A fixture for grinding and clamping workpieces at the tip of a gas turbine rotor

Abstract

The present invention discloses a fixture for grinding and clamping a workpiece at the tip of a gas turbine rotor, comprising: a fixture body, the workpiece is clamped by the fixture bodies on both sides, and the fixture body is provided with a first gas detection hole, a second gas detection hole, a first pressure indicator, a second pressure indicator and a first threaded pump. The present invention discloses a fixture for grinding and clamping a workpiece at the tip of a gas turbine rotor, the fixtures on both sides of the workpiece use a static pressure expansion method to clamp the workpiece and an independent oil supply system feedback, when the pressure value changes, real-time feedback can be provided through the pressure indicator, and the static pressure expansion sleeve and the adjustment pad are adjusted to achieve a suitable match between the fixture and the machine tool. Among them, once the fixture is adjusted, it can be automatically centered without additional adjustment each time it is clamped, which reduces the time for adjusting the fixture each time it is clamped, reduces the processing auxiliary cost, and thus improves the processing efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of machine tool processing, and in particular to a fixture for grinding and clamping a workpiece at a gas turbine rotor blade tip. Background Art

[0002] The machine tool fixture is a device used to fix the processing object in the mechanical manufacturing process so that it occupies the correct position to accept construction or inspection. When processing the workpiece on the machine tool, in order to make the surface of the workpiece meet the technical requirements such as the size, geometric shape and relative position accuracy with other surfaces specified in the drawing, the workpiece must be installed (positioned) and clamped before processing. The machine tool fixture is one of the important contents of production preparation and one of the main tasks of the production process design of parts products. The existing machine tool fixture has no independent oil supply system, and the clamping force is unstable. When the clamping force is unstable, it is impossible to guarantee the continued processing of the workpiece and meet the accuracy of the workpiece. In addition, a lot of time is required to adjust each time the workpiece is clamped, which seriously increases the processing auxiliary cost and reduces the processing efficiency. Summary of the invention

[0003] The invention provides a fixture for grinding and clamping a workpiece at the tip of a gas turbine rotor, so as to solve the problem that the fixture has no independent oil supply system and the clamping workpiece is unstable.

[0004] In order to achieve the above object, the technical solution of the present invention is:

[0005] A fixture for grinding and clamping a workpiece at the tip of a gas turbine rotor, comprising: a fixture body, the workpiece being clamped by the fixture bodies on both sides, the fixture body being provided with a first pressure indicator, a second pressure indicator and a first threaded pump, the first pressure indicator and the second pressure indicator being provided with a first cavity, the first cavity being filled with hydraulic oil, and the pressure value being fed back through the first pressure indicator and the second pressure indicator; the fixture body being provided with a first oil inlet hole, a second oil inlet hole, a first oil circuit and a second oil circuit, the first oil inlet hole and the second oil inlet hole being both arranged on the second oil circuit, and the first oil circuit and the second oil circuit being communicated with the first cavity and the second cavity; a static pressure expansion sleeve being provided on a side of the fixture body close to the workpiece, the static pressure expansion sleeve being communicated with the first oil circuit and the second oil circuit, and the hydraulic oil entering the static pressure expansion sleeve through the first oil inlet hole and the second oil inlet hole.

[0006] Furthermore, the fixture body is provided with a first air detection hole and a second air detection hole, both of which are air tightness detection holes connected to an external air detection valve to provide air tightness feedback.

[0007] Furthermore, a nut, a ball valve, a piston and a second cavity are arranged in the first threaded pump. The nut is twisted to squeeze the ball valve, and the piston is pushed to fill the second cavity with hydraulic oil.

[0008] Furthermore, an adjustment pad and a positioning cone are provided on one side of the fixture body away from the workpiece, the center of the positioning cone is the same as the center of the fixture body, and the adjustment pad is arranged around the outer circle of the positioning cone.

[0009] Furthermore, a second threaded pump is provided in the clamp body, and a pre-load plunger is provided in the second threaded pump.

[0010] Furthermore, the first pressure indicator and the first threaded pump are arranged on the same radial line, and the length of the same radial line is smaller than the diameter of the clamp body; the second pressure indicator and the second threaded pump are arranged on the same radial line, and the length of the same radial line is smaller than the diameter of the clamp body.

[0011] Furthermore, the first pressure indicator is provided with at least one scale.

[0012] Furthermore, a quick-connect connector is provided in the clamp body, and the quick-connect connector is detachable.

