A kind of eccentric through-hole shaft flattening fixture

Abstract

The present application belongs to the technical field of flat grinding jigs, and particularly relates to a flat grinding jig for eccentric through-hole shafts. The flat grinding jig comprises a base, a front positioning block arranged at the front end of the base, a first rear positioning block and a second rear positioning block arranged at the rear end of the base, wherein the first rear positioning block and the second rear positioning block are each provided with a rear positioning block through hole coaxial with the front positioning block through hole, and a pin shaft sequentially penetrating the front positioning block through hole of the first front positioning block, the eccentric through hole of the workpiece, the rear positioning block through hole of the first rear positioning block and the second rear positioning block. The workpiece is rotated around the pin shaft, and after the cylindrical surface of the workpiece is in contact with the upper surface of the base, the workpiece cannot be rotated, thereby achieving positioning of the workpiece. The flat grinding jig has the advantages of simple structure, strong adaptability, accurate control of the flat surface angle, high flat grinding efficiency of the eccentric through-hole shaft, low cost and simple maintenance.

Description

Technical Field

[0001] This invention belongs to the technical field of grinding molds, specifically relating to a grinding mold for an eccentric through-hole shaft. Background Technology

[0002] Currently, the flat surface machining of eccentric through-hole shafts often faces the dual challenges of precision and efficiency. For example... Figure 1 As shown, this type of workpiece requires the flat surface to form a specific angle with the line connecting the center of the eccentric hole and the outer circle. Traditional flat grinding fixtures lack an effective angle positioning mechanism and rely on complex jigs for adjustment, resulting in long processing cycles and large flat surface angle deviations (usually exceeding ±5°). Existing flat grinding fixtures for eccentric through-hole shafts use an integral fixed stop, which is inconvenient to install and remove, and has a single positioning reference, making it difficult to adapt to workpieces of different sizes. In addition, the lack of a splash-proof structure during processing poses safety hazards, and impurities easily accumulate, affecting positioning accuracy. Current flat grinding of eccentric through-hole shafts achieves angle control through multi-step processing, but the process is cumbersome, costly, and cannot simultaneously achieve high efficiency and high precision. Therefore, there is an urgent need for a flat grinding fixture with a simple structure, strong adaptability, and the ability to precisely control the flat surface angle to solve the problems of low efficiency, high cost, and difficult maintenance in existing technologies. Summary of the Invention

[0003] This invention addresses the problems of existing grinding jigs for eccentric through-hole shafts, such as complex structure, poor adaptability, inability to precisely control the flatness angle, low processing efficiency, high cost, and difficult maintenance. It proposes a grinding jig for eccentric through-hole shafts, comprising: a base with a flat top surface for supporting the workpiece and serving as a positioning reference;

[0004] A front positioning block is located at the front end of the base, and its end face has a front positioning block through hole;

[0005] The first rear positioning block and the second rear positioning block are located at the rear end of the base. Both the first rear positioning block and the second rear positioning block are provided with rear positioning block through holes, which are coaxial with the front positioning block through holes.

[0006] The pin passes through the front positioning block through hole of the first front positioning block and the eccentric through hole of the workpiece, the first rear positioning block and the rear positioning block through hole of the second rear positioning block in sequence; the workpiece rotates around the pin, and after its cylindrical surface contacts the upper surface of the base, it cannot rotate, thereby realizing the positioning of the workpiece.

[0007] The first and second side plates are symmetrically connected to both sides of the base and are bolted to the base, the front positioning block, the first rear positioning block, and the second rear positioning block, respectively. They are used to connect the base, the front positioning block, the first rear positioning block, and the second rear positioning block and to prevent the workpiece from flying out. Both the first and second side plates are provided with elongated grooves for the discharge of dirt and impurities.

[0008] The stop blocks are located outside the first and second rear positioning blocks and are used to limit the axial displacement of the workpiece.

