Clamping tool for shaft part gear shaping
By designing a reference base, a positioning base, and a clamping mechanism, the problems of inaccurate alignment and deformation of shaft parts were solved, enabling high-precision gear hobbing, reducing scrap rate and production costs, and improving processing efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CHONGQING GEARBOX
- Filing Date
- 2025-05-23
- Publication Date
- 2026-05-19
AI Technical Summary
The existing chuck clamping method cannot effectively ensure the accurate alignment of shaft parts, resulting in substandard gear cutting accuracy. Furthermore, the parts are prone to deformation during the processing, leading to a high scrap rate and increased production costs.
The fixture employs a reference base, a positioning base, and a clamping mechanism. Precise positioning is achieved by aligning the reference cylinder with the center of the worktable. The positioning cylinder is coaxial with the reference cylinder for auxiliary support. The clamping blocks are slidably connected to accommodate different sizes. The clamping blocks are designed with a concave arc surface to increase the contact area, and the electric clamping blocks improve clamping efficiency.
It improves the machining accuracy of gear hobbing, reduces the scrap rate, reduces material waste and production costs, and enhances processing efficiency and equipment applicability.
Smart Images
Figure CN224254382U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of fixture and tooling technology, specifically to a clamping fixture for gear shaping of shaft parts. Background Technology
[0002] In the field of gear shaping for shaft parts, ensuring machining accuracy has always been a core objective pursued by the industry. However, in current machining practices, a series of thorny issues affecting accuracy and cost frequently arise.
[0003] In actual gear hobbing operations, despite operators' best efforts to follow standard procedures and meticulously adjust equipment parameters, the final machined shaft parts often exhibit significant deviations in tooth profile from the designed standard tooth profile. This deviation leads to unstable meshing and reduced transmission efficiency during subsequent assembly and operation, severely impacting the overall performance and service life of the mechanical products.
[0004] Further observation of the machined shaft parts, especially slender shafts, reveals that some parts exhibit bending deformation. This causes the journal position to deviate from the ideal state, making high-precision fitting impossible. Even with strict control over cutting parameters and tool condition during machining, this deformation problem is difficult to eliminate completely. Once a part is deformed, it is highly likely to become scrap, resulting in a significant waste of raw materials. Simultaneously, because scrapped parts require reprocessing resources, production costs also increase substantially.
[0005] A deeper investigation into the root causes of these problems revealed a close connection with the clamping process. From the perspective of processing phenomena and results, the currently widely used chuck clamping method cannot effectively ensure the accurate alignment of parts, and also has obvious shortcomings in maintaining the stability of the processing process. These problems urgently need to be solved. Utility Model Content
[0006] The present invention aims to provide a clamping fixture for gear shaping of shaft parts. This fixture can stably and accurately fix and hold shaft parts, solving the problem that the existing chuck clamping cannot be aligned, resulting in substandard gear shaping accuracy.
[0007] To achieve the above objectives, the present invention adopts the following technical solution: a clamping fixture for gear shaping of shaft parts, comprising a reference base, a positioning base, and a clamping mechanism. The reference base includes a reference flange and a reference cylinder. The reference flange is fixed to the bottom of the reference cylinder. The inner diameter of the reference cylinder is equal to the diameter of the non-machined end of the shaft part. The center of the reference cylinder coincides with the center point of the worktable. The reference flange is detachably connected to the worktable. The positioning base includes a positioning cylinder and an upper flange and a lower flange fixed to both ends of the positioning cylinder. The inner diameter of the positioning cylinder is larger than the outer diameter of the reference flange. The positioning cylinder is coaxial with the reference cylinder. The lower flange is detachably connected to the worktable. The clamping mechanism includes multiple clamping seats and clamping blocks. The clamping seats are detachably connected to the upper flange at equal intervals. The clamping blocks are slidably connected to the clamping seats. The sliding path of the clamping blocks points to the axis of the shaft part.
[0008] The beneficial effects of this plan are:
[0009] 1. Precise Alignment and Positioning: This clamping fixture, through the setting of a reference base, with the inner diameter of the reference cylinder equal to the diameter of the non-machined end of the shaft part, and the center of the reference cylinder coinciding with the center point of the worktable, enables the shaft part to quickly and accurately find its relative position with the worktable during clamping, achieving precise initial positioning. Compared with traditional clamping methods that are difficult to align with the center of the worktable, this greatly improves the alignment accuracy, ensures the accuracy of the relative movement between the tool and the part during gear shaping, thereby improving the machining accuracy of the tooth profile and ensuring the meshing accuracy and transmission performance of the gear.
