CN109967789B - Ultrasonic broach, efficient and precise ultrasonic broaching device and broaching process thereof - Google Patents

Abstract

The invention discloses an ultrasonic broaching tool, an efficient and precise ultrasonic broaching device and a broaching process thereof. The existing broach and broaching machine do not have an integrated information acquisition device and have short service life. The invention relates to an ultrasonic broach, which comprises an ultrasonic transducer, a detection assembly and a broach body. The detection assembly comprises a detection substrate, a laser transceiving belt, an image sensor, an axial pressure sensor, a first radial pressure sensor and a second radial pressure sensor. The invention relates to a high-efficiency precise ultrasonic broaching device, which comprises a broaching machine body, a grating and the ultrasonic broaching tool. The broaching machine body comprises a broaching machine driving assembly, a machine body, a broaching machine guide rail and a quick positioning and clamping device; the invention has the measuring functions of the broach three-way vibration value, the broach axial tension, the broach displacement value, the workpiece dimension based on the image and the like. And real-time detection data is provided for a working condition feedback loop and a shutdown control loop of the control system. The invention can effectively prolong the service life of the broach.

Description

Ultrasonic broach, efficient and precise ultrasonic broaching device and broaching process thereof

Technical Field

The invention belongs to the technical field of intelligent manufacturing, and particularly relates to an ultrasonic broaching tool, an efficient and precise ultrasonic broaching device and a broaching process of the ultrasonic broaching tool.

Background

High-efficiency and precise numerical control broaching equipment is high-end manufacturing equipment and is indispensable key equipment for intelligent manufacturing. The high-efficiency precision broaching process is mainly used in the automobile industry and the aviation industry, and is a main processing method and means for high-precision core parts of automobiles and airplanes, such as an engine, a gear box, a differential mechanism, a transmission shaft system, a brake system, a hub unit, a steering gear and the like. The high-end of the high-efficiency precise numerical control broaching process is applied to the fields of military industry and aerospace aviation, such as the processing of high-precision core parts of gun barrels, aircraft engines and the like. In the manufacturing industries of modern automobile industry, engineering machinery and the like, parts are produced by gradually adopting broaching instead of the traditional machining modes of slotting, milling, planing and the like. Therefore, the level of technology of broaching also indicates the level of manufacturing industry of automobiles and the like in the country from one side. At present, domestic high-end numerical control broaching processes and equipment mainly depend on import, and take Germany as the first thing. Domestic broaching machine enterprises are still in the initial and long-term stage.

The key parts of the automobile and the airplane are mostly made of materials difficult to process, such as high-temperature alloy, powder high-temperature alloy, titanium alloy and the like, the parts are complex in shape, high in dimensional precision requirement, strict in technical condition and high in requirements on the surface quality and surface integrity of the parts, and the service life and the safety and reliability of the automobile and the airplane are directly influenced by the processing quality. On the other hand, especially for the processing of automobile parts, the requirement on the production efficiency is higher and higher due to the fact that the product updating speed is higher.

In recent years, with the continuous progress and development of vehicle engineering and aircraft engine technologies, the machining technology of these key parts has been greatly improved, and the direction of automation, integration, precision and high efficiency, such as composite technology and numerical control machining, is promoted and developed from the traditional machining technology and means. For the processing of key parts of automobiles and airplanes with complex shapes, the traditional numerical control milling or broaching processing mode and equipment are basically adopted at present. Due to the complex shape and many processing procedures, the main problems of processing efficiency, precision and the like generally exist. Therefore, the invention provides an efficient and precise ultrasonic broaching process and a control system, which comprise a broaching process based on an ultrasonic technology, a control system based on multi-mode conversion and corresponding processing equipment, and greatly improve the processing efficiency and prolong the service life of a cutter on the premise of ensuring the processing precision, thereby obviously reducing the production cost.

Disclosure of Invention

The invention aims to provide an ultrasonic broaching tool, an efficient and precise ultrasonic broaching device and a broaching process thereof.

The invention relates to an ultrasonic broach, which comprises an ultrasonic transducer, a detection assembly and a broach body. The detection assembly comprises a detection substrate, a laser transceiving belt, an image sensor, an axial pressure sensor, a first radial pressure sensor and a second radial pressure sensor. The laser transceiver is surrounded on the detection substrate. The detection base body comprises a left end cover, a middle end seat, a guide compression ring, a right end seat and a pull rod. The left end cover, the guide compression ring, the middle end seat and the right end seat are sequentially and fixedly connected. An axial pressure sensor is arranged in the left end cover. The pull rod consists of a connecting shaft and a left end seat which are integrally formed. The inner end of the connecting shaft is connected with the left end seat. The end of the left end seat close to the connecting shaft is positioned in the left end cover. The axial pressure sensor is positioned between the left end cover and the left end seat;

and a first separation lug is arranged on the end surface of the left end seat far away from the connecting shaft. A first accommodating groove is formed in the side face, close to the left end cover, of the middle end seat. The first accommodating groove is in a long strip shape. Both ends of first holding recess all are provided with first radial pressure sensor. The first separating projection extends into the first accommodating groove and is positioned between the two first radial pressure sensors.