[0009] According to the above-described flattening die for an eccentric through-hole shaft, the center of the through hole of the front positioning block is L1 at a distance from the upper surface of the base, and L2 at a distance from the outer side of the front positioning block. The lower surfaces of the first and second rear positioning blocks are in contact with the base, and the front of the first rear positioning block is in contact with the workpiece. By adjusting the sizes of L1 and L2, the rotation angle of the workpiece is controlled so that the surface of the workpiece to be flattened is parallel to the upper surface of the base.

[0010] According to the above-described flattening die for an eccentric through-hole shaft, the base, front positioning block, first rear positioning block, second rear positioning block, and pin are made of hardened steel with a surface hardness ≥55HRC to reduce wear.

[0011] According to the above-described flattening die for an eccentric through-hole shaft, the pin surface is provided with anti-slip texture to enhance friction with the workpiece; the inner sides of the first side plate and the second side plate are provided with a rubber buffer layer.

[0012] According to the above-described eccentric through-hole shaft flattening die, the bottom of the base is provided with a positioning keyway for quick alignment with the surface of the surface grinder.

[0013] According to the above-described eccentric through-hole shaft flattening die, the gap between the stop block and the magnetic suction surface of the flat grinding machine is ≤0.1mm to prevent grinding wheel interference. The stop block is a replaceable structure, and its contact surface is coated with a polyurethane wear-resistant layer.

[0014] According to the above-described flattening die for an eccentric through-hole shaft, a copper sleeve is embedded in the through hole of the front positioning block to reduce pin wear.

[0015] According to the above-described flattening die for an eccentric through-hole shaft, the installation positions of the first rear positioning block and the second rear positioning block are provided with scales for precise adjustment of L1 and L2.

[0016] According to the above-described flattening die for an eccentric through-hole shaft, the bottom surface of the elongated groove of the first side plate and the second side plate is provided with an outward tilt angle of 10°-15° to guide the debris to be discharged in a directional manner.

[0017] According to the above-described eccentric through-hole shaft grinding die, the base surface is provided with a coolant guide groove to reduce the grinding temperature.

[0018] The beneficial effects of the present invention are as follows:

[0019] 1. This invention, through the connection structure of a front stop, a first rear positioning stop, and a second rear positioning stop, controls the flat surface angle deviation within ±3°, thus improving accuracy. The front positioning stop, through the precise design of L1 and L2, defines the initial angle of the workpiece; the connection structure of the first and second rear positioning stops ensures that the flat surface of the workpiece is parallel to the base plane after rotation, eliminating offset errors caused by gravity. Compared to existing technologies, the angle control accuracy is improved by 40%.

[0020] 2. The present invention features a detachable first rear positioning block, a second rear positioning block, and a block that magnetically engage with each other on a surface grinder, reducing workpiece loading and unloading time to 30 seconds per piece and improving efficiency.

[0021] 3. This invention adopts a modular design, allowing the same fixture to accommodate workpieces of different sizes, thus reducing costs; no special fixtures are required. The base and pins made of hardened steel have a lifespan of over 100,000 cycles, and maintenance costs are only 1 / 3 of those of traditional fixtures.

[0022] 4. The first and second side plates of this invention act as physical barriers, effectively blocking flying debris and enhancing safety. Combined with the chip removal function of the elongated groove, the risk of workplace injury is reduced. The magnetic fixing method of the stop block avoids the loosening problems that may be caused by traditional mechanical clamping, and significantly improves processing stability.

[0023] 5. The coolant guide groove on the base surface of this invention increases the coolant utilization rate by 70% and reduces waste liquid discharge; the high wear resistance of the quenched parts reduces the material replacement frequency, making it environmentally friendly and energy-saving; compared with traditional processes, the overall energy consumption is reduced by 25%. Attached Figure Description

[0024] Figure 1 This is the front view of a shaft workpiece with an eccentric through hole and a flat surface.

[0025] Figure 2 This is a left view of a shaft workpiece with an eccentric through hole and a flat surface.

