Tool capable of controlling pre-tightening force and application

Abstract

The tool capable of controlling the pre-tightening force comprises a base module, an adjustable supporting and pressing mechanism module and an auxiliary supporting and pressing mechanism module capable of presetting the tightening force. The base module comprises a base (21), an inner hexagon screw C and a limiting block (13); three groups of threaded holes for fixing the adjustable supporting and pressing mechanism are distributed on the circular base; three to five T-shaped grooves are formed; the adjustable supporting and pressing module comprises a fixed base, a top ball B (25), a threaded ejector rod, an inner hexagon screw E and a supporting screw, and the fixed base is fixed to three sets of threaded holes used for fixing the adjustable supporting and pressing mechanism in the base (21) through the inner hexagon screw F. The convex spherical surface of the top ball B is plugged into the concave spherical surface of the threaded ejector rod (26). The threaded ejector rod moves up and down in a matched threaded pin hole in the fixed base (23); the jacking force can be preset to assist in supporting the pressing mechanism; a hydraulic jacking column (3) is installed on the movable base, a jacking ball A is arranged above the hydraulic jacking column, and the hydraulic jacking column can move up and down.

Description

Technical Field

[0001] The invention relates to a tool with controllable pre-tightening force, which is used to process thin-walled components such as a cavity stabilizer. Background Art

[0002] With the continuous development of modern aviation technology, the performance requirements for engines in various aircraft, such as starting, climbing, and emergency response, are constantly increasing. To address this problem, the concept of afterburner was proposed. The afterburner utilizes the residual oxygen in the exhaust of the main combustion chamber to inject fuel, which is then burned in the afterburner. This effectively increases the temperature of the gas in a very short time, thereby increasing the engine thrust. Because the afterburner is located after the turbine, the air velocity in the afterburner is extremely high, far exceeding the propagation speed of the flame. Furthermore, because the airflow in the afterburner originates from the main combustion chamber, its oxygen content is much lower than that of the main combustion chamber, which poses a significant challenge to stable combustion in the afterburner. To achieve a stable flame, a cavity stabilizer is introduced into the afterburner.

[0003] Due to the design requirements of modern aircraft engines, all bosses, shapes, holes, inner cavities, inclined holes and slots on the upper part need to be machined to meet the technical requirements of the drawing design. However, there are both circumferential distribution and inclined surface distribution, which forces us to choose five-axis equipment for processing to ensure that the workpiece is fully processed according to the design requirements. This has increased huge costs. In addition, due to the limitations of the spindle head structure of the five-axis machine tool (generally requiring a gantry-type five-axis machining center), our tool overhang is very long, which is very prone to sudden situations such as tool chattering during the processing, causing tool damage and low efficiency. In response to the above problems, combined with the equipment currently on the market, we have developed the following process plan: on the 805 three-axis vertical machining center, equipped with a rotary table and an angle head, and by designing a set of tooling with controllable pre-tightening force to process thin-walled components such as cavity stabilizers, we have completed the processing of thin-walled cylindrical disc components (with complex internal structures) such as cavity stabilizers.

[0004] The overall requirement for processing thin-walled parts such as cavity stabilizers is that the workpiece is clamped by a tool with controllable pre-tightening force (appropriate pre-tightening force). Too tight a clamping force will cause the thin-walled workpiece to deform or too loose a clamping force will cause the workpiece to be unable to be clamped, which may cause displacement of the workpiece during processing. The cavity stabilizer has a complex structure, a disc-shaped thin-walled cavity structure. The cavity flame stabilizer is a key component in the scramjet engine combustion chamber for enhancing fuel mixing and maintaining flame stability. Its core feature is the flame stabilization effect achieved through the recirculation zone formed in the cavity. Figure 1 As shown, the parts can only be produced by 3D printing, and the precision is far from enough to be used directly in the engine. Summary of the Invention

[0005] The purpose of the present invention is to propose a tooling with controllable pre-tightening force and its application. With the help of this tooling, a three-axis vertical machining center equipped with a turntable and an angle head can be used to process thin-walled components such as cavity stabilizers, which can reduce costs and ensure stable product quality.

[0006] The technical solution of the present invention is a tool with controllable pre-tightening force, comprising a base module, an adjustable support and clamping mechanism module, and an auxiliary support and clamping mechanism module with presettable tightening force;

[0007] The base module consists of a base 21, a hexagon socket screw C, and a stopper 13. Three sets of threaded holes are distributed on the circular base for fixing the adjustable support and clamping mechanism. There are also three to five T-slots for installing the auxiliary support and clamping mechanism with preset top tightening force. A stopper 13 fixed by a hexagon socket screw C is provided at the notch of each T-slot, forming the base module.