And a second accommodating groove is formed in one side, far away from the left end cover, of the middle end seat. The second accommodating groove is in a long strip shape. And second radial pressure sensors are arranged at two ends of the second accommodating groove. The inner end face of the right end seat is provided with a second partition lug. The second separating convex block extends into the first accommodating groove and is positioned between the two second radial pressure sensors. The right end seat is embedded with an image sensor. The connecting shaft is fixed with one end of the ultrasonic transducer. The outer end of the right end seat is fixed with one end of the broach body.

Furthermore, the laser transceiver band is provided with a plurality of laser transmitters and a plurality of laser receivers which are arranged along the circumferential direction of the middle end seat.

Furthermore, a stepped through hole is formed in the left end cover. The hole section with the larger aperture on the stepped through hole is positioned on one side of the left end cover close to the guide compression ring. The axial pressure sensor is annular and is arranged in a hole section with a larger aperture on the stepped through hole. The shaft section with the smaller bore diameter on the connecting shaft passes through the central hole of the axial pressure sensor and the hole section with the smaller bore diameter on the stepped through hole. The sum of the thickness of the axial pressure sensor and the thickness of the shaft section with the larger bore diameter on the connecting shaft is equal to the length of the hole section with the larger bore diameter on the stepped through hole.

Further, the length direction of the second accommodating groove is perpendicular to the length direction of the first accommodating groove. And the end surface of the left end seat far away from the connecting shaft is also provided with two anti-rotation convex strips. The first separation lug is positioned between the two anti-rotation convex strips. Two anti-rotation grooves are further formed in the side face, close to the left end cover, of the middle end seat. The two anti-rotation convex strips are respectively embedded into the two anti-rotation grooves, and a CCD camera is adopted by a camera of the image sensor.

The invention relates to a high-efficiency precise ultrasonic broaching device, which comprises a broaching machine body, a grating and the ultrasonic broaching tool. The broaching machine body comprises a broaching machine driving assembly, a machine body, a broaching machine guide rail and a quick positioning and clamping device; the broaching machine guide rails are fixed on the machine body; the grating is fixed on one side of the lathe bed. The rapid positioning and clamping device comprises a slide carriage guide rail, a slide carriage, a positioning and clamping block, a slide carriage V-shaped block and a clamping driving assembly; the slide carriage and the broaching machine guide rail form a sliding pair; the slide carriage guide rail is fixed on the slide carriage; the two positioning clamping blocks and the slide carriage guide rail form a sliding pair; the two positioning clamping blocks are driven by the clamping driving component to move in the opposite direction or in the opposite direction; the slide carriage V-shaped block is fixed on the slide carriage; the top of the slide carriage V-shaped block is provided with a V-shaped positioning groove; the two positioning clamping blocks are both positioned above the slide carriage V-shaped block; the number of the rapid positioning and clamping devices is two; a slide carriage in one of the quick positioning and clamping devices is driven by a broaching machine driving assembly; the ultrasonic broach also comprises two broach clamping sections. The two broach clamping sections are respectively fixed with the ultrasonic transducer and the other end of the broach body. The two broach clamping sections are respectively arranged on the slide carriage V-shaped blocks of the two rapid positioning and clamping devices.

Further, the arrangement direction of the slits on the grating is parallel to the length direction of the broaching machine guide rail.

Furthermore, the bottoms of the opposite side surfaces of the two positioning clamping blocks are respectively provided with a positioning inclined surface which inclines downwards; and the symmetrical surfaces of the two positioning datum surfaces of the V-shaped positioning groove are superposed with the symmetrical surfaces of the positioning inclined surfaces on the two positioning clamping blocks.

Further, the broaching machine driving assembly comprises a photoelectric encoder, a broaching machine driving motor and a broaching machine screw rod; the broaching machine lead screw is supported on the machine body; the broaching machine driving motor is fixed on the machine body, and an output shaft is fixed with one end of a broaching machine screw rod; the photoelectric encoder is fixed with the broaching machine driving motor, and the input shaft is fixed with the output shaft of the broaching machine driving motor. A nut is fixed at the bottom of the slide carriage in the quick positioning and clamping device driven by the broaching machine driving assembly; the nut and the broaching machine screw form a screw pair.

The clamping driving assembly comprises a slide carriage lead screw and a positioning and clamping motor; the slide carriage lead screw is supported on the slide carriage; the slide carriage lead screw adopts a bidirectional lead screw; the positioning and clamping motor is fixed on the positioning and clamping box body, and an output shaft is fixed with one end of the slide carriage lead screw; the two positioning clamping blocks and two spiral sections on the slide carriage lead screw with opposite rotation directions respectively form a spiral pair.

The broaching process of the high-efficiency precise ultrasonic broaching device is as follows:

firstly, a worker sets a mode variable M; if M is set to be 0, the broaching machine driving assembly operates in a life mode; if M is set to 1, the broaching machine driving assembly operates in the efficiency mode.

Step two, calling technological parameters: cutting speed V₁Stable speed V₂Time to cut-in t₁Stable broaching duration t₂(ii) a Ultrasonic frequency f, ultrasonic amplitude h. Wherein, V₁＝b·V₂；0.4≤b≤0.6。

And step three, the broaching machine driving assembly positively drives the rapid positioning and clamping device, the ultrasonic transducer is started to drive the ultrasonic broaching tool to feed, and broaching is started.