[0026] Figure 3 This is a three-dimensional schematic diagram of the structure of a flattening die for mounting an eccentric through-hole shaft according to the present invention. Figure 1 .

[0027] Figure 4 This is a three-dimensional schematic diagram of the structure of a flattening die for mounting an eccentric through-hole shaft according to the present invention. Figure 2 .

[0028] Figure 5 This is a schematic diagram of the positioning structure for mounting workpieces using a flattening die for an eccentric through-hole shaft according to the present invention.

[0029] Figure 6This is a front view of the front positioning block 21 for mounting a workpiece in a flattening die for an eccentric through-hole shaft according to the present invention.

[0030] Figure 7 A perspective view of the structure of the front positioning block 21 for mounting the workpiece in a flattening die for an eccentric through-hole shaft according to the present invention.

[0031] Figure 8 This is a partial structural diagram of a flattening die for an eccentric through-hole shaft according to the present invention.

[0032] Figure 9 This is a schematic diagram of the structure of a flattening die for an eccentric through-hole shaft according to the present invention.

[0033] In the diagram: 1-pin, 3-base, 5-workpiece, 6-stop, 21-front positioning stop, 22-first rear positioning stop, 23-second rear positioning stop, 41-first side plate, 42-second side plate. Detailed Implementation

[0034] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0035] like Figure 1 , Figure 2 As shown: The workpiece is an eccentric through-hole shaft with a flat surface. The angle between the line connecting the midpoint of the flat surface and the center of the eccentric through-hole shaft and the line connecting the eccentric hole and the center of the eccentric through-hole shaft is the flat surface angle deviation θ, and its accuracy requirement is ±3°.

[0036] like Figures 3 to 9 As shown: A flattening die for an eccentric through-hole shaft according to this embodiment includes:

[0037] The base 3 has a flat top surface, which is used to support the workpiece 5 and serve as a positioning reference.

[0038] A front positioning block 21 is set at the front end of the base 3, and its end face is provided with a front positioning block through hole;

[0039] The first rear positioning block 22 and the second rear positioning block 23 are located at the rear end of the base 3. Both the first rear positioning block 22 and the second rear positioning block 23 are provided with rear positioning block through holes, which are coaxial with the front positioning block through holes.

[0040] The pin 1 passes through the front positioning block through hole of the first front positioning block 21 and the eccentric through hole of the workpiece 5, the rear positioning block through hole of the first rear positioning block 22 and the second rear positioning block 23 in sequence; the workpiece 5 rotates around the pin 1, and after its cylindrical surface contacts the upper surface of the base 3, it cannot rotate, thereby realizing the positioning of the workpiece 5.

[0041] The first side plate 41 and the second side plate 42 are symmetrically connected to both sides of the base 3, and are bolted to the base 3 and the front positioning block 21, the first rear positioning block 22, and the second rear positioning block 23, respectively. They are used to connect the base 3, the front positioning block 21, the first rear positioning block 22, and the second rear positioning block 23 and to prevent the workpiece 5 from flying out. Both the first side plate 41 and the second side plate 42 are provided with elongated grooves for the discharge of dirt and impurities, and to prevent dirt from affecting the positioning of the fixture.

[0042] The stop 6 is located outside the first rear positioning stop 22 and the second rear positioning stop 23, and is fixed to the surface grinder by magnetic attraction to limit the axial displacement of the workpiece 5.

[0043] The center of the front positioning block 21 is L1 from the upper surface of the base 3 and L2 from the outer side of the front positioning block 21. The lower surfaces of the first rear positioning block 22 and the second rear positioning block 23 are in contact with the base 3. The front of the first rear positioning block 22 is in contact with the workpiece 5. By adjusting the size of L1 and L2, the rotation angle of the workpiece 5 is controlled so that the flat surface of the workpiece 5 to be processed is parallel to the upper surface of the base 3.

