Installation method of motor temperature sensor for fine sand machine

Abstract

The invention discloses an installation method of a motor temperature sensor for a fine sand machine, which comprises the following steps of: processing a through hole on a motor junction box cover, manufacturing uniformly distributed grooves on the inner and outer surfaces of the junction box cover close to the through hole, enabling the temperature sensor to pass through the through hole, and screwing the inside and the outside by nuts, uniformly-distributed grooves are formed in the surface, opposite to the junction box cover, of the nut, a rubber gasket is placed between the nut and the junction box cover, a thin iron wire is wound on the threaded groove exposed out of the inner side of the junction box close to the nut end and is knotted, strong glue is smeared on the surface of the thin iron wire, and the junction box cover is formed. After the glue is dried, wrapping the surface of the glue with an insulating tape; and a thin iron wire is wound on the threaded groove exposed outside the junction box cover close to the nut end and is knotted. According to the method, ore dust is prevented from entering the junction box, the sensing end of the sensor is prevented from dust interference, and the installed temperature sensor is stable and reliable, does not make contact with a circuit and is easy to maintain.

Description

[0001] The invention patent belongs to the technical field of mine machinery maintenance, and particularly relates to a temperature sensor installation method on a motor of a fine sand machine. BACKGROUND

[0002] The fine sand machine is a machine for producing artificial sand. In the case of increasingly scarce natural sand resources, artificial sand is the first choice of substitute. The power of the fine sand machine is generally between 100-350 kw. When working, the fine sand machine has large vibration, large dust and large noise. When the fine sand machine encounters large stone blocks or stone blocks with high hardness or is congested, the motor temperature may be increased due to excessive load. When the temperature of the motor shell reaches 70 DEG C, manual intervention must be performed, otherwise the motor may be burned out. The sand making in the mine field adopts a flow line operation. The burning out of the motor will cause the stop of the operation of the mining, ore transportation and ore processing machines, and great loss will be brought to production.

[0003] At present, enterprises rely on two ways to prevent the burning out of the motor of the fine sand machine. One way is to prevent the burning out of the motor through manual inspection. When checking, the worker holds an infrared temperature measuring instrument to check the temperature of the motor shell at a close distance. Since the monitored shell position is random, the detected temperature difference is large, and the detected temperature cannot well reflect the early warning temperature. The other way is to reasonably control the feeding amount of the fine sand machine to prevent large stone blocks from being stuck and prevent the feeding amount from being too large to cause congestion.

[0004] In 2024, Li Congquan, an associate professor of Tianmen Vocational College, disclosed the project of "Hubei Provincial Academy of Sciences and Expert Enterprise Line" (Ehuanli 2024 [No. 31]) at the request of Yinfen Mining Industry Co., Ltd. to solve the problem of burning out of the motor of the fine sand machine when working. In the implementation process of the project, the enterprise party gave great support, and the Enshi Secondary Vocational School gave great support. The school's resources were used to consult the industry technology development trend, a sample machine was developed, and related tests were conducted. Previously, relevant scientific researchers engaged in the research of motor temperature sensing. Since the working conditions of the motor used are different from the crushing of ore, the method used is also different, which is summarized as follows.

[0005] Chen Biao, Cui Shunyu, Sun Sheng and others disclosed an invention technology of motor temperature detection, and the patent name is "a temperature sensor installation method on a flat wire stator and a flat wire stator", and the patent application number is 202010592478.3. The method is to sleeve a heat shrink tube on a flat copper winding, insert a sensor between the heat shrink tube and the flat copper, and then weld. The heat shrink tube is shrunk by heat to fix the sensor on the flat copper winding. The method uses the coating and drop paint process. The coating powder and paint skin are easy to fall off during the operation of the motor, which affects the normal operation of the motor.

[0006] Hu Yan, Tan Mingqi, Rui Chaojie, etc. in December 2022 disclosed a motor temperature detection technology, which installs a sensor on the flat wire stator. When making, a pre-embedded part is arranged in the middle of the flat copper winding twist head section. After overall coating, the pre-embedded part is taken out, thus forming a hollow cavity with a wall thickness of 0.4 to 0.6 mm. The temperature sensor is fixed in the hollow cavity by glue. Fixing the sensor on the motor stator can accurately detect the motor temperature and has good practicability on small and medium-sized motors. The problem is that the sensor is glued in the hollow cavity with strong glue. If the sensor fails, taking out the sensor will inevitably damage the wall forming the hollow cavity, and even the adjacent paint may be damaged.