[0013] Furthermore, a protective cover and a drainage hole are also provided in the clamp body.

[0014] Furthermore, a conical surface is provided at one end of the fixture body away from the workpiece, and the angle between the conical surface and the machine tool is 7°7'30".

[0015] The present invention discloses a fixture for grinding and clamping a workpiece at the tip of a gas turbine rotor. The fixtures on both sides of the workpiece use a static pressure expansion method to clamp the workpiece and an independent oil supply system for feedback. When the pressure value changes, real-time feedback can be provided through a pressure indicator to adjust the fixture body so that the fixture body and the workpiece, and the fixture body and the machine tool are properly matched. Once the fixture body is adjusted, it can be automatically centered without additional adjustment each time it is clamped, which reduces the time for adjusting the fixture each time it is clamped, reduces the processing auxiliary cost, and thus improves the processing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0017] Figure 1 It is a schematic diagram of the structure of a fixture for grinding and clamping a workpiece for a gas turbine rotor blade tip according to the present invention;

[0018] Figure 2A cross-sectional view of a fixture for grinding and clamping a workpiece for a gas turbine rotor blade tip according to the present invention;

[0019] Figure 3 It is a structural schematic diagram of the active end static pressure clamp of the present invention;

[0020] Figure 4 It is a left side view of the active end static pressure fixture of the present invention;

[0021] Figure 5 A cross-sectional view of the active end static pressure fixture of the present invention;

[0022] Figure 6 The second cross-sectional view of the active end static pressure fixture of the present invention;

[0023] Figure 7 It is a structural schematic diagram of the active end static pressure fixture during gas inspection of the present invention;

[0024] Figure 8 It is a cross-sectional view of the static pressure clamp at the driven end of the present invention;

[0025] Fig. 9 It is a structural schematic diagram of the invention when the static pressure fixture at the driven end is pneumatically inspected;

[0026] Fig.10 It is a partial enlarged view of the conical surface of the present invention.

[0027] In the figure, 1, workpiece, 2, transition piece, 3, active end static pressure fixture, 4, driven end static pressure fixture, 5, first air inspection hole, 6, second air inspection hole, 7, first pressure indicator, 8, first threaded pump, 9, adjustment pad, 10, positioning cone, 11, drainage hole, 12, protective cover, 13, quick connector, 14, oil inlet hole, 15, first oil circuit, 16, first cavity, 17, second oil circuit, 18, static pressure expansion sleeve, 19, preload plunger, 20, second pressure indicator, 21, second threaded pump, 22, nut, 23, ball valve, 24, piston, 25, second oil inlet hole, 26, second cavity, 27, fixture body. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] like Figure 1-2The fixture for grinding and clamping a workpiece for a gas turbine rotor blade tip is shown, comprising: a fixture body 27, a workpiece 1 is clamped by the fixture bodies 27 on both sides, and the fixture body 27 is provided with a first pressure indicator 7, a second pressure indicator 20 and a first thread pump 8; the first pressure indicator 7 and the second pressure indicator 20 are both provided with a first cavity 16, the first cavity 16 is filled with hydraulic oil, and the pressure value is fed back through the first pressure indicator 7 and the second pressure indicator 20; the fixture body is provided with a first oil inlet hole 14, a second oil inlet hole 25, a first oil circuit 15 and a second oil circuit 17, the first oil inlet hole 14 and the second oil inlet hole 25 are both arranged on the second oil circuit 17, and the first oil circuit 15 and the second oil circuit 17 are interconnected with the first cavity 16 and the second cavity 26; the side of the fixture body 27 close to the workpiece 1 is provided with a static pressure expansion sleeve 18, the static pressure expansion sleeve 18 is connected with the first oil circuit 15 and the second oil circuit 17, and the hydraulic oil enters the pressurized cavity through the first oil inlet hole 14 and the second oil inlet hole 25. Further, the fixture body 27 is also provided with a first gas detection hole 5 and a second gas detection hole 6, the first gas detection hole 5 and the second gas detection hole 6 are both air tightness detection holes, and are connected to an external gas detection valve to feedback air tightness. Further, the first threaded pump 8 is provided with a nut 22, a ball valve 23, a piston 24 and a second cavity 26, and the nut 22 is screwed to squeeze the ball valve 23, and the piston 24 is pushed to fill the second cavity 26 with hydraulic oil. Furthermore, a second threaded pump 21 is provided in the clamp body 27 , and a pre-compression plunger 19 is provided in the second threaded pump 21 .

