A rigidity-damping-adjustable damping boring bar

Abstract

The application discloses a rigidity-damping-adjustable damping boring bar, and belongs to the technical field of cutting processing.The rigidity-damping-adjustable damping boring bar is used for solving the problem of poor damping rigidity adjusting effect of the existing damping boring bar.Two rigidity adjusting units and one damping adjusting unit are coaxially arranged in the inner cavity of the boring bar, the two rigidity adjusting units are symmetrically fixed to the two sides of the damping adjusting unit, the rigidity adjusting units at the two ends are respectively installed in the inner cavity of the boring bar through shaft shoulders, and the inner cavity of the boring bar is filled with damping liquid.The rigidity adjusting unit comprises heating ceramics, a variable-rigidity control module and a connecting block, the connecting block is provided with the variable-rigidity control module in the cantilever beam sleeve, and the heating ceramics is used for heating the variable-rigidity control module to change the rigidity of the boring bar.When the heating ceramics heats the variable-rigidity control module, the No.1 supporting rod and the No.2 supporting rod are stretched and straightened with the temperature rising, the inner ring is rotated in the circumferential direction when the No.1 supporting rod is stretched, the suspended end of the No.2 supporting rod is inserted into the corresponding tooth groove, and the rigidity of the boring bar is continuously increased in the process that the supporting rods are stretched and straightened.

Description

Technical Field

[0001] The invention relates to a vibration-damping boring bar structure with adjustable stiffness and damping, belonging to the technical field of cutting processing. Background Art

[0002] Boring bars are widely used in deep-hole machining. However, due to the low rigidity of their cantilever beam structure, vibration often occurs when the length-to-diameter ratio is large. Furthermore, during the boring process, the boring bar must penetrate the workpiece, creating a closed working environment where the bar's real-time processing status cannot be directly observed. The contact between the boring bar and the workpiece is complicated by vibration, cutting heat, and cutting forces. Poor bar processing can damage the workpiece's surface quality, impacting both the workpiece's dimensional accuracy and the boring machine's efficiency.

[0003] Existing vibration-damping boring bars provide functions of adjustable damping and adjustable stiffness, but the adjustment effects are not ideal. Summary of the Invention

[0004] Aiming at the problem that the damping stiffness adjustment effect of the existing vibration-damping boring bar is poor, the present invention provides a vibration-damping boring bar with adjustable stiffness and damping.

[0005] The present invention discloses a vibration-damping boring bar with adjustable stiffness and damping. The inner cavity of the boring bar 3 is coaxially provided with two stiffness adjustment units and one damping adjustment unit. The two stiffness adjustment units are symmetrically fixed on both sides of the damping adjustment unit. The stiffness adjustment units at both ends are each mounted on the inner cavity of the boring bar through a shaft shoulder 4. The inner cavity of the boring bar is filled with damping fluid 11.

[0006] The stiffness adjustment unit includes a heating ceramic 5, a variable stiffness control module 6 and a connecting block 7;

[0007] The connecting block 7 includes a cylindrical body 7-1, an outer stop 7-2, a cantilever beam 7-3 and a threaded mounting rod 7-4. The outer end face of the cylindrical body 7-1 extends radially outward through a circle of outer stop 7-2. A cantilever beam 7-3 is provided at the center of the outer end face of the cylindrical body 7-1. A variable stiffness control module 6 is provided on the cantilever beam 7-3. An axial gap is formed between the variable stiffness control module 6 and the outer end face of the cylindrical body 7-1. The heating ceramic 5 is coaxially provided on the outer end face of the variable stiffness control module 6 and is used to heat the variable stiffness control module 6 to change the stiffness of the boring bar. A threaded mounting rod 7-4 is provided at the center of the inner end face of the cylindrical body 7-1 for threaded connection with the damping adjustment unit.

