Ultrasonic vibration assisted brazing device for superhard abrasive formed grinding wheel and method of operation thereof

Abstract

The application provides a kind of superhard abrasive forming grinding wheel ultrasonic vibration auxiliary brazing device and its operating method, the device includes motion control system, ultrasonic vibration system, high-frequency induction brazing system and forming grinding wheel fixing device, the forming grinding wheel to be brazed is fixed on the fixing device by spring chuck.The motion control system is composed of a slider placed on a moving guide rail and an electric mechanism controlling its movement, which can control the speed and direction of the slider moving up and down on the guide rail;The ultrasonic vibration system includes two ultrasonic vibration amplitude rods, piezoelectric ceramic transducers, and an external ultrasonic power supply.Each piezoelectric ceramic ultrasonic amplitude rod can provide longitudinal vibration, and two-dimensional elliptical ultrasonic vibration during brazing is achieved by combining the longitudinal vibration in two perpendicular directions;The brazing head driven by the motion control system moves up and down according to the brazing progress, and the induction coil inside the brazing head circulates cooling water.The application solves the problems of uneven distribution of brazing filler metal, low processing quality, excessive concentration of brazing temperature, and serious metallurgical reaction during the brazing process of the forming grinding tool.

Description

Technical Field

[0001] This invention relates to the field of machining technology, specifically to an ultrasonic vibration-assisted brazing device for forming superhard abrasive grinding wheels and its operating method. Background Technology

[0002] Ordinary high-frequency induction brazing is currently one of the common manufacturing methods for welding abrasives in superhard abrasives. However, due to its concentrated heating area, short heating time, and poor heat preservation effect, this method easily leads to uneven distribution of abrasive grains on the surface of the abrasive after brazing, thereby reducing the holding strength and exposure height of the abrasive grains. In addition, in the processing of shaped abrasives, due to the relatively complex surface structure of shaped abrasives, the irregular flow of the brazing filler metal during the brazing process will exacerbate the irregularity of the surface of the abrasive after brazing. At the same time, the uneven temperature distribution during the brazing of shaped abrasives will lead to more severe metallurgical reactions during the brazing process, affecting the stability of the abrasive grain bond strength on the surface of the shaped abrasive.

[0003] Ultrasonic vibration-assisted brazing is a brazing method that utilizes the cavitation and acoustic flow effects generated by ultrasound in liquid brazing filler metal to achieve material bonding, resulting in localized high temperature and pressure, as well as micro-jets. The cavitation effect refers to the periodically changing ultrasound waves causing the pressure field in the liquid brazing filler metal to continuously alternate between positive and negative pressure. When under negative pressure, tiny bubbles in the liquid brazing filler metal are stretched; when under positive pressure, the bubbles are crushed. During this process, high temperature and pressure, as well as micro-jets, occur at the locations of the bubbles. The ultrasonic cavitation effect during brazing effectively spreads the brazing filler metal on the surface of the grinding wheel, improving problems such as weld seams, uneven filler metal distribution, insufficient holding force for abrasive grains, and poor abrasive grain contours. For high-frequency brazing of shaped grinding wheels, using specific ultrasonic vibration modes can achieve even better grinding performance.

[0004] Southwest Jiaotong University's invention patent application, publication number CN113539866A, discloses a method for fabricating memristors using ultrasonic-assisted brazing. First, an intermediate dielectric layer is prepared using a one-step anodic oxidation process. A pure titanium sheet is pretreated, and an electrolyte is prepared. Using a platinum sheet as the cathode and the titanium sheet as the anode, oxidation is carried out at 60 V DC for 2 hours to obtain titanium oxide nanotubes. Then, ultrasonic-assisted brazing is performed to fabricate the top electrode. Pure Sn brazing filler metal is placed at one end of an Al sheet, and the entire sheet is heated to 280 ℃. When the pure Sn brazing filler metal melts, ultrasonic waves are applied to the other side of the Al sheet. The ultrasonic frequency is 20 kHz, the power is 700 W, and the amplitude is 2 μm. The first ultrasonic application lasts for 0.1 s, the second for 2 s, and so on until the brazing filler metal fills the gap. This ultrasonic-assisted brazing method achieves the fabrication of a top electrode / TiO2 / Ti memristor device. The operation is simple and exhibits the resistive switching characteristics unique to memristors.