If M is 0, the first ultrasonic broachThe front t of the workpiece is cut into by one cutter tooth₁The feeding speed of the ultrasonic broach is maintained at V within the time₁. Thereafter, the feed rate of the ultrasonic broach was maintained at V₂. If M is equal to 1, each cutter tooth of the ultrasonic broaching cutter cuts into the workpiece before t₁The feeding speed of the ultrasonic broach is maintained at V within the time₁. The feeding speed of the ultrasonic broach is maintained at V in other feeding time₂。

The axial pressure sensor continuously detects the magnitude of the axial load force F in the broach feeding process. If F is greater than or equal to F_{License plate}And then the broaching machine driving assembly and the ultrasonic transducer are closed. F_{License plate}Is the maximum allowable pulling force of the ultrasonic broach.

The laser transceiving belt is matched with the grating to continuously detect the current position value X of the broach, and if X is more than or equal to X_{Final (a Chinese character of 'gan')}Then the broaching machine driving unit stops moving and proceeds to step four. X_{Final (a Chinese character of 'gan')}Is the feeding termination position of the ultrasonic broach.

The first radial pressure sensor and the second radial pressure sensor respectively detect the magnitude of two radial load forces of the broach; and the resultant force of the pressures obtained by the two sensors which detect the pressures in the two first radial pressure sensors and the two second radial pressure sensors is used as the vibration force. The vibration acceleration a is obtained from the vibration force.

If a is greater than or equal to a_Threshold(s)And then the broaching machine driving assembly and the ultrasonic transducer are closed. If a > a_{License plate}+△a_{License plate}Then V will be₂Reduce △ V to V₁Is updated to V₂B times of the total weight of the composition. If a < a_{License plate}△a_{License plate}Then V will be₂Increase △ V, change V₁Is updated to V₂B times of the total weight of the composition. a is_Threshold(s)Is the ultimate vibration acceleration of the ultrasonic broach. a is_{License plate}△ a being the best allowable vibration acceleration of ultrasonic broach_{License plate}Is the vibration acceleration range radius of the ultrasonic broach, △ V is the single adjustment of the feed speed of the ultrasonic broach.

And step four, shooting the picture of the workpiece by the image sensor. And (4) processing the image of the obtained picture to judge whether the broaching part of the workpiece meets the processing requirement. If the machining requirements are not met, the broaching machine driving assembly and the ultrasonic transducer are usedAre all closed. If the machining requirement is met, the broaching machine driving assembly reversely drives the rapid positioning and clamping device, and the ultrasonic broaching tool retracts at a speed V_{Go back to}And (5) returning. The laser transceiving belt is matched with the grating, and the current position value X of the broach is continuously detected; until X ═ X₀And if so, entering the step five. X₀Is the initial position of the ultrasonic broach.

Step five, if the next workpiece needs broaching, the step three is carried out after the workpiece is replaced; otherwise, broaching is finished.

The invention has the beneficial effects that:

1. the invention has a main channel for broaching feeding and ultrasonic control, a working condition feedback loop for displacement detection, speed detection, tension detection and vibration detection, a shutdown control loop for product size detection and out-of-tolerance judgment, and a cutter service life prediction unit. The broaching process has two modes of efficiency and service life which can be selected. Efficiency mode: cutting t of the first tooth₁The speed is halved in the time period, and then full-speed broaching is carried out, wherein all the subsequent cutter teeth are cut in at full speed, so that the broaching efficiency is improved. Life mode: the cut t of each cutter tooth₁Speed halving within a time period, followed by t₂Full speed broaching is performed during the time period to protect each tooth, thereby increasing the useful life of the broach.

2. The detection assembly of the present invention integrates a laser transceiver belt 13, an image sensor 14, an axial pressure sensor 16, a first radial pressure sensor 20, a second radial pressure sensor 24, and a grating 22. The device has the measuring functions of a broach three-way vibration value, broach axial tension, broach displacement value, image-based workpiece dimension and the like. And real-time detection data is provided for a working condition feedback loop and a shutdown control loop of the control system.

3. The invention designs a broach rapid positioning and clamping device which comprises a machine body 8-1, a guide rail 8-2, a slide carriage 8-3, a lead screw 8-4, a transmission case 8-5, a forward and reverse integrated lead screw nut pair 8-6, a clamping device guide rail 8-7, a V-shaped clamping block 8-8, a broach clamping section 8-9, a V-shaped positioning block 8-10, a servo motor 8-11 and the like. After the broaching tool is placed on the V-shaped positioning block 8-10, the servo motor 8-11 directly drives the forward and reverse integrated screw nut pair 8-6 to drive the V-shaped clamping block 8-8, so that the broaching tool is quickly positioned and clamped, the auxiliary time is reduced, and the broaching efficiency is improved.

4. On the premise of ensuring the machining precision, the invention greatly improves the machining efficiency and prolongs the service life of the cutter, thereby obviously reducing the production cost. Therefore, the method has remarkable economic, social and environmental benefits.

