A BTA tool connector with a variable-angle tiltable bearing shell

Abstract

The present invention belongs to the technical field of BTA deep hole cutting tools, and particularly relates to a BTA tool connector with a variable-angle tilting bearing bush; one end of the BTA tool connector is a drill bit connection end, the other end is a drill pipe connection end, and several tilting bearing pads are evenly distributed around the circumference of the middle connector base; the circumferential tilting bearing pads on the connector base have a thin end and a thick end, a telescopic mechanism is connected between the thick end side and the connector base, and a spherical hinge mechanism is connected between the thin end side and the connector base; the telescopic mechanism changes the lifting angle of the tilting bearing bush to cause a change in the clearance between it and the workpiece hole wall, thereby generating different dynamic pressure oil films; this BTA tool connector integrates mechanics and electronics, has a simple structure, low cost, and is convenient to use. By controlling the lifting angle of the tilting bearing bush to change the dynamic pressure oil film, the active control of the roundness morphology during the cutting process of the BTA tool is further studied.

Description

Technical Field

[0001] The present invention belongs to the technical field of BTA deep hole cutting tools, and particularly relates to a BTA tool connector with a variable-angle tilting bearing bush. Background Art

[0002] The radial movement trajectory of the BTA tool determines the roundness morphology of the deep hole. Whether the cancellation mechanism between the movement trajectory and various factors can be revealed is the key issue determining the roundness morphology of the deep hole. However, the traditional method of passively controlling roundness with a single factor can hardly meet the requirements of the BTA deep hole roundness morphology under the influence of multiple factors. In the research on the control theory of the BTA deep hole machining roundness morphology, most still remain at the single-factor and passive control level, lacking a multi-factor collaborative and active control strategy after the discovery of hole shape out-of-tolerance. No one has proposed a method for actively controlling the BTA deep hole roundness morphology online by combining the hydrodynamic rheological characteristics of the cutting fluid with the piezoelectric measurement means of the tool radial force. Therefore, it is necessary to design a connector with a tilting bearing bush to realize the formation of a hydrodynamic oil film, and actively control the thickness of the formed hydrodynamic oil film to control the BTA deep hole roundness morphology, so as to facilitate the subsequent research on the active control of the BTA deep hole roundness morphology. Summary of the Invention

[0003] The present invention provides a connector with a variable-angle tilting bearing bush, which can form a hydrodynamic oil film during the BTA tool deep hole machining process, so as to study the hydrodynamic support and flow deformation characteristics of the cutting fluid, and further study the active control theory of the BTA deep hole machining process roundness morphology.

[0004] The present invention adopts the following technical scheme: A BTA tool connector with a variable-angle tilting bearing bush, one end of the BTA tool connector is a drill bit connection end, the other end is a drill pipe connection end, and several tilting bearing bushes are evenly distributed around the circumference of the middle connector base; the tilting bearing bushes on the circumferential direction of the connector base have a thin end and a thick end, and a telescopic mechanism is connected between the thick end side and the connector base, and a spherical hinge mechanism is connected between the thin end side and the connector base; the telescopic mechanism changes the lifting angle of the tilting bearing bush to change the clearance between it and the workpiece hole wall, thereby generating different hydrodynamic oil films.

[0005] Further, the telescopic mechanism acts on the tilting bearing bush through a lever mechanism;

[0006] The lever mechanism includes two straight rods, a bent rod and a telescopic mechanism connecting plate; the first straight rod of the lever mechanism coaxially connects the connector base and the tilting bearing bush, and the first straight rod acts as the lever fulcrum, with the bent rod and the telescopic mechanism connecting plate connected to both sides of the rod body respectively. The cantilever end of the telescopic mechanism connecting plate is connected to the telescopic mechanism, and the cantilever end of the bent rod is connected to the second straight rod of the lever mechanism, and the second straight rod is connected to the tilting bearing bush.

[0007] Further, the telescopic mechanism includes a shape memory alloy, a piezoelectric ceramic, and a sleeve. The piezoelectric ceramic and the shape memory alloy are sequentially installed in the sleeve. The piezoelectric ceramic and the shape memory alloy are respectively connected to a power source by wires. The sleeve is installed on the connector base, and the shape memory alloy is connected to the telescopic mechanism connecting plate. When the shape memory alloy is energized, it deforms and shortens, which is the coarse adjustment. By applying different voltages to the piezoelectric ceramic, the deformation amount of the piezoelectric ceramic is changed, which is the fine adjustment.