[0008] The adjustable support and clamping module includes a fixed base, a top ball B25, a threaded push rod, an hexagon socket screw E (rod), and a support screw. The fixed base 23 is fixed to the base through the hexagon socket screw F24. Three groups of threaded holes 23-1 for fixing the adjustable support and clamping mechanism, the convex spherical surface of the top ball B is inserted into the concave spherical surface of the threaded push rod 26, and the external thread of the threaded push rod is engaged with the threaded pin hole provided on the fixed base 23. The threaded push rod moves up and down in the matching threaded pin hole in the fixed base 23, so that the flat part of the top ball B25 can always maintain contact with one surface or at least three points when it contacts the plane of the workpiece or a surface that is not very flat; then screw the support screw (rod) 19 into the threaded hole of the pressure plate 20 and adjust it to a suitable length. Screw one end of the pressure plate onto the support screw, press the pressure plate on the appropriate position of the workpiece, and use the upper end of the hexagon socket screw E18 to pass through the hole on the pressure plate and the lower end of the hexagon socket screw E18 to be screwed into the screw hole on the fixed base to fix the center of the pressure plate to clamp the workpiece;

[0009] The pre-settable tightening force auxiliary support clamping mechanism includes a jacking ball A, a hydraulic jacking column 3, a sealing ring B16, a hexagon socket pressure screw, a movable base 8, a T-block, a hexagon socket tightening screw A, a steel ball 4 and a spring 5, a hexagon socket tightening screw B11, and a sealing pressure relief seat 10; the hexagon socket screw D for fixing is inserted from above into the corresponding screw hole of the movable base, and a T-block 14 is installed below the hexagon socket screw D; the T-block is installed in the T-slot on the base module;

[0010] The hydraulic jack 3 is installed on the movable base 8. The top of the hydraulic jack 3 is the jack ball A. The hydraulic jack 3 can move up and down, so that the flat part of the jack ball A can always maintain a single surface or at least three points of contact when it contacts the plane of the workpiece or a surface that is not very flat; then screw the support screw (rod 19) into the threaded hole of the pressure plate 20 and adjust it to a suitable length. Screw one end of the pressure plate 20 onto the support screw, press the pressure plate onto the appropriate position of the workpiece, and pass the upper end of the hexagon socket screw E18 through the hole in the pressure plate and the lower end of the hexagon socket screw E18 is screwed into the screw hole on the fixed base to fix the center of the pressure plate to press the workpiece;

[0011] Insert the steel ball 4 and spring 5 into the inner hole of the sealing pressure relief seat 10 in sequence, screw the hexagon socket set screw B11 into the sealing pressure relief seat 10 to form a new assembly, insert this new assembly into the inner hole of the hydraulic jack 3, and use the hexagon socket screw B9 to fix the new assembly on the movable base 8.

[0012] A threaded hole is provided at the rear end of the movable base 8, which can be used to inject an appropriate amount of hydraulic oil into the inner cavity of the movable base 8. The cylindrical end of the hexagonal pressure screw 17 with the sealing ring B16 installed on the cylindrical end is inserted into the corresponding hole at the rear end of the movable base 8 and the thread of the hexagonal pressure screw 17 is screwed into the movable base 8.

[0013] At this point, the main body of the auxiliary support and clamping mechanism with preset jacking force is formed. By placing a weight of appropriate weight on the upper plane of the top ball A1 (simulating the preset jacking force), and then continuously screwing in the hexagon socket pressure screw 17, the hydraulic oil fills the inner cavity of the movable base 8 and forms a certain pressure value. By adjusting the depth of the hexagon socket tightening screw B11 screwed into the sealing pressure relief seat 10, the elastic force of the spring 5 is changed, so that the steel ball 4 is separated from the contact with the upper conical surface of the inner hole of the sealing pressure relief seat 10 when the force is appropriate, thereby removing the excessive pressure in the movable base 8, and thus obtaining the desired preset jacking force.

[0014] Furthermore, the convex spherical surface of the top ball A1 is installed into the concave spherical surface of the hydraulic jack column 3, and the assembly is inserted into the movable base 8 with the sealing ring A6 installed. The direction is adjusted so that the cylindrical surfaces of the two hexagon socket set screws A2 are respectively vertically inserted into the two long grooves on the side of the hydraulic jack column 3.

[0015] Finally, screw the support screw 19 into the threaded hole 23-1 of the pressure plate 20, adjust it to the appropriate length, press the pressure plate on the appropriate position of the workpiece, and tighten the workpiece with the hexagon socket screw E18.

[0016] Thus, a component is formed which can preset a pressing force to assist in supporting the pressing mechanism.

[0017] The tooling with controllable pre-tightening force of the present invention is used for processing thin-walled cylindrical or disc-shaped parts such as cavity stabilizers.