[0044] The base 3, front positioning block 21, first rear positioning block 22, second rear positioning block 23 and pin 1 are made of hardened steel with a surface hardness ≥55HRC to reduce wear.

[0045] The surface of the pin 1 is provided with anti-slip texture to enhance the friction with the workpiece 5; the inner sides of the first side plate 41 and the second side plate 42 are provided with rubber buffer layers.

[0046] The base 3 has a positioning keyway at the bottom for quick alignment with the surface of the grinding machine. The gap between the stop 6 and the magnetic surface of the grinding machine is ≤0.1mm to prevent interference with the grinding wheel. The stop 6 is a replaceable structure, and its contact surface is coated with a polyurethane wear-resistant layer.

[0047] A copper sleeve is embedded in the through hole of the front positioning block 21 to reduce wear on the pin 1. The installation positions of the first rear positioning block 22 and the second rear positioning block 23 are equipped with scales for precise adjustment of L1 and L2.

[0048] The bottom surfaces of the elongated grooves on the first side plate 41 and the second side plate 42 are provided with an outward tilt angle of 10°-15° to guide the directional discharge of debris. The surface of the base 3 is provided with coolant guide grooves to reduce grinding temperature.

[0049] The base 3 in this embodiment is made of hardened steel and has dimensions of 300mm × 150mm × 30mm. The surface is ground to Ra0.8, and the bottom is set with a positioning keyway 3-1 to match the surface grinder.

[0050] Front positioning block 21: Dimensions are 50mm×30mm×20mm, with a central through hole diameter of Φ12H7. It is fixed to the front end of the base 3 by an M8 screw. The center of the through hole is 25mm from the bottom surface and 10mm from the side wall.

[0051] The dimensions of the first rear positioning block 22 and the second rear positioning block 23 are both 40mm×25mm×15mm, and their bottom surfaces are in contact with the base 3. The adjustable spacing range is 50-100mm.

[0052] Pin 1 has a diameter of Φ12g6 and a length of 200mm, and its surface is high-frequency quenched to 60HRC.

[0053] The side plate 4 is 15mm thick, the elongated groove is Φ10mm wide, and the outward tilt angle is 15°. It is fixed to both sides of the base 3 with M10 bolts.

[0054] The stop block 6 is L-shaped, with dimensions of 60mm×20mm×10mm. The magnetic surface is nickel-plated, and the gap between it and the surface grinder is controlled at 0.05mm.

[0055] Assembly process:

[0056] Install base 3 onto the surface of the surface grinder and quickly align it using the positioning keyway.

[0057] The front positioning block 21 is fixed at the front end of the base 3, and the pin 1 is inserted and passes through the eccentric through hole of the workpiece 5.

[0058] Place the first rear positioning block 22 and the second rear positioning block 23 at the rear end of the base 3, and adjust the spacing to match the length of the workpiece 5 to ensure that the workpiece 5 can rotate freely.

[0059] Install the first side plate 41 and the second side plate 42, and tighten the bolts to a torque of 20 N·m.

[0060] Rotate the workpiece 5 until its cylindrical surface contacts the base 3, place the stop block 6 outside the second rear positioning stop block 23, and activate the magnetic attraction function of the surface grinder to fix the workpiece 5.

[0061] Processing operations:

[0062] Start the grinding wheel and feed it along the 5-axis of the workpiece to grind the flat surface to the required size.

[0063] During processing, debris is discharged through the elongated grooves of the first side plate 41 and the second side plate 42, and coolant is evenly covered on the surface of the base 3 through the guide groove to reduce the processing temperature.

[0064] After the machining is completed, release the stop 6, remove the workpiece 5, and repeat the above steps to process the next piece.

[0065] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only for the purpose of helping to understand the method and core ideas of the present invention. The above descriptions are only preferred embodiments of the present invention. It should be noted that due to the limitations of textual expression, while there are objectively infinite specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of the present invention, and can also combine the above technical features in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the inventive concept and technical solution to other situations without modification, should all be considered within the scope of protection of the present invention.

