An automatic indexing device based on a subdivided multi-tooth indexing table

Abstract

This invention belongs to the field of precision machining and measurement technology, and relates to an automatic indexing device based on a multi-tooth subdivision indexing table. Its features include: a multi-tooth subdivision indexing table (5), with a subdivision drive mechanism (1) connected to one side of the table; a coarse indexing drive mechanism (3) and a lifting drive mechanism (4) connected to the other side of the table; and a connecting plate (2) at the bottom of the table (5), which is fixedly mounted on the upper surface of a worktable (6). The advantages of this invention are: it can achieve automatic indexing at any angle, has a simple structure, good reliability, and improves measurement accuracy and efficiency.

Description

Technical Field

[0001] This invention belongs to the field of precision machining and measurement technology, and relates to an automatic indexing device based on a multi-tooth indexing table. Background Technology

[0002] Multi-tooth indexing tables are high-precision angle reference instruments widely used in machining and measurement fields. Utilizing the multi-tooth averaging effect, multi-tooth indexing tables possess excellent positioning and indexing accuracy, far exceeding that of rotary tables. They can be used as angle references for measurement and as indexing devices for precision machining, and are widely applied in scientific research and production units. A multi-tooth indexing table is a high-precision angle measuring tool composed of two end-face toothed discs with the same outer diameter, tooth profile, and tooth pitch. End-face teeth with a trapezoidal tooth profile are provided on the lower end face of the upper toothed disc and the upper end face of the lower toothed disc. When the end-face teeth of the upper and lower toothed discs engage, the upper and lower toothed discs automatically center. In use, the lower toothed disc is generally fixed, while the upper toothed disc is raised and disengaged from the lower toothed disc, allowing it to rotate relative to the lower toothed disc. After rotation, the upper toothed disc descends, and upon re-engaging, the indexing purpose is achieved based on the number of teeth rotated. The existing multi-tooth indexing tables in China generally have an accuracy of 0.5″, while high-precision multi-tooth indexing tables can achieve an accuracy of 0.2″.

[0003] Invention patent [CN202310811072.3] discloses a subdivision adjustment mechanism, featuring continuous subdivision, high indexing accuracy, and convenient operation. Based on this, invention patent [CN202211463009.7] discloses a subdivisible multi-tooth indexing table, which can achieve arbitrary angle indexing while maintaining the indexing accuracy of a multi-tooth indexing table. The subdivision multi-tooth indexing table can be used not only with combination fixture components but also independently for general machine tool processing such as drilling, milling, planing, boring, and grinding of precision parts with high angle requirements. Existing domestic subdivision multi-tooth indexing tables can achieve an overall indexing accuracy of 0.2″ and a comprehensive indexing accuracy of 1″. During operation, the toothed disc on the multi-tooth indexing table is lifted and rotated to the desired integer degree, then lowered to re-engage with the lower toothed disc, and then rotated to the desired minute and second position via the subdivision drive mechanism. Traditional subdivision multi-tooth indexing tables use manual methods to achieve the lifting, indexing, and rotation of the subdivision drive mechanism. This method is cumbersome to operate and may cause errors due to manual lifting and rotating of the multi-tooth indexing table, leading to faults such as tooth misalignment, tooth misalignment, and stalling. This can reduce the angle output or measurement accuracy of the multi-tooth indexing table, and in severe cases, even damage the mechanical structure of the multi-tooth indexing table, causing significant losses.

[0004] An existing multi-tooth indexing stage based on program control can achieve fully automatic measurement, is easy to operate, save time, and reduce errors caused by manual operation. However, it can only achieve integer angle positioning and cannot achieve arbitrary angle indexing. Invention patent [CN202311475440.8] discloses a grating-based multi-tooth indexing stage control device. Although it can obtain the real-time angle value of the multi-tooth indexing stage through the grating and achieve closed-loop control, effectively avoiding interference from electrical, magnetic, and force fields on the angle output or measurement, thus reducing the failure rate and maintainability of the multi-tooth indexing stage and improving its angle output or measurement accuracy, it can only achieve integer angle positioning, with a minimum indexing angle of (360 / number of teeth on the tooth plate)°, and cannot perform actual indexing. Furthermore, its closed-loop control makes its manufacturing cost too high. Currently, domestic sensor testing requires high-precision small-angle subdivision near specific angle positions, and these angles may not be divisible by 360. Existing multi-tooth indexing stages cannot meet these requirements. Summary of the Invention

