A sealed hydraulic clamp

Abstract

The present application relates to the field of machining, more particularly to a sealed hydraulic clamp. A sealed hydraulic clamp, comprising a clamping sleeve, a driving mechanism, a sealing structure, a hydraulic oil supply system and a workpiece positioning assembly; the clamping sleeve is a double-sealed glued steel sleeve with upper and lower sealing rings, the contact surfaces of the clamping sleeve, the driving mechanism and the workpiece positioning assembly are provided with same-direction taper sealing grooves and same-direction taper sealing surfaces; the driving mechanism can drive the clamping sleeve to move along the axial direction to realize clamping or loosening of the workpiece gear ring; the sealing structure can always maintain a sealed state during movement of the clamping sleeve, preventing iron filings and debris generated during machining from entering the inside of the clamp. A new type of sealed hydraulic clamp is provided, which is easy to clamp and easy to remove chips, has good dynamic balance, sufficient rigidity and can stably ensure positioning accuracy.

Description

Technical Field

[0001] This invention relates to the field of machining, and more specifically to a sealed hydraulic clamp. Background Technology

[0002] In the machining of internal gears for large gear rings in planetary transmission mechanisms, iron filings are generated during gear shaping or turning processes. The impact of these filings on workpiece positioning accuracy is a long-standing problem. Existing machining methods have significant drawbacks: requiring calibration machining for each workpiece leads to extremely low efficiency; chuck clamping makes it difficult to guarantee positioning accuracy for larger workpieces; and using adhesive sleeves for positioning results in filings that cannot be cleaned after entering the sleeve, gradually reducing positioning accuracy. Summary of the Invention

[0003] To overcome the shortcomings of existing technologies, this invention provides a sealed hydraulic clamp, which aims to solve the problems in the machining of gear ring parts, such as the impact of iron filings on positioning accuracy, low clamping efficiency, and difficulty in maintaining positioning accuracy over a long period of time. It provides a new type of sealed hydraulic clamp that is easy to clamp, easy to remove chips, has good dynamic balance, sufficient rigidity, and can stably guarantee positioning accuracy.

[0004] A sealed hydraulic clamp includes a clamp, a drive mechanism, a sealing structure, a hydraulic oil supply system, and a workpiece positioning assembly. The clamp is a double-sealed adhesive steel sleeve with built-in upper and lower sealing rings. The contact surfaces between the clamp, the drive mechanism, and the workpiece positioning assembly are provided with unidirectional tapered sealing grooves and unidirectional tapered sealing surfaces. The drive mechanism can drive the clamp to move axially to clamp or release the workpiece gear ring. The sealing structure can maintain a sealed state during the movement of the clamp, preventing iron filings and debris generated during processing from entering the interior of the clamp.

[0005] The drive mechanism is a single-cylinder structure, including an annular cylinder at the upper end, an oil-sealed piston, and a compression spring at the lower end. The annular cylinder pushes the oil-sealed piston downward through hydraulic oil, which drives the jacket downward to achieve clamping. When the annular cylinder is depressurized, the compression spring pushes the jacket upward to reset, thus achieving the release action.

[0006] The drive mechanism is a dual-cylinder structure, including an upper annular cylinder and an upper oil-sealed piston at the upper end, and a lower annular cylinder and a lower oil-sealed piston at the lower end. The upper annular cylinder pushes the upper oil-sealed piston downward through hydraulic oil, causing the jacket to move downward to achieve clamping. The lower annular cylinder pushes the lower oil-sealed piston upward through hydraulic oil, causing the jacket to move upward to achieve release, forming a mutual pressure return.

[0007] The sealing structure includes an upper sealing ring, a lower sealing ring, a unidirectional tapered sealing groove, and a unidirectional tapered sealing surface. The upper sealing ring and the unidirectional tapered sealing groove on the upper cover of the cylinder form an inverted seal, and the lower sealing ring and the unidirectional tapered sealing surface form a synchronous contact seal. The two always maintain a gapless fit when the jacket moves up and down.

[0008] The hydraulic oil supply system includes a hydraulic transition rod, a rotary joint, and a pipeline joint located at the center of the machine tool spindle. The hydraulic transition rod has a hollow structure, with its lower end connected to the machine tool hydraulic pipeline through the rotary joint, and its upper end connected to the oil cylinder of the drive mechanism through the pipeline joint, forming a closed hydraulic passage.

