Cylinder finishing fixture

Abstract

The cylinder fine machining clamp comprises a clamp main body and a tension bolt, characterized in that the clamp main body comprises a solid shaft and a tension sleeve coaxially fixed with the solid shaft, the inner cavity of the tension sleeve is in threaded cooperation with the tension bolt, the solid shaft is provided with an O-shaped ring, the outer end of the tension sleeve is provided with an open ring made of high polymer material, a cylinder gap fit sleeve is sleeved on the tension sleeve, the inner wall of the cylinder is supported by the O-shaped ring and the open ring, the inner end surface of the cylinder abuts against the solid shaft, and the open ring is tightly expanded on the inner wall of the cylinder by the expansion of the tension sleeve along with the tightening of the tension bolt. The utility model utilizes the characteristics that the tension sleeve and the open ring can be expanded and deformed, forms the expansion of the cylinder, guarantees the reliability of the cylinder clamping positioning, avoids the inner wall of the cylinder from being scratched by the clamp during the fine machining process, guarantees that the quality of the inner wall of the cylinder is not affected by the fine machining, and improves the quality of the oil cylinder.

Description

Technical Field

[0001] This utility model relates to a cylinder barrel precision turning fixture for precision turning of cylinder barrels. Background Technology

[0002] The cylinder barrel of a hydraulic cylinder is usually a honed tube made from standard cold-drawn tubing through a scraping and honing process, with an inner wall roughness of Ra0.4 or less. When the piston is working, the guide band on the piston and the lip seal slide on the inner wall of the cylinder barrel. The lip seal is made of rubber. If there are defects such as burrs, scratches, or clamping damage on the inner wall of the cylinder barrel, the seal is easily scratched and broken during the sliding process, causing premature failure of the hydraulic cylinder. Therefore, the inner wall of the cylinder must be free of defects such as burrs, scratches, and clamping marks. However, in order to assemble the guide seat in the cylinder, it is necessary to form an annular step surface and end face chamfer on the inner wall of the front end of the cylinder through precision machining. During the precision machining of the cylinder, a long three-jaw chuck is generally used to tighten the inner wall of the cylinder. The three-jaw chuck and the inner wall of the cylinder are in hard metal-to-metal contact. During the precision machining process, scratches, abrasions, pressure marks, and burrs on the inner wall of the cylinder are easily caused. These defects are one of the factors that reduce the quality of the hydraulic cylinder. Therefore, avoiding scratches on the inner wall of the cylinder by the fixture during the precision machining process is a technical problem that needs to be solved to improve the quality of the hydraulic cylinder. Utility Model Content

[0003] The cylinder precision machining fixture provided by this utility model utilizes the characteristic that both the expansion sleeve and the open ring can be expanded and deformed to form a tension on the cylinder, ensuring the reliability of the cylinder clamping and positioning, avoiding scratches on the inner wall of the cylinder by the fixture during the precision machining process, ensuring that the quality of the inner wall of the cylinder is not affected by the precision machining, and improving the quality of the hydraulic cylinder.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows: A cylinder precision machining fixture, comprising a fixture body and a tensioning bolt, characterized in that: the fixture body includes a solid shaft and an expansion sleeve coaxially fixed to the solid shaft, the inner cavity of the expansion sleeve is threadedly engaged with the tensioning bolt, an O-ring is clamped on the solid shaft, and an open ring made of polymer material is clamped on the outer end of the expansion sleeve, the cylinder is fitted onto the expansion sleeve with clearance, and the inner wall of the cylinder is supported by the O-ring and the open ring, the inner end face of the cylinder abuts against the solid shaft, and the expansion sleeve expands as the tensioning bolt is tightened, tightening the open ring on the inner wall of the cylinder.

[0005] Preferably, the front end of the expansion sleeve is a reduced diameter end with a smaller diameter, forming a transition step surface on the expansion sleeve. The open ring is clamped to the front end of the expansion sleeve and abuts against the transition step surface, and the outer diameter of the open ring is larger than the outer diameter of the expansion sleeve.