[0005] The invention patent application CN109759741A filed by Chongqing University of Technology discloses a brazing powder and brazing method for ultrasonic-assisted brazing. This invention provides brazing powder and a brazing method for ultrasonic-assisted brazing. The brazing powder is a powder composed of tin-copper powder, tin-silver-copper powder, or a mixture of tin-copper powder and tin-silver-copper powder, and is uniformly mixed with any one, two, three, four, or five active nanoparticles of nickel powder, cobalt powder, copper powder, tin powder, and titanium powder with a diameter in the range of 1-1000 nm, at a mass ratio not exceeding 20%. The ultrasonic-assisted brazing powder and brazing method of the present invention achieve low welding temperature, utilize active nanoparticles, and generate heat through the oscillation of the ultrasonic generator to promote a metallurgical reaction between the solder or nanoparticles and the base material, realizing low-temperature interconnection of lead-free solder in a fully solid or semi-solid state. The welding temperature is more than 30°C lower than that of traditional liquid interconnection. The oscillation activation and friction generated by the ultrasonic generator promote the rupture of the oxide film on the surface of the base material, achieving the effect of film removal, reducing gas pollution generated by welding flux, resulting in less welding pollution and higher joint quality.

[0006] A patent application filed by Beijing Institute of Technology, publication number CN113000967A, discloses a method and apparatus for ultrasonic-assisted high-frequency brazing of micro-sized superhard cutting tools. The welding method involves first precisely clamping the tool head and shank, then activating the measuring device, followed by starting the ultrasonic vibrator and performing high-frequency brazing under ultrasonic assistance, and finally shutting down the entire apparatus and removing the welded superhard cutting tool. The ultrasonic-assisted brazing apparatus for micro-sized superhard cutting tools consists of four parts: a clamping device, a measuring device, an ultrasonic assisting device, and a high-frequency brazing device. The clamping device precisely clamps the tool shank and tool head, the measuring device measures temperature and pressure in real time, and the ultrasonic-assisted high-frequency brazing technology improves the brazing quality of micro-sized superhard cutting tools. Its structure is simple, operation is convenient, and it significantly improves the welding performance of micro-sized superhard cutting tools.

[0007] Currently, brazing technology is widely used in the welding of various superhard abrasives. However, there are few methods and devices for ultrasonic vibration-assisted induction brazing for grinding wheel machining, especially for the machining of shaped grinding wheels. Ultrasonic vibration-assisted induction brazing devices with a single vibration direction have limited vibration modes, which are effective in lifting the grinding wheel. Furthermore, frequent device replacement is required for grinding heads with different shank diameters, which greatly reduces machining efficiency. Therefore, there is an urgent need to develop a two-dimensional ultrasonic vibration-assisted induction brazing device for shaped grinding wheels. Summary of the Invention

[0008] To address the shortcomings of existing conventional brazing and single-vibration-direction ultrasonic brazing devices in improving the grinding performance of superhard abrasive grinding wheels, this invention designs an ultrasonic vibration-assisted brazing device for superhard abrasive forming grinding wheels and its operation method. The device has a simple assembly structure, good induction brazing efficiency, and is suitable for two-dimensional ultrasonic vibration-assisted brazing of various forming grinding wheels.

[0009] To achieve the above-mentioned objectives, the technical solution adopted by the present invention is as follows:

[0010] An ultrasonic vibration-assisted brazing device for forming superhard abrasive grinding wheels includes a motion control system, an ultrasonic vibration system, a high-frequency induction brazing system, and a fixing device for forming grinding wheels. The forming grinding wheel to be brazed is fixed to the center of the base by a spring clamp placed in the cylindrical groove in the center of the support base.