[0005] To address the problems of existing indexing devices being unable to achieve automatic indexing at arbitrary angles, and the interference of human operation, electrical, magnetic fields, and force fields on angle output or measurement affecting the efficiency and stability of angle measurement, this invention provides an automatic indexing device based on a subdivision multi-tooth indexing table. The device is characterized by including a subdivision multi-tooth indexing table, with a subdivision drive mechanism connected to one side of the subdivision multi-tooth indexing table.

[0006] The other side of the multi-tooth indexing table is connected to a coarse indexing drive mechanism and a lifting drive mechanism.

[0007] A connecting plate is installed at the bottom of the multi-tooth indexing table, and the table is fixedly mounted on the upper surface of the worktable through the connecting plate.

[0008] The automatic indexing device for the multi-tooth indexing table described above is characterized in that: the subdivision drive mechanism includes: a subdivision drive motor, which is mounted on a subdivision drive motor bracket.

[0009] The microstepping drive motor bracket is equipped with a ball bearing cross slider coupling.

[0010] The microstepping drive motor bracket is fixed on the worktable;

[0011] The microstepping drive motor is connected to one end of the shaft of the ball bearing cross slider coupling;

[0012] The other end of the ball joint is connected to the subdivision hub shaft of the subdivision multi-tooth indexing table; the ball joint enables backlash-free rotation and relative axial movement between the subdivision drive motor spindle and the subdivision hub of the subdivision multi-tooth indexing table.

[0013] The automatic indexing device for the subdivision multi-tooth indexing table described above is characterized in that: the subdivision drive motor, the ball cross slider coupling, and the subdivision hub shaft of the subdivision multi-tooth indexing table are located on the same axis.

[0014] The automatic indexing device for the subdivided multi-tooth indexing table described above is characterized in that: the ball cross slider coupling includes a guide sleeve, and the guide sleeve is provided with positioning balls and moving balls.

[0015] The positioning bead is set in the hole in the side wall of the positioning bead sleeve, and the movable bead is set in the hole in the side wall of the movable bead sleeve.

[0016] The positioning bead sleeve is equipped with a micro-bead drive motor connecting shaft, the moving bead sleeve is equipped with a micro-bead hub connecting shaft, and a bead frame is provided at one end of the micro-bead hub connecting shaft.

[0017] The automatic indexing device for the multi-tooth indexing table described above is characterized in that: the positioning beads and the guide sleeve are assembled together by an interference fit; the micro-stepping drive motor connecting shaft is interference-fitted with the bead frame and the micro-stepping hub connecting shaft.

[0018] The movable ball bearing is interference-fitted with the micro-stepping hub connecting shaft, and the micro-stepping hub connecting shaft is interference-fitted with the guide sleeve;

[0019] The output shaft axis of the microstepping drive motor is coaxial with the microstepping hub axis of the microstepping multi-tooth indexing table.

[0020] The automatic indexing device for the subdivided multi-tooth indexing table described above is characterized in that: the coarse indexing drive mechanism includes an indexing drive motor bracket, the indexing drive motor bracket is connected to a connecting plate, and the connecting plate is connected to the worktable.

[0021] The indexing drive motor is mounted on the indexing drive motor bracket; the output shaft of the indexing drive motor is connected to the drive synchronous belt pulley.

[0022] A timing belt is installed on the driving timing pulley, and the timing belt is connected to the driven timing pulley;

[0023] The indexing drive motor and the indexing drive motor bracket are fixedly connected by screws, and the driven synchronous pulley is set on the ring surface of the subdivided multi-tooth indexing table.

[0024] The automatic indexing device for the subdivided multi-tooth indexing table described above is characterized in that: the lifting drive mechanism includes: a lifting drive motor, and the lifting drive motor is mounted on the lifting drive motor adapter plate;

[0025] The lifting drive motor adapter plate is fixedly connected to the lifting drive motor bracket.

[0026] The output shaft of the lifting drive motor is connected to the lifting shaft of the subdivided multi-tooth indexing table via a coupling.