Drawings

FIG. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is a sectional view of section A-A in FIG. 1 (the view reflects the vertical relationship between the moving direction of the positioning and clamping block 8-4 and the moving direction of the slide carriage 8-3; in the positioning and clamping case 8-5, the positioning and clamping block 8-4 positions and clamps the clamping section 1-7 of the draw carriage under the driving of the positioning and clamping motor 8-1 and the slide carriage lead screw 8-6);

fig. 3 is a partially enlarged view of a portion D in fig. 1;

FIG. 4 is a cross-sectional view of section B-B of FIG. 3 (which reflects the position of the first radial pressure sensor 20 in the sensing assembly);

FIG. 5 is a cross-sectional view of section C-C of FIG. 3 (which reflects the position of the second radial pressure sensor 24 in the sensing assembly);

FIG. 6 is a control block diagram of the present invention;

FIG. 7 is a schematic diagram of the speed variation of the feeding process in the efficiency mode of the present invention;

FIG. 8 is a schematic diagram of the speed variation of the feeding process in the life mode of the present invention;

fig. 9 is a flow chart of the broaching process of the present invention.

Detailed Description

The invention is further described below with reference to the accompanying drawings.

As shown in fig. 1, the high-efficiency precise ultrasonic broaching device comprises a broaching machine body, a grating 22, an ultrasonic broaching tool and a controller. The broaching machine body comprises a photoelectric encoder 1, a broaching machine driving motor 2, a machine body 3, a bearing 4, a bearing seat 5, a broaching machine guide rail 6, a broaching machine screw 7 and a quick positioning and clamping device 8. Two broaching machine guide rails 6 are fixed on the machine body 3. The grating 22 is fixed on one side of the bed 3. The arrangement direction of the slits on the grating 22 is parallel to the longitudinal direction of the broaching machine guide 6. The bearing seat 5 is fixed at one end of the lathe bed 3. One end of a broaching machine screw 7 and the bearing seat 5 form a revolute pair through the bearing 4. The broaching machine driving motor 2 is fixed on the lathe bed 3, and an output shaft is fixed with one end of a broaching machine lead screw 7. The photoelectric encoder 1 is fixed with the broaching machine driving motor 2, and the input shaft is fixed with the output shaft of the broaching machine driving motor 2.

As shown in figures 1 and 2, the rapid positioning and clamping device 8 comprises a positioning and clamping motor 8-1, a slide carriage V-shaped block 8-2, a slide carriage 8-3, a positioning and clamping box body 8-5, a slide carriage screw 8-6, a slide carriage guide rail 8-7 and a positioning and clamping block 8-4. The slide carriage 8-3 and the two broaching machine guide rails 6 form a sliding pair. The positioning clamping box body 8-5 is fixed on the slide carriage 8-3. Two slide carriage guide rails 8-7 are fixed on the positioning clamping box body 8-5. The axes of the slide carriage guide rails 8-7 are vertical to the axis of the broaching machine guide rail 6. The slide carriage screw 8-6 is supported on the positioning clamping box body 8-5. The slide carriage lead screw 8-6 adopts a bidirectional lead screw. The positioning and clamping motor 8-1 is fixed on the positioning and clamping box body 8-5, and an output shaft is fixed with one end of the slide carriage screw 8-6. The two positioning clamping blocks 8-4 and the two slide carriage guide rails 8-7 form a sliding pair. The two positioning clamping blocks 8-4 and two spiral sections with opposite rotation directions on the slide carriage lead screw 8-6 respectively form a spiral pair. When the slide carriage screw 8-6 rotates, the two positioning clamping blocks 8-4 slide towards or away from each other. The bottoms of the opposite side surfaces of the two positioning clamping blocks 8-4 are provided with positioning inclined planes which incline downwards. The slide carriage V-shaped block 8-2 is fixed on the positioning clamping box body 8-5. The top of the slide carriage V-shaped block 8-2 is provided with a V-shaped positioning groove. The two positioning clamping blocks 8-4 are both positioned above the slide carriage V-shaped block 8-2. The symmetrical surfaces of the two positioning datum surfaces of the V-shaped positioning groove are superposed with the symmetrical surfaces of the positioning inclined surfaces on the two positioning clamping blocks 8-4.

The quick positioning and clamping devices 8 are two in total. A nut is fixed on the slide carriage 8-3 in one of the quick positioning and clamping devices 8. The nut and the broaching machine screw 7 form a screw pair.

As shown in fig. 1, 3, 4 and 5, the ultrasonic broach includes a broach clamping section 9, an ultrasonic transducer 10, a detection assembly and a broach blade 23. The detection assembly comprises a detection matrix, a laser transceiver band 13, an image sensor 14, an axial pressure sensor 16, a first radial pressure sensor 20 (not visible in fig. 3) and a second radial pressure sensor 24. The detection base body comprises a left end cover 15, a middle end seat 19, a guide compression ring 12, a right end seat 21, a pull rod and a screw 17. The left end cover 15, the guide compression ring 12, the middle end seat 19 and the right end seat 21 are sequentially arranged and connected and are connected through screws 17 (a plurality of screws are divided into two groups, one group of screws is fixedly connected with the left end cover 15, the guide compression ring 12 and the laser transceiving belt 13, and the other group of screws is fixedly connected with the laser transceiving belt 13 and the right end seat 21).