[0008] The variable stiffness control module 6 includes an outer ring 6-1, an inner ring 6-2, a No. 1 support rod 6-3, and a No. 2 support rod 6-4. The outer ring 6-1 and the inner ring 6-2 are coaxially sleeved. The inner surface of the outer ring 6-1 is uniformly distributed with m arc blocks 6-6 along the circumferential direction. The arm thickness of the arc blocks 6-6 increases sequentially along the circumferential direction. Continuous tooth grooves 6-7 are provided on the inner arc surface of the arc blocks 6-6.

[0009] m No. 1 support rods 6-3 are evenly distributed around the circumference. The inner end of the No. 1 support rod 6-3 is hinged to the inner ring 6-2, and the outer end of the No. 1 support rod 6-3 is hinged to the outer ring 6-1, and is hinged between the two arc blocks 6-6. All hinges are realized through the hinge support block 6-5.

[0010] m No. 2 support rods 6-4 are evenly distributed around the circumference and staggered with m No. 1 support rods 6-3. The inner ends of the No. 2 support rods 6-4 are fixedly connected to the inner ring 6-2, and the outer ends of the No. 2 support rods 6-4 are suspended in the air.

[0011] When the heating ceramic 5 heats the variable stiffness control module 6, support rod No. 1 6-3 and support rod No. 2 6-4 stretch and straighten as the temperature rises. When support rod No. 1 6-3 stretches, the inner ring 6-2 rotates circumferentially, driving the suspended end of support rod No. 2 6-4 to be inserted into the tooth groove 6-7 at the corresponding position of the outer ring 6-1. In the process of the two support rods stretching and straightening, the stiffness of the boring bar continues to increase.

[0012] Preferably, the No. 1 support rod 6 - 3 is an S-shaped sheet plate, and the No. 2 support rod 6 - 4 is a scimitar-shaped sheet plate.

[0013] Preferably, the continuous tooth grooves 6 - 7 provided on the inner arc surface of the arc block 6 - 6 are steps with an included angle.

[0014] Preferably, the heating ceramic 5 and a portion of the outer ring 6 - 1 are interference fit with the shaft shoulder 4 , and the inner ring 6 - 2 is interference fit with the cantilever beam 7 - 3 .

[0015] Preferably, the damping adjustment unit includes a spring 8, an electromagnet sleeve 9 and a mass 10. The mass 10 includes a cylindrical body 10-1, an axial guide rail 10-2, a radial flow channel 10-3 and a mounting screw hole 10-4. A mounting screw hole 10-4 is provided at the center of each of the left and right end faces of the cylindrical body 10-1. The mounting screw holes 10-4 cooperate with the threaded mounting rods 7-4 of the connecting blocks 7 to securely connect the mass 10 to the two connecting blocks 7.

[0016] N axial guide rails 10-2 are uniformly distributed along the circumferential direction on the outer surface of the cylinder 10-1. N radial flow channels 10-3 are provided inside the cylinder 10-1, and a flow channel opening of the radial flow channel 10-3 is provided at the center between two adjacent axial guide rails 10-2. The n radial flow channels 10-3 are connected inside the cylinder 10-1.

[0017] Two electromagnet sleeves 9 are nested on the outer surface of the cylindrical body 10-1. A spring 8 is provided on the outside of the cylindrical body 7-1 of the connecting block 7 and between the electromagnet sleeve 9 and the outer stop 7-2 of the connecting block 7. The electromagnet sleeve 9 includes an annular body 9-1, a slide groove 9-3, and a coil 9-4. The inner surface of the annular body 9-1 is provided with n slide grooves 9-3. The electromagnet sleeve 9 slides axially along the mass block 10 using the n slide grooves 9-3 and n axial guide rails 10-2. The coil 9-4 is wound on the outer surface of the annular body 9-1.

[0018] When the electromagnetic sleeve 9 is not energized initially, the two springs 8 release the prestress to push the two electromagnetic sleeves 9 together, closing the flow channel openings of all radial flow channels 10 - 3 ;

[0019] When the electromagnet sleeves 9 are energized, the two electromagnet sleeves 9 repel each other and move to both sides, exposing the flow channel opening of the radial flow channel 10-3. The opening of the flow channel is changed by setting the power supply size, and then the amount of damping fluid passing through the radial flow channel 10-3 is adjusted to achieve the optimal vibration damping.