[0009] The single-cylinder structure has a three-way pipe joint. Hydraulic oil flows through the rotary joint, hydraulic transition rod, three-way pipe joint, and annular cylinder to drive the oil-sealed piston.

[0010] The pipeline joint of the dual-cylinder structure is an elbow joint. Hydraulic oil is introduced into the upper annular cylinder and the lower annular cylinder through the rotary joint, hydraulic transition rod and elbow joint respectively, so as to drive the lower oil-sealed piston and the upper oil-sealed piston.

[0011] It also includes a rigid guide port. The upper cover of the cylinder is provided with a rigid guide port. The rigid guide port is located near the workpiece loading end. It has a preset gap and chamfer between itself and the workpiece gear ring, which can guide the workpiece gear ring to be loaded quickly.

[0012] A engagement taper is provided between the jacket and the fixture body.

[0013] The beneficial effects of the sealed hydraulic clamp of the present invention are:

[0014] The jacket's built-in upper and lower sealing rings, along with the co-directional tapered sealing groove and co-directional tapered sealing surface, can completely prevent iron filings and debris from entering the fixture, effectively ensuring the stability of positioning accuracy.

[0015] The fixture is easy to clamp, easy to remove chips, has good dynamic balance, and sufficient rigidity, which improves the processing quality and efficiency;

[0016] Single-cylinder structures are relatively simple, while twin-cylinder structures are more reliable and have a wider range of applications. Attached Figure Description

[0017] The present invention will now be described in further detail with reference to the accompanying drawings and specific implementation methods.

[0018] Figure 1 This is a schematic diagram of the structure of a sealed hydraulic clamp;

[0019] Figure 2 This is a schematic diagram of a single-cylinder structure.

[0020] Figure 3 for Figure 2 Enlarged view of region A in the middle;

[0021] Figure 4 This is a schematic diagram of a twin-cylinder structure.

[0022] Figure 5 for Figure 4 Enlarged view of region A in the middle;

[0023] Figure 6 for Figure 2 Enlarged view of region B in the middle;

[0024] Figure 7 This is a schematic diagram of the jacket structure;

[0025] 1. Jacket; 2. Annular cylinder; 3. Hydraulic circuit; 4. Rigid guide port; 5. Upper sealing ring of the jacket; 6. Same-direction tapered sealing groove; 9. Lower sealing ring of the jacket; 10. Same-direction tapered sealing surface; 11. Engagement taper; 13. Machine tool spindle; 14. Pipe joint; 15. Hydraulic transition rod; 16. Rotary joint; 18. Compression spring; 19. Oil-sealed piston; 20. Cylinder cover; 21. Upper annular cylinder; 29. ​​Lower oil-sealed piston; 31. Lower annular cylinder; 34. Upper oil-sealed piston; 35. Fixture body; 36. Workpiece gear ring. Detailed Implementation

[0026] like Figure 2-3 As shown:

[0027] Implementation process of single-cylinder structure:

[0028] Workpiece clamping: The workpiece gear ring 36 is inserted into the outside of the clamp 1 through the rigid guide port 4. The gap and chamfer design of the rigid guide port 4 enable the workpiece to be quickly and accurately positioned.

[0029] Clamping operation: The machine tool control system issues a clamping command, the machine tool hydraulic system starts, and the hydraulic oil enters the annular cylinder 2 through the hydraulic inlet joint, rotary joint 16, hydraulic transition rod 15, pipeline joint 14, and hydraulic circuit 3. The pressure in the annular cylinder 2 increases, pushing the oil-sealed piston 19 to move downward. The lower end face of the oil-sealed piston 19 contacts the upper end face of the jacket 1, causing the jacket 1 to move downward against the elastic force of the compression spring 18. When the jacket 1 moves downward, it achieves contraction and clamping through the engagement taper 11. At this time, the compression spring 18 is compressed and stores elastic potential energy.