[0027] The lifting drive motor bracket is bolted to the connecting plate.

[0028] The automatic indexing device for the subdivided multi-tooth indexing table described above is characterized in that: the flatness of the worktable surface of the subdivided multi-tooth indexing table is <1µm, and the parallelism relative to the indexing plane is ≤2μm.

[0029] The automatic indexing device for the subdivision multi-tooth indexing table described above is characterized in that: the number of pulses for one revolution of the subdivision drive motor is ≥300.

[0030] The automatic indexing device for the subdivision multi-tooth indexing table described above is characterized in that: the number of pulses for one revolution of the subdivision drive motor is 350.

[0031] Advantages of this invention compared to existing technologies:

[0032] 1. The sub-indexing drive mechanism, coarse indexing drive mechanism, and lifting drive mechanism are respectively connected to the subdivision multi-tooth indexing table. The subdivision multi-tooth indexing table has high precision and realizes automatic indexing of any angle by the automatic indexing device. At the same time, it reduces the cost of the automatic indexing device, is easy to manufacture, and is simple to operate.

[0033] 2. The ball-and-slider coupling is placed between the subdivision hub of the subdivision multi-tooth indexing table and the subdivision drive motor. The output shaft axis of the subdivision drive motor is coaxial with the subdivision hub axis of the subdivision multi-tooth indexing table. The ball-and-slider coupling can realize backlash-free rotation and relative axial movement between the main shaft of the subdivision drive motor and the subdivision hub of the subdivision multi-tooth indexing table, ensuring the indexing accuracy of the automatic indexing device.

[0034] 3. The flatness of the contact surface between the subdivision drive motor bracket and the worktable should be controlled within 1µm through grinding. The flatness of the contact surface between the indexing drive motor bracket and the connecting plate should be within 1µm. The flatness of the upper and lower end faces of the connecting plate should be within 1µm, and the parallelism between the upper end face and the lower end face should be within 1µm, which further ensures the indexing accuracy of the automatic indexing device. Attached Figure Description

[0035] Figure 1 A schematic diagram of an automatic indexing device based on a multi-tooth indexing table.

[0036] Figure 2 A schematic diagram of the subdivision drive mechanism.

[0037] Figure 3 A schematic diagram of the structure of a beaded cross-slider coupling.

[0038] Figure 4 A schematic diagram of the guide sleeve.

[0039] Figure 5Schematic diagram of the internal structure of the ball joint.

[0040] Figure 6 Schematic diagram of the internal structure of a ball joint with cross-slider (without positioning ball joint and moving ball joint).

[0041] Figure 7 A schematic diagram of the structure of the connecting shaft of the microstepping drive motor.

[0042] Figure 8 A schematic diagram of the structure of the dense bead frame.

[0043] Figure 9 A schematic diagram of the subdivided hub connecting shaft.

[0044] Figure 10 A schematic diagram of the coarse indexing drive mechanism.

[0045] Figure 11 A schematic diagram of the lifting drive mechanism.

[0046] Figure 12 A schematic diagram of the structure of a multi-tooth indexing table.

[0047] Reference numerals in the attached figures: 1: Microstepping drive mechanism; 1-1: Microstepping drive motor; 1-2: Microstepping drive motor bracket; 1-3: Bead cross slider coupling; 1-3-1: Guide sleeve; 1-3-2: Positioning beads; 1-3-3: Moving beads; 1-3-4: Microstepping drive motor connecting shaft; 1-3-5: Bead frame; 1-3-6: Microstepping hub connecting shaft; 2: Connecting plate; 3: Coarse indexing drive mechanism; 3-1: Indexing drive motor bracket; 3-2: Driving synchronous pulley; 3-3: Indexing drive motor; 3-4: Synchronous belt; 3-5: Driven synchronous pulley; 4: Lifting drive mechanism; 4-1: Lifting drive motor; 4-2: Adapter plate; 4-3: Lifting drive motor bracket; 4-4: Coupling; 5: Microstepping multi-tooth indexing table; 5-1: Microstepping hub; 5-2: Microstepping multi-tooth indexing table worktable; 5-3: Microstepping multi-tooth indexing table lifting shaft; 6: Worktable. Detailed Implementation