[0020] Preferably, the annular body 9 - 1 of the electromagnet sleeve 9 is made of an iron-cobalt alloy material.

[0021] Beneficial effects of the present invention:

[0022] The boring bar provided by the present invention can adjust its stiffness to meet the requirements of different working conditions. It also has a vibration reduction function. The function adjustment parts of the boring bar described in the present invention are all designed inside the boring bar. This strengthens the boring bar's own function without affecting the boring bar's machining operation in deep holes, effectively reduces the boring bar's vibration, and improves cutting efficiency.

[0023] The variable stiffness structure in the vibration-damping boring bar of the present invention consists of an inner ring, a nickel-titanium alloy support rod and an outer ring. The hinge support blocks of the inner ring and the outer ring are hinged to the two ends of support rod No. 1. The hinge support blocks are fixedly connected to the inner and outer rings. The inner ring and the support rod can rotate relative to each other in the radial direction. Support rod No. 2 is fixedly connected to the inner ring. The width of the outer ring of the stiffness design of the present invention is greater than the width of the inner ring, and the heating ceramic therein is a cylinder with a certain width, which is attached to the outside of the variable stiffness structure and clamped to the inner wall of the boring bar by the shoulder. The positive effect of this stiffness design is that not only can its stiffness change be controlled by heating the ceramic, but its stiffness change is a rigidity change. Compared with the traditional boring bar, it has a good stiffness change to find the optimal vibration reduction stage of the boring bar.

[0024] The variable damping structure in the vibration-damping boring bar of the present invention is mainly composed of a mass block with a guide rail and a flow channel, an electromagnet sleeve, a spring, and a connecting block. The connecting block is connected to the mass block by screws, and the spring is clamped between the connecting block and the sleeve by the connecting block. Therefore, the spring provides a pre-tightening force for the sleeve so that the two sleeves at both ends are tightly closed when no power is applied. The opening of the flow channel in the mass block is controlled by providing a force corresponding to the current applied to the electromagnet sleeve, thereby achieving a change in damping to adjust the vibration of the boring bar and achieve the best vibration reduction effect. Therefore, the present invention can adjust the vibration of the boring bar over a large range by finding the optimal vibration reduction effect through the change in the stiffness and damping of the boring bar. The leads required in the design are all led out through the shoulder openings on both sides and connected to the required electrical energy equipment from the outside. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a structural schematic diagram of a vibration-damping boring bar with adjustable stiffness and damping according to the present invention;

[0026] Figure 2 This is a schematic diagram of the variable stiffness and variable damping structure of the boring bar cavity;

[0027] Figure 3 yes Figure 2 AA section view;

[0028] Figure 4 It is a schematic diagram of the three-dimensional structure of the mass block;

[0029] Figure 5 is the main view of the mass block;

[0030] Figure 6 yes Figure 5 BB cross-sectional view;

[0031] Figure 7 yes Figure 5 CC cross-sectional view;

[0032] Figure 8 It is a schematic diagram of the three-dimensional structure of the connecting block;

[0033] Figure 9 is an axial cross-sectional view of the connecting block;

[0034] Figure 10 It is a schematic diagram of the three-dimensional structure of the electromagnet sleeve;

[0035] Figure 11 It is the main view of the electromagnet sleeve;

[0036] Figure 12 is a schematic diagram of the planar structure of the variable stiffness control module in an unheated state;

[0037] Figure 13It is a schematic diagram of the three-dimensional structure of the variable stiffness control module in an unheated state;

[0038] Figure 14 It is a schematic diagram of the planar structure of the variable stiffness control module, in the heating state;

[0039] Figure 15 It is a schematic diagram of the three-dimensional structure of the variable stiffness control module in the heating state.

