A cam mechanism type axial vibration drilling device

Abstract

This invention relates to a cam-mechanism type axial vibration drilling device, comprising a servo motor, a motor support, an upper cam, a rolling spline shaft, a rolling spline pair, a spindle support, a lower cam, a spring end cap, a spring, and a spring baffle. The servo motor is connected to one end of the rolling spline shaft. One end of the motor support is fixedly connected to the rear end of the spindle support by bolts, and the other end is fixedly connected to the servo motor. The rolling spline shaft passes through the end cap of the motor support. The spindle support is located on the outside of the rolling spline shaft. A pair of rolling bearings are located at both ends between the spindle support and the rolling spline shaft, with the pair of rolling bearings arranged at opposite ends of the spindle support. The front end of the spindle support is coaxially fixed to the rolling spline shaft with the lower cam by bolts. A rolling spline pair is located on the outside of the spline portion of the rolling spline shaft, and the rear end of the rolling spline pair is fixedly connected to the upper cam by bolts. This device can transmit a large torque while moving in the axial direction, thus improving drilling efficiency.

Description

Technical Field

[0001] The invention relates to the field of mechanical vibration, in particular to a cam mechanism type axial vibration drilling device. Technical Background

[0002] Vibration drilling is a pulse cutting method. During the cutting process, a certain regular vibration is applied to the workpiece or tool, thereby reducing the cutting force, enhancing chip removal, and improving the processing quality and cutting efficiency of the hole. However, in the traditional vibration-assisted drilling device, a vibration motor is installed at the tail of the drilling device to provide periodic vibration. This not only makes the vibration attenuated during transmission and fails to achieve the ideal vibration law when transmitted to the drill bit, but also is accompanied by problems such as the self-synchronization of the vibration motor. In addition, the device is too large and heavy, which is not easy to miniaturize.

[0003] Chinese patent ZL201080052001.0 discloses an axial processing device. Its characteristics include the use of a bearing with a rolling component and an elastic reset component. The rolling component in the bearing rolls on the corrugated raceway of the axial part, which can periodically move the traveling gear along the traveling direction of the shaft during processing. The elastic reset component pushes the traveling gear in the opposite direction of the movement of the shaft during processing, so that the rotation of the shaft is accompanied by axial vibration movement. The invention abandons the traditional method of using a vibration motor to generate vibration, solves the problems of self-synchronization of the vibration motor, etc., has a compact structure, reduced volume and weight, and is used for hole expansion, but has the following disadvantages: 1. The device adopts gear transmission, has high manufacturing and installation precision requirements, complex processing, high manufacturing cost, and poor replaceability. 2. Since the gear in the device rotates in the needle roller bearing and moves axially, the needle roller bearing has a large friction coefficient, generates a lot of heat at high speed, is easy to deform, is very sensitive to the deformation or installation error of the shaft, and has a small axial displacement, so the processing efficiency is limited. Summary of the invention

[0004] In view of the shortcomings of the prior art, the technical problem to be solved by the present invention is to provide a cam mechanism type axial vibration drilling device. During the drilling process, the upper cam, the lower cam and the spring in the vibration mechanism cooperate to achieve regular vibration in the axial direction; through the cooperation of the spline shaft and the rolling spline pair, a large torque can be transmitted while moving in the axial direction, thereby improving the drilling efficiency.

[0005] The technical solution adopted by the present invention to solve the technical problem is to provide a cam mechanism type axial vibration drilling device, including a servo motor, a motor support, and an upper cam; the characteristic is that the device also includes a rolling spline shaft, a rolling spline pair, a main shaft support, a lower cam, a spring end cover, a spring, and a spring baffle;

[0006] The servo motor is connected to one end of the rolling spline shaft through a coupling; one end of the motor support is fixedly connected to the rear end of the spindle support through bolts, and the other end is fixedly connected to the servo motor; the rolling spline shaft passes through the end cover of the motor support, and a spindle support is arranged on the outside of the rolling spline shaft, and a pair of rolling bearings are arranged at both ends between the spindle support and the rolling spline shaft. The pair of rolling bearings are arranged at both ends of the spindle support and are positioned by the spindle support, the end cover of the motor support and the shoulder of the spline shaft respectively; the front end of the spindle support is coaxially fixed to the rolling spline shaft with the lower cam through bolts, and two grooves are opened on the spline shaft outside the pair of rolling bearings, and sealing rings are placed in the grooves for sealing;