The left end cover 15 is provided with a step through hole. The hole section with the larger aperture on the stepped through hole is positioned on one side of the left end cover 15 close to the guide compression ring 12. A circular axial pressure sensor 16 is arranged in the hole section with larger aperture on the stepped through hole. The pull rod consists of a connecting shaft 11 and a left end seat 18 which are integrally formed. The inner end of the connecting shaft 11 is connected with the left end seat 18. The connecting shaft 11 passes through a central hole of the axial pressure sensor 16 and a hole section with a smaller hole diameter on the stepped through hole. The end of the left end seat 18 close to the connecting shaft 11 is located in the hole section with larger aperture on the stepped through hole. When the connecting shaft 11 and the left end cover 15 are relatively pulled (in the broach feeding state), the connecting shaft 11 and the left end cover 15 generate pressure on the axial pressure sensor 16, and further the axial load in the broach feeding process is obtained.

The end of the left end seat 18 far from the connecting shaft 11 passes through the guide compression ring 12. The end surface of the left end seat 18 far away from the connecting shaft 11 is provided with a first separation lug 18-1 and two anti-rotation convex strips 18-2. The first separation convex block 18-1 is positioned between the two anti-rotation convex strips 18-2. The side surface of the middle end seat 19 close to the left end cover 15 is provided with a first accommodating groove and two anti-rotation grooves. The two anti-rotation convex strips 18-2 are respectively embedded into the two anti-rotation grooves, so that the left end cover 15 and the middle end seat 19 cannot rotate relatively. The first accommodating groove is in a long strip shape. The length direction of the first accommodating groove is parallel to the length direction of the two anti-rotation grooves. Both ends of the first receiving groove are provided with first radial pressure sensors 20. The first partition projection 18-1 extends into the first receiving recess and is located between the two first radial pressure sensors 20. When the ultrasonic broach vibrates along the length of the first receiving groove, the left end seat 18 will press the two first radial pressure sensors 20 at different times. The vibration strength of the ultrasonic broach along the length direction of the first accommodation groove can be judged according to the pressure detected by the first radial pressure sensor 20.

The outer side surface of the middle seat 19 is embedded with a laser transmitting-receiving belt 13 surrounding the middle seat 19. The laser transceiver belt 13 is provided with a plurality of laser transmitters and a plurality of laser receivers arranged along the circumferential direction of the middle base 19, so that the laser transceiver belt 13 can transmit and receive laser light along each radial direction of the middle base 19. Therefore, no matter the ultrasonic broach is not required to be circumferentially positioned on the broaching machine body, the laser can be ensured to be emitted to the grating 22, so that the displacement of the ultrasonic broach is determined.

The middle part of the side surface of the middle end seat 19 far away from the left end cover 15 is provided with a clamping groove. The inner end of the right end seat 21 is inserted into the engaging groove of the middle end seat 19. The bottom of the clamping groove is provided with a second accommodating groove. The second accommodating groove is in a long strip shape. The length direction of the second accommodating groove is perpendicular to the length direction of the first accommodating groove. Second radial pressure sensors 24 are provided at both ends of the second receiving groove. The inner end surface of the right end seat 21 is provided with a second partition lug. The second partition protrusion extends into the first receiving groove and is located between the two second radial pressure sensors 24. The vibration direction detected by the second radial pressure sensor 24 is orthogonal to the vibration direction detected by the first radial pressure sensor. The side of the right end seat 21 away from the middle end seat 19 is embedded with the image sensor 14. The camera of the image sensor 14 employs a CCD camera.

The end part of the connecting shaft 11 extending out of the left end cover 15 is fixed with one end of the ultrasonic transducer 10 through a pin. The outer end of the right end seat 21 is fixed with one end of the broach body 23 through a pin. The ultrasonic transducer 10 and the other end of the broach body 23 are respectively fixed with the two broach clamping sections 9. The two broach clamping sections 1-17 are respectively arranged on the V-shaped grooves of the slide carriage V-shaped block 8-2 on the two rapid positioning and clamping devices 8 and are clamped by the positioning and clamping blocks 8-4.

Six detection signal input interfaces of the controller are respectively connected with signal output interfaces of the photoelectric encoder 1, the axial pressure sensor 16, the two first radial pressure sensors 20 and the two second radial pressure sensors 24. The image signal input interface of the controller is connected to the signal output interface of the image sensor 14. Three motor control interfaces of the controller are respectively connected with the control input interfaces of the broaching machine driving motor 2 and the two positioning and clamping motors 8-1 through motor drivers. The ultrasonic control interface of the controller is connected with the control input interface of the ultrasonic generator. The communication interface of the controller is connected with the communication interface of the laser transceiver band 13.

The broaching process of the high-efficiency precise ultrasonic broaching device is divided into an efficiency mode and a service life mode. The efficiency mode aims at achieving high processing efficiency; the life mode aims to extend the service life of the ultrasonic broach. The control block diagram in the broaching process of the present invention is shown in fig. 6.

When the machine is started, the working personnel select to operate in a life mode or an efficiency mode. The controller provides operation and control parameters and sends control instructions to the motor driver and the ultrasonic transducer respectively. The two forward channels interact, and the ultrasonic transducer acts on the feed motion of the broach, so that the broaching precision and efficiency are improved.