[0048] Preferred Implementation Method 1

[0049] Reference Figures 1 to 8 The present invention provides an automatic indexing device based on a multi-tooth indexing table with subdivision, which is implemented as follows:

[0050] The automatic device includes a micro-indexing drive mechanism 1, a ball joint 1-3, a connecting plate 2, a coarse indexing drive mechanism 3, a lifting drive mechanism 4, and a micro-indexing multi-tooth indexing table 5. The bottom surface of the micro-indexing multi-tooth indexing table is fastened to the connecting plate 2 with countersunk screws, and the connecting plate 2 is then fastened to the table surface of the worktable 6 with screws. On the far left of the device, the micro-indexing drive mechanism 1 includes a micro-indexing drive motor 1-1 and a micro-indexing drive motor bracket 1-2, which is fixed to the worktable 6 with screws. The micro-indexing drive motor 1-1 is a 17-bit magnetic encoder servo motor. The micro-indexing drive motor bracket 1-2 is made of 304 stainless steel, and the flatness of the contact surface between the micro-indexing drive motor bracket 1-2 and the worktable 6 should be controlled within 1µm through grinding. The micro-indexing drive motor connecting shaft 1-3-4 is assembled with the micro-indexing drive motor output shaft and fastened together with set screws. The micro-indexing hub connecting shaft 1-3-6 is connected to the micro-indexing hub 5-1. The microstepping drive mechanism 1 is connected to the microstepping hub 5-1 of the microstepping multi-tooth indexing table via a ball joint 1-3.

[0051] The ball joint 1-3 includes a guide sleeve 1-3-1, positioning balls 1-3-2, moving balls 1-3-3, a drive motor connecting shaft 1-3-4, a ball frame 1-3-5, and a sub-branch hub connecting shaft 1-3-6. The guide sleeve 1-3-1 is made of bearing steel. The axial length of the positioning ball 1-3-2 should be greater than half the working length of the drive motor connecting shaft 1-3-4. The axial length of the moving ball 1-3-3 should be greater than half the working length of the sub-branch hub connecting shaft 1-3-6. The length of the ball frame 1-3-5 should be greater than half the key length of the sub-branch hub connecting shaft 1-3-6. The positioning ball 1-3-2, the drive motor connecting shaft 1-3-4, and the guide sleeve 1-3-1 should be assembled together using an interference fit. The drive motor connecting shaft 1-3-4, the ball frame 1-3-5, and the sub-branch hub connecting shaft 1-3-6 should also be assembled together using an interference fit. The movable ball bearing 1-3-3, the subdivision hub connecting shaft 1-3-6, and the guide sleeve 1-3-1 should be assembled together using an interference fit.

[0052] The coarse indexing drive mechanism 3 includes an indexing drive motor bracket 3-1, a driving synchronous pulley 3-2, an indexing drive motor 3-3, a synchronous belt 3-4, and a driven synchronous pulley 3-5. The indexing drive motor 3-3 is a stepper motor, which is fastened to the indexing drive motor bracket 3-1 with screws. The indexing drive motor bracket 3-1 is made of 304 stainless steel, and the flatness of its contact surface with the connecting plate 2 should be controlled within 1µm. The connecting plate 2 is also made of 304 stainless steel, and the flatness of its upper and lower end faces should be controlled within 1µm, as should the parallelism of the upper end face relative to the lower end face. The connecting plate 2 is fastened to the worktable with screws. The driving synchronous pulley 3-2 is made of aluminum alloy and has 24 teeth. The driving synchronous pulley 3-2 is mounted on the indexing drive motor 3-3. The driving synchronous pulley 3-2 and the driven synchronous pulley 3-5 are connected by a synchronous belt 3-4. The synchronous belt 3-4 is an S3M model with 301 teeth and a length of 902 mm. The driven synchronous pulley 3-5 is made of aluminum alloy and has 240 teeth. It is mounted on the subdivision multi-tooth indexing table 5-2 and fastened to it with set screws. The driven synchronous pulley 3-5 is coaxial with the subdivision multi-tooth indexing table 5-2, and the upper end face of the driven synchronous pulley 3-5 is on the same plane as the table surface of the subdivision multi-tooth indexing table 5-2. It is particularly important to note that when the upper and lower gears of the subdivision multi-tooth indexing table 5-2 are engaged, the upper end face of the driving synchronous pulley 3-2 and the upper end face of the driven synchronous pulley 3-5 should be on the same plane, and the synchronous belt 3-4 should be in a relaxed state. When the upper gear plate on the multi-tooth indexing table 5-2 is lifted, the timing belt 3-4 is tightened.