[0030] Machining process: The fixture rotates with the machine spindle 13 to perform gear turning or gear shaping. The iron filings generated during machining are discharged outward under the action of centrifugal force. Since the upper sealing ring 5 of the jacket and the same-direction tapered sealing groove 6, and the lower sealing ring 9 of the jacket and the same-direction tapered sealing surface 10 always maintain sealed contact without gaps, the iron filings cannot enter the interior of the fixture.

[0031] Release operation: After processing is completed, a release command is issued, the annular cylinder 2 is depressurized, the compression spring 18 releases its elastic potential energy, and pushes the jacket 1 upward. The jacket 1 drives the oil-sealed piston 19 to move upward. The hydraulic oil in the annular cylinder 2 returns to the machine tool oil tank through the original pipeline. The jacket 1 is separated from the workpiece gear ring 36, and the workpiece gear ring 36 can be removed.

[0032] like Figure 4-6 As shown:

[0033] Implementation process of the twin-cylinder structure:

[0034] Workpiece clamping: Insert the workpiece gear ring 36 into the outer side of the clamp 1 through the rigid guide port 4.

[0035] Clamping operation: When a clamping command is issued, the machine tool hydraulic system supplies oil to the upper annular cylinder 21. The hydraulic oil enters the upper annular cylinder 21 through the double-circuit rotary joint, hydraulic transition rod 15, pipeline joint 14, and upper cylinder hydraulic circuit 3. The pressure inside the upper annular cylinder 21 increases, pushing the upper oil seal piston 34 to move downward, which in turn moves the jacket 1 downward. When the jacket 1 moves downward, it achieves contraction and clamping through the engagement taper 11. At this time, the lower annular cylinder 31 is in a depressurized state, and the hydraulic oil inside it returns to the oil tank through the corresponding pipeline.

[0036] Processing procedure: The upper sealing ring 5 of the jacket and the same-direction tapered sealing groove 6, and the lower sealing ring 9 of the jacket and the same-direction tapered sealing surface 10 prevent iron filings from entering.

[0037] Release operation: When the release command is issued, the upper annular cylinder 21 is depressurized, and at the same time the lower annular cylinder 31 is supplied with oil. The hydraulic oil pushes the lower oil-sealed piston 29 to move upward, which in turn moves the jacket 1 upward. The oil-sealed piston 19 moves upward with the jacket 1, and the hydraulic oil in the upper annular cylinder 21 returns to the oil tank through the original pipeline. The jacket 1 is separated from the workpiece gear ring 36, and the processing is completed.

[0038] like Figure 2-7 As shown:

[0039] The upper sealing ring 5 of the jacket 1 is inverted and sealed by the same-direction tapered sealing groove 6 provided on the upper cover 20 of the cylinder. Because it is a same-direction tapered surface, the contact surface is always in stable contact when the jacket 1 moves up and down. Therefore, the machining chips and debris can never enter. The lower sealing ring 9 of the jacket is also in synchronous contact with the same-direction tapered sealing surface 10, and no gap is ever generated. Therefore, the debris also cannot enter the contact surface of the fixture.

[0040] like Figure 3 and 5 As shown:

[0041] Because of the addition of the upper cover 20 of the hydraulic cylinder, which is equipped with a rigid guide port 4, the inner hole of which can be set with a larger gap and chamfer with the workpiece, making it more convenient to guide the workpiece to be loaded.

[0042] like Figure 1-7 As shown:

[0043] This fixture incorporates a hydraulic transition rod 15, utilizing the machine tool's own hydraulic system. The fixture's built-in annular cylinder 2 generates clamping pressure and counter-force, avoiding the complexity of the connection mechanism and the difficulty in preventing chip ingress inherent in traditional methods using machine tool cylinders for clamping. Because the rubber sleeve's conical surface has a strong force-amplifying effect, it is perfectly adequate for the hydraulic pressure capabilities of modern machine tools. Using a sealing ring as the cylinder piston is both practical and reliable.

[0044] like Figure 1-7 As shown:

[0045] The jacket 1 comes with an upper sealing ring 5 and a lower sealing ring 9 to enhance the sealing effect; it is designed with a unidirectional tapered sealing groove 6 and a unidirectional tapered sealing surface 10 to ensure that the sealing surfaces are always in stable contact when the jacket 1 moves; it adopts an oil-sealed piston 19 to improve the sealing performance of the hydraulic drive; it adopts a mutual pressure return type single cylinder with mutual pressure between the oil cylinder and the spring, and a double cylinder with mutual pressure between the upper and lower oil cylinders to ensure the reliability of the return; it adds a hydraulic transition rod 15 oil supply structure to make reasonable use of the space of the machine tool spindle 13; it has a rigid guide port 4 to facilitate the installation of the workpiece gear ring 36.