The laser transceiver belt 13 is matched with the grating to detect the speed of the broach, and the displacement of the broach is calculated through the initial position of the laser transceiver belt 13 and the change curve of the speed to form a speed feedback loop and a displacement feedback loop. The axial pressure sensor 16 detects the magnitude of the axial load force in the feeding process of the broach, and the average value of the pressure detected by the axial pressure sensor 16 in the preset time is used as the tension magnitude of the broach to form a tension feedback loop. The amount of change (fluctuation portion) in the pressure detected by the axial pressure sensor 16 is the axial vibration force of the broach, which can reflect the strength of axial vibration of the broach.

Since the left end seat 18 can perform a radial slight displacement in the middle end seat 19, and the right end seat 21 can also perform a radial slight displacement in the middle end seat 19, the left end seat 18 and the right end seat 21 respectively press the corresponding first radial pressure sensor 20 and the second radial pressure sensor 24 during the movement. The pressures detected by the first radial pressure sensor 20 and the second radial pressure sensor 24 can reflect the vibration intensities of the broach in two different radial directions, and a three-way vibration feedback loop is formed by matching the axial vibration intensity detected by the upper axial pressure sensor 16.

Among the four feedback loops, the speed detection feedback loop is used for stabilizing the broaching feeding speed; and the tension, displacement and three-way vibration detection feedback loop is used for carrying out self-adaptive control on the operation parameters. And the image sensor detects the size of the workpiece, and the machine is stopped if the size parameter or the surface roughness of the workpiece cannot meet the use requirement. According to the change of the tension value, the service life of the broach can be predicted, and display and alarm indication are performed.

As shown in fig. 9, the broaching process of the high-efficiency precise ultrasonic broaching device is as follows:

firstly, a worker sets a mode variable M; if M is set to 0, the broaching machine driving motor 2 operates in the life mode; if M is set to 1, the broaching machine driving motor 2 is operated in the efficiency mode.

Step two, calling optimized process parameters: cut-in speed V1 and steady speed V₂Time to cut-in t₁Stable broaching duration t₂(ii) a Ultrasonic frequency f, ultrasonic amplitude h. Wherein the steady speed V₂Setting the feeding speed in the cutting process of the conventional broaching machine; v₁＝b·V₂(ii) a B is more than or equal to 0.4 and less than or equal to 0.6. Cut-in duration t₁Stable broaching duration t₂The ultrasonic frequency f and the ultrasonic amplitude h reach values with good broaching effect in a selection test.

And step three, the broaching machine drives the motor 2 to rotate forwards, the ultrasonic transducer is started to drive the broaching tool to feed, and broaching is started.

If M is 0, the speed change of the ultrasonic broach in one feeding motion is as shown in fig. 7; the method specifically comprises the following steps: the first cutter tooth of the ultrasonic broach cuts into the front t of the workpiece₁The feeding speed of the ultrasonic broach is maintained at V within the time₁. Thereafter, the feed rate of the ultrasonic broach was maintained at V₂. If M is 1, the speed change of the ultrasonic broach in one feeding motion is shown in fig. 8; the method specifically comprises the following steps: each cutter tooth of the ultrasonic broaching cutter cuts into the front t of the workpiece₁The feeding speed of the ultrasonic broach is maintained at V within the time₁. The feeding speed of the ultrasonic broach in other feeding time is allIs maintained at V₂. T in FIG. 8₂For the feeding speed of the ultrasonic broach to be maintained at V₂A single time duration of.

The axial pressure sensor 16 continuously detects the magnitude of the axial load force F during the broach feeding. If F is greater than or equal to F_{License plate}And if so, giving an overload alarm, and turning off the broaching machine driving motor 2 and the ultrasonic transducer. F_{License plate}Is the maximum allowable pulling force of the ultrasonic broach. And the controller interpolates and calculates the predicted value of the residual service life of the ultrasonic broach according to the magnitude and the change condition of the axial load force F and displays the predicted value.

The laser transceiver band 13 is matched with the grating to continuously detect the current position value X and the speed V of the broach if X is more than or equal to X_{Final (a Chinese character of 'gan')}If yes, the broaching is completed, the broaching machine driving motor 2 stops rotating, and the process goes to step four. X_{Final (a Chinese character of 'gan')}Is the feeding termination position of the ultrasonic broach.

The first radial pressure sensor 20 and the second radial pressure sensor 24 respectively detect the magnitude of two radial load forces of the broach; the resultant of the pressures obtained by the two sensors that detect the pressures in the two first radial pressure sensors 20 and the two second radial pressure sensors 24 is used as the vibration force. The vibration acceleration a is obtained from the vibration force.

When a is more than or equal to a_Threshold(s)And if so, alarming by excessive vibration and stopping the machine. If a_{License plate}-△a_{License plate}≤a≤a_{License plate}+△a_{License plate}And then, the vibration value is in an allowable range, and the operation parameters are not required to be changed. If a > a_{License plate}+△a_{License plate}If the vibration value is too large, the machining precision and the service life of the tool are reduced, the broaching speed is reduced, and V is set₂Reduce △ V to V₁Is updated to V₂B times of the total weight of the composition. If a < a_{License plate}-△a_{License plate}If the vibration value is too small, the broaching capability is not exerted, the machining efficiency is lowered, and V is set₂Increase △ V, change V₁Is updated to V₂B times of the total weight of the composition. a is_Threshold(s)Is the ultimate vibration acceleration of the ultrasonic broach. a is_{License plate}△ a being the best allowable vibration acceleration of ultrasonic broach_{License plate}Is the vibration acceleration range radius of the ultrasonic broach, △ V is the single adjustment of the feed speed of the ultrasonic broach.