[0053] The lifting drive mechanism 4 consists of a lifting drive motor 4-1, an adapter plate 4-2, a lifting drive motor bracket 4-3, and a coupling 4-4. The lifting drive motor 4-1 is a stepper motor, connected to the adapter plate 4-2 with screws, and then securely mounted on the lifting drive motor bracket 4-3. The lifting drive motor bracket 4-3 is threaded onto the connecting plate 2 and is made of 304 stainless steel. The adapter plate 4-2 is also made of 304 stainless steel, and the flatness of its two working surfaces should be controlled within 1µm, as should the parallelism of the two surfaces. The output shaft of the lifting drive motor 4-1 is connected to the subdivision multi-tooth indexing lifting shaft 5-3 via the coupling 4-4. The subdivision multi-tooth indexing lifting shaft 5-3 rotates 180° at a time, and the coupling 4-4 ​​is a rigid coupling.

[0054] Furthermore, the present invention also provides a method for implementing an automatic indexing device based on a multi-tooth indexing table:

[0055] Taking an output angle of 28°34′28″ as an example, the implementation steps of this automatic indexing device are explained:

[0056] Step 1: Clean the workpiece that needs to be measured or processed, removing oil and other contaminants. Secure the workpiece to be processed or measured onto the subdivided multi-tooth indexing table 5-2 using screws.

[0057] Step 2: Turn on the power and return the subdivision drive mechanism and the coarse indexing drive mechanism to the absolute zero position.

[0058] Step 3: Start the lifting drive motor 4-1 in the lifting drive mechanism 4. Driven by the lifting drive motor 4-1, the lifting shaft 5-3 of the multi-tooth indexing table rotates, thereby lifting the upper tooth plate of the multi-tooth indexing table.

[0059] Step 4: After the toothed disc on the multi-tooth indexing table is lifted, start the indexing drive motor 3-3 in the indexing drive mechanism 4. The rotation of the indexing drive motor 3-3 drives the active synchronous pulley 3-2 to rotate, which in turn drives the driven synchronous pulley 3-5 to rotate through the synchronous belt 3-4, thus rotating the upper toothed disc on the multi-tooth indexing table to the position of 28°30′, achieving coarse indexing at the position of 28°30′.

[0060] Step 5: Then, start the lifting drive motor 4-1 in the lifting drive mechanism 4, so that it drives the lifting shaft 5-3 of the subdivision multi-tooth indexing table to rotate, so that the upper tooth plate of the subdivision multi-tooth indexing table is lowered and meshed with the lower tooth plate for positioning, thus completing the fine indexing at the 28°30′ position.

[0061] Step 6: Start the microstepping drive motor 1-1 in the microstepping drive mechanism 1, which drives the ball bearing cross slider coupling 1-3 to move linearly along the axial direction while rotating on the fixed axis. The ball bearing cross slider coupling 1-3 drives the microstepping hub 5-1 of the microstepping multi-tooth indexing table to rotate while moving axially, turning the microstepping hub 5-1 to 4′28″, completing the microstepping indexing, and finally realizing the automatic precision indexing of the indexing table at 28°34′28″.