[0007] A rolling spline pair is arranged on the outer side of the spline part of the rolling spline shaft, the rear end of the rolling spline pair is fixedly connected to the upper cam by bolts, the front end of the rolling spline pair is fixedly connected to the drill shaft by bolts, an oil filling hole is opened on the outer side of the rolling spline pair, the oil filling hole is a through hole, connecting the retaining frame and the oil nozzle in the rolling spline pair; the oil nozzle is installed near the through hole on the outer surface of the rolling spline pair; the upper cam is opened with uniformly distributed through holes on one side facing the lower cam, a ball bearing is embedded in the through hole, and a rolling component is arranged in the ball bearing; wherein the ball bearing and the through hole are transition fit;

[0008] The lower cam is provided with a corrugated raceway for rolling of the rolling component, the maximum depth of the corrugated raceway is less than or equal to the diameter of the rolling component, and the number of corrugations in the corrugated raceway is consistent with the number of ball bearings;

[0009] A spring end cover is arranged on the inner side surrounded by the drill shaft and the rolling spline pair, close to one end of the rolling spline pair. A plurality of spring grooves for installing springs are arranged at the front end of the spring end cover. A spring baffle is arranged at the front end of the spring end cover, and a spring is placed between the spring baffle and the spring end cover.

[0010] The end of the rolling spline shaft is provided with threads and keyways, and the front end of the spring baffle is positioned and prevented from loosening by means of a stop washer and a round nut; the drill bit is put into the collet, the collet is installed in the nut, and the end of the drill shaft is connected to the nut through threads.

[0011] The lower cam structure is in the shape of a two-stage circular ring as a whole. The ring end surface of the large ring is provided with a mounting through hole for fixing to the main shaft bracket, and is fixedly connected to the front end of the main shaft bracket by bolts; the ring end surface of the small ring is provided with a corrugated raceway, and the corrugated raceway is tangent to the rolling component in the ball bearing.

[0012] The shape of the corrugations in the corrugated track is set to be a sine or cosine corrugation.

[0013] A shaft shoulder is provided on one side of the upper cam facing the rolling spline pair, and is fixed in cooperation with the rolling spline pair.

[0014] Compared with the prior art, the utility model has the following beneficial effects:

[0015] (1) The device adds a rolling spline pair, wherein the multiple balls in the rolling spline pair can roll in the cage in the rolling spline pair, achieving a greater load-bearing capacity than when using needle bearings and ordinary splines, and can transmit greater torque while performing linear motion. In addition, the use of a rolling spline pair can control the clearance in the rotation direction to zero clearance or interference, and can perform high-speed linear motion and high-speed rotational motion, and has a longer life.

[0016] (2) The grease nozzle is installed on the outside of the rolling spline pair. Its oil filling hole is located in the middle of the ball cage, passing through the spline pair and connecting the cage and the grease nozzle. Grease can be added to the balls in the cage regularly through the grease nozzle, which has good lubrication and further ensures the performance and life of the rolling spline pair and the spline shaft.

[0017] (3) The vibration mechanism in the device adopts an upper cam and a lower cam, which are used in combination with a ball spline pair and a spring. The upper cam and the lower cam have the characteristics of simple processing, low manufacturing cost and high replaceability.

[0018] (4) This device uses double-row rolling bearings, which can withstand bidirectional axial loads and can withstand greater axial loads than single-row bearings.

[0019] (5) This device not only realizes the vibration drilling performance, but also adds a ball spline pair, which has the advantages of high transmission efficiency, high positioning accuracy, good synchronization performance, and long service life. The upper and lower cams are adopted to reduce the cost while realizing the function. The overall device has a compact and simple structure, and can be made into a miniaturized handheld vibration drilling device, or it can be connected to a linear motion platform and installed on a machine tool for use.