Step four,The image sensor takes a picture of the workpiece and uploads the picture to the controller. And the controller performs image processing on the obtained picture and judges whether the broaching part of the workpiece meets the processing requirement. If the machining requirements are not met, an out-of-tolerance alarm is given, and the broaching machine driving motor and the ultrasonic transducer are both closed. If the machining requirement is met, the broaching machine driving motor 2 rotates reversely, and the ultrasonic broaching tool retracts at a speed V_{Go back to}And (5) returning. The laser transceiving belt 13 is matched with the grating to continuously detect the current position value X of the broach; until X ═ X₀And if so, entering the step five.

Step five, if the next workpiece needs broaching, the step three is carried out after the workpiece is replaced; otherwise, broaching is finished.

Claims (10)

1. An ultrasonic broach comprises an ultrasonic transducer, a detection assembly and a broach body; the method is characterized in that: the detection assembly comprises a detection substrate, a laser transceiving belt, an image sensor, an axial pressure sensor, a first radial pressure sensor and a second radial pressure sensor; the laser transceiver is surrounded on the detection substrate; the detection base body comprises a left end cover, a middle end seat, a guide compression ring, a right end seat and a pull rod; the left end cover, the guide compression ring, the middle end seat and the right end seat are sequentially and fixedly connected; an axial pressure sensor is arranged in the left end cover; the pull rod consists of a connecting shaft and a left end seat which are integrally formed; the inner end of the connecting shaft is connected with the left end seat; the end of the left end seat close to the connecting shaft is positioned in the left end cover; the axial pressure sensor is positioned between the left end cover and the left end seat;

a first separating lug is arranged on the end surface of the left end seat far away from the connecting shaft; a first accommodating groove is formed in the side face, close to the left end cover, of the middle end seat; the first accommodating groove is in a long strip shape; two ends of the first accommodating groove are provided with first radial pressure sensors; the first separating lug extends into the first accommodating groove and is positioned between the two first radial pressure sensors;

a second accommodating groove is formed in one side, far away from the left end cover, of the middle end seat; the second accommodating groove is in a long strip shape; two ends of the second accommodating groove are provided with second radial pressure sensors; the end surface of the inner end of the right end seat is provided with a second partition lug; the second separating lug extends into the first accommodating groove and is positioned between the two second radial pressure sensors; an image sensor is embedded on the right end seat; the connecting shaft is fixed with one end of the ultrasonic transducer; the outer end of the right end seat is fixed with one end of the broach body.

2. The ultrasonic broach according to claim 1, characterized in that: the laser receiving and dispatching belt is provided with a plurality of laser transmitters and a plurality of laser receivers which are arranged along the circumferential direction of the middle end seat.

3. The ultrasonic broach according to claim 1, characterized in that: the left end cover is provided with a stepped through hole; the hole section with the larger aperture on the stepped through hole is positioned on one side of the left end cover close to the guide compression ring; the axial pressure sensor is annular and is arranged in a hole section with larger aperture on the stepped through hole; the connecting shaft penetrates through a central hole of the axial pressure sensor and a hole section with a smaller aperture on the stepped through hole.

4. The ultrasonic broach according to claim 1, characterized in that: the length direction of the second accommodating groove is perpendicular to that of the first accommodating groove; the end surface of the left end seat far away from the connecting shaft is also provided with two anti-rotation convex strips; the first separation lug is positioned between the two anti-rotation convex strips; the side surface of the middle end seat close to the left end cover is also provided with two anti-rotation grooves; the two anti-rotation convex strips are respectively embedded into the two anti-rotation grooves.

5. The ultrasonic broach according to claim 1, characterized in that: the camera of the image sensor adopts a CCD camera.

6. High-efficient accurate supersound broaching device, including the broaching machine body, its characterized in that: further comprising a grating and the ultrasonic broach of claim 1; the broaching machine body comprises a broaching machine driving assembly, a machine body, a broaching machine guide rail and a quick positioning and clamping device; the broaching machine guide rails are fixed on the machine body; the grating is fixed on one side of the lathe bed; the rapid positioning and clamping device comprises a slide carriage guide rail, a slide carriage, a positioning and clamping block, a slide carriage V-shaped block and a clamping driving assembly; the slide carriage and the broaching machine guide rail form a sliding pair; the slide carriage guide rail is fixed on the slide carriage; the two positioning clamping blocks and the slide carriage guide rail form a sliding pair; the two positioning clamping blocks are driven by the clamping driving component to move in the opposite direction or in the opposite direction; the slide carriage V-shaped block is fixed on the slide carriage; the top of the slide carriage V-shaped block is provided with a V-shaped positioning groove; the two positioning clamping blocks are both positioned above the slide carriage V-shaped block; the number of the rapid positioning and clamping devices is two; a slide carriage in one of the quick positioning and clamping devices is driven by a broaching machine driving assembly; the ultrasonic broach also comprises two broach clamping sections; the two broach clamping sections are respectively fixed with the ultrasonic transducer and the other end of the broach body; the two broach clamping sections are respectively arranged on the slide carriage V-shaped blocks of the two rapid positioning and clamping devices.