[0008] Further, the ball hinge mechanism includes a spring, a limit sleeve, a connecting rod, and a spherical body. The spring, the connecting rod, and the spherical body are supported by the limit sleeve. There are spherical bodies at both the upper and lower ends of the limit sleeve. The upper spherical body is hinged to the tilting bearing bush, and the lower spherical body is hinged to the connector base. The spring and the connecting rod are connected in series between the upper spherical body and the lower spherical body. In the initial state, the spring pulls the thin end of the tilting bearing bush close to the connector base. When the telescopic mechanism works, the thick end of the tilting bearing bush swings towards the connector base. Under the action of the lever mechanism, the spring is stretched, and the thin end of the tilting bearing bush is lifted, reducing the angle of the tilting bearing bush.

[0009] Further, the three tilting bearing bushes are evenly distributed and circumferentially surround the connector base.

[0010] Further, both ends of the bent rod are connected to the midpoints of the two straight rods, and the bent rod is in close contact with the connector base.

[0011] Further, each tilting bearing bush is configured with two sets of ball hinge mechanisms, and the two sets of ball hinge mechanisms are symmetrically distributed on both sides of the bent rod.

[0012] Further, a heat insulation layer is provided in the sleeve.

[0013] Compared with the prior art, the advantages of the present invention are as follows:

[0014] A BTA tool connector with a tilting bearing bush with variable angle provided by the present invention integrates mechanics and electronics, has a simple structure, low cost, and is convenient to use. By controlling the lifting angle of the tilting bearing bush, the hydrodynamic oil film is changed, and further, the active control of the roundness morphology during the cutting process of the BTA tool is deeply studied. The shape memory alloy and the piezoelectric ceramic are controlled by an external circuit to expand and contract, and the lever is used to expand the lifting angle of the tilting bearing bush. The gap between the workpiece surface and the tilting bearing bush changes to generate different hydrodynamic oil films. This makes the active control means of the roundness morphology during the BTA machining process tend to be high-precision, which is an important breakthrough in the active control technology of roundness morphology. Description of the Drawings

[0015] Figure 1 is a structural schematic diagram of the present invention;

[0016] Figure 2 is a structural schematic diagram of the ball hinge mechanism;

[0017] Figure 3 is Figure 1 a sectional view taken along the A-A direction in

[0018] In the figure: 1 - drill bit connection end; 2 - bushing; 3 - first straight rod; 4 - second straight rod; 5 - telescopic mechanism; 5.1 - heat insulation plate; 5.2 - shape memory alloy; 5.3 - piezoelectric ceramic; 5.4 - sleeve; 6 - telescopic mechanism connection plate; 7 - bent rod; 8 - shaft shoulder; 9 - ball hinge mechanism; 9.1 - spherical body; 9.2 - spring; 9.3 - limit sleeve; 9.4 - connecting rod; 10 - connector base; 11 - drill pipe connection end; 12 - tiltable bearing bush. Specific embodiments

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0020] As Figure 1 , Figure 2 , Figure 3 shown: A BTA tool connector with a tiltable bearing bush with variable angle. One end of the BTA tool connector is the drill bit connection end 1, the other end is the drill pipe connection end 11, and several tiltable bearing bushes 12 are evenly distributed around the circumference of the intermediate connector base 10; the tiltable bearing bushes 12 on the circumferential direction of the connector base 10 have a thin end and a thick end. One side of the thick end is connected to the connector base 10 by a telescopic mechanism 5, and one side of the thin end is connected to the connector base 10 by a ball hinge mechanism 9; the telescopic mechanism 5 changes the lifting angle of the tiltable bearing bush 12 to change the gap between it and the workpiece hole wall, thereby generating different dynamic pressure oil films.

