8 and the second thermocouple wire 3. By programming the FPGA module, the multi-channel voltage signals acquired by the NI-9202 acquisition module are amplified, filtered, and synthesized, outputting a single-channel signal, which is then input to the computer 11 through the Compact RIO output interface. The LabVIEW software on the computer 11 allows for convenient communication with the NI-9202 acquisition module, defining the sampling frequency of the NI-9202 acquisition module. Preferably, setting the acquisition frequency fs of a single channel to 2.5kHz to 3kHz is sufficient to meet the requirements. Then, the temperature curves of each measurement point within the grinding arc are output by comparing the results with the constantan wire electromotive force-temperature (ET) calibration curve obtained before the experiment using LabVIEW software.

[0048] It should be noted that the NI-9202 acquisition module has an analog input module with 16 synchronously sampled differential input channels. Each channel has a maximum sampling frequency of 10kHz and a scanning function, which can be configured to continuously acquire data from all channels. It also has a configurable filter to reduce noise and improve signal acquisition quality.

[0049] In this embodiment, mica sheets and constantan wire are placed in the peristaltic grinding specimen, and the hot end of the constantan wire, which is clamped inside the specimen, is connected by a compensating wire. When the grinding wheel performs peristaltic grinding feed, the constantan wire and the mica sheet used for insulation are broken, forming a hot junction, which constitutes the hot end of a semi-artificial thermocouple. Since the grinding arc is far from the cold end signal line, the temperature at the cold end signal line hardly changes, forming the cold end of the semi-artificial thermocouple. This forms a semi-artificial thermocouple device that can stably output a thermoelectric signal. By calibrating the relationship between the electromotive force and temperature of the constantan wire, the temperature field in the grinding arc region can be measured by the voltage difference between the cold and hot ends. In this embodiment, the peristaltic grinding specimen is obliquely cut along the grinding direction, and multiple constantan wires are placed at intervals. This generates a stable and non-interfering temperature signal during the peristaltic grinding process. A semi-artificial thermocouple device converts the temperature difference between the grinding arc and the bottom of the specimen into a voltage signal. This signal is acquired by a data acquisition system, input into a computer, and compared with the calibrated electromotive force-temperature (ET) curve of the constantan wires, outputting the temperature signal. This allows for rapid and low-cost measurement of the temperature field of the grinding arc in laboratory or working environments.

[0050] In the description of this invention, it should be understood that the terms "upper", "lower", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0051] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0052] In this invention, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0053] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0054] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0055] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for measuring the temperature field of a creep grinding arc based on a semi-artificial thermocouple, characterized in that, include: A plurality of first thermocouple wires (2) perpendicular to the grinding surface and insulated from the peristaltic grinding specimen (1) are arranged at intervals inside the peristaltic grinding specimen (1), and a second thermocouple wire (3) is arranged on the peristaltic grinding specimen (1) at a position away from the first thermocouple wires (2). One end of the plurality of first thermocouple wires (2) can contact the grinding equipment (4); the plurality of first thermocouple wires (2) are arranged at equal intervals, and the distance between two adjacent first thermocouple wires (2) is 1mm to 2mm. The other ends of several first thermocouple wires (2) and second thermocouple wires (3) are respectively connected to the signal acquisition module (5); The grinding equipment (4) is used to grind the peristaltic grinding specimen (1). When the grinding equipment (4) comes into contact with the first thermocouple wire (2), the signal acquisition module (5) is used to acquire the thermoelectric signal. The arrangement of several first thermocouple wires (2) perpendicular to the grinding surface and insulated from the peristaltic grinding specimen (1) within the peristaltic grinding specimen (1) specifically includes: The peristaltic grinding specimen (1) is obliquely cut into two halves along the grinding direction, and several receiving grooves (7) are opened at intervals on the cut surface of one half. The first thermocouple wire (2) is placed in the receiving groove (7) and the peristaltic grinding specimen (1) and the first thermocouple wire (2) are insulated by mica sheet (6).

2. The method for measuring the temperature field of creep grinding arc based on a semi-artificial thermocouple according to claim 1, characterized in that, The thickness of the mica sheet (6) is no greater than 10 μm.

3. The method for measuring the temperature field of creep grinding arc based on a semi-artificial thermocouple according to claim 1, characterized in that, After the first thermocouple wire (2) is correspondingly placed in the receiving groove (7) and the peristaltic grinding specimen (1) is insulated from the first thermocouple wire (2) using mica sheet (6), the method further includes: The two halves of the specimen and the mica sheet (6) were bonded together using an adhesive.

4. The method for measuring the temperature field of creep grinding arc based on a semi-artificial thermocouple according to claim 3, characterized in that, The thickness of the adhesive layer formed by the adhesive is no greater than 10 μm.

5. The method for measuring the temperature field of creep grinding arc based on a semi-artificial thermocouple according to claim 1, characterized in that, After acquiring thermoelectric signals using the signal acquisition module (5), the method further includes: Temperature is calculated using the calibrated thermoelectric signal and its relationship with temperature.

6. The method for measuring the temperature field of creep grinding arc based on a semi-artificial thermocouple according to claim 1, characterized in that, The other ends of several first thermocouple wires (2) are connected to the signal acquisition module (5) using a compensating wire bundle (8).

7. A peristaltic grinding arc temperature field measurement system based on a semi-artificial thermocouple, characterized in that, For implementing the creep grinding arc temperature field measurement method based on a semi-artificial thermocouple as described in any one of claims 1 to 6, the measurement system includes: A plurality of first thermocouple wires (2) are arranged at intervals in the peristaltic grinding specimen (1). The plurality of first thermocouple wires (2) are perpendicular to the grinding surface. The plurality of first thermocouple wires (2) are insulated from the peristaltic grinding specimen (1). One end of the plurality of first thermocouple wires (2) can contact the grinding equipment (4). The second thermocouple wire (3) is connected to the peristaltic grinding specimen (1) at a position away from the first thermocouple wire (2); The signal acquisition module (5) is connected to the other end of several first thermocouple wires (2) and second thermocouple wires (3). When the grinding equipment (4) comes into contact with the first thermocouple wires (2), the signal acquisition module (5) is used to acquire thermoelectric signals.

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