Sealed hydraulic clamp

Abstract

The invention relates to the field of machining, in particular to a sealed hydraulic clamp. A sealed hydraulic clamp comprises 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-sealing adhesive steel sleeve with an upper sealing ring and a lower sealing ring. The contact face of the clamping sleeve, the driving mechanism and the workpiece positioning assembly is provided with a homodromous taper sealing groove and a homodromous taper sealing face. The driving mechanism can drive the clamping sleeve to move in the axial direction so as to clamp or loosen a workpiece gear ring. The sealing structure can keep a sealing state all the time in the moving process of the clamping sleeve, and iron scraps generated during machining are prevented from entering the clamp. The novel sealed hydraulic clamp is easy to clamp and discharge chips, good in dynamic balance, sufficient in rigidity and capable of stably guaranteeing positioning precision.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of machining, in particular to a sealed hydraulic clamp. BACKGROUND

[0002] In the process of machining the inner teeth of large gear rings in planetary transmission mechanism, the use of gear shaping or gear turning process will produce iron filings, which have a long-term impact on the positioning accuracy of workpieces. The existing machining methods have obvious defects: if each workpiece is subjected to correction machining, the efficiency will be extremely low; if clamping jaws are used for clamping machining, the positioning accuracy of larger workpieces is difficult to guarantee; if a clamping sleeve is used for clamping positioning, the iron filings will enter the inside of the sleeve and cannot be cleaned, which will gradually reduce the positioning accuracy. SUMMARY

[0003] In order to overcome the shortcomings of the prior art, the present application provides a sealed hydraulic clamp, which aims to solve the problems of the influence of iron filings on the positioning accuracy, low clamping efficiency, and the difficulty in maintaining the positioning accuracy for a long time in the machining of existing gear ring parts, and provides a new sealed hydraulic clamp which is easy to clamp and easy to remove iron filings, has good dynamic balance, sufficient rigidity, and can stably guarantee the positioning accuracy.

[0004] 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 adhesive steel sleeve with upper and lower sealing rings, and the contact surfaces of the clamping sleeve, the driving mechanism, and the workpiece positioning assembly are provided with same-direction tapered sealing grooves and same-direction tapered sealing surfaces; the driving mechanism can drive the clamping sleeve to move axially to clamp or release the workpiece gear ring; the sealing structure can always maintain a sealed state during the movement of the clamping sleeve to prevent iron filings generated during machining from entering the inside of the clamp.

[0005] The driving mechanism is a single-cylinder structure, comprising an annular oil cylinder at the upper end, an oil-sealed piston, and a compression spring at the lower end; the annular oil cylinder pushes the oil-sealed piston downward through hydraulic oil to drive the clamping sleeve to move downward to achieve clamping; the compression spring pushes the clamping sleeve upward to reset when the annular oil cylinder is de-pressurized, to achieve the release action.

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

[0007] The sealing structure comprises an upper sealing ring of the collet, a lower sealing ring of the collet, a same-direction taper sealing groove and a same-direction taper sealing surface; the upper sealing ring of the collet and the same-direction taper sealing groove arranged on the upper cover of the oil cylinder form an inverted sealing, and the lower sealing ring of the collet and the same-direction taper sealing surface form a synchronous contact sealing, and the two always keep gapless fitting when moving up and down the collet.

[0008] The hydraulic oil supply system comprises a hydraulic transition rod arranged at the center of the main shaft of the machine tool, a rotary joint and a pipeline joint; the hydraulic transition rod is a hollow structure, the lower end of the hydraulic transition rod is connected with the hydraulic pipeline of the machine tool through the rotary joint, and the upper end of the hydraulic transition rod is communicated with the oil cylinder of the driving mechanism through the pipeline joint, so that a closed hydraulic passage is formed.

[0009] The pipeline joint of the single-cylinder structure is a tee joint, and the hydraulic oil flows through the rotary joint, the hydraulic transition rod, the tee joint and the oil circuit of the annular oil cylinder, so that the oil-sealed piston is driven.

[0010] The pipeline joint of the double-cylinder structure is a bend joint, and the hydraulic oil is respectively introduced into the upper annular oil cylinder and the lower annular oil cylinder through the rotary joint, the hydraulic transition rod and the bend joint, so that the lower oil-sealed piston and the upper oil-sealed piston are driven.