Claims

1. A sealed hydraulic clamp, characterized in that: The fixture includes a clamp (1), a drive mechanism, a sealing structure, a hydraulic oil supply system, and a workpiece positioning assembly. The clamp (1) is a double-sealed adhesive steel sleeve with upper and lower sealing rings. The contact surfaces of the clamp (1) with the drive mechanism and the workpiece positioning assembly are provided with a co-directional tapered sealing groove (6) and a co-directional tapered sealing surface (10). The drive mechanism can drive the clamp (1) to move axially to clamp or release the workpiece gear ring (36). The sealing structure can maintain a sealed state during the movement of the clamp (1) to prevent iron filings and debris generated during processing from entering the fixture. The drive mechanism is a single-cylinder structure, including an annular cylinder (2) at the upper end, an oil-sealed piston (19) and a compression spring (18) at the lower end; the annular cylinder (2) pushes the oil-sealed piston (19) downward through hydraulic oil, which drives the jacket (1) downward to achieve clamping; the compression spring (18) pushes the jacket (1) upward to reset when the annular cylinder (2) is depressurized, thus achieving the release action; The drive mechanism is a double-cylinder structure, including an upper annular cylinder (21) and an upper oil-sealed piston (34) at the upper end, and a lower annular cylinder (31) and a lower oil-sealed piston (29) at the lower end. The upper annular cylinder (21) pushes the upper oil-sealed piston (34) downward through hydraulic oil, thereby driving the jacket (1) downward to achieve clamping. The lower annular cylinder (31) pushes the lower oil-sealed piston (29) upward through hydraulic oil, thereby driving the jacket (1) upward to achieve release, forming a mutual pressure return. The sealing structure includes an upper sealing ring (5), a lower sealing ring (9), a unidirectional tapered sealing groove (6), and a unidirectional tapered sealing surface (10). The upper sealing ring (5) and the unidirectional tapered sealing groove (6) provided on the upper cover (20) of the cylinder form an inverted seal, and the lower sealing ring (9) and the unidirectional tapered sealing surface (10) form a synchronous contact seal. The two always maintain a gapless fit when the jacket (1) moves up and down.

2. A sealed hydraulic clamp according to claim 1, characterized in that: The hydraulic oil supply system includes a hydraulic transition rod (15), a rotary joint (16), and a pipeline joint (14) located at the center of the machine tool spindle (13). The hydraulic transition rod (15) is a hollow structure. Its lower end is connected to the machine tool hydraulic pipeline through the rotary joint (16), and its upper end is connected to the oil cylinder of the drive mechanism through the pipeline joint (14), forming a closed hydraulic passage.

3. A sealed hydraulic clamp according to claim 1, characterized in that: The single-cylinder pipe joint (14) is a three-way pipe joint. Hydraulic oil flows through the oil passage of the rotary joint (16), hydraulic transition rod (15), three-way pipe joint, and annular cylinder (2) to drive the oil-sealed piston (19).

4. A sealed hydraulic clamp according to claim 1, characterized in that: The pipe joint (14) of the dual-cylinder structure is a bend joint. Hydraulic oil is fed into the upper annular cylinder (21) and the lower annular cylinder (31) through the rotary joint (16), the hydraulic transition rod (15) and the bend joint, respectively, to drive the lower oil-sealed piston (29) and the upper oil-sealed piston (34).

5. A sealed hydraulic clamp according to claim 1, characterized in that: It also includes a rigid guide port (4). The upper cover (20) of the oil cylinder is provided with a rigid guide port (4). The rigid guide port (4) is located near the workpiece loading end. It has a preset gap and chamfer between it and the workpiece gear ring (36), which can guide the workpiece gear ring (36) to be loaded quickly.

6. A sealed hydraulic clamp according to claim 1, characterized in that: A engagement taper (11) is provided between the sleeve (1) and the fixture body (35).

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