[0020] In summary, the device of the present application has a simple and compact structure, high efficiency, easy use, low cost, small size and light weight, is easy to miniaturize, and has a long life. Compared with the background technology patent, the device can be used in high-speed and deep and long hole processing situations, with a rotation speed of more than 800r / min, and can ensure coaxiality during high-speed rotation, and is more practical. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structure of a cam mechanism type axial vibration drilling device according to an embodiment of the present invention, in a sectional front view.

[0022] Figure 2 The isometric view of the lower cam of an embodiment of a cam mechanism type axial vibration drilling device of the present invention.

[0023] Figure 3 The present invention is a front view of a lower cam of an embodiment of a cam mechanism type axial vibration drilling device.

[0024] Figure 4 for Figure 3 AA section view.

[0025] Figure 5 for Figure 3 BB cross-sectional view.

[0026] Figure 6 for Figure 3 CC cross-sectional view.

[0027] Figure 7 A front view of a ball bearing of an embodiment of a cam mechanism type axial vibration drilling device of the present invention.

[0028] Figure 8 The present invention is a front view of an upper cam assembly of a cam mechanism type axial vibration drilling device according to an embodiment of the present invention.

[0029] Fig. 9 It is a cross-sectional view of an upper cam assembly DD of an embodiment of a cam mechanism type axial vibration drilling device of the present invention.

[0030] In the figure: 1. servo motor; 2. motor support; 3. coupling; 4. spindle bracket; 5. rolling bearing; 6. lower cam; 7. bolt; 8. upper cam; 9. oil nozzle; 10. spring end cover; 11. rolling spline shaft; 12. sealing ring; 13. rolling component; 14. ball bearing; 15. rolling spline pair; 16. spring; 17. spring baffle; 18. stop washer; 19. round nut; 20. drill shaft; 21. collet; 22. nut; 23. drill bit. DETAILED DESCRIPTION

[0031] The specific embodiments of the present invention are given below. The specific embodiments are only used to further illustrate the present invention in detail and do not limit the protection scope of the present application.

[0032] The present invention provides a cam mechanism type axial vibration drilling device (see Figure 1 , referred to as the device), including a rolling spline shaft 11, a rolling spline pair 15, a spindle bracket 4, a lower cam 6, a spring end cover 10, a spring 16, a spring baffle 17, a stop washer 18, a servo motor 1, a motor support 2, an upper cam 8, and a round nut 19;

[0033] The above-mentioned lower cam 6, ball bearing 14, upper cam 8, rolling spline pair 15, spring end cover 10, spring 16, spring baffle 17, stop washer 18, round nut 19 constitute a vibration mechanism;

[0034] The servo motor 1 provides a power source and is connected to one end of the rolling spline shaft 11 through a coupling 3; one end of the motor support 2 is fixedly connected to the rear end of the spindle support 4 through bolts, and the other end is fixedly connected to the servo motor 1; the rolling spline shaft 11 passes through the end cover of the motor support, and the spindle support 4 is arranged on the outside of the rolling spline shaft. A pair of rolling bearings 5 ​​are arranged at both ends between the spindle support 4 and the rolling spline shaft. The pair of rolling bearings 5 ​​are arranged at both ends of the spindle support and are positioned by the spindle support 4, the end cover of the motor support 2 and the shoulder of the spline shaft respectively; the front end of the spindle support is coaxially fixed to the rolling spline shaft with the lower cam 6 through bolts, and two grooves are opened on the spline shaft outside the pair of rolling bearings (i.e., the matching surface between the end cover of the motor support 2 and the roller spline shaft 11, and the matching surface between the lower cam 6 and the rolling spline shaft 11), and a sealing ring 12 is placed in the groove for sealing;