[0062] Through the above steps, the angles of parts can be processed and measured more conveniently, with higher precision, and automatically. The detailed description of the present invention is merely a preferred embodiment and does not limit the scope of the invention. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the invention, and all such modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. An automatic indexing device based on a multi-tooth indexing table, characterized in that: It includes a multi-tooth indexing table (5), and a multi-tooth indexing table (5) is connected to a multi-tooth indexing mechanism (1) on one side. The other side of the subdivided multi-tooth indexing table (5) is connected to the coarse indexing drive mechanism (3) and the lifting drive mechanism (4); A connecting plate (2) is provided at the bottom of the multi-tooth indexing table (5), and is fixedly installed on the upper surface of the worktable (6) through the connecting plate (2); The microstepping drive mechanism (1) includes: a microstepping drive motor (1-1), which is mounted on a microstepping drive motor bracket (1-2); The microstepping drive motor bracket (1-2) is equipped with a ball bearing cross slider coupling (1-3). The microstepping drive motor bracket (1-2) is fixed on the worktable (6); The microstepping drive motor (1-1) is connected to one end of the shaft of the micro-bead cross slider coupling (1-3); The other end of the ball joint (1-3) is connected to the shaft of the subdivision hub (5-1) of the subdivision multi-tooth indexing table; the ball joint (1-3) can realize backlash-free rotation and relative axial movement between the main shaft of the subdivision drive motor (1-1) and the subdivision hub (5-1) of the subdivision multi-tooth indexing table; The ball joint (1-3) includes a guide sleeve (1-3-1), and a positioning ball (1-3-2) and a moving ball (1-3-3) are provided inside the guide sleeve (1-3-1). The positioning bead (1-3-2) is set in the hole in the side wall of the positioning bead sleeve, and the movable bead (1-3-3) is set in the hole in the side wall of the movable bead sleeve. The positioning bead sleeve is equipped with a micro-bead drive motor connecting shaft (1-3-4), the moving bead sleeve is equipped with a micro-bead hub connecting shaft (1-3-6), and a bead frame (1-3-5) is provided at one end of the micro-bead hub connecting shaft (1-3-6). The coarse indexing drive mechanism (3) includes an indexing drive motor bracket (3-1), which is connected to a connecting plate (2), and the connecting plate (2) is connected to a worktable (6). The indexing drive motor bracket (3-1) is equipped with an indexing drive motor (3-3); the output shaft of the indexing drive motor (3-3) is connected to the drive synchronous pulley (3-2); A timing belt (3-4) is installed on the driving timing pulley (3-2), and the timing belt (3-4) is connected to the driven timing pulley (3-5); The indexing drive motor (3-3) and the indexing drive motor bracket (3-1) are fixedly connected by screws, and the driven synchronous pulley (3-5) is set on the ring surface of the subdivided multi-tooth indexing table (5).

2. The automatic indexing device for a multi-tooth indexing table as described in claim 1, characterized in that: The spindles of the microstepping drive motor (1-1), the ball joint cross slider coupling (1-3), and the microstepping multi-tooth indexing table microstepping hub (5-1) are located on the same axis.

3. The automatic indexing device for a multi-tooth indexing table as described in claim 2, characterized in that: The positioning beads (1-3-2) and the guide sleeve (1-3-1) are assembled together by interference fit; the microstepping drive motor connecting shaft (1-3-4) is interference-fitted with the bead frame (1-3-5) and the microstepping hub connecting shaft (1-3-6); The movable ball bearing (1-3-3) is interference-fitted with the subdivision hub connecting shaft (1-3-6), and the subdivision hub connecting shaft (1-3-6) is interference-fitted with the guide sleeve (1-3-1). The output shaft axis of the microstepping drive motor (1-1) is coaxial with the microstepping hub (5-1) axis of the microstepping multi-tooth indexing table.

4. The automatic indexing device for a multi-tooth indexing table as described in claim 3, characterized in that: The lifting drive mechanism (4) includes: a lifting drive motor (4-1), which is mounted on the lifting drive motor adapter plate (4-2); The lifting drive motor adapter plate (4-2) is fixedly connected to the lifting drive motor bracket (4-3). The output shaft of the lifting drive motor (4-1) is connected to the lifting shaft (5-3) of the subdivision multi-tooth indexing table via a coupling (4-4); The lifting drive motor bracket (4-3) is bolted to the connecting plate (2).

5. The automatic indexing device for a multi-tooth indexing table as described in claim 1 or 4, characterized in that: The flatness of the multi-tooth indexing table (5) is <1µm, and the parallelism relative to the indexing plane is ≤2μm.

6. The automatic indexing device for a multi-tooth indexing table as described in claim 5, characterized in that: The number of pulses for one revolution of the microstepping drive motor (1-1) is ≥300.

7. The automatic indexing device for a multi-tooth indexing table as described in claim 6, characterized in that: The number of pulses for one revolution of the microstepping drive motor (1-1) is 350.

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