7. The high efficiency precision ultrasonic broaching device of claim 6, wherein: the arrangement direction of the slits on the grating is parallel to the length direction of the broaching machine guide rail.

8. The high efficiency precision ultrasonic broaching device of claim 6, wherein: the bottoms of the opposite side surfaces of the two positioning clamping blocks are respectively provided with a positioning inclined plane which inclines downwards; and the symmetrical surfaces of the two positioning datum surfaces of the V-shaped positioning groove are superposed with the symmetrical surfaces of the positioning inclined surfaces on the two positioning clamping blocks.

9. The high efficiency precision ultrasonic broaching device of claim 6, wherein: the broaching machine driving assembly comprises a photoelectric encoder, a broaching machine driving motor and a broaching machine screw rod; the broaching machine lead screw is supported on the machine body; the broaching machine driving motor is fixed on the machine body, and an output shaft is fixed with one end of a broaching machine screw rod; the photoelectric encoder is fixed with the broaching machine driving motor, and the input shaft is fixed with the output shaft of the broaching machine driving motor; a nut is fixed at the bottom of the slide carriage in the quick positioning and clamping device driven by the broaching machine driving assembly; the nut and a broaching machine screw form a screw pair;

the clamping driving assembly comprises a slide carriage lead screw and a positioning and clamping motor; the slide carriage lead screw is supported on the slide carriage; the slide carriage lead screw adopts a bidirectional lead screw; the positioning and clamping motor is fixed on the positioning and clamping box body, and an output shaft is fixed with one end of the slide carriage lead screw; the two positioning clamping blocks and two spiral sections on the slide carriage lead screw with opposite rotation directions respectively form a spiral pair.

10. A broaching process of the high-efficiency precise ultrasonic broaching device according to claim 6, wherein: firstly, a worker sets a mode variable M; if M is set to be 0, the broaching machine driving assembly operates in a life mode; if M is set to 1, the broaching machine driving assembly operates in an efficiency mode;

step two, calling technological parameters: cutting speed V₁Stable speed V₂Time to cut-in t₁Stable broaching duration t₂(ii) a Ultrasonic frequency f, ultrasonic amplitude h; wherein, V₁＝b·V₂；0.4≤b≤0.6；

Step three, the broaching machine driving assembly positively drives the rapid positioning and clamping device, the ultrasonic transducer is started to drive the ultrasonic broaching tool to feed, and broaching is started;

if M is equal to 0, the first cutter tooth of the ultrasonic broaching cutter cuts into the workpiece before t₁The feeding speed of the ultrasonic broach is maintained at V within the time₁(ii) a Thereafter, the feed rate of the ultrasonic broach was maintained at V₂(ii) a If M is equal to 1, each cutter tooth of the ultrasonic broaching cutter cuts into the workpiece before t₁The feeding speed of the ultrasonic broach is maintained at V within the time₁(ii) a The feeding speed of the ultrasonic broach is maintained at V in other feeding time₂；

The axial pressure sensor continuously detects the magnitude of the axial load force F in the broach feeding process; if F is greater than or equal to F_{License plate}If the ultrasonic transducer is not in the ultrasonic state, the broaching machine driving assembly and the ultrasonic transducer are closed; f_{License plate}The maximum allowable pulling force of the ultrasonic broach;

the laser transceiving belt is matched with the grating to continuously detect the current position value X of the broach, and if X is more than or equal to X_{Final (a Chinese character of 'gan')}If so, stopping the movement of the broaching machine driving assembly and entering a step four; x_{Final (a Chinese character of 'gan')}Is the feed termination position of the ultrasonic broach;

the first radial pressure sensor and the second radial pressure sensor respectively detect the magnitude of two radial load forces of the broach; the resultant force of the pressures obtained by the two sensors which detect the pressures in the two first radial pressure sensors and the two second radial pressure sensors is used as a vibration force; calculating vibration acceleration a according to the vibration force;

if a is greater than or equal to a_Threshold(s)If the ultrasonic transducer is not in the ultrasonic state, the broaching machine driving assembly and the ultrasonic transducer are closed; if a > a_{License plate}+△a_{License plate}Then V will be₂Reduce △ V to V₁Is updated to V₂B times of; if a < a_{License plate}△a_{License plate}Then V will be₂Increase △ V, change V₁Is updated to V₂B times of; a is_Threshold(s)Is the ultimate vibration acceleration of the ultrasonic broach; a is_{License plate}△ a being the best allowable vibration acceleration of the ultrasonic broach_{License plate}△ V is the single adjustment of the feed speed of the ultrasonic broach;

step four, the image sensor shoots the picture of the workpiece; judging whether the broaching part of the workpiece meets the processing requirement or not by carrying out image processing on the obtained picture; if the processing requirements are not met, the broaching machine driving assembly and the ultrasonic transducer are closed; if the machining requirement is met, the broaching machine driving assembly reversely drives the rapid positioning and clamping device, and the ultrasonic broaching tool retracts at a speed V_{Go back to}Backing; the laser transceiving belt is matched with the grating, and the current position value X of the broach is continuously detected; until X ═ X₀If yes, entering the step five; x₀Is the initial position of the ultrasonic broach;

step five, if the next workpiece needs broaching, the step three is carried out after the workpiece is replaced; otherwise, broaching is finished.

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