[0040] Reference numerals:

[0041] 1. Cutter head, 2. Cutter head connector, 3. Boring bar, 4. Shoulder, 5. Heating ceramic;

[0042] 6. Variable stiffness control module, 6-1. Outer ring, 6-2. Inner ring, 6-3. Support rod No. 1, 6-4. Support rod No. 2, 6-5. Hinge support block, 6-6. Arc block, 6-7. Tooth groove;

[0043] 7. Connecting block, 7-1. Cylindrical body, 7-2. Outer retaining edge, 7-3. Cantilever beam, 7-4. Threaded mounting rod;

[0044] 8. Spring;

[0045] 9. Electromagnet sleeve, 9-1. Annular body, 9-2. Annular groove, 9-3. Slide groove, 9-4. Coil;

[0046] 10. Mass block, 10-1. Cylinder, 10-2. Axial guide rail, 10-3. Radial flow channel, 10-4. Mounting screw hole;

[0047] 11. Damping fluid. DETAILED DESCRIPTION

[0048] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0049] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0050] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0051] Specific implementation method 1: Figures 1 to 15 This embodiment describes a kind of vibration-damping boring bar with adjustable stiffness and damping, see Figure 1The vibration damping boring bar includes a boring bar 3, a cutter head connector 2 and a cutter head 1. The boring bar 3 is provided with an inner cavity with a front end opening. The cutter head connector 2 is provided at the front end opening of the inner cavity. The cutter head connector 2 is connected to the cutter head 1.

[0052] Two stiffness adjustment units and one damping adjustment unit are coaxially arranged in the inner cavity of the boring bar 3. The two stiffness adjustment units are symmetrically fixed on both sides of the damping adjustment unit. The stiffness adjustment units at both ends are respectively installed in the inner cavity of the boring bar through a shaft shoulder 4. The inner cavity of the boring bar is filled with damping fluid 11.

[0053] The boring bar of this embodiment includes two major adjustment functions, stiffness adjustment and damping adjustment.

[0054] See also Figure 2 、 3 , 8, 9, 12-15, the stiffness adjustment unit includes a heating ceramic 5, a variable stiffness control module 6 and a connecting block 7;

[0055] The connecting block 7 includes a cylindrical body 7-1, an outer stop 7-2, a cantilever beam 7-3 and a threaded mounting rod 7-4. The outer end face of the cylindrical body 7-1 extends radially outward through a circle of outer stop 7-2; a cantilever beam 7-3 is arranged at the center of the outer end face of the cylindrical body 7-1, and a variable stiffness control module 6 is arranged on the cantilever beam 7-3. There is an axial gap between the variable stiffness control module 6 and the outer end face of the cylindrical body 7-1, and the heating ceramic 5 is coaxially arranged on the outer end face of the variable stiffness control module 6 and is used to heat the variable stiffness control module 6 to change the stiffness of the boring bar; a threaded mounting rod 7-4 is arranged at the center of the inner end face of the cylindrical body 7-1 for threaded connection with the damping adjustment unit.

[0056] The variable stiffness control module 6 includes an outer ring 6-1, an inner ring 6-2, a No. 1 support rod 6-3 and a No. 2 support rod 6-4; see Figure 12-15 The outer ring 6-1 and the inner ring 6-2 are coaxially sleeved inside and outside, and the inner surface of the outer ring 6-1 is uniformly distributed with m arc blocks 6-6 along the circumferential direction. The arm thickness of the arc blocks 6-6 increases sequentially along the circumferential direction, and continuous tooth grooves 6-7 are provided on the inner arc surface of the arc blocks 6-6;

[0057] m No. 1 support rods 6-3 are evenly distributed around the circumference. The inner end of the No. 1 support rod 6-3 is hinged to the inner ring 6-2, and the outer end of the No. 1 support rod 6-3 is hinged to the outer ring 6-1, and is hinged between the two arc blocks 6-6. All hinges are realized through the hinge support block 6-5.

[0058] m No. 2 support rods 6-4 are evenly distributed around the circumference and staggered with m No. 1 support rods 6-3. The inner ends of the No. 2 support rods 6-4 are fixedly connected to the inner ring 6-2, and the outer ends of the No. 2 support rods 6-4 are suspended in the air.