[0035] A rolling spline pair 15 is provided on the outer side of the spline part of the rolling spline shaft, the rear end of the rolling spline pair 15 is fixedly connected to the upper cam 8 by bolts 7, and the front end of the rolling spline pair is fixedly connected to the drill shaft 20 by bolts. An oil filling hole is opened on the outer side of the rolling spline pair 15, and the rolling spline pair contains a retainer, and the retainer has balls. The oil filling hole is a through hole, connecting the retainer and the oil nozzle 9 in the rolling spline pair; the oil nozzle 9 is installed near the through hole on the outer surface of the rolling spline pair 15, and the contact part of the oil nozzle and the rolling spline pair 15 and the rolling spline shaft 11 is connected through the oil filling hole; the upper cam 8 is opened on the side facing the lower cam 6 with uniformly distributed through holes (such as Figure 8 and Fig. 9 ), a ball bearing 14 is embedded in the through hole, and a rolling component 13 is arranged in the ball bearing 14; wherein the ball bearing 14 and the through hole are transitionally matched; a shoulder is provided on the side of the upper cam facing the rolling spline pair 15, which is fixed with the rolling spline pair.

[0036] The lower cam structure is in the shape of a two-stage circular ring. The ring end surface of the large ring is provided with a mounting through hole for fixing with the spindle bracket, and is fixedly connected with the front end of the spindle bracket 4 by bolts. A corrugated raceway 6-1 is provided in the ring end surface of the small ring, which is tangent to the rolling components in the ball bearing 14 (i.e., point contact). And the number of ball bearings is equal to the number of corrugations on the lower cam surface. The maximum depth of the corrugated raceway is less than or equal to the diameter of its rolling components. The number of corrugations in the corrugated raceway is consistent with the number of ball bearings. After installation, the rolling components in the ball bearings can just roll in the corresponding corrugations of the corrugated raceway. The shape of the corrugations in the corrugated track is set to sine or cosine corrugations. At this time, the lower cam follows the sine or cosine motion law, with small impact and smooth movement.

[0037] A spring end cover 10 is arranged on the inner side surrounded by the drill shaft 20 and the rolling spline pair 15, near one end of the rolling spline pair. A plurality of spring grooves for installing springs 16 are arranged at the front end of the spring end cover. A spring baffle 17 is arranged at the front end of the spring end cover. Springs 16 are placed between the spring baffle and the spring end cover. The number of springs is equal to the number of spring grooves on the spring end cover 10. The rolling spline shaft 11 has threads and keyways at the end, and the front end of the spring baffle 17 is positioned and prevented from loosening by a locking washer 18 and a round nut 19. The drill bit 23 is placed in the collet 21, the collet 21 is installed in the nut 22, and the end of the drill shaft 20 is connected to the nut 22 by threads.

[0038] The working principle and working process of the cam mechanism type axial vibration drilling device of the present invention are:

[0039] The servo motor is connected to the rolling spline shaft through a coupling. When the servo motor is started, its output shaft drives the rolling spline shaft and the rolling spline pair to rotate together. Since the rolling spline pair and the drill shaft are fixedly connected by bolts, the drill bit on the drill shaft is further driven to rotate together, thereby realizing the rotation function of the drill bit.

[0040] On the other hand, since the cam mechanism is used as the vibration source, the upper cam is embedded with a ball bearing and fixedly connected by bolts and a rolling spline pair. One side of the lower cam is a corrugated raceway 6-1, and is fixedly connected to the spindle bracket by bolts; when the servo motor drives the rolling spline shaft and the rolling spline pair to rotate together, the upper cam rotates with the rolling spline shaft at the same speed, and the lower cam is fixed with the spindle bracket. At this time, the upper cam and the lower cam form a relative rotation, and the rolling parts in the ball bearing of the upper cam will rotate relatively on the corrugated raceway of the lower cam surface. Because the depth of the corrugated raceway is a fixed amplitude, the upper cam will have an axial displacement in the axial direction. When the rolling parts on the ball bearing rotate to the highest point of the corrugated raceway, the spring will exert a rebound force on the rolling spline pair to make the rolling parts continue to rotate and return to the lowest point. At this time, the drill bit on the drill shaft completes a cycle of vibration. This is repeated, and continuous periodic axial vibration can be formed on the drill bit.

[0041] Example

[0042] In this embodiment, the number of ball bearings is 3 (such as Figure 8 and 9 ). The number of periods of the sinusoidal surface of the corrugated raceway of the lower cam is 3, and the amplitude is 0.1-0.5mm.

