A grinding jig for one-axis cone hole

Abstract

The utility model belongs to gearbox frock technical field relates to a grinding fixture of one axle taper hole. Including base, the base is provided with left guide rail and right guide rail symmetry, left guide rail and right guide rail on the sliding panel of slidingly arranged, the fixed connection of fixed seat is established on the sliding panel, the fixed seat is provided with the fixed hole that cooperates with one axle. The utility model discloses a grinding fixture of one axle taper hole, through the fixed hole design that cooperates with one axle on fixed seat, realized the accurate positioning of workpiece clamping. This structure can effectively eliminate the centering error caused by the wear of traditional three jaw chuck, the poor difference of clamping surface cleanliness, ensure the reference uniformity of taper hole processing, thereby stable control taper hole roundness and surface roughness. The left guide rail and right guide rail of symmetry setting and the sliding cooperation of sliding panel, have built the rigid guide system, the linearity of motion trajectory and the repeat positioning accuracy have improved significantly, avoid the workpiece deflection or vibration caused by uneven stress in the clamping process.

Description

Technical Field

[0001] This utility model belongs to the field of gearbox tooling technology, and relates to a grinding fixture for a single-axis tapered hole. Background Technology

[0002] With the rapid development of the automotive industry, the performance requirements for transmissions have increased significantly, among which the assembly accuracy of the transmission shaft and its related components has become a key technical indicator. The roundness of the tapered bore of the transmission shaft needs to be controlled within 0.005mm, and the surface roughness needs to reach Ra0.2μm, which places extremely high demands on the machining process. However, conventional machining methods have significant limitations and are difficult to meet the needs of mass production.

[0003] Currently, CNC lathes are commonly used in conjunction with three-jaw chucks for taper hole machining. While three-jaw chucks offer advantages such as fast clamping speed and wide applicability, their centering accuracy is significantly affected by jaw wear, the cleanliness of the clamping surfaces, and the jaw installation sequence. The centering accuracy of a manual three-jaw chuck is typically around 0.1mm, and although a hydraulic three-jaw chuck can improve repeatability to within 0.03mm, it still cannot meet the requirements for high-precision taper hole machining. Furthermore, the 7 / 24 taper fit between the CNC lathe spindle taper hole and the tool holder has an inherent defect: the taper hole at the front of the spindle expands under centrifugal force, resulting in radial clearance at the rear of the mating surface (AT4 grade taper tolerance reaches 13μm), causing tool wobble and spindle dynamic balance problems. To counteract the expansion, excessive tensile force (4-8 times the standard value) must be applied, but this accelerates wear on the spindle inner bore, shortens the life of the front bearing, and cannot consistently achieve a surface roughness of Ra0.2μm. For special structures such as thin-walled tapered fittings, traditional clamping methods easily lead to cutting vibration and workpiece deformation. For example, when machining the outer diameter and end face of a 3mm thick thin-walled tapered fitting, axial clamping or the addition of process ribs makes it difficult to meet technical requirements due to axial cutting force and thermal deformation. Furthermore, it is impossible to complete multiple machining operations in a single clamping, severely restricting production efficiency. For instance, the Chinese invention patent application number 201310212162.7, "A Special Fixture for Precision Grinding of Spindle Taper Holes," fails to meet existing requirements in terms of accuracy and stability.

[0004] In summary, existing technologies have significant shortcomings in terms of precision, efficiency, and adaptability: the precision bottleneck of three-jaw clamping, the spindle rigidity limitation of CNC lathes, and the efficiency defects of gear hobbing processes all fail to meet the high-precision, mass production, and stable production requirements of the gearbox shaft taper hole. Utility Model Content

[0005] The purpose of this utility model is to solve the technical problems of the shortcomings of existing single-axis fixtures in terms of accuracy, efficiency and adaptability, and to provide a grinding fixture for a single-axis tapered hole.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, this utility model discloses a grinding fixture for a single-axis tapered hole, including a base, on which a left guide rail and a right guide rail are symmetrically arranged; a sliding plate is slidably arranged on the left guide rail and the right guide rail; a positioning seat is fixedly connected to the sliding plate, and the positioning seat is provided with a positioning hole that cooperates with the single axis.

[0007] Further improvements are made in the following aspects: The skateboard has a handle on its outer side along its sliding direction.

[0008] A baffle is provided behind the base along the sliding direction of the skateboard, and the baffle is higher than the height of the skateboard.

[0009] An adjustable screw is provided on the front side of the baffle for positioning the slide plate.

[0010] The positioning seat is symmetrically provided with several pin holes for inserting stop pins to position a shaft.

[0011] The parallelism between the left and right guide rails is within 0.01 mm.

[0012] The base is provided with several mounting holes for fixing the base to the worktable of the grinding machine using connectors.

[0013] The base is an I-shaped structure including an upper top surface and a lower bottom surface.

[0014] Both the top and bottom surfaces are provided with U-shaped grooves along the sliding direction of the slide plate to accommodate the lower end of a shaft.

[0015] The lengths of the left and right guide rails are greater than the length of the base.