[0030] In this embodiment, preferably, Figure 1-2 As shown, in order to facilitate the clamping of the workpiece 1, a transition piece 2 is set on one side of the workpiece, and the clamps on both sides are set as an active end static pressure clamp 3 and a driven end static pressure clamp 4. Setting these two clamps can avoid wrong transfer on the one hand, and on the other hand, the active end static pressure clamp 3 adopts an internal expansion clamping method, and the driven end static pressure clamp 4 adopts an external expansion clamping method; as shown in FIG. Figure 5-9 As shown, the active end static pressure fixture 3 and the driven end static pressure fixture 4 are both provided with a first air detection hole 5, a first pressure indicator 7, a first screw pump 8, a second air detection hole 6, a second pressure indicator 20 and a second screw pump 21; the first air detection hole 5 and the second air detection hole 6 are both air tightness detection holes, which are connected to an external air detection valve to feedback air tightness; the first pressure indicator 7 and the second pressure indicator 20 have the same internal structure, and the first pressure indicator 7 is provided with a first cavity 16, and the first cavity 16 is filled with hydraulic oil. Figure 6As shown, a nut 22, a ball valve 23, a piston 24 and a second cavity 26 are provided in the first threaded pump 8. The nut 22 is turned to squeeze the ball valve 23, and the piston 24 is pushed to fill the second cavity 26 with hydraulic pressure. A preload plunger 19 is also provided in the second threaded pump 21. The pressure value in the static pressure fixture 4 at the driven end is observed by turning the preload plunger 19 before the fixture leaves the factory. After the fixture leaves the factory, the second threaded pump 21 does not participate in the work. The first air detection hole 5 and the second air detection hole 6 are provided on the end faces of the active end static pressure fixture 3 and the driven end static pressure fixture 4. When the workpiece 1 is close to the fixtures on both sides, the first air detection hole 5 and the second air detection hole 6 on the fixtures on both sides will be blocked. At this time, the internal pressure of the first air detection hole 5 and the second air detection hole 6 increases. An external air detection valve is used to detect the pressure of the first air detection hole 5 and the second air detection hole 6 at this time. When the air detection valve gives pressure feedback, it indicates that the position of the workpiece 1 is installed in place. The first oil inlet 14 and the second oil inlet 25 are both arranged on the second oil circuit 17. By screwing the nut 22 of the first screw pump 8 to squeeze the ball valve 23 and push the piston 24 to fill the second cavity 26 with hydraulic oil, the hydraulic oil enters the second oil circuit 17 from the through hole of the first screw pump, enters the pressurized cavity through the first oil inlet 14 and the second oil inlet 25, and then enters the second screw pump, and then enters the second pressure indicator 20. After the pressure in the clamp body 27 is fed back through the first pressure indicator 7 and the second pressure indicator 20, the first screw pump 8 is adjusted according to the change of the pressure value to make the static pressure expansion sleeve 18 expand evenly and clamp the workpiece. The working principle and process of the active end static pressure clamp 3 and the driven end static pressure clamp 4 are the same. The cavity of the first screw pump 8 and the first pressure indicator 7 and the static pressure expansion sleeve 18 are interconnected through the channels of the first oil circuit 15 and the second oil circuit 17. The clamp is debugged by the pre-load plunger 19 before leaving the factory. In normal operation, the pre-load plunger 19 does not participate in the work. After the pre-load plunger 19 adjusts the pressure, the pre-load plunger 19 is locked. After the clamp has been used for a long time, with the high-speed rotation of the high-speed workpiece, when the clamp cannot be released smoothly, the pressure is adjusted by the pre-load plunger 19.

[0031] In this embodiment, the first thread pump 8 adopts a manual thread pump, and the active end static pressure clamp 3 and the driven end static pressure clamp 4 on both sides supply oil and pressurize the static pressure expansion sleeve 18 through the manual thread pump oil supply system, and the real-time pressure value is obtained through further feedback of the pressure value, so as to meet the clamping force required on both sides of the workpiece 1. The static pressure expansion sleeve 18 expands evenly under the action of hydraulic oil to clamp the workpiece. The oil supply system of the clamp adopts a sealing device, and the pressure can reach up to 40MPa. The scale of the pressure indicator 7 can display a maximum of 36MPa. Among them, all radial oil ports are sealed with thread glue, and the oil ports in the axial direction adopt special oil filling holes, which can be repaired through the oil filling holes during maintenance.