Claims

1. A flattening die for an eccentric through-hole shaft, characterized in that, include: The base (3) has a flat top surface, which is used to support the workpiece (5) and serve as a positioning reference. A front positioning block (21) is set at the front end of the base (3), and its end face is provided with a front positioning block through hole; The first rear positioning block (22) and the second rear positioning block (23) are located at the rear end of the base (3). The first rear positioning block (22) and the second rear positioning block (23) are both provided with rear positioning block through holes, which are coaxial with the front positioning block through holes. The pin (1) passes through the front positioning block through hole of the first front positioning block (21) and the eccentric through hole of the workpiece (5), the first rear positioning block (22) and the rear positioning block through hole of the second rear positioning block (23) in sequence; the workpiece (5) rotates around the pin (1), and after its cylindrical surface contacts the upper surface of the base (3), it cannot rotate, thereby realizing the positioning of the workpiece (5); The first side plate (41) and the second side plate (42) are symmetrically connected to the two sides of the base (3) and are bolted to the base (3) and the front positioning block (21), the first rear positioning block (22), and the second rear positioning block (23) respectively. They are used to connect the base (3), the front positioning block (21), the first rear positioning block (22), and the second rear positioning block (23) and to prevent the workpiece (5) from flying out. The first side plate (41) and the second side plate (42) are both provided with elongated grooves for the discharge of dirt and impurities. The stop (6) is located outside the first rear positioning stop (22) and the second rear positioning stop (23) to limit the axial displacement of the workpiece (5).

2. An eccentric through-hole shaft flattening jig according to claim 1, characterized in that: The center of the front positioning block (21) is L1 above the upper surface of the base (3) and L2 away from the outer side of the front positioning block (21). The lower surfaces of the first rear positioning block (22) and the second rear positioning block (23) are in contact with the base (3). The front of the first rear positioning block (22) is in contact with the workpiece (5). By adjusting the size of L1 and L2, the rotation angle of the workpiece (5) is controlled so that the flat surface of the workpiece (5) to be processed is parallel to the upper surface of the base (3).

3. An eccentric through-hole shaft truing fixture according to claim 2, wherein: The base (3), front positioning block (21), first rear positioning block (22), second rear positioning block (23) and pin (1) are made of hardened steel with a surface hardness ≥55HRC to reduce wear.

4. An eccentric through-hole shaft truing fixture according to claim 3, wherein: The pin (1) has anti-slip texture on its surface to enhance friction with the workpiece (5); the inner sides of the first side plate (41) and the second side plate (42) are provided with rubber buffer layers.

5. The flattening die for an eccentric through-hole shaft according to claim 4, characterized in that: The base (3) has a positioning keyway at the bottom for quick alignment with the surface of the grinding machine.

6. The flattening die for an eccentric through-hole shaft according to claim 5, characterized in that: The gap between the stop (6) and the magnetic surface of the flat grinder is ≤0.1mm to prevent interference with the grinding wheel. The stop (6) is a replaceable structure and its contact surface is coated with a polyurethane wear-resistant layer.

7. The flattening die for an eccentric through-hole shaft according to claim 6, characterized in that: The front positioning block (21) has a copper sleeve embedded in its front positioning block through hole to reduce wear on the pin (1).

8. The flattening die for an eccentric through-hole shaft according to claim 7, characterized in that: The first rear positioning block (22) and the second rear positioning block (23) are equipped with scales at their installation positions for precise adjustment of L1 and L2.

9. A flattening die for an eccentric through-hole shaft according to claim 8, characterized in that: The bottom surface of the elongated groove of the first side plate (41) and the second side plate (42) is provided with an outward tilt angle of 10°-15° to guide the debris to be discharged in a directional manner.

10. A flattening die for an eccentric through-hole shaft according to claim 9, characterized in that: The base (3) has a coolant guide groove on its surface to reduce the grinding temperature.

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