[0006] Preferably, the front end of the solid shaft is a reduced diameter end with a smaller diameter, and a transition step surface two is formed on the solid shaft. The outer diameter of the front end of the solid shaft is equal to the outer diameter of the rear end of the expansion sleeve. The O-ring is tightened in the annular groove opened at the front end of the solid shaft. The outer diameter of the O-ring is larger than the outer diameter of the front end of the solid shaft. The cylinder is sleeved on the front end of the solid shaft and abuts against the transition step surface two.

[0007] Preferably, the expansion sleeve has a cutting line extending axially inward from the outer end face, the inner end of the cutting line is close to the inner end of the expansion sleeve, and the cutting lines are evenly spaced along the circumference of the expansion sleeve to divide the expansion sleeve into multiple segments.

[0008] Preferably, the tail of the tensioning bolt is a cone shape with a gradually increasing outer diameter, and the opening at the front end of the expansion sleeve is a flared mouth that matches the tail of the tensioning bolt. As the tensioning bolt is tightened, the tail of the tensioning bolt extends from the flared mouth into the inner cavity of the expansion sleeve to expand the expansion sleeve.

[0009] Preferably, the opening ring is made of Teflon.

[0010] The beneficial effects of this utility model are: This utility model relates to a cylinder barrel precision machining fixture, in which a solid shaft and an expansion sleeve are coaxially fixed. When clamping the cylinder barrel, the cylinder barrel is first fitted onto the expansion sleeve with a clearance fit, allowing the O-ring and cotter ring to support the cylinder barrel. The expansion bolt is then tightened into the expansion sleeve, causing it to expand. As the expansion sleeve expands, the cotter ring is tightened against the inner wall of the cylinder barrel, creating tension. The solid shaft is then clamped onto the three-jaw chuck of the lathe, completing the cylinder barrel clamping. During precision machining, the cylinder barrel rotates synchronously with the three-jaw chuck. The fixture utilizes the fact that both the expansion sleeve and the cotter ring can be expanded... The large deformation characteristic is achieved by using a tensioning bolt to expand the expansion sleeve, which then tightens the open ring against the inner wall of the cylinder, creating tension on the cylinder. This presses the inner end of the cylinder against the solid shaft, positioning the cylinder on the fixture and ensuring reliable cylinder clamping and positioning. The O-ring is made of rubber, and the open ring is made of polymer material, which will not damage the inner wall of the cylinder during precision machining. This avoids scratching the inner wall of the cylinder by the fixture during precision machining, ensuring that the quality of the inner wall of the cylinder is not affected by precision machining and improving the quality of the hydraulic cylinder. Attached Figure Description

[0011] Figure 1 A schematic diagram of a cylinder barrel being clamped in a cylinder barrel precision machining fixture of the utility model.

[0012] Figure 2 for Figure 1 A magnified view of the location of the centrally located opening ring.

[0013] Figure 3 This is a diagram illustrating a price increase / decrease pattern.

[0014] Figure 4 for Figure 1 A magnified view of the location of the O-ring. Detailed Implementation

[0015] The following is combined with Figures 1-4 The embodiments of this utility model will be described in detail below.

[0016] A cylinder precision machining fixture, comprising a fixture body and a tensioning bolt 3, characterized in that: the fixture body comprises a solid shaft 1 and an expansion sleeve 2 coaxially fixed to the solid shaft 1, the inner cavity of the expansion sleeve 2 being threadedly engaged with the tensioning bolt 3, an O-ring 4 being clamped on the solid shaft 1, and an open ring 5 made of polymer material being clamped on the outer end of the expansion sleeve 3, the cylinder 100 being fitted onto the expansion sleeve 2 with clearance, and the inner wall of the cylinder being supported by the O-ring 4 and the open ring 5, the inner end face of the cylinder abutting against the solid shaft 1, the expansion sleeve 2 expanding as the tensioning bolt 3 is tightened, tightening the open ring 5 onto the inner wall of the cylinder.