[0016] Compared with the prior art, the present invention has the following beneficial effects: This utility model discloses a grinding fixture for a single-axis tapered hole. Through the design of a positioning hole on the positioning seat that mates with the single axis, precise workpiece positioning is achieved. This structure effectively eliminates centering errors caused by jaw wear and differences in the cleanliness of the clamping surfaces in traditional three-jaw chucks, ensuring the consistency of the datum for tapered hole machining, thereby stably controlling the roundness and surface roughness of the tapered hole. Symmetrically arranged left and right guide rails slide in conjunction with the slide plate, constructing a rigid guiding system. When the slide plate moves along the guide rails, the straightness of the motion trajectory and the repeatability of positioning are significantly improved, avoiding workpiece skewing or vibration caused by uneven force during clamping, providing stable support conditions for the grinding process. The fixture operation process is simplified, with fewer clamping steps, enabling rapid tool setting and machining when used with a grinding machine. Compared to the traditional process that requires multiple adjustments to clamping parameters, this design, through a standardized positioning structure, reduces the single-piece machining time to 2 minutes, while also supporting continuous clamping of batches of workpieces, significantly improving the production line cycle time. The synergistic effect of precise positioning and stable clamping reduces the risk of dimensional deviations or surface quality defects in the tapered hole caused by clamping errors. The workpiece experiences uniform stress during machining, minimizing the impact of deformation and thermal deformation on accuracy in thin-walled parts, thus effectively reducing the scrap rate. The locating hole and shaft mating design is versatile, adaptable to different specifications of shaft workpieces. The application range can be expanded simply by adjusting the locating seat parameters, meeting the flexible production needs of machining tapered holes for various gearboxes. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a front view of a grinding fixture for a single-axis tapered hole according to an embodiment of the present invention; Figure 2 This is a top view of a grinding fixture for a single-axis tapered hole according to an embodiment of the present invention; Figure 3 This is a top view of the working state of a grinding fixture for a single-axis tapered hole in this embodiment of the present invention when it moves out of the slide plate and loads a part. Figure 4 This is a side view of the working state of a grinding fixture for a single-axis tapered hole in this embodiment of the present invention when it moves out of the slide plate and loads a part; Figure 5 This is a top view of the working state of a grinding jig with a single-axis tapered hole pushed into a sliding plate and processing a part in an embodiment of the present utility model; Figure 6This is a side view of the working state of a grinding fixture with a single-axis tapered hole in an embodiment of the present invention when it is pushed into a sliding plate to process parts.

[0019] The components are: 1-base; 2-right guide rail; 3-M8 x40 socket head cap screw; 4-stop pin; 5-positioning seat; 6-left guide rail; 7-handle; 8-M8 stud; 9-baffle; 10-M8 T-nut; 11-M8x80 socket head cap screw; 12-slide plate. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0021] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0022] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0023] In the description of the embodiments of this utility model, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model product is in use, they are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the utility model. Furthermore, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0024] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0025] In the description of the embodiments of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0026] The present invention will now be described in further detail with reference to the accompanying drawings: See Figure 1 and Figure 2 This utility model discloses a grinding fixture for a single-axis tapered hole, including a base 1. The base 1 has several mounting holes for fixing the base 1 to the worktable of a grinding machine using connectors. The base 1 is an I-shaped structure including an upper top surface and a lower bottom surface. U-shaped grooves are provided on both the upper top surface and the lower bottom surface along the sliding direction of the sliding plate 12 to accommodate the lower end of the single-axis. The lengths of the left guide rail 6 and the right guide rail 2 are greater than the length of the base 1. The left guide rail 6 and the right guide rail 2 are symmetrically arranged on the base 1, and the parallelism of the left guide rail 6 and the right guide rail 2 is within 0.01mm. The sliding plate 12 is slidably arranged on the left guide rail 6 and the right guide rail 2, and a handle 7 is provided on the outer side of the sliding plate 12 along its sliding direction. A positioning seat 5 is fixedly connected to the sliding plate 12. The positioning seat 5 has a positioning hole that cooperates with the single-axis, and several pin holes are symmetrically arranged on the positioning seat 5 for inserting stop pins to position the single-axis. A baffle 9 is provided behind the base 1 along the sliding direction of the slide plate 12. The baffle 9 is higher than the height of the slide plate 12. An adjustable screw 11 is provided on the front side of the baffle 9 for positioning the slide plate 12.