[0011] The rigid guide opening is arranged on the upper cover of the oil cylinder, and the rigid guide opening is arranged close to the workpiece loading end, and a preset gap and a chamfer are arranged between the rigid guide opening and the workpiece gear ring, so that the workpiece gear ring can be quickly loaded.

[0012] The collet and the jig body are provided with a joint taper.

[0013] The sealing hydraulic clamp has the following advantages:

[0014] The upper and lower sealing rings of the collet are matched with the same-direction taper sealing groove and the same-direction taper sealing surface, so that iron filings and debris can be completely prevented from entering the inside of the clamp, and the stability of the positioning accuracy is effectively ensured.

[0015] The clamp is easy to clamp and easy to remove chips, has good dynamic balance and sufficient rigidity, and improves the machining quality and efficiency.

[0016] The single-cylinder structure is relatively simple, the double-cylinder structure is more reliable to use, and the application range is wider. BRIEF DESCRIPTION OF DRAWINGS

[0017] The application will be further described in detail below in combination with the drawings and specific implementation methods.

[0018] Figure 1 Fig. 1 is a structural schematic view of a sealing hydraulic clamp;

[0019] Figure 2 Fig. 3 is a structural schematic view of a single-cylinder structure;

[0020] Figure 3 For Figure 2 enlarged view of area A;

[0021] Figure 4 structure diagram of double-cylinder structure;

[0022] Figure 5 For Figure 4 enlarged view of area A;

[0023] Figure 6 For Figure 2 enlarged view of area B;

[0024] Figure 7 structure diagram of jacket;

[0025] Jacket 1; annular oil cylinder 2; hydraulic circuit 3; rigid guide port 4; upper jacket sealing ring 5; homodromous taper sealing groove 6; lower jacket sealing ring 9; homodromous taper sealing surface 10; joint taper 11; machine tool spindle 13; pipeline joint 14; hydraulic transition rod 15; rotary joint 16; compression spring 18; oil seal type piston 19; upper annular oil cylinder 21; lower oil seal type piston 29; lower annular oil cylinder 31; upper oil seal type piston 34; clamp body 35; workpiece gear ring 36. DETAILED DESCRIPTION

[0026] As Figures 2-3 shown:

[0027] Single-cylinder structure implementation process:

[0028] Workpiece clamping: the workpiece gear ring 36 is sleeved into the outside of the jacket 1 through the rigid guide port 4, and the gap and chamfer design of the rigid guide port 4 enables the workpiece to be quickly and accurately positioned.

[0029] Clamping operation: the clamping instruction is issued through the machine tool control system, the machine tool hydraulic system is started, the hydraulic oil enters the annular oil cylinder 2 through the hydraulic oil inlet joint, the rotary joint 16, the hydraulic transition rod 15, the pipeline joint 14, and the hydraulic circuit 3, the pressure in the annular oil cylinder 2 rises, the oil seal type piston 19 is pushed to move downward, the lower end surface of the oil seal type piston 19 contacts the upper end surface of the jacket 1, the jacket 1 is driven to move downward against the elastic force of the compression spring 18, and the jacket 1 is retracted and clamped through the joint taper 11 when moving downward, at this time the compression spring 18 is compressed and stores elastic potential energy.

[0030] Processing process: the clamp rotates with the machine tool spindle 13, and processes gear cutting or gear shaping, etc., the iron filings generated during processing are discharged outward under the action of centrifugal force, and since the upper jacket sealing ring 5 and the homodromous taper sealing groove 6, and the lower jacket sealing ring 9 and the homodromous taper sealing surface 10 always maintain sealing contact without gaps, the iron filings cannot enter the inside of the clamp.

[0031] Loosen operation: after processing, send loose command, annular cylinder 2 pressure relief, compression spring 18 release elastic potential, push up the clamp sleeve 1, clamp sleeve 1 drive oil seal type piston 19 upward, hydraulic oil in annular cylinder 2 through the original pipeline return machine tool oil tank, clamp sleeve 1 and workpiece gear ring 36 disengaged, remove workpiece gear ring 36.