[0017] The cylinder barrel precision machining fixture described above has a solid shaft 1 and an expansion sleeve 2 coaxially fixed. When clamping the cylinder barrel, first, the cylinder barrel 100 is fitted onto the expansion sleeve 2, so that the O-ring 4 and the cotter ring 5 respectively support the cylinder barrel. Then, the tensioning bolt 3 is tightened into the expansion sleeve 2, causing the expansion sleeve 2 to expand. The cotter ring 5 is tightened against the inner wall of the cylinder barrel as the expansion sleeve 2 expands, forming a tension on the cylinder barrel. Next, the solid shaft is clamped onto the three-jaw chuck of the lathe, forming a clamping mechanism for the cylinder barrel. During precision machining, the cylinder barrel 100 will rotate synchronously with the three-jaw chuck. Utilizing the expansion sleeve 2 and the cotter ring 5... The cylinder features the ability to expand and deform. The expansion bolt 3 expands the expansion sleeve 2, and the expanded expansion sleeve 2 tightens the open ring 5 on the inner wall of the cylinder, forming a tension on the cylinder. The inner end of the cylinder is pressed against the solid shaft 1, forming the positioning of the cylinder on the fixture, ensuring the reliability of the cylinder clamping and positioning. The O-ring 4 is made of rubber, and the open ring 5 is made of polymer material. During the precision machining process, it will not damage the inner wall of the cylinder, avoid the inner wall of the cylinder being scratched by the fixture during the precision machining process, ensure that the quality of the inner wall of the cylinder is not affected by the precision machining, and improve the quality of the hydraulic cylinder.

[0018] The expansion sleeve 2 has a smaller diameter at its front end, forming a transition step surface 21. An open ring 5 is clamped to the front end of the expansion sleeve 2 and abuts against the transition step surface 21. The outer diameter of the open ring 5 is larger than the outer diameter of the expansion sleeve 2. As shown in the attached diagram, the outer diameter of the front end of the expansion sleeve 2 is smaller than its rear outer diameter. A transition step surface 21 is formed at the transition point between the two outer diameters. The open ring 5 is clamped to the front end of the expansion sleeve, and its inner end abuts against the transition step surface 21, positioning the open ring 5 on the expansion sleeve 2. The outer diameter of the open ring 5 is larger than the outer diameter of the expansion sleeve 2. When the cylinder 100 is fitted onto the expansion sleeve 2, it contacts the open ring 5, forming radial support. The expansion sleeve 2 and the cylinder 100 form a clearance fit. When the expansion sleeve 2 is expanded, the extrusion force on the expansion sleeve 2 is transmitted to the open ring 5, causing the opening of the open ring 5 to expand, thus tightening the open ring 5 against the inner wall of the cylinder.

[0019] The solid shaft 1 has a smaller diameter at its front end, forming a transition step surface 11. The outer diameter of the front end of the solid shaft 1 is equal to the outer diameter of the rear end of the expansion sleeve 2. An O-ring 4 is clamped in an annular groove at the front end of the solid shaft 1. The outer diameter of the O-ring 4 is larger than the outer diameter of the front end of the solid shaft 1. The cylinder 100 is fitted onto the front end of the solid shaft 1 and rests against the transition step surface 11. The outer diameter of the front end of the solid shaft 1 is smaller than its rear outer diameter, forming the transition step surface 11 at the transition point between the two outer diameters. The rear end face of the cylinder 100 abuts against the transition step surface 11, providing axial positioning for the cylinder 100. The inner wall of the cylinder 100 contacts the O-ring 4, providing radial support for the front end of the cylinder 100, thus creating a clearance fit between the front end of the solid shaft 1 and the cylinder 100.

[0020] The expansion sleeve 2 has cutting lines 22 extending axially inward from its outer end. The inner end of the cutting lines 22 is close to the inner end of the expansion sleeve 2. The cutting lines 22 are evenly spaced along the circumference of the expansion sleeve 2, dividing it into multiple segments. The expansion sleeve 2 is divided into multiple segments by the cutting lines 22, ensuring that the tension force of each segment is evenly transmitted to the opening ring 5 when the expansion sleeve 2 is expanded. This ensures that the opening ring 5 is evenly tensioned along the circumference of the cylinder inner wall, improving the reliability of the clamping.