[0010] 2. Stable clamping: The positioning cylinder is coaxial with the reference cylinder, and the lower flange is detachably connected to the worktable, which plays an auxiliary support and positioning role for shaft parts. It makes up for the shortcomings of traditional single-end clamping, effectively restricts the bending deformation of shaft parts caused by cutting force, self-weight and other factors during the processing, improves the stability of parts during the processing, and reduces the scrap rate.
[0011] 3. Flexible and adjustable clamping mechanism: Multiple clamping seats in the clamping mechanism are detachably connected to the upper flange at equal intervals, and the clamping block is slidably connected to the clamping seats, with the sliding path pointing towards the axis of the shaft part. This allows the clamping fixture to be flexibly adjusted according to the size and shape of different shaft parts, making it more adaptable and expanding the application range of the clamping fixture.
[0012] 4. Easy disassembly and installation: The reference flange of the reference seat, the lower flange of the positioning seat, and the clamping seat of the clamping mechanism are all detachable, making it easier and faster to install shaft parts or maintain and replace the tooling during use. This helps to improve processing efficiency and reduce the time wasted on clamping and tooling adjustment.
[0013] 5. Cost Reduction: This clamping fixture improves the precision of gear shaping for shaft parts, reduces the scrap rate, and minimizes material waste caused by scrapped parts. Simultaneously, the convenient disassembly and installation methods and flexible adjustment capabilities improve processing efficiency and reduce processing time, thereby lowering overall production costs and increasing production efficiency.
[0014] Furthermore, the upper flange is provided with multiple sets of fixing holes that correspond one-to-one with the clamping seat. Each set of fixing holes includes four fixing holes that correspond to the four corners of the clamping seat. The fixing hole sets are divided into inner fixing hole sets and outer fixing hole sets according to their distance from the center.
[0015] To accommodate the machining of shaft parts of different sizes, the fixing hole group is divided into an inner fixing hole group and an outer fixing hole group according to its circumferential position. When machining shaft parts of standard size, the clamping seat is installed and connected to the inner fixing hole group. For shaft parts of large size with larger diameter, when the clamping seat is fixed in the inner fixing hole group, the clamping block is basically pressed against the side wall of the shaft part before it extends, which cannot provide effective clamping. Therefore, it is necessary to adjust the position of the clamping seat and install it in the outer fixing hole group to provide a stable clamping force.
[0016] Furthermore, the end clamping surface of the clamping block is a concave arc surface, and the diameter of the concave arc surface is equal to the diameter of the largest specification shaft part.
[0017] In the above-described design, the clamping surface of the clamping block is a flat plane, resulting in a small contact area with the shaft-like parts during clamping, which hinders clamping stability. Therefore, the clamping surface at the end of the clamping block is designed as a concave arc surface, effectively increasing the clamping area and improving clamping stability. The diameter of the concave arc surface is designed to match the diameter of the largest shaft-like parts suitable for this device. This eliminates the need for other clamping block specifications; only this one specification is required to process various shaft-like parts.
[0018] Furthermore, the lower flange is provided with four U-shaped slots at equal intervals along the circumference, and the angle between the diagonal line connecting the U-shaped slots and the line connecting the adjacent fixing hole group is 45°.
[0019] To facilitate flexible adjustment and alignment, four U-shaped slots are provided on the lower flange. Bolts are used to fix the positioning seat and the worktable through these U-shaped slots. Traditional threaded holes, which are fixed in position, cannot be flexibly adjusted. In this design, after the positioning seat is basically aligned and lowered, it can be pre-tightened before further alignment. At this point, the U-shaped slots can be flexibly adjusted in position, and after the final position is determined, it can be further tightened. To improve installation efficiency, only four U-shaped slots and bolts are provided. Each bolt needs to withstand the reaction force from the clamping block. To improve the service life of the structure, the position of the U-shaped slots is specially designed so that the angle between the diagonal line and the line connecting the adjacent fixing hole group is 45°. The reaction force after each clamping block is clamped is borne by two bolts. The same bolt is subjected to two forces in different directions, some of which cancel each other out. With this arrangement, the force borne by each bolt is minimized.
[0020] Furthermore, multiple observation holes are provided at equal intervals along the circumference on the side wall of the middle part of the positioning cylinder.
[0021] In the above scheme, the positioning cylinder is a closed structure, making it impossible to observe and adjust the position when lowering shaft-like parts. If the bottom of the shaft-like part is not aligned with the reference cylinder, a gantry crane must be used to lift the shaft-like part and readjust its position before it can be placed into the reference cylinder, affecting the overall operational efficiency. Therefore, to facilitate the adjustment of the position of the shaft-like parts, multiple observation holes are set in the middle of the positioning cylinder. Assistants can use these observation holes to assist the operators in lowering the shaft-like parts into place in one go, improving the overall installation efficiency. Furthermore, the observation holes can also serve as holes for hoisting the positioning seat. The original hoisting method typically involved clamping the upper flange to lift the positioning seat, which was not very stable. With the observation holes, these holes can serve as hook points for hoisting, ensuring a very stable installation and improving the convenience and safety of the installation.