[0011] The motion control system consists of a slider placed on a moving guide rail and a motor that controls its movement. The motor is connected to a PLC control system of a computer, which can control the speed and direction of the slider's up and down movement on the guide rail, thereby ensuring that the coil maintains a suitable direction and speed of movement during the brazing process.

[0012] The ultrasonic vibration system consists of two ultrasonic vibration amplitude rods, a piezoelectric ceramic transducer, and an amplitude rod support base. The two ultrasonic vibration amplitude rods are respectively connected to the front and side of the support base. The amplitude rod support base has a groove in the center. The amplitude rod is connected to the groove through a flange. The amplitude rod support base is bolted to the vibration damping plate. The piezoelectric ceramic transducer is bolted to the large end of the amplitude rod and the rear cover plate.

[0013] The aforementioned ultrasonic vibration-assisted high-frequency induction brazing superhard abrasive forming grinding wheel device has two threaded sleeves on the two sides of the base supporting the forming grinding wheel, and the small end of the piezoelectric ceramic ultrasonic amplitude transformer has a corresponding thread for connecting the amplitude transformer to the base.

[0014] The aforementioned ultrasonic vibration-assisted high-frequency induction brazing superhard abrasive forming grinding wheel device has a cylindrical groove connected to the bottom at the center of the base supporting the forming grinding wheel. The bottom plate inside the cylindrical groove is machined with a tapered hole that matches the spring collet and has a protruding cylindrical section. The outer side has threads for engaging with a nut to fix the spring collet. The forming grinding wheel of various sizes can be adapted by adjusting the spring collet.

[0015] The aforementioned ultrasonic vibration-assisted high-frequency induction brazing device for forming superhard abrasive grinding wheels has a pair of air inlets 31 on the side of the protective cover, connected to an external argon gas pipe. During induction brazing, argon protective gas is introduced through the air inlets. An air outlet 32 ​​is located on the other side for gas discharge and circulation. A pair of threaded holes are located at the bottom of the protective cover, allowing it to be bolted to a circular groove in the center of the base for fixation to the support base. The top of the protective cover has threads for connection to a protective cover, which consists of a main protective cover and a smaller secondary protective cover, accommodating different sized forming grinding wheels during induction brazing.

[0016] The aforementioned ultrasonic vibration-assisted high-frequency induction brazing device for forming superhard abrasive grinding wheels mainly consists of a brazing head and an induction coil connected to a high-frequency brazing machine. The induction coil is connected to the brazing head by soldering. The brazing head is fixed to a support plate on a movable slider of the guide rail by bolts through two protruding threaded holes. The coil is hollow inside and is connected to an external cooling water circulation system through the brazing head.

[0017] The method for ultrasonic vibration-assisted brazing of superhard abrasive grinding wheels based on the above-mentioned ultrasonic vibration-assisted high-frequency induction brazing device for forming superhard abrasive grinding wheels comprises the following steps:

[0018] (1) Start the PLC control system connected to the motor and set the appropriate motor movement direction and speed during induction brazing.

[0019] (2) Turn on the external water pump to allow the cooling water to circulate in the induction coil for several minutes until the cooling water circulation is smooth.

[0020] (3) Fix the forming grinding wheel to be brazed in the center of the support base with a spring clamp, and at the same time turn on the ultrasonic power supply connected to the ultrasonic vibration system. The piezoelectric ceramic transducer converts the electrical signal into mechanical vibration, which drives the amplitude transformer to vibrate. The amplitude transformer transmits the vibration to the support base platform through the small end, so that the forming grinding wheel in the brazing process will vibrate accordingly. According to the vibration mode requirements of brazing, the ultrasonic power supply connected to one or two ultrasonic amplitude transformers can be selectively turned on.