[0021] The tensioning bolt 3 has a conical tail with a gradually increasing outer diameter. The opening at the front end of the expansion sleeve 2 is a flared mouth 23 that matches the tail of the tensioning bolt 3. As the tensioning bolt 3 is tightened, the tail of the tensioning bolt 3 extends from the flared mouth 23 into the inner cavity of the expansion sleeve 2, thus expanding the expansion sleeve 2. As shown in the figure, the tail of the tensioning bolt 3 is conical, and the front opening of the expansion sleeve 2 is a flared mouth 23 that matches the tail of the tensioning bolt 3. When the tensioning bolt 3 is screwed into the expansion sleeve 2, as the tensioning bolt 3 gradually goes deeper, the tail of the tensioning bolt 3 extends from the flared mouth 23 into the inner cavity of the expansion sleeve 2, thus expanding the expansion sleeve 2. The expanded expansion sleeve 2 transmits the extrusion force to the open ring 5, tightening the open ring 5 against the inner wall of the cylinder, thus achieving reliable tensioning and positioning of the cylinder.

[0022] The open ring 5 is made of Teflon. Teflon has a low coefficient of friction and excellent dimensional stability, which ensures that the open ring 5 will firmly tighten the inner wall of the cylinder during the cylinder precision machining process and will not scratch the inner wall of the cylinder.

[0023] The technical solutions of the embodiments of this utility model have been fully described above with reference to the accompanying drawings. It should be noted that the described embodiments are only a part of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

Claims

1. A cylinder precision machining fixture, comprising a fixture body and a tensioning bolt, characterized in that: The fixture body includes a solid shaft and an expansion sleeve coaxially fixed to the solid shaft. The inner cavity of the expansion sleeve is threadedly engaged with the tensioning bolt. An O-ring is clamped on the solid shaft, and an open ring made of polymer material is clamped on the outer end of the expansion sleeve. The cylinder is fitted onto the expansion sleeve with clearance, and the inner wall of the cylinder is supported by the O-ring and the open ring. The inner end face of the cylinder abuts against the solid shaft. The expansion sleeve expands as the tensioning bolt is tightened, tightening the open ring on the inner wall of the cylinder.

2. The cylinder precision machining fixture according to claim 1, characterized in that: The front end of the expansion sleeve is a reduced diameter end with a smaller diameter, forming a transition step surface one on the expansion sleeve. The open ring is clamped to the front end of the expansion sleeve and abuts against the transition step surface one. The outer diameter of the open ring is larger than the outer diameter of the expansion sleeve.

3. The cylinder precision machining fixture according to claim 2, characterized in that: The front end of the solid shaft is a reduced diameter end with a smaller diameter. A transition step surface two is formed on the solid shaft. The outer diameter of the front end of the solid shaft is equal to the outer diameter of the rear end of the expansion sleeve. An O-ring is tightened in the annular groove opened at the front end of the solid shaft. The outer diameter of the O-ring is larger than the outer diameter of the front end of the solid shaft. The cylinder is sleeved on the front end of the solid shaft and abuts against the transition step surface two.

4. The cylinder barrel precision machining fixture according to claim 1, characterized in that: The expansion sleeve has a cutting line extending from the outer end face inward along the axial direction. The inner end of the cutting line is close to the inner end of the expansion sleeve. The cutting lines are evenly distributed along the circumference of the expansion sleeve, dividing the expansion sleeve into multiple segments.

5. The cylinder precision machining fixture according to claim 4, characterized in that: The tail of the tensioning bolt is a cone shape with a gradually increasing outer diameter. The opening at the front end of the expansion sleeve is a flared mouth that matches the tail of the tensioning bolt. As the tensioning bolt is tightened, the tail of the tensioning bolt extends from the flared mouth into the inner cavity of the expansion sleeve, thus expanding the expansion sleeve.

6. The cylinder precision machining fixture according to claim 1, characterized in that: The opening ring is made of Teflon.

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