[0007] Yang Changjun, Fu Guangze, Pan Rongfu, etc. disclosed a motor electric control junction box copper bar temperature detection system in January 2023, with a patent number CN202222890257.1. The technical feature is that the copper bar is connected with the output wiring section, and the temperature sensor is stacked on the output wiring terminal through an insulating gasket. One temperature sensor is installed on each output wiring terminal to detect the temperature of each copper bar. This installation method directly contacts the sensor with the circuit, and the temperature detection circuit will be subjected to a large current impact at the moment of motor starting, which is not suitable for use on a 300kw or more high-power motor.

[0008] Considering the high power, strong current and strong vibration of the fine sand machine motor, it is not suitable to monitor the temperature of the coil winding in a contact manner. The temperature of the motor should be monitored in a non-contact manner. The infrared temperature sensor can avoid the influence of the motor circuit on the detection circuit. In addition, the fine sand processing workshop has a lot of dust, so the use of infrared temperature sensors to monitor signals needs to solve the problems of signal fidelity and installation reliability. SUMMARY

[0009] To solve the problems raised in the above background art, the present application provides a method for installing a motor temperature sensor for monitoring a fine sand machine.

[0010] The infrared temperature sensor used has a cylindrical shape, and the outer circular surface is threaded throughout. The technical steps are as follows: 1. A hole is made on the fine sand machine junction box cover, the center of the hole is aligned with the middle of the copper bar in the junction box, the two ends of the hole are chamfered, small grooves are made on the two end faces of the through hole, the grooves are distributed at equal angles in the radial direction, and the depth of the grooves is controlled within the range of 0.5 to 1.5 mm. 2. The sensing end of the temperature sensor passes through the hole made on the motor junction box cover and protrudes 30mm. The sensor is aligned with the copper bar in the junction box and does not contact the copper bar.

[0011] 3. The sensor is fixed by a nut, a rubber washer is placed between the nut and the cover of the terminal box, and a small groove is made on the end surface of the nut and the rubber washer.

[0012] 4. The sensor is wound with a thin iron wire on the thread groove exposed on the inside and outside of the cover of the terminal box, the diameter of the iron wire is selected to be close to the size of the thread pitch, the length of the wound iron wire is 20 to 40 mm, and the head and tail of the wound iron wire are connected.

[0013] 5. The surface of the wound iron wire is coated with strong glue, and then the surface of the glue is wrapped with insulating tape after the glue is dry.

[0014] 6. Preferably, the hole on the cover of the terminal box and the outer diameter of the temperature sensor are gap-fitted.

[0015] 7. Preferably, the surface of the glue is wrapped with insulating tape, and the insulating tape is wound 2 to 3 layers.

[0016] Compared with the prior art, the beneficial effects of the present application are: 1. In the present application, an infrared temperature sensor is installed on the cover of the terminal box of the fine sand machine, the sensor is aligned with the center position of the copper bar in the terminal box, and there is no contact with the motor circuit. Avoid the impact of strong current on the temperature detection circuit when the motor starts, and has the characteristics of easy maintenance, and the temperature detection system is not affected by the motor current.

[0017] 2. In the present application, a small radial groove is made on the side of the nut and the rubber washer, and the rubber is embedded in the small groove when the rubber washer is elastically deformed when tightening the nut. This technology can prevent the nut from returning due to vibration. Similarly, small grooves are made on the end surfaces of the through holes on the cover of the terminal box, and the rubber washer will be embedded in the small groove when tightening the nut. This technology can also prevent the rubber washer from returning due to vibration.