[0022] Furthermore, the clamping block is an electric clamping block, which includes an electric push rod.
[0023] To further improve the overall clamping and fixing efficiency as well as the machining efficiency of shaft parts, the clamping block was improved to an electric clamping block driven by an electric actuator, which can quickly clamp shaft parts through the electric actuator, greatly improving the clamping and fixing efficiency. Attached Figure Description
[0024] Figure 1 This is a schematic diagram of the overall structure of Embodiment 1 of this utility model.
[0025] Figure 2 This is an exploded view of the overall structure of Embodiment 1 of this utility model.
[0026] Figure 3 for Figure 1 Top view.
[0027] Figure 4 for Figure 3 AA sectional view.
[0028] Figure 5 for Figure 3 View A. Detailed Implementation
[0029] The following detailed description illustrates the specific implementation method:
[0030] The reference numerals in the accompanying drawings include: reference seat 1, positioning seat 2, clamping mechanism 3, shaft part 4, reference flange 11, reference cylinder 12, positioning cylinder 21, upper flange 22, lower flange 23, inner fixing hole group 24, outer fixing hole group 25, observation hole 26, U-shaped slot hole 27, clamping seat 31, and clamping block 32.
[0031] Example 1 is basically as shown in the appendix. Figure 1-5 As shown:
[0032] As attached Figure 1 and attached Figure 2 As shown, a clamping fixture for gear shaping of shaft parts includes a reference base 1, a positioning base 2, and a clamping mechanism 3. The reference base 1 includes a reference flange 11 and a reference cylinder 12. The reference flange 11 is fixed to the lower part of the reference cylinder 12. The inner diameter of the reference cylinder 12 is equal to the diameter of the bottom of the shaft part 4 to be machined. The center of the reference cylinder 12 coincides with the center point of the worktable. The reference flange 11 is fixed to the worktable surface by bolts. The coincidence of the central axis of the reference cylinder 12 with the center of the worktable ensures accurate positioning. After the reference base 1 is adjusted and installed in place, the precise position of the bottom of the shaft part 4 can be determined through the reference base 1.
[0033] As attached Figure 2 and attached Figure 3 As shown, the middle part of the positioning base 2 is a positioning cylinder 21. The upper and lower ends of the positioning base 2 are an upper flange 22 and a lower flange 23, respectively. The upper flange 22 and the lower flange 23 are fixedly connected to the two ends of the positioning cylinder 21. The inner diameter of the positioning cylinder 21 is larger than the outer diameter of the reference cylinder 12 to facilitate the replacement of reference bases 1 of different specifications. The positioning cylinder 21 is provided with multiple observation holes 26 at equal intervals along the circumference. Multiple reinforcing ribs are provided between the upper and lower flanges 23 at equal intervals along the central axis of the cylinder. The reinforcing ribs are used to strengthen the structural strength.
[0034] The lower flange 23 has four U-shaped slots 27 on its circumference. The angle between the diagonal line connecting the U-shaped slots 27 and the line connecting the adjacent fixing hole group is 45°. The lower flange 23 is coaxially fixed to the worktable surface with the reference cylinder 12 by bolts through the U-shaped slots 27. The position of the U-shaped slots 27 is specially designed so that the angle between the diagonal line connecting them and the line connecting the adjacent fixing hole group is 45°. The reaction force after each clamping block 32 is clamped is borne by two bolts. The same bolt is subjected to two forces in different directions, and part of them cancel each other out. With this arrangement, the force borne by each bolt is minimized.
[0035] The clamping mechanism 3 includes a clamping seat 31 and a clamping block 32, as shown in the attached figure. Figure 5 As shown, the end clamping surface of the clamping block 32 is a concave arc surface, and the diameter of the concave arc surface is equal to the diameter of the largest size shaft part 4. Designing the end clamping surface of the clamping block 32 as a concave arc surface effectively increases the clamping area of the clamping block 32 and improves clamping stability. By designing the size of the concave arc surface of the clamping block 32 to match the diameter of the largest size shaft part 4, only one size of clamping block 32 is needed to accommodate various sizes of shaft parts 4 processed by this device.
[0036] like Figure 2 As shown, the clamping block 32 is slidably connected in the clamping seat 31. The upper flange 22 is provided with multiple sets of fixing holes corresponding one-to-one with the clamping seat 31. Each set of fixing holes includes four fixing holes corresponding to the four corners of the clamping seat 31. The fixing hole sets are divided into inner fixing hole set 24 and outer fixing hole set 24 according to their distance from the center. When the clamping seat 31 is fixed in the inner fixing hole set 24, it is used to clamp the shaft parts 4 of conventional size and the thin shaft parts 4. When the clamping seat 31 is fixed in the outer fixing hole set 25, it is used to clamp the shaft parts 4 of larger size. The bottom of the shaft part 4 is inserted and fixed in the reference cylinder 12, and the clamping block 32 extends out and fits against the side wall of the shaft part 4 to complete the clamping and fixing.