[0018] Beneficial effects: The fixture of the present invention uses the principle of three points to determine a surface, which is very convenient and quick when adjusting the workpiece. At the same time, by pre-setting the pre-tightening force to assist in supporting the workpiece, the deformation of the workpiece during the clamping process is effectively controlled, laying a solid foundation for stable quality. The use of a fixture with controllable pre-tightening force to process thin-walled cylinders (frustum, etc.) or disc-shaped parts such as cavity stabilizers, the design, use and process of the fixture of the present invention can greatly reduce the processing cost of this type of product, with high efficiency, controllable cost and stable product quality. It can meet the requirements of completing the machining and inspection of parts through the processes of turning, inspection and milling by clamping the parts once. Of course, thin-walled parts such as cavity stabilizers are generally cylinders, discs or cones. The clamping of the present invention can be used for vertical turning, milling, boring and other machining, which can greatly improve the machining accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram of the workpiece structure processed by the present invention;

[0020] Figure 2 It is a schematic structural diagram of a partial cross-section of the tooling of the present invention;

[0021] Figure 3 This is a schematic diagram of the base module structure of the tooling of the present invention;

[0022] Figure 4 A schematic diagram of the structure of the adjustable support and pressing mechanism of the tooling of the present invention;

[0023] Figure 5 yes Figure 4 sectional view of

[0024] Figure 6A Schematic diagram of the forward structure of the movable base;

[0025] Figure 6B Schematic diagram of the rear structure of the movable base;

[0026] Figure 7 Sealing pressure relief seat 10

[0027] Figure 8 Schematic diagram of the structure of the hydraulic jack 3;

[0028] Figure 9 Schematic diagram of fixed base 23;

[0029] Figure 10 Schematic diagram of the structure of threaded push rod 26.

[0030] Figure 11 It is a schematic diagram of the top ball structure of the present invention. DETAILED DESCRIPTION

[0031] Parts markings in the figure: top ball 1, hexagon socket set screw A2, hydraulic top column 3, steel ball 4, spring 5, sealing ring A6, hexagon socket screw A7, movable base 8, hexagon socket screw B9, sealing pressure relief seat 10, hexagon socket set screw B11, hexagon socket screw C12, limit block 13, T-block 14, T-slot 14-1, hexagon socket screw D15, sealing ring B16, hexagon socket pressure screw 17, hexagon socket screw E18, support screw 19, pressure plate 20, base 21, workpiece 22, fixed base 23; hydraulic top column installation position 3-1, top ball installation position 3-2, hexagon socket Screw E18 mounting position 18-1, hexagon socket set screw A2 mounting position 2-1; hexagon socket pressure screw mounting position 17-1, limit surface 3-3, hydraulic oil inlet 3-4, seal ring mounting groove 3-5, hexagon socket screw D15 mounting position 15-1; in the pressure relief seat 10: oil groove 10-1, spring mounting position 5-1, hexagon socket screw B mounting position 9-1, hexagon socket set screw B mounting position 11-1; fixed base 23, threaded push rod mounting position 26-1, hexagon socket screw F mounting position 24-1, hexagon socket screw E mounting position 18-1; threaded push rod 26. Schematic diagram of the hydraulic push column 3 structure.

[0032] With the help of this tooling, a three-axis vertical machining center is equipped with a turntable and an angle head, and a tooling with controllable pre-tightening force is used to process thin-walled components such as cavity stabilizers. The design, use and process of the tooling of the present invention can greatly reduce the processing cost of this type of product, with higher efficiency, controllable cost and stable product quality.

[0033] 1. Process flow of using the tooling of the present invention

[0034] Since the blank of the cavity stabilizer is a 3D printed part, its consistency is not very good, and due to design requirements, its wall thickness is only 2 mm to 3 mm. The structural rigidity is not very good and it is easy to deform when affected by external forces.

[0035] Faced with the above problems, we designed a process flow for machining the cavity stabilizer on a three-axis vertical machining center equipped with a rotary table and an angle head: mark the upper and lower and angular reference lines, check the allowance of each machining surface---clamp the workpiece on the special tooling as required---turn the upper plane and outer cylindrical reference surface of the part---blue light scanning to determine the allowance of each surface of the workpiece---rough turn the part's outer shape and inner cavity---aging treatment---fine turn each surface of the part---use the rotary table for rough and fine milling of the part's inner and outer bosses---clamp and clean the workpiece---mark and mark---final inspection of the part.