[0018] 3. In the present application, a thin iron wire is wound on the thread groove, strong glue is coated on the surface of the thin iron wire, and then insulating tape is wrapped on the surface of the glue. This measure can further prevent the nut from loosening and ensure that the sensor can be reliably installed on the cover of the terminal box when the fine sand machine is working. BRIEF DESCRIPTION OF DRAWINGS

[0019] Fig. 1 is a schematic diagram of the sensor installation structure; Fig. 2 is a schematic diagram of the small groove structure on the end surface of the nut; Fig. 3 is a schematic diagram of the front surface structure of the terminal box cover; Fig. 4 is a schematic diagram of the back surface structure of the terminal box cover; Fig. 5 is a schematic diagram of the reinforcing structure of strong glue and insulating tape.

[0020] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0021] Please refer to Figs. 1-2 The present application provides a method for installing a motor temperature sensor for monitoring a fine sand machine, and the installation structure comprises: a terminal box cover 1, a rubber gasket 2, a nut 3, an infrared temperature sensor 4, and a wire 5. A through hole 7 is processed on the motor terminal box cover 1, the temperature sensor 4 passes through the through hole 7 and extends into the inside of the terminal box cover 1 by 30 mm, the rubber gasket 2 is placed between the nut 3 and the inner surface of the terminal box cover 1, the wire 5 is wound along the thread groove from the nut 3, the strong glue 10 is applied on the surface of the wire 5, and the insulating tape 11 is wrapped on the surface of the glue after the glue is dry. The method comprises the following steps: 1. Remove the terminal box cover 1 of the motor of the fine sand machine, and clean the dust on the front and back of the terminal box cover 1.

[0022] 2. Draw the position line of the through hole 7 by a fitter. The tools used include a marking needle, a sample punch, and a 0.5 kg hand hammer. The through hole 7 is a Φ16 mm diameter hole. The line drawn should be clear, the sample punch eyes on the circle should be evenly distributed, the sample punch eye at the center of the circle is the position of the drill, the sample punch eye at the center of the circle should be slightly larger, and the sample punch eye at the center of the circle should be aligned with the center of the copper bar inside the terminal box.

[0023] 3. Drill the through hole 7 on the terminal box cover 1. Before drilling, select the equipment, tool, and clamp. The tool selected is a Φ16 mm twist drill. The sensor 4 is in a cylindrical shape, and the outer body is threaded. The major diameter of the thread is Φ16. A Φ16 twist drill is selected to drill the hole. The equipment can be a vertical drilling machine, and the clamp is selected to be a flat tongs. After drilling the hole, the two ends of the hole are blunt with a file, and the drilled inner hole is polished with sandpaper.

[0024] 4. Make an end face groove 8 of the through hole 7 on the outside of the terminal box cover 1. The groove is 60° equiangularly distributed, the depth of the groove is controlled to be 1 mm, and the width of the groove 8 is 2 mm.

[0025] The machining of the groove 8 can be completed on a horizontal milling machine. The tool uses a high-speed steel disc-shaped milling blade, the thickness of the blade is 2 mm, a universal dividing head is used as a clamp, the position of the tool is adjusted, and the machining is completed by one pass. After milling the groove 8, the sharp edge of the groove 8 is blunt with a file by the fitter. This method for machining the groove 8 can obtain higher precision.

[0026] The groove 8 can also be made by a fitter. The fitter first marks the distribution position of the groove 8. The equipment used is a handheld small cutting machine. The tools used are a high-quality resin cutting disc, a 6-inch file, and sandpaper. The thickness of the cutting disc is 1mm. The fixture used is a bench vise. When manually grinding, the workpiece must be clamped in the bench vise. The fitter must wear a protective mask and safety glasses. No one should stand in the direction of the cutting disc's rotation to ensure personal safety. After grinding, the sharp edges of the groove 8 should be blunted and sanded with sandpaper.

[0027] 5. Machining a small groove 9 on the inner side of the junction box, using the same method as step 4.

[0028] 6. Make evenly distributed small grooves 6 at one end of the nut 3. The small grooves are distributed at equal angles of 60°. The depth of the small grooves is controlled at 1mm and the width of the small grooves 6 is 2mm.

[0029] The small groove 6 can be machined on a horizontal milling machine. The cutting tool is a high-speed steel disc milling insert with a thickness of 2 mm. A universal indexing head is used as a fixture. After adjusting the tool position, the machining is completed in one pass. After milling the small groove 6, the fitter uses a file to blunt the sharp edges of the small groove 6. High precision can be obtained by machining the small groove 6 with a milling machine.