[0043] The device of the present invention has large bearing capacity and torque transmission, good lubrication effect, long service life, simple and compact structure, small size and light weight, and is easy to miniaturize. It can effectively solve the problems of low rotation speed, poor heat dissipation effect and poor processing quality when processing deep and long holes of difficult-to-process composite materials.

[0044] Anything not described in the present invention is applicable to the prior art.

Claims

1. A cam mechanism type axial vibration drilling device, comprising a servo motor, a motor support, and an upper cam; characterized in that: The device also includes a rolling spline shaft, a rolling spline pair, a main shaft bracket, a lower cam, a spring end cover, a spring, and a spring baffle; The servo motor is connected to one end of the rolling spline shaft through a coupling; one end of the motor support is fixedly connected to the rear end of the spindle support through bolts, and the other end is fixedly connected to the servo motor; the rolling spline shaft passes through the end cover of the motor support, and a spindle support is arranged on the outside of the rolling spline shaft, and a pair of rolling bearings are arranged at both ends between the spindle support and the rolling spline shaft. The pair of rolling bearings are arranged at both ends of the spindle support and are positioned by the spindle support, the end cover of the motor support and the shoulder of the spline shaft respectively; the front end of the spindle support is coaxially fixed to the rolling spline shaft with the lower cam through bolts, and two grooves are opened on the spline shaft outside the pair of rolling bearings, and sealing rings are placed in the grooves for sealing; A rolling spline pair is arranged on the outer side of the spline part of the rolling spline shaft, the rear end of the rolling spline pair is fixedly connected to the upper cam by bolts, the front end of the rolling spline pair is fixedly connected to the drill shaft by bolts, an oil filling hole is opened on the outer side of the rolling spline pair, the oil filling hole is a through hole, connecting the retaining frame and the oil nozzle in the rolling spline pair; the oil nozzle is installed near the through hole on the outer surface of the rolling spline pair; the upper cam is opened with uniformly distributed through holes on one side facing the lower cam, a ball bearing is embedded in the through hole, and a rolling component is arranged in the ball bearing; wherein the ball bearing and the through hole are transition fit; The lower cam is provided with a corrugated raceway for rolling of the rolling component, the maximum depth of the corrugated raceway is less than or equal to the diameter of the rolling component, and the number of corrugations in the corrugated raceway is consistent with the number of ball bearings; A spring end cover is arranged on the inner side surrounded by the drill shaft and the rolling spline pair, close to one end of the rolling spline pair, a front end of the spring end cover is provided with a plurality of spring grooves for installing springs, a spring baffle is arranged at the front end of the spring end cover, and a spring is placed between the spring baffle and the spring end cover; The end of the rolling spline shaft has a thread and a keyway, and the front end of the spring baffle is positioned and prevented from loosening by a stop washer and a round nut; the drill bit is placed in the collet, the collet is installed in the nut, and the end of the drill shaft is connected to the nut through a thread; The device can be used in high-speed, deep and long hole processing situations. The speed can reach more than 800r / min, and the coaxiality can be guaranteed during high-speed rotation. The multiple balls in the rolling spline pair can roll in the cage in the rolling spline pair, and can transmit greater torque while performing linear motion. The use of the rolling spline pair can control the clearance in the rotation direction to zero clearance or interference, and can perform high-speed linear motion and high-speed rotational motion.

2. The drilling device according to claim 1, characterized in that: The lower cam structure is in the shape of a two-stage circular ring as a whole. The ring end surface of the large ring is provided with a mounting through hole for fixing to the main shaft bracket, and is fixedly connected to the front end of the main shaft bracket by bolts; the ring end surface of the small ring is provided with a corrugated raceway, and the corrugated raceway is tangent to the rolling component in the ball bearing.

3. The drilling device according to claim 1, characterized in that: The shape of the corrugations in the corrugated track is set to be a sine or cosine corrugation.

4. The drilling device according to claim 1, characterized in that: A shaft shoulder is provided on one side of the upper cam facing the rolling spline pair, and is fixed in cooperation with the rolling spline pair.

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