[0032] like Figure 3 and 4 As shown, further, an adjustment pad 9 and a positioning cone 10 are provided on the side of the fixture body 27 away from the workpiece 1, the center of the positioning cone 10 is the same as the center of the fixture body 27, and the adjustment pad 9 is arranged around the outer circle of the positioning cone 10. In this embodiment, the adjustment pad 9 and the positioning cone 10 are arranged on the end face away from the workpiece 1. After the workpiece 1 is clamped by the active end static pressure fixture 3 and the driven end static pressure fixture 4 on both sides, when it is installed on the sharpening machine, the adjustment pad 9 will contact the sharpening machine before the positioning cone 10. After the adjustment pad 9 contacts the sharpening machine, the adjustment pad 9 is gradually ground so that the fixture and the machine reach an appropriate matching position. After the positioning cone 10 is accurately positioned with the sharpening machine, the positional relationship between the fixture holding the workpiece 1 and the sharpening machine is fixed. Among them, once the fixture is adjusted, each subsequent clamping can be automatically centered without additional adjustment, saving time and enabling efficient positioning.

[0033] Furthermore, the first pressure indicator 7 and the first thread pump 8 are arranged on the same radial line, and the length of the same radial line is less than the diameter of the fixture body. Furthermore, the second pressure indicator 20 and the second thread pump 21 are arranged on the same radial line, and the length of the same radial line is less than the diameter of the fixture body. In this embodiment, the maximum rotation speed of the fixture body can reach 4500rpm. Since the sharpening machine tool will generate a large centrifugal force when running at high speed, the first pressure indicator 7 and the first thread pump 8 and the second pressure indicator 20 and the second thread pump 21 are arranged on the center line away from the active end static pressure fixture 3 and the driven end static pressure fixture 4, which can effectively resist the centrifugal force generated during high-speed rotation.

[0034] Furthermore, the first pressure indicator 7 is provided with at least one scale. In this embodiment, the first pressure indicator 7 and the second pressure indicator 20 are two different pressure scales. When the fixture clamps the workpiece 1, the force nut of the first threaded pump 8 is screwed with an Allen wrench, and the two different scales of the exposed first pressure indicator 7 and the second pressure indicator 20 are observed to determine the pressure range inside the fixture.

[0035] Furthermore, a quick-insert connector 13 is also provided in the clamp body, and the quick-insert connector 13 is detachable. Furthermore, a protective cover 12 and a drain hole 11 are also provided in the active end static pressure clamp 3 and the driven end static pressure clamp 4. In this embodiment, no-load pressurization work cannot be performed when the clamp is used, because no-load pressurization will cause the static pressure expansion sleeve to rupture, causing damage to the clamps on both sides. Pressurization work can only be performed when the clamp is equipped with a workpiece or a protective cover 12. When the workpiece rotates at high speed on the sharpening machine, the heat generated in the workpiece 1 can be discharged through the drain hole 11 after being cooled by air, so as to remove water droplets and dissipate heat and reduce temperature.

[0036] Furthermore, a conical surface is provided at one end of the fixture body away from the workpiece 1, and the angle between the conical surface and the machine tool is 7°7'30". Figure 2 and 10 As shown, in this embodiment, when the clamps on both sides are connected to the sharpening machine, a standard cone angle α is adopted, wherein the value of α is 7°7'30", and the clamp and the sharpening machine are adjusted by grinding the adjustment pad 9 to achieve a suitable matching position. The clamp is repeatedly positioned so that its accuracy is controlled to be less than 0.005mm, and the positioning position accuracy of the positioning cone core 10 is less than 0.01mm.

[0037] The steps of clamping the workpiece using the clamping method of the gas turbine rotor blade tip grinding clamping workpiece are as follows:

[0038] The first step is to use an Allen wrench to tighten the force nuts of the manual second threaded pump 21 on the active end static pressure fixture 3 and the driven end static pressure fixture 4, observe the scale of the exposed second pressure indicator 20, and determine the pressure range inside the fixture by the high and low pressure scales.

[0039] Step 2: When the pressure range reaches the beating value, clamp the workpiece 1 with the active end static pressure fixture 3 and the driven end static pressure fixture 4, and then connect the first gas detection hole 5 and the second gas detection hole 6 to the external gas detection valve for detection. When the gas detection valve gives pressure feedback, it indicates that the position of the workpiece 1 is in place.