[0030] The groove 6 can also be made by a fitter. The fitter first marks the distribution position of the groove 6. The equipment used is a handheld small cutting machine. The tools used are a high-quality resin cutting disc, a 6-inch file, and sandpaper. The thickness of the cutting disc is 1mm. The fixture used is a bench vise. When manually grinding, the workpiece must be clamped in the bench vise. The fitter must wear a protective mask and safety glasses. No one should stand in the direction of the cutting disc's rotation to ensure personal safety. After grinding, the sharp edges of the groove 6 should be blunted and sanded with sandpaper.

[0031] 7. Fix the temperature sensor 4 on the junction box cover 1. The sensing end of the sensor 4 passes through the through hole 7 on the motor junction box cover and extends 30mm. Ensure that it does not contact the copper busbar. Place elastic washers inside and outside, and tighten the nuts 3 on both sides.

[0032] 8. Wrap the wire 5 around the threaded groove of the sensor 4 on the outer surface of the junction box cover 1, starting from the end face of the tightened nut 3, with a wrapping length of 20mm. The first and last ends of the wire 5 are connected. The method of wrapping the wire on the inner side is the same as that on the outer side.

[0033] 9. Apply casting adhesive 10 evenly to the surface of the wound iron wire 5. After the casting adhesive has solidified, wrap it with insulating tape 11. Wrap two layers of insulating tape. The main component of casting adhesive 10 is epoxy resin, which has strong adhesion.

[0034] The strong glue coated on the surface of the winding iron wire 5 can also be AB glue. The main component of AB glue is epoxy resin and curing agent. The AB glue can also obtain the reinforcing effect close to the casting glue by being mixed uniformly at a ratio of 1:1 before use.

[0035] Finally, it needs to be made clear that the above embodiments only illustrate the mounting technical solutions of the present application, but do not limit the same. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can still be modified or the technologies therein can be replaced by equivalents; and the modifications or replacements do not depart from the spirit and scope of the mounting technical solutions of the present application.

Claims

1. An installation method for a motor temperature sensor for a fine sander, wherein a through hole (7) is machined on the motor junction box cover (1), the temperature sensor (4) passes through the through hole (7) and extends 30mm out of the inner side of the junction box cover (1), the temperature sensor (4) is fixed on the outer side of the junction box cover (1) with a nut (3), and a rubber washer (2) is placed between the nut (3) and the outer side of the junction box cover (1); the temperature sensor (4) is fixed on the inner side of the junction box cover (1) with a nut and a rubber washer, and the process is the same as that on the outer side.

2. According to claim 1, the installation method of the motor temperature sensor for a fine sander is as follows: a thin iron wire (5) is wound around the exposed thread groove near the nut end on the outside of the junction box cover (1), and the winding length is controlled within the range of 20 to 40 mm. Strong glue (10) is applied to the surface of the thin iron wire (5), and after the glue dries, insulating tape (11) is wrapped around the glue surface. A thin iron wire is wound around the inside of the junction box cover (1) near the nut end, glue is applied, and insulating tape is wrapped. The process method is the same as that for the outside.

3. The installation method of a motor temperature sensor for a fine sander according to claim 1, characterized in that, A through hole (7) is machined on the junction box cover (1). The center of the through hole (7) is aligned with the copper busbar inside the junction box. The sharp edges of both ends of the through hole (7) are beveled off, and it is clearance-fitted with the outer diameter of the sensor (4).

4. The installation method of a motor temperature sensor for a fine sander according to claim 1, characterized in that, A small groove (9) is made on the inner end face of the through hole (7), and a small groove (8) is made on the outer end face of the through hole (7). The grooves are radially and equally distributed, and the depth of the grooves is controlled within the range of 0.5 to 1.5 mm.

5. The installation method of a motor temperature sensor for a fine sander according to claim 3, characterized in that, A groove (6) is made on the mating surface of the nut (3) and the rubber washer (2). The groove (6) is radially evenly distributed and the depth of the groove (6) is controlled within the range of 0.5 to 1.5 mm. The temperature sensor (3) is fixed with a nut on the inside of the junction box cover (1). A groove is made at one end of the nut. The method of making the groove (6) is the same as the method of making the groove (6) on the outside nut (3).

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