[0032] As shown in Figures 4-6

[0033] Double cylinder structure implementation process:

[0034] Workpiece clamping: workpiece gear ring 36 through rigid guide port 4 sleeve into the clamp sleeve 1 outside.

[0035] Clamping operation: send clamping command, machine tool hydraulic system to the upper annular cylinder 21 oil supply, hydraulic oil through double circuit rotary joint, hydraulic transition rod 15, pipe joint 14, upper cylinder hydraulic circuit 3 into the upper annular cylinder 21, the pressure in the upper annular cylinder 21 rises, push the upper oil seal type piston 34 downward, drive the clamp sleeve 1 downward, clamp sleeve 1 through the joint taper 11 to achieve shrinkage clamping when moving down, the lower annular cylinder 31 is in the state of pressure relief, its internal hydraulic oil through the corresponding pipeline return tank.

[0036] Processing process: clamp sleeve upper seal ring 5 and the same direction taper sealing groove 6, clamp sleeve lower seal ring 9 and the same direction taper sealing surface 10, prevent iron filings into.

[0037] Loosen operation: send loose command, upper annular cylinder 21 pressure relief, at the same time, lower annular cylinder 31 oil supply, hydraulic oil push down the oil seal type piston 29 upward, drive the clamp sleeve 1 upward, oil seal type piston 19 with clamp sleeve 1 up, hydraulic oil in the upper annular cylinder 21 through the original pipeline return tank, clamp sleeve 1 and workpiece gear ring 36 disengaged, complete processing.

[0038] As shown in Figures 2-7

[0039] Clamp sleeve 1 upper end of the clamp sleeve upper seal ring 5 is set by the same direction taper sealing groove 6 of the cylinder upper cover 20 inverted sealing, because it is the same direction taper, the contact surface is always stable contact when the clamp sleeve 1 moves up and down. Therefore, the processing of iron filings and broken ends can not enter. Clamp sleeve lower seal ring 9 is also in synchronous contact with the same direction taper sealing surface 10, always without any gap, so the broken ends can not enter the contact surface of the clamp.

[0040] As shown in Figure 3 and 5

[0041] ​​​Because the oil cylinder upper cover 20 is added, the rigid guide hole 4 is arranged on the oil cylinder upper cover 20, and the inner hole can be provided with a large gap and chamfer relative to the workpiece, so that the workpiece is more convenient to be guided to be loaded.

[0042] As Figures 1-7 shown:

[0043] The hydraulic transition rod 15 of the clamp utilizes the hydraulic system of the machine tool itself, the clamp generates clamping pressure and counter thrust by the annular oil cylinder 2, the problems of complex connection mechanism and difficulty in preventing debris from entering are avoided when the machine tool oil cylinder is clamped in the traditional method. Because the rubber sleeve conical surface has a strong reinforcing effect, the hydraulic pressure possessed by the modern machine tool is completely sufficient. The sealing ring is used as the oil cylinder piston, which is practical and reliable.

[0044] As Figures 1-7 shown:

[0045] The clamp sleeve 1 is provided with the upper clamp sleeve sealing ring 5 and the lower clamp sleeve sealing ring 9, the sealing effect is enhanced; the same direction taper sealing groove 6 and the same direction taper sealing surface 10 are designed, the sealing surface is always stably contacted when the clamp sleeve 1 moves; the oil seal type piston 19 is adopted, the sealing property of the hydraulic drive is improved; the mutual pressure type return single cylinder type is adopted, the oil cylinder and the spring are mutually pressed, the double cylinder type is adopted, the upper and lower oil cylinders are mutually pressed, the return reliability is guaranteed; the hydraulic transition rod 15 is additionally arranged, the machine tool main shaft 13 space is reasonably utilized; the rigid guide hole 4 is provided, the workpiece gear ring 36 is conveniently loaded.

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 unidirectional tapered sealing groove (6) and a unidirectional 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.

2. A sealed hydraulic clamp according to claim 1, characterized in that: 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.

3. A sealed hydraulic clamp according to claim 1, characterized in that: 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.

4. A sealed hydraulic clamp according to claim 1, characterized in that: 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.

5. 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.

6. A sealed hydraulic clamp according to claim 2, 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).

7. A sealed hydraulic clamp according to claim 3, 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).

8. A sealed hydraulic clamp according to claim 4, 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.

9. 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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