[0027] This utility model discloses a grinding fixture for a single-axis tapered hole. Through the design of a positioning hole on the positioning seat that mates with the single axis, precise workpiece positioning is achieved. This structure effectively eliminates centering errors caused by jaw wear and differences in the cleanliness of the clamping surfaces in traditional three-jaw chucks, ensuring the consistency of the datum for tapered hole machining, thereby stably controlling the roundness and surface roughness of the tapered hole. Symmetrically arranged left and right guide rails slide in conjunction with the slide plate, constructing a rigid guiding system. When the slide plate moves along the guide rails, the straightness of the motion trajectory and the repeatability of positioning are significantly improved, avoiding workpiece skewing or vibration caused by uneven force during clamping, providing stable support conditions for the grinding process. The fixture operation process is simplified, with fewer clamping steps, enabling rapid tool setting and machining when used with a grinding machine. Compared to the traditional process that requires multiple adjustments to clamping parameters, this design, through a standardized positioning structure, reduces the single-piece machining time to 2 minutes, while also supporting continuous clamping of batches of workpieces, significantly improving the production line cycle time. The synergistic effect of precise positioning and stable clamping reduces the risk of dimensional deviations or surface quality defects in the tapered hole caused by clamping errors. The workpiece experiences uniform stress during machining, minimizing the impact of deformation and thermal deformation on accuracy in thin-walled parts, thus effectively reducing the scrap rate. The locating hole and shaft mating design is versatile, adaptable to different specifications of shaft workpieces. The application range can be expanded simply by adjusting the locating seat parameters, meeting the flexible production needs of machining tapered holes for various gearboxes.

[0028] Example 1 A grinding fixture for a single-axis tapered hole enables rapid production changeover and ensures stable and effective accuracy of the tapered hole. To achieve rapid production changeover, a vertical fixture structure is adopted. The base 1 can be quickly installed on a CNC grinding machine, and the stop pin 4 allows for quick installation and fixation of the parts.

[0029] The precision machining fixture includes: base 1, right guide rail 2, M8 x40 socket head cap screw 3, stop pin 4, positioning seat 5, left guide rail 6, handle 7, M8 stud 8, baffle 9, M8 T-nut 10, M8x80 socket head cap screw 11, and slide plate 12.

[0030] The grinding fixture uses M16 hex socket screws to connect the base 1 to the grinding machine worktable. The right guide rail 2 and the left guide rail 6 are installed at both ends of the base 1 and fixed with M8 x40 hex socket screws 3 to ensure that the parallelism of the right guide rail 2 and the left guide rail 6 is within 0.01mm. Two stop pins 4 are installed in the pin holes of the positioning seat 5. The whole assembly is installed on the slide plate 12 and fixed with M8 x40 hex socket screws 3. Then the entire slide plate assembly is installed on the guide rail and can slide freely. The baffle 9 is fixed to the rear end of the base by M8 studs 8 and M8 T-nuts 10. M8 x80 hex socket screws 11 are fixed on the baffle and are at the same height as the slide plate 12.

[0031] This fixture is easy to operate, uses a grinding machine, and allows for rapid processing in just 2 minutes. It also produces consistent accuracy in the tapered hole, meeting drawing requirements. This fixture not only improves workpiece processing efficiency but also reduces scrap rates, thus meeting workshop production needs.

[0032] The working process of this utility model is as follows: First, adjust the M8x80 socket head cap screw 11 to determine the position of the slide plate, ensuring that the locating seat 5 coincides with the center of the tool. For example... Figure 3 and Figure 4 As shown, pull out the slide plate, insert the shaft into the positioning seat 5, and use the stop pins 4 to insert into the aligned part holes from the pin holes at both ends of the positioning seat 5 to fix it. The operator holds the handle 7 and pushes the slide plate 12 into the grinding machine for processing, as shown. Figure 5 and Figure 6 As shown.

[0033] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A grinding fixture for a single-axis tapered hole, characterized in that, Includes a base (1), on which a left guide rail (6) and a right guide rail (2) are symmetrically arranged; a sliding plate (12) is slidably arranged on the left guide rail (6) and the right guide rail (2); a positioning seat (5) is fixedly connected to the sliding plate (12), and the positioning seat (5) is provided with a positioning hole that cooperates with a shaft; the positioning seat (5) is symmetrically provided with a number of pin holes for inserting stop pins to position the shaft.

2. The grinding fixture for a single-axis tapered hole according to claim 1, characterized in that, The skateboard (12) has a handle (7) on the outside along its sliding direction.

3. The grinding fixture for a single-axis tapered hole according to claim 1, characterized in that, A baffle (9) is provided behind the base (1) along the sliding direction of the slide plate (12), and the baffle (9) is higher than the height of the slide plate (12).

4. The grinding fixture for a single-axis tapered hole according to claim 3, characterized in that, An adjustable screw (11) is provided on the front side of the baffle (9) for positioning the slide plate (12).

5. The grinding fixture for a single-axis tapered hole according to claim 1, characterized in that, The parallelism between the left guide rail (6) and the right guide rail (2) is within 0.01 mm.

6. The grinding fixture for a single-axis tapered hole according to claim 1, characterized in that, The base (1) is provided with several mounting holes for fixing the base (1) on the grinding machine worktable using connectors.

7. The grinding fixture for a single-axis tapered hole according to claim 1, characterized in that, The base (1) is an I-shaped structure including an upper top surface and a lower bottom surface.

8. The grinding fixture for a single-axis tapered hole according to claim 7, characterized in that, Both the top and bottom surfaces are provided with U-shaped grooves along the sliding direction of the slide plate (12) to accommodate the lower end of a shaft.

9. The grinding fixture for a single-axis tapered hole according to claim 1, characterized in that, The lengths of the left guide rail (6) and the right guide rail (2) are greater than the length of the base (1).

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