[0037] The specific implementation method is as follows:
[0038] Select the installation position of the clamping mechanism 3 according to the size of the shaft part 4 to be processed. If it is used to clamp the shaft part 4 of a regular size and the shaft part 4 of a thin size, select the inner fixing hole group 24 for installation and connection. If it is used to clamp the shaft part 4 of a regular size and the shaft part 4 of a thin size, select the outer fixing hole group 25 for installation and connection. After completing the connection between the clamping mechanism 3 and the positioning seat 2, align the center of the reference seat 1 with the center point of the operating table to perform the initial installation of the reference seat 1. After pre-tightening, use a dial indicator to adjust the reference seat 1 for centering. After the position of the reference seat 1 is adjusted to the correct position, tighten the bolts to complete the fixation of the reference seat 1. Then, operate the gantry hook to lift and install the positioning seat 2 on the observation hole 26. After adjusting the positioning seat 2 to be approximately coaxial with the reference cylinder 12, lower the positioning seat 2 and perform the pre-tightening operation. Then, use a dial indicator to adjust the position and tighten the bolts to complete the fixation of the positioning seat 2. Then, operate the gantry crane to lift the shaft part 4. When the shaft part 4 is coaxial with the positioning seat 2, lower it so that its lower part is inserted into the reference cylinder 12. Since the lower part has already been calibrated and the positioning is correct, after the shaft part 4 is lowered into place, only the upper position needs to be calibrated. Use a dial indicator for calibration. If the shaft part 4 shows a positional deviation, adjust the position of the clamping block 32 until the overall position is adjusted correctly. The internal structure after the overall adjustment is as shown in the attached figure. Figure 4 As shown, the gear cutting of the four ends of the shaft part can then begin.
[0039] Example 2:
[0040] The difference from Embodiment 1 is that the clamping block 32 is an electrically driven clamping block, which is driven to move by an electric actuator. The rest is the same as in Embodiment 1, and will not be described again here.
[0041] The above descriptions are merely embodiments of this utility model. Commonly known technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solution of this utility model. These modifications and improvements should also be considered within the scope of protection of this utility model, and will not affect the effectiveness of the implementation of this utility model or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.
Claims
1. A clamping fixture for gear hobbing of shaft parts, characterized in that: The system includes a reference base, a positioning base, and a clamping mechanism. The reference base includes a reference flange and a reference cylinder. The reference flange is fixed to the bottom of the reference cylinder, and the inner diameter of the reference cylinder is equal to the diameter of the non-machined end of the shaft part. The center of the reference cylinder coincides with the center point of the worktable, and the reference flange is detachably connected to the worktable. The positioning base includes a positioning cylinder and upper and lower flanges fixed to both ends of the positioning cylinder. The inner diameter of the positioning cylinder is larger than the outer diameter of the reference flange, and the positioning cylinder is coaxial with the reference cylinder. The lower flange is detachably connected to the worktable. The clamping mechanism includes multiple clamping seats and clamping blocks. The clamping seats are detachably connected to the upper flange at equal intervals, and the clamping blocks are slidably connected to the clamping seats. The sliding path of the clamping blocks points to the axis of the shaft part.
2. The clamping fixture for gear shaping of shaft parts according to claim 1, characterized in that: The upper flange is provided with multiple sets of fixing holes that correspond one-to-one with the clamping seat. Each set of fixing holes includes four fixing holes that correspond to the four corners of the clamping seat. The fixing hole sets are divided into inner fixing hole sets and outer fixing hole sets according to their distance from the center.
3. The clamping fixture for gear shaping of shaft parts according to claim 2, characterized in that: The end clamping surface of the clamping block is a concave arc surface, and the diameter of the concave arc surface is equal to the diameter of the largest specification shaft part.
4. The clamping fixture for gear shaping of shaft parts according to claim 3, characterized in that: The lower flange is provided with four U-shaped slots at equal intervals along the circumference, and the angle between the diagonal line connecting the U-shaped slots and the line connecting the adjacent fixing hole group is 45°.
5. The clamping fixture for gear hobbing of shaft parts according to claim 4, characterized in that: Multiple observation holes are evenly spaced along the circumference on the side wall of the middle part of the positioning cylinder.
6. The clamping fixture for gear shaping of shaft parts according to claim 5, characterized in that: The clamping block is an electric clamping block, which includes an electric push rod.