[0021] The telescopic mechanism 5 acts on the tiltable bearing bush 12 through a lever mechanism; the lever mechanism includes two straight rods, a bent rod 7 and a telescopic mechanism connection plate 6; the first straight rod 3 of the lever mechanism coaxially connects the connector base 10 and the tiltable bearing bush 12. The two ends of the first straight rod 3 are inserted into the holes of the connector shaft shoulder and are fixed on the connector base 10 through a ring. The first straight rod 3 can rotate and serves as the lever fulcrum. The two sides of the rod body are respectively connected to the bent rod 7 and the telescopic mechanism connection plate 6. The cantilever end of the telescopic mechanism connection plate 6 is connected to the telescopic mechanism 5, and the cantilever end of the bent rod 7 is connected to the second straight rod 4 of the lever mechanism. The second straight rod 4 is connected to the tiltable bearing bush 12. During the working process, the lever mechanism can cooperate with the telescopic mechanism 5 to increase the lifting angle of the tiltable bearing bush 12.

[0022] The telescopic mechanism 5 includes a shape memory alloy 5.2, a piezoelectric ceramic 5.3, and a sleeve 5.4. The piezoelectric ceramic 5.3 and the shape memory alloy 5.2 are sequentially installed in the sleeve 5.4. The piezoelectric ceramic 5.3 and the shape memory alloy 5.2 are respectively connected to a power source by wires. The sleeve 5.4 is installed on the connector base 10, and the shape memory alloy 5.2 is connected to the telescopic mechanism connecting plate 6. When the shape memory alloy 5.2 is energized, its temperature changes. After reaching the limit range, the shape memory alloy 5.2 deforms and shortens, which is the coarse adjustment. Applying different voltages to the piezoelectric ceramic 5.3 changes the deformation amount of the piezoelectric ceramic 5.3, which is the fine adjustment. Under the combined action of the two, the thick end of the tilting pad 12 drops slightly, and the thin end is lifted up.

[0023] An insulating layer 5.1 is provided in the sleeve 5.4, and the insulating layer 5.1 plays a heat preservation effect, making the telescopic amount of the shape memory alloy change stably.

[0024] The ball hinge mechanism 9 includes a spring 9.2, a limit sleeve 9.3, a connecting rod 9.4, and a spherical body 9.1. The spring 9.2, the connecting rod 9.4, and the spherical body 9.1 are supported by the limit sleeve 9.3. There are spherical bodies 9.1 at both the upper and lower ends of the limit sleeve 9.3. The upper spherical body is hinged to the tilting pad 12, and the lower spherical body is hinged to the connector base 10. The spring 9.2 and the connecting rod 9.4 are connected in series between the upper spherical body and the lower spherical body. In the initial state, the spring 9.2 pulls the thin end of the tilting pad 12 close to the connector base 10, and at this time, the angle of the tilting pad 12 is the largest. When the piezoelectric ceramic 5.3 and the shape memory alloy 5.2 are energized and the telescopic mechanism 5 works, the piezoelectric ceramic 5.3 and / or the shape memory alloy 5.2 shortens, the thick end of the tilting pad 12 swings towards the connector base 10, and under the action of the lever mechanism, the spring 9.2 is stretched, and the thin end of the tilting pad 12 is lifted up, reducing the angle of the tilting pad 12.

[0025] The lifting displacement range of the tilting pad 12 is about 0 - 1 mm; the angle range is 0° - 3°.

[0026] The three tilting pads 12 are evenly distributed and circumferentially surround the connector base 10.

[0027] Both ends of the bent rod 7 are connected to the midpoints of the two straight rods, and the bent rod 7 is in close contact with the connector base 10.

[0028] Each tilting pad 12 is configured with two sets of ball hinge mechanisms 9, and the two sets of ball hinge mechanisms 9 are symmetrically distributed on both sides of the bent rod 7.

[0029] A BTA tool connector with a variable-angle tilting bearing bush is used in BTA deep-hole machining. One end of the connector is connected to a BTA drill bit, and the other end is connected to a drill pipe. During the machining process, the spring 9.2 in the ball hinge mechanism 9 is in its initial state, and the thin end of the tilting bearing bush 12 is close to the connector base 10. At this time, the angle of the tilting bearing bush 12 is the largest. When the piezoelectric ceramic 5.3 and the shape memory alloy 5.2 are energized, the telescopic mechanism 5 comes into play. After the shape memory alloy 5.2 is energized, its temperature changes. When it reaches the limit range, the shape memory alloy 5.2 deforms and shortens. This is the coarse adjustment. The piezoelectric ceramic 5.3 changes the deformation amount of the piezoelectric ceramic by applying different voltages. This is the fine adjustment. Under the combined action of the two, the thick end of the tilting bearing bush 12 drops slightly. Under the action of the lever mechanism, the spring in the ball hinge mechanism 9 is stretched, and the thin end is lifted, thereby reducing the angle of the tilting bearing bush 12. At this time, a dynamic pressure oil film will be generated between the connector and the inner surface of the machined workpiece.