[0021] (4) High-purity argon gas is continuously introduced through the inlet and outlet of the protective cover for several minutes until the original air inside the protective cover is exhausted. The PLC control system controls the induction coil to enter the appropriate brazing position of the protective cover, turns on the high-frequency induction brazing machine, continuously increases the brazing current, and keeps the cooling water circulating. After the brazing filler melts, the PLC control system raises the induction coil to avoid overheating during the brazing process. The sealing gasket inside the protective cover can play a good sealing role. Beneficial effects

[0022] (1) In the device provided by the present invention, the high-frequency induction brazing head is installed on the movable slider. The slider drives the brazing head to move along the guide rail of the moving table. The slider is controlled by a motor connected to the PLC system, which can realize the scanning brazing method in the induction brazing process, thereby reducing defects such as loss of brazing material on the surface of the forming grinding wheel after brazing and reduced holding force caused by excessively concentrated brazing temperature and untimely cooling.

[0023] (2) In the device provided by the present invention, the forming grinding wheel is held by an adjustable spring chuck fixed to the center of the support base. Through the adjustability of the spring chuck, it can adapt to the clamping of forming grinding wheels of different sizes, thus avoiding the need to frequently replace the appropriate device due to the size change of the brazed forming grinding wheel.

[0024] (3) In the device provided by the present invention, ultrasonic vibration is applied to the support platform by a piezoelectric ceramic ultrasonic amplitude transformer, and in combination with scanning induction brazing, the fluidity of the brazing filler metal during the brazing process can be increased, the uneven heating of the brazing filler metal can be reduced, and the cavitation effect of ultrasonic vibration can reduce the internal air bubbles when the brazing filler metal and the substrate are combined after brazing, thereby improving the spreadability of the brazing filler metal and thus improving the processing performance of the formed grinding wheel after brazing.

[0025] (4) In the device provided by the present invention, the ultrasonic vibration mode that can be changed during the induction brazing process is realized by two piezoelectric ceramic ultrasonic amplitude transformers connected to the front and the side. Depending on the structure of the induction brazing forming grinding wheel, one piezoelectric ceramic ultrasonic amplitude transformer can be used to realize one-dimensional longitudinal vibration or two piezoelectric ceramic ultrasonic amplitude transformers can be used to realize two-dimensional elliptical vibration, thereby improving the applicability of the overall ultrasonic vibration system. Attached Figure Description

[0026] Figure 1 This is an overall schematic diagram of an ultrasonic vibration-assisted brazing device for forming superhard abrasive grinding wheels according to the present invention;

[0027] Figure 2 This is a schematic diagram of a mobile station;

[0028] Figure 3 This is a schematic diagram of the induction brazing device 3;

[0029] Figure 4 This is a schematic diagram of a piezoelectric ceramic ultrasonic system;

[0030] Figure 5 This is a schematic diagram of the amplitude transformer support 8;

[0031] Figure 6 This is a three-dimensional schematic diagram of the forming grinding wheel support base 10;

[0032] Figure 7 for Figure 6 The front view;

[0033] Figure 8 This is a schematic diagram of a spring collet;

[0034] Figure 9 This is a schematic diagram of an argon gas protective shield;

[0035] Figure 10 This is a schematic diagram of the main protective cover;

[0036] Figure 11 This is a schematic diagram of the secondary protective cover;

[0037] Figure 12 This is a schematic diagram of the brazing effect after ultrasonic vibration-assisted brazing.

[0038] Figure 13 A schematic diagram showing the specific components of the abrasive tool to be brazed, including the argon gas protective cover;

[0039] Figure 14 This is a schematic diagram showing the modes and ultrasonic vibration direction of the piezoelectric ceramic amplitude transformer at the operating frequency.