[0040] Step 3: After the second pressure value reaches the requirement and the active end static pressure fixture 3 and the driven end static pressure fixture 4 on both sides of the workpiece 1 are tested, pressurize and lock the workpiece body.

[0041] In this embodiment, the hydraulic oil is squeezed by the nut 22 of the first threaded pump 8, so that the ball valve 23 is pushed by the ball valve 23 to move the piston, so that the hydraulic oil enters the second oil circuit 17 through the oil hole along the edge of the first threaded pump 8, and enters the pressurized cavity through the first oil inlet hole 14 and the second oil inlet hole 25 on the second oil circuit 17. The hydraulic oil enters the oil hole of the second threaded pump 21, and then enters the cavity of the second pressure indicator 20. According to the change of the pressure value, the first threaded pump 8 is adjusted to make the static pressure expansion sleeve 18 expand evenly to clamp the workpiece. The working principles and processes of the active end static pressure clamp 3 and the driven end static pressure clamp 4 are the same. Among them, the second threaded pump 21 is used for debugging before leaving the factory and does not participate in the work during normal operation.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A fixture for grinding and clamping a workpiece at a gas turbine rotor blade tip, characterized in that: include: A clamp body (27), wherein the workpiece (1) is clamped by the clamp bodies (27) on both sides, wherein the clamp body (27) is provided with a first pressure indicator (7), a second pressure indicator (20) and a first screw pump (8), wherein the first pressure indicator (7) and the second pressure indicator (20) are both provided with a first cavity (16), wherein the first cavity (16) is filled with hydraulic oil, and the pressure value is fed back through the first pressure indicator (7) and the second pressure indicator (20); wherein the clamp body is provided with a first oil inlet hole (14), a second oil inlet hole (25), a first oil circuit ( 15) and a second oil circuit (17), the first oil inlet hole (14) and the second oil inlet hole (25) are both arranged on the second oil circuit (17), and the first oil circuit (15) and the second oil circuit (17) are communicated with the first cavity (16) and the second cavity (26); a static pressure expansion sleeve (18) is provided on a side of the fixture body (27) close to the workpiece (1), the static pressure expansion sleeve (18) is communicated with the first oil circuit (15) and the second oil circuit (17), and hydraulic oil enters the static pressure expansion sleeve (18) through the first oil inlet hole (14) and the second oil inlet hole (25); The first threaded pump (8) is provided with a nut (22), a ball valve (23), a piston (24) and a second cavity (26); the nut (22) is turned to squeeze the ball valve (23), and the piston (24) is pushed so that the second cavity (26) is filled with hydraulic oil; A second threaded pump (21) is also provided in the clamp body (27), and a pre-compression plunger (19) is provided in the second threaded pump (21); The first pressure indicator (7) and the first threaded pump (8) are arranged on the same radial line, and the length of the same radial line is less than the diameter of the clamp body; the second pressure indicator (20) and the second threaded pump (21) are arranged on the same radial line, and the length of the same radial line is less than the diameter of the clamp body.

2. A fixture for grinding and clamping a workpiece for a gas turbine rotor blade tip according to claim 1, characterized in that: The clamp body (27) is also provided with a first air detection hole (5) and a second air detection hole (6), both of which are air tightness detection holes connected to an external air detection valve to provide air tightness feedback.

3. A fixture for grinding and clamping a workpiece for a gas turbine rotor blade tip according to claim 1, characterized in that: An adjustment pad (9) and a positioning cone (10) are provided on a side of the clamp body (27) away from the workpiece (1); the center of the positioning cone (10) is the same as the center of the clamp body (27); and the adjustment pad (9) is arranged around the outer circle of the positioning cone (10).

4. A fixture for grinding and clamping a workpiece for a gas turbine rotor blade tip according to claim 1, characterized in that: The first pressure indicator (7) is provided with at least one scale.

5. A fixture for grinding and clamping a workpiece for a gas turbine rotor blade tip according to claim 1, characterized in that: A quick-insert connector (13) is also provided in the clamp body (27), and the quick-insert connector (13) is detachable.

6. A fixture for grinding and clamping a workpiece for a gas turbine rotor blade tip according to claim 1, characterized in that: A protective cover (12) and a drainage hole (11) are also provided in the clamp body (27).

7. A fixture for grinding and clamping a workpiece for a gas turbine rotor blade tip according to claim 1, characterized in that: The end of the clamp body (27) away from the workpiece (1) is also provided with a conical surface, and the angle between the conical surface and the machine tool is 7°7'30".

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