[0059] When the heating ceramic 5 heats the variable stiffness control module 6, support rod No. 1 6-3 and support rod No. 2 6-4 stretch and straighten as the temperature rises. When support rod No. 1 6-3 stretches, the inner ring 6-2 rotates circumferentially, driving the suspended end of support rod No. 2 6-4 to be inserted into the tooth groove 6-7 at the corresponding position of the outer ring 6-1. In the process of the two support rods stretching and straightening, the stiffness of the boring bar continues to increase.

[0060] The continuous tooth grooves 6-7 provided on the inner arc surface of the arc block 6-6 are steps with an angle.

[0061] The heating ceramic 5 and a portion of the outer ring 6 - 1 are interference fit with the shaft shoulder 4 , and the inner ring 6 - 2 is interference fit with the cantilever beam 7 - 3 .

[0062] Variable stiffness principle: When the heating ceramic 5 does not heat the variable stiffness control module 6, the initial shapes of the two types of support rods are: support rod 6-3 No. 1 is an S-shaped sheet plate, and support rod 6-4 No. 2 is a scimitar-shaped sheet plate, see Figure 12 and Figure 13 At this time, there are only m No. 1 support rods 6-3 supporting the inner and outer rings, and the stiffness is related to the support rods; when the heating ceramic 5 heats the variable stiffness control module 6, the No. 1 support rod 6-3 and the No. 2 support rod 6-4 stretch and straighten as the temperature rises. When the No. 1 support rod 6-3 stretches, the inner ring 6-2 rotates circumferentially, thereby driving the cantilever beam 7-3 to rotate. The connecting block 7 rotates together with the cantilever beam 7-3 as an integral part, and the mass block 10 fixed to it rotates together. During the rotation process, 2 The suspended end of the No. 1 support rod 6-4 is inserted into the tooth groove 6-7 at the corresponding position of the outer ring 6-1. In the process of the two support rods stretching and straightening, the tooth groove positions are different. At this time, the two types of support rods support the inner and outer rings, and the rigidity of the boring bar increases. As the degree of straightening increases, the rigidity gradually increases. Due to the large number of steps, the rigidity change also has a certain amount of change. In addition, there is a time difference between the No. 1 support rod 6-3 and the No. 2 support rod 6-4 when they straighten under temperature changes. During this period of time, the rigidity continues to increase. When it reaches Figure 14 、 15 The stiffness is maximum in the vertical position shown.

[0063] See also Figure 2-7 , 10 and 11, the damping adjustment unit includes a spring 8, an electromagnet sleeve 9 and a mass block 10, and the mass block 10 includes a cylinder 10-1, an axial guide rail 10-2, a radial flow channel 10-3 and a mounting screw hole 10-4; a mounting screw hole 10-4 is provided at the center of each of the left and right end faces of the cylinder 10-1, and the mounting screw hole 10-4 cooperates with the threaded mounting rod 7-4 of the connecting block 7 to fix the mass block 10 to the two connecting blocks 7 together;

[0064] N axial guide rails 10-2 are uniformly distributed along the circumferential direction on the outer surface of the cylinder 10-1. N radial flow channels 10-3 are provided inside the cylinder 10-1, and a flow channel opening of the radial flow channel 10-3 is provided at the center between two adjacent axial guide rails 10-2. The n radial flow channels 10-3 are connected inside the cylinder 10-1.

[0065] Two electromagnet sleeves 9 are nested on the outer surface of the cylindrical body 10-1. A spring 8 is provided on the outside of the cylindrical body 7-1 of the connecting block 7 and between the electromagnet sleeve 9 and the outer stop 7-2 of the connecting block 7. The electromagnet sleeve 9 includes an annular body 9-1, a slide groove 9-3 and a coil 9-4. The inner surface of the annular body 9-1 is provided with n slide grooves 9-3, and the slide grooves 9-3 are axial. The electromagnet sleeve 9 slides axially along the mass block 10 by using the n slide grooves 9-3 and the n axial guide rails 10-2. The outer surface of the annular body 9-1 is provided with an annular groove 9-2, and the coil 9-4 is wound in the annular groove 9-2 on the outer surface of the annular body 9-1.