[0040] The components include: 1. Moving platform guide rail; 2. Control motor; 3. Induction brazing device; 4. Induction coil; 5. Piezoelectric ceramic amplitude transformer I; 7. Piezoelectric ceramic amplitude transformer II; 6. Protective cover; 8. Amplifier bracket; 9. Argon gas protective cover; 10. Forming grinding wheel support base; 11. Vibration damping plate; 12. Platform support rib; 13. Fixed bracket; 14. Threaded hole; 15. Induction brazing device brazing head; 16. Induction coil connector; 17. Bolt; 18. Rear cover plate; 19. Piezoelectric ceramic sheet. 9. Electrode plate - 20. Flange - 21. Amplitude rod - 22. Connecting thread - 23. Connecting groove - 24. Threaded hole - 25. Cylindrical groove - 26. Connecting threaded sleeve I - 27. Connecting threaded sleeve II - 28. Threaded hole - 29. Threaded hole - 30. Air inlet - 31. Air outlet - 32. Connecting thread - 33. High frequency induction brazing machine - 34. PLC control system - 35. Ultrasonic power supply - 36. External cooling water circulation system - 37. Water tank - 38. Water pump - 39. Detailed Implementation

[0041] The technical solution of the present invention will be described in detail below with reference to specific embodiments:

[0042] Example

[0043] Figure 1 This is a schematic diagram of an ultrasonic vibration-assisted brazing device for forming superhard abrasive grinding wheels according to the present invention. (Refer to...) Figure 1As shown, the device includes: a motion control system, a high-frequency induction brazing system, an ultrasonic vibration system, and a forming grinding wheel fixing system. The bottoms of each of these systems are fixed to the vibration-damping base plate 11. The motion control system includes a moving stage, a moving stage guide rail 1, and a slider 2 controlled by a motor, with the motor connected to an external computer PLC program. The high-frequency induction brazing system includes an induction brazing device 3, an induction coil 4, and an external high-frequency induction brazing machine and cooling water circulation system. The ultrasonic vibration system includes a piezoelectric ceramic ultrasonic amplitude transformer I 5, a piezoelectric ceramic ultrasonic amplitude transformer II 7, an ultrasonic amplitude transformer bracket 8, and an external ultrasonic power supply. The forming grinding wheel fixing system includes an argon gas protective cover 9 and a support base 10. The bottoms of the guide rail 1, the ultrasonic amplitude transformer bracket 8, and the support base 10 are all fixed to the vibration-damping base plate 11.

[0044] The ultrasonic vibration system transmits amplified longitudinal vibrations to the support base platform of the forming grinding wheel fixing system through two mutually perpendicular amplitude rods, thereby causing the forming grinding wheel to produce two-dimensional elliptical vibrations during the brazing process. The motion control system moves the induction coil 4 of the high-frequency induction brazing system up and down within the argon gas protective cover of the forming grinding wheel fixing system according to the brazing progress. During the brazing process, the cooling water circulation system flows through the induction coil 4 to achieve real-time cooling.

[0045] Figure 2 The diagram shows the moving stage. The moving stage guide rail and the slider 2 are movably connected in an interlocking manner. The slider 2 is connected to the PCL system control system 35. Under the control of the PCL system control system 35, the slider slides in the guide rail. The top of the slider 2 is provided with a support platform for connecting the high-frequency brazing head. The platform and the side wall of the slider are provided with platform support ribs 12. There is a pair of protruding brackets 13 on the platform, which have threaded holes for connecting with the brazing head.

[0046] Figure 3 This is a schematic diagram of the brazing head 15 of the induction brazing device. The bottom of the brazing head 15 is bolted to an induction coil connector 16, and a sealing gasket is placed at the connection point. The induction coil 4 is soldered to the induction coil connector 16. The threaded hole 14 on the side of the brazing head 15 is connected to the aforementioned bracket 13 via bolts and the threaded hole, fixing the induction brazing device to the slider. Under the control of the PCL system control system 35, the slider moves the brazing head of the induction brazing device up and down. The brazing head of the induction brazing device is connected to the high-frequency induction brazing machine 34 and the external cooling water circulation system 37. The induction coil is hollow inside, and cooling water from the external cooling water circulation system circulates inside during the brazing process to ensure the induction coil maintains a normal temperature during induction brazing.