[0030] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A BTA tool connector with a variable-angle tilting bearing bush, characterized in that: One end of the described BTA tool connector is the drill bit connection end (1), and the other end is the drill pipe connection end (11). A plurality of tilting pad bearings (12) are evenly distributed around the circumference of the middle connector base (10); the tilting pad bearings (12) on the circumferential direction of the connector base (10) have a thin end and a thick end. A telescopic mechanism (5) is connected between the thick end side and the connector base (10), and a spherical hinge mechanism (9) is connected between the thin end side and the connector base (10); the telescopic mechanism (5) changes the lifting angle of the tilting pad bearing (12) to change the clearance between it and the workpiece hole wall, thereby generating different dynamic pressure oil films. The described telescopic mechanism (5) acts on the tilting pad bearing (12) through a lever mechanism. The lever mechanism includes two straight rods, a bent rod (7) and a telescopic mechanism connecting plate (6); the first straight rod (3) of the lever mechanism coaxially connects the connector base (10) and the tilting pad bearing (12). The first straight rod (3) acts as the lever fulcrum. The two sides of the rod body are respectively connected to the bent rod (7) and the telescopic mechanism connecting plate (6). The cantilever end of the telescopic mechanism connecting plate (6) is connected to the telescopic mechanism (5), and the cantilever end of the bent rod (7) is connected to the second straight rod (4) of the lever mechanism. The second straight rod (4) is connected to the tilting pad bearing (12). The described telescopic mechanism (5) includes a shape memory alloy (5.2), a piezoelectric ceramic (5.3) and a sleeve (5.4). The piezoelectric ceramic (5.3) and the shape memory alloy (5.2) are successively installed in the sleeve (5.4). The piezoelectric ceramic (5.3) and the shape memory alloy (5.2) are respectively connected to a power source by wires; the sleeve (5.4) is installed on the connector base (10), and the shape memory alloy (5.2) is connected to the telescopic mechanism connecting plate (6); after the shape memory alloy (5.2) is energized, it deforms and shortens, which is the coarse adjustment; applying different voltages to the piezoelectric ceramic (5.3) changes the deformation amount of the piezoelectric ceramic (5.3), which is the fine adjustment.

2. The BTA tool connector with a variable-angle tilting bearing bush according to claim 1, characterized in that: The described spherical hinge mechanism (9) includes a spring (9.2), a limit sleeve (9.3), a connecting rod (9.4) and a spherical body (9.1). The spring (9.2), the connecting rod (9.4) and the spherical body (9.1) are supported by the limit sleeve (9.3). There are spherical bodies (9.1) at both the upper and lower ends of the limit sleeve (9.3). The upper spherical body is hinged to the tilting pad bearing (12), and the lower spherical body is hinged to the connector base (10). The spring (9.2) and the connecting rod (9.4) are connected in series between the upper spherical body and the lower spherical body; in the initial state, the spring (9.2) pulls the thin end of the tilting pad bearing (12) close to the connector base (10); when the telescopic mechanism (5) works, the thick end of the tilting pad bearing (12) swings towards the connector base (10). Under the action of the lever mechanism, the spring (9.2) is stretched, and the thin end of the tilting pad bearing (12) is lifted, reducing the angle of the tilting pad bearing (12).

3. The BTA tool connector with a variable-angle tilting bearing bush according to claim 1, characterized in that: The three described tilting pad bearings (12) are evenly distributed and circumferentially surround the connector base (10).

4. A BTA tool connector with a variable-angle tilting bearing bush according to claim 2, characterized in that: The two ends of the described bent rod (7) are connected to the midpoints of the two straight rods, and the bent rod (7) is in close contact with the connector base (10).

5. A BTA tool connector with a variable-angle tilting bearing bush according to claim 2, characterized in that: Each of the tilting journal bearings (12) is provided with two sets of spherical hinge mechanisms (9), and the two sets of spherical hinge mechanisms (9) are symmetrically distributed on both sides of the bent rod (7).

6. The BTA tool connector with a variable-angle tiltable bearing bush according to claim 1, characterized in that: A heat insulation layer (5.1) is provided in the sleeve (5.4).

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