[0066] When the electromagnetic sleeve 9 is not energized initially, the two springs 8 release the prestress to push the two electromagnetic sleeves 9 together, closing the flow channel openings of all radial flow channels 10 - 3 ;

[0067] When the electromagnet sleeves 9 are energized, the two electromagnet sleeves 9 repel each other and move to both sides, exposing the flow channel opening of the radial flow channel 10-3. The opening of the flow channel is changed by setting the power supply size, and then the amount of damping fluid passing through the radial flow channel 10-3 is adjusted to achieve the optimal vibration damping.

[0068] The annular body 9 - 1 of the electromagnet sleeve 9 is made of an iron-cobalt alloy material.

[0069] Variable damping principle: The inner cavity of the boring bar 3 is filled with damping fluid. When the opening degree of the radial flow channel 10-3 is 100%, 0% and any opening in between, the damping value of the boring bar is different. This embodiment realizes damping adjustment by changing the opening degree. The opening degree of the radial flow channel 10-3 is adjusted by two electromagnet sleeves 9 on the outer surface of the mass block 10.

[0070] The spring 8 is preloaded during installation, and the two electromagnet sleeves 9 move toward the center under the pressure of the preload. When energized, the two electromagnet sleeves 9 repel each other, and the top pressure exerted by the spring 8 on the electromagnet sleeves 9 counteracts the repulsive force of the two electromagnet sleeves 9. The two electromagnet sleeves 9 and the mass block 10 can slide axially again, and slide to a balanced position under the joint action of the above two forces. The two electromagnet sleeves 9 block the opening size of the radial flow channel 10-3, that is, the size of the opening.

[0071] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely illustrative of the principles and applications of the invention. It should be understood that many modifications may be made to the illustrative embodiments, and that other arrangements may be devised, without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in ways other than those described in the original claims. It should also be understood that features described in conjunction with individual embodiments may be used in conjunction with other described embodiments.

Claims

1. A stiffness and damping adjustable vibration-damping boring bar, characterized in that: Two stiffness adjustment units and one damping adjustment unit are coaxially arranged in the inner cavity of the boring bar (3), the two stiffness adjustment units are symmetrically fixed to both sides of the damping adjustment unit, the stiffness adjustment units at both ends are respectively installed in the inner cavity of the boring bar through a shaft shoulder (4), and the inner cavity of the boring bar is filled with damping fluid (11); The stiffness adjustment unit includes a heating ceramic (5), a variable stiffness control module (6) and a connecting block (7); The connecting block (7) comprises a cylindrical body (7-1), an outer retaining edge (7-2), a cantilever beam (7-3) and a threaded mounting rod (7-4); the outer end face of the cylindrical body (7-1) extends radially outwardly with a circle of outer retaining edge (7-2); a cantilever beam (7-3) is arranged at the center of the outer end face of the cylindrical body (7-1); a variable stiffness control module (6) is sleeved on the cantilever beam (7-3); an axial gap is formed between the variable stiffness control module (6) and the outer end face of the cylindrical body (7-1); the heating ceramic (5) is coaxially arranged on the outer end face of the variable stiffness control module (6) and is used to heat the variable stiffness control module (6) to change the stiffness of the boring bar; a threaded mounting rod (7-4) is arranged at the center of the inner end face of the cylindrical body (7-1) and is used to be threadedly connected to the damping adjustment unit; The variable stiffness control module (6) comprises an outer ring (6-1), an inner ring (6-2), a No. 1 support rod (6-3) and a No. 2 support rod (6-4); the outer ring (6-1) and the inner ring (6-2) are coaxially sleeved inside and outside, and m arc blocks (6-6) are uniformly distributed along the circumferential direction on the inner circular surface of the outer ring (6-1), the arm thickness of the arc blocks (6-6) increases sequentially along the circumferential direction, and continuous tooth grooves (6-7) are provided on the inner arc surface of the arc blocks (6-6); m No. 1 support rods (6-3) are evenly distributed around the circumference, the inner end of the No. 1 support rod (6-3) is hinged to the inner ring (6-2), the outer end of the No. 1 support rod (6-3) is hinged to the outer ring (6-1), and the hinges are hinged between the two arc blocks (6-6), and all hinges are realized through the hinge support block (6-5); m No. 2 support rods (6-4) are evenly distributed in the circumferential direction and staggered with m No. 1 support rods (6-3); the inner ends of the No. 2 support rods (6-4) are fixedly connected to the inner ring (6-2), and the outer ends of the No. 2 support rods (6-4) are suspended in the air; When the heating ceramic (5) heats the variable stiffness control module (6), the No. 1 support rod (6-3) and the No. 2 support rod (6-4) stretch and become straightened as the temperature rises. When the No. 1 support rod (6-3) stretches, the inner ring (6-2) rotates circumferentially, driving the suspended end of the No. 2 support rod (6-4) to be inserted into the tooth groove (6-7) at the corresponding position of the outer ring (6-1). In the process of the two support rods stretching and straightening, the stiffness of the boring bar continues to increase.