[0047] Figure 4This is a schematic diagram of a piezoelectric ceramic amplitude transformer, which includes an amplitude transformer and a transducer. The transducer consists of piezoelectric ceramic plates 19, electrode plates 20, a rear cover plate 18, and bolts 17. Four electrode plates are sandwiched between five piezoelectric ceramic plates, which are pressed together by bolts 17 and the rear cover plate 18, and connected to the large end of the amplitude transformer through a threaded hole at the rear end. The amplitude transformer is a stepped amplitude transformer 22, with the large and small ends being cylinders of different diameters, connected in the middle by a cylindrical transition. A flange 21 is provided at the vibration node, and the transducer is connected to the large end of the large end of the large end of the large end of the small ... Figure 5 The ultrasonic amplitude transformer bracket shown mates with the connecting groove 24, and the bracket is connected to the vibration damping base plate 11 through the threaded hole 25 at the bottom. The small end of the amplitude transformer has a thread 23 for connecting to the support base platform. In this embodiment, there are two piezoelectric ceramic amplitude transformers, respectively arranged on the front and side of the support base platform, to achieve two-dimensional elliptical vibration. The reason why the amplitude transformers are not arranged in a relative manner in this invention is that a relative arrangement would cause the amplitude to cancel or weaken in the transverse wave direction.

[0048] Figure 6 This is a schematic diagram of the support base for the forming grinding wheel. Figure 7 The front view shows an arc-shaped groove in the center of the support base. The bottom plate inside the groove is machined with a tapered hole that matches the spring collet and has a protruding cylindrical section. The outer side is threaded to cooperate with the nut to fix the spring collet used to clamp the molded mold. On the front and side of the top platform of the support base, there are connecting threaded sleeves I27 and II28, respectively, to connect the two piezoelectric ceramic amplitude transformers mentioned above. A pair of threaded holes 29 are opened in the central convex cylindrical groove to fix the argon gas protective cover. O-rings are placed between the argon gas protective cover and the cylindrical groove.

[0049] Figure 8 This is a schematic diagram of a spring collet. The adjustable spring collet size can accommodate different forming wheel sizes, and its overall shape and dimensions match the groove in the center of the forming wheel support base. Before brazing, the forming wheel is held in place by the small end of the spring collet, with the large end facing down in the groove of the support base. Then, a protective cover is installed on the forming wheel support base. The forming wheel is placed in a closed space with the help of the protective cover and the protective cap. The induction coil extends into the protective cover through the hole at the top of the main protective cap to perform brazing on the wheel.

[0050] Figure 9 The diagram shows an argon gas protective cover. A threaded hole 30 is provided on the side wall near the bottom, which is fixed to the threaded hole 29 of the above-mentioned forming grinding wheel support base by bolts to connect the support base. A pair of air inlets 31 are opened on the side wall near the top of the argon gas protective cover, and a corresponding air outlet 32 ​​is opened on the other side. During the induction brazing process, high-purity argon gas is continuously introduced from the air inlets and outlets to ensure that the forming grinding wheel substrate is not oxidized during the brazing process. The top of the protective cover has a thread 33 that matches the protective cover.

[0051] Figure 10 The diagram shows the main protective cover, which is fixed to the argon gas protective cover by the internal thread at the bottom, and has an external thread at the top for connecting the smaller secondary protective cover. Figure 11 This is a schematic diagram of the secondary protective cover, used for sealing with a smaller protective cover. During induction brazing, either the main or secondary protective cover can be unscrewed depending on the size of the corresponding brazing forming grinding wheel. After removing the secondary protective cover, the coil enters the protective cover through the opening for brazing. If the coil size is too large, the main protective cover can also be removed directly, and the coil can be inserted directly into the protective cover for brazing.

[0052] The method for ultrasonic vibration-assisted brazing of superhard abrasive grinding wheels based on the above-mentioned ultrasonic vibration-assisted high-frequency induction brazing device for forming superhard abrasive grinding wheels comprises the following steps:

[0053] (1) Start the PLC control system connected to the motor and set the appropriate motor movement direction and speed during induction brazing.

[0054] (2) Turn on the external water pump to allow the cooling water to circulate in the induction coil for several minutes until the cooling water circulation is smooth.

[0055] (3) Fix the forming grinding wheel to be brazed with a spring clip and place it in the groove in the center of the support base. Fix the protective cover and protective cap. Turn on the ultrasonic power supply connected to the ultrasonic vibration system. The piezoelectric ceramic transducer converts the electrical signal into mechanical vibration, which drives the amplitude transformer to vibrate. The amplitude transformer transmits the vibration to the support base platform from the front and / or side through the small end, thereby causing the forming grinding wheel to generate two-dimensional vibration during the brazing process. According to the vibration mode requirements of brazing, the ultrasonic power supply connected to one or two ultrasonic amplitude transformers can be selectively turned on.

[0056] (4) High-purity argon gas is continuously introduced through the inlet and outlet of the protective cover for several minutes until the original air inside the protective argon gas cover is exhausted. Through the PLC control system, the induction coil is controlled to enter the appropriate brazing position of the protective cover, the high-frequency induction brazing machine is turned on, the brazing current is continuously increased, and the cooling water is kept circulating. After the brazing filler melts, the induction coil is raised by moving the slider in the guide rail of the moving table using the PLC control system to avoid overheating during the brazing process. The sealing gasket inside the protective cover can play a good sealing role. Figure 12 The comparison shows the effect of the bonding between the filler metal and abrasive grains on the surface of the forming grinding wheel before and after the application of ultrasonic vibration assistance. It can be seen that the cavitation effect of two-dimensional elliptical ultrasonic vibration reduces the internal air bubbles when the filler metal bonds with the substrate after brazing, thus improving the spreadability of the filler metal. Moreover, the filler metal is evenly distributed, and the brazing temperature is evenly distributed.

[0057] The contents described in the embodiments of this invention are merely simple examples of the implementation of the inventive concept. The scope of protection of this invention should not be limited to the specific forms described in the embodiments. Any simple modifications made according to this invention should be within the scope of protection of this invention.

Claims

1. An ultrasonic vibration-assisted brazing device for forming superhard abrasive grinding wheels, characterized in that, include: The motion control system, high-frequency induction brazing system, ultrasonic vibration system, and forming grinding wheel fixing system are all fixed at the bottom of the anti-vibration base plate (11). The ultrasonic vibration system transmits the amplified longitudinal vibration to the support base platform of the forming grinding wheel fixing system through two mutually perpendicular amplitude rods, thereby causing the forming grinding wheel to generate two-dimensional elliptical vibration during the brazing process. The motion control system drives the induction coil (4) of the high-frequency induction brazing system to move up and down within the argon gas protective cover of the forming grinding wheel fixing system according to the brazing progress. During the brazing process, the cold water of the cooling water circulation system flows through the induction coil (4) to achieve real-time cooling. The motion control system includes a moving stage, a moving stage guide rail (1), and a slider (2) controlled by a motor. The motor is externally connected to the PCL system control system (35). The moving stage guide rail and the slider (2) are movably connected in an interlocking manner. Under the control of the PCL system control system, the slider slides within the guide rail. The high-frequency induction brazing system includes an induction brazing device (3) and an external high-frequency induction brazing machine and a cooling water circulation system; one end of the induction coil (4) on the brazing head of the induction brazing device extends into the forming grinding wheel fixing system, and the cooling water circulates in the coil to cool it in real time. The ultrasonic vibration system includes a transducer, two piezoelectric ceramic ultrasonic amplitude transformers, an ultrasonic amplitude transformer support (8), and an external ultrasonic power supply. The forming grinding wheel fixing system includes an argon gas protective cover (9) and a support base (10). The support base (10) has a groove in the center of its panel. The spring collet that holds the forming grinding wheel is placed in the groove, and the brazing process is sealed by means of the protective cover. The bottoms of the moving stage, the ultrasonic amplitude rod support (8), and the support base (10) are fixed on the vibration-damping base plate; The amplitude rod is a stepped amplitude rod with cylinders of different diameters at the large and small ends, and a transition connection in the middle. A flange (21) is provided at the vibration node, which is matched with the connecting groove (24) of the ultrasonic amplitude rod bracket. The small end of the amplitude rod is connected to the support base platform by a thread. There are two amplitude rods, which are respectively set on the front and side of the support base platform to realize two-dimensional elliptical vibration.