2. The stiffness and damping adjustable vibration-damping boring bar according to claim 1, characterized in that: The No. 1 support rod (6-3) is an S-shaped sheet plate, and the No. 2 support rod (6-4) is a scimitar-shaped sheet plate.

3. The stiffness and damping adjustable vibration-damping boring bar according to claim 1, characterized in that: The continuous tooth grooves (6-7) arranged on the inner arc surface of the arc block (6-6) are steps with an included angle.

4. The stiffness and damping adjustable vibration-damping boring bar according to claim 1, characterized in that: The heating ceramic (5) and a portion of the outer ring (6-1) are interference-fitted with the shaft shoulder (4), and the inner ring (6-2) is interference-fitted with the cantilever beam (7-3).

5. The stiffness and damping adjustable vibration-damping boring bar according to claim 1, characterized in that: The damping adjustment unit comprises a spring (8), an electromagnet sleeve (9) and a mass block (10); the mass block (10) comprises a cylinder (10-1), an axial guide rail (10-2), a radial flow channel (10-3) and a mounting screw hole (10-4); a mounting screw hole (10-4) is respectively provided at the center of the left and right end faces of the cylinder (10-1); the mounting screw hole (10-4) cooperates with a threaded mounting rod (7-4) of the connecting block (7) to fix the mass block (10) and the two connecting blocks (7) together; N axial guide rails (10-2) are uniformly distributed along the circumferential direction on the outer surface of the cylinder (10-1); n radial flow channels (10-3) are provided inside the cylinder (10-1); and a flow channel opening of the radial flow channel (10-3) is provided at the center position between two adjacent axial guide rails (10-2); the n radial flow channels (10-3) are connected inside the cylinder (10-1); Two electromagnet sleeves (9) are nested on the outer surface of the cylinder (10-1); a spring (8) is arranged outside the cylindrical body (7-1) of the connecting block (7) and between the electromagnet sleeve (9) and the outer stop edge (7-2) of the connecting block (7); the electromagnet sleeve (9) comprises an annular body (9-1), a slide groove (9-3) and a coil (9-4); n slide grooves (9-3) are arranged on the inner surface of the annular body (9-1); the electromagnet sleeve (9) slides axially along the mass block (10) by using the n slide grooves (9-3) and n axial guide rails (10-2); and the coil (9-4) is wound on the outer surface of the annular body (9-1); When the electromagnetic sleeve (9) is not energized initially, the two springs (8) release the prestress to push the two electromagnetic sleeves (9) together, closing the flow channel openings of all radial flow channels (10-3); When the electromagnet sleeves (9) are energized, the two electromagnet sleeves (9) repel each other and move toward both sides, exposing the flow channel opening of the radial flow channel (10-3). The opening degree of the flow channel opening is changed by setting the magnitude of the energization, thereby adjusting the amount of damping fluid passing through the radial flow channel (10-3) to achieve optimal vibration damping.

6. The stiffness and damping adjustable vibration-damping boring bar according to claim 1, characterized in that: The annular body (9-1) of the electromagnet sleeve (9) is made of an iron-cobalt alloy material.

Images