2. The ultrasonic vibration-assisted brazing device for forming superhard abrasive grinding wheels according to claim 1, characterized in that, The transducer includes piezoelectric ceramic plates, electrode plates, a rear cover plate, and bolts. Four electrode plates are sandwiched between five piezoelectric ceramic plates, which are pressed together by bolts and the rear cover plate, and connected to the large end of the amplitude rod through a threaded hole at the rear end of the amplitude rod.

3. The ultrasonic vibration-assisted brazing device for forming superhard abrasive grinding wheels according to claim 1, characterized in that, The upper panel of the support base has a central opening, and a groove is provided between the upper and lower panels. The shape and size of the groove match the spring collet used to hold the molded mold, and the two are fixed by threads. Connecting threaded sleeves are provided on the front and side of the upper panel of the support base to connect the two amplitude rods. Threaded holes (29) are provided on the protruding connecting piece of the central opening to fix the argon gas protective cover.

4. The ultrasonic vibration-assisted brazing device for forming superhard abrasive grinding wheels according to claim 3, characterized in that, Before brazing, the small end of the spring collet is used to hold the shaped grinding wheel, and the large end is placed downward in the groove of the support base. The protective cover is installed above the groove to create a closed space. The induction coil extends into the protective cover through the hole at the top of the protective cover to braze the grinding wheel.

5. The ultrasonic vibration-assisted brazing device for forming superhard abrasive grinding wheels according to claim 3, characterized in that, The protective cover has a threaded hole (30) on the side wall near the bottom, which is fixed to the threaded hole (29) of the forming grinding wheel support base by bolts to connect the support base. A pair of air inlets are opened on the side wall near the top of the protective cover, and a corresponding air outlet is opened on the other side. During the induction brazing process, high-purity argon gas is continuously introduced from the air inlets and outlets to ensure that the forming grinding wheel substrate is not oxidized during the brazing process.

6. The ultrasonic vibration-assisted brazing device for forming superhard abrasive grinding wheels according to claim 1, characterized in that, The top of the slider (2) is provided with a support platform for connecting the high-frequency brazing head. The platform and the side wall of the slider are provided with platform support ribs (12). A pair of protruding brackets (13) are provided on the platform, with threaded holes for connecting with the brazing head.

7. The operating method of the ultrasonic vibration-assisted brazing device for forming superhard abrasive grinding wheels according to claim 1, characterized in that, The steps are as follows: (1) Start the PLC control system connected to the motor and set the appropriate motor movement direction and speed during induction brazing; (2) Turn on the external water pump to allow the cooling water to circulate within the induction coil for several minutes until the cooling water circulation is smooth. (3) Fix the forming grinding wheel to be brazed with spring clips and place it in the groove in the center of the support base. Fix the protective cover and protective cap. Turn on the ultrasonic power supply connected to the ultrasonic vibration system. After the piezoelectric ceramic transducer converts the electrical signal into mechanical vibration, it drives the amplitude rod to vibrate. The amplitude rod transmits the vibration to the support base platform from the front and / or side through the small end, so that the forming grinding wheel in the brazing process generates two-dimensional vibration. According to the vibration mode requirements of brazing, turn on the ultrasonic power supply connected to one or two ultrasonic amplitude rods. (4) High-purity argon gas is continuously introduced through the air inlet and outlet of the protective cover until the original air is exhausted. The PLC control system controls the induction coil to enter the appropriate brazing position of the protective cover, turns on the high-frequency induction brazing machine, continuously increases the brazing current, keeps the cooling water circulating, and after the brazing filler melts, the PLC control system uses the slider to move and lift the induction coil in the guide rail of the moving table to avoid overheating during the brazing process.

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