[0036] In the process of the present invention, since the parts are 3D printed workpieces, we first mark the upper and lower reference lines and angular reference lines of the parts according to the reference plane of the rough drawing, and roughly check whether there is any allowance on each processing surface. After confirming the allowance, the workpiece is placed on a special tooling (i.e., the tooling of the present invention), and the workpiece is clamped according to the previous marking as the reference. Then, it is put on the lathe, and the outer circle and plane reference are rough-turned. Then, blue light scanning is used to finally confirm that there is no problem with the clamping of the workpiece (if the scan finds that there is no allowance in some places, the workpiece needs to be re-clamped, and the outer circle and plane are rough-turned, and blue light scanning is performed again until it is qualified). After the blue light inspection, the shape and inner cavity of the part are rough-turned, and then natural aging is performed. After aging, each surface is fine-turned. After the turning is completed, the workpiece is mounted on the turntable of the vertical machining center together with the tooling, and the angle head is used to process the surfaces, holes, grooves, etc. that need to be processed. Finally, the workpiece is clamped, cleaned, and marked. Finally, the part is finally inspected.

[0037] By adopting this set of process flow, the length of the process route is shortened, the flow speed of the workpiece is effectively increased, and the efficiency is improved. The rough, semi-finishing to finishing and natural aging methods are adopted to effectively control the deformation of the parts. At the same time, because we adopt the method of secondary blank allowance detection, the one-time qualified rate of the parts is guaranteed, and the quality of the product is stabilized.

[0038] 2. Specific structure of tooling

[0039] Design according to parts processing requirements Figure 2 As shown, it can meet the requirements of completing the turning, inspection, and milling processes of parts through a single clamping operation. This fixture uses the principle of three points to determine a surface, making it very convenient and quick to adjust the workpiece. At the same time, by pre-setting the pre-tensioning force to assist in supporting the workpiece, it effectively controls the workpiece deformation during the clamping process, laying a solid foundation for stable quality.

[0040] The tooling mainly consists of three parts: a base module, an adjustable support and clamping mechanism module, and an auxiliary support and clamping mechanism module with preset top clamping force.

[0041] (1) Base module

[0042] Figure 3 As shown, the base module consists of a base 21, hexagon socket head screws C12, and a stopper 13. Three sets of four screw holes are located on the circular base 21, threaded holes for securing the adjustable support and clamping mechanism. There are also five T-slots for mounting the auxiliary support and clamping mechanism with presettable tightening force. Each T-slot has a stopper 13 secured by two hexagon socket head screws C12. This completes the base module.

[0043] Adjustable support and clamping mechanism, such as Figure 4As shown, the adjustable support and clamping mechanism secures the fixed base 23 to the base 21 using four hexagon socket screws F24. The convex surface of the top ball B25 is inserted into the concave surface of the threaded push rod 26. By pinching and rotating the knurled surface of the threaded push rod 26, the threaded push rod 26 engages with the thread of the fixed base 23, allowing the threaded push rod 26 to move up and down within the mating pin hole in the fixed base 23. This ensures that the flat surface of the top ball B25 maintains a single surface or at least three points of contact when contacting a flat or uneven surface, thus ensuring the stability of the contact surface. Support screws 19 are then screwed into the threaded holes of the pressure plate 20 and adjusted to the appropriate length. The pressure plate 20 is then pressed against the workpiece in the desired position, and the workpiece is then clamped with the hexagon socket screws E18. This completes the modular assembly of the adjustable support and clamping mechanism.

[0044] Presettable tightening force to assist in supporting the clamping mechanism:

[0045] Insert the convex surface of the jack ball A1 into the concave surface of the hydraulic jack column 3. Insert the assembly into the movable base 8, which has been fitted with the sealing ring A6. Adjust the orientation so that the cylindrical surfaces of the two hexagon socket set screws A fit into the two long grooves on the side of the hydraulic jack column 3. Insert the steel ball 4 and the spring 5 into the inner hole of the sealing pressure relief seat 10 in sequence. Thread the hexagon socket set screw B11 into the sealing pressure relief seat 10 to form a new assembly. Insert this new assembly into the inner hole of the hydraulic jack column 3 and secure it to the movable base 8 with the hexagon socket screw B9.

[0046] At the same time, an appropriate amount of hydraulic oil is injected into the inner cavity of movable base 8 through the threaded hole at the rear end of movable base 8. The cylindrical end of hexagon socket pressure screw 17, with sealing ring 16 installed on the cylindrical end, is inserted into the corresponding hole at the rear end of movable base 8, and the threads of hexagon socket pressure screw 17 are screwed into movable base 8. This now forms the main part of the preset tightening force auxiliary support and clamping mechanism. By placing an appropriately heavy object (simulating the preset tightening force) on the upper surface of ball 1 (A), and continuously screwing in hexagon socket pressure screw 17, the hydraulic oil fills the inner cavity of movable base 8 and builds a certain pressure. By adjusting the depth of hexagon socket pressure screw 11 into the sealing pressure relief seat 10, the spring force of spring 5 is adjusted, so that steel ball 4 disengages from the tapered surface of the inner hole of sealing pressure relief seat 10 when the appropriate force is applied, thereby relieving the excess pressure in movable base 8 and achieving the desired preset tightening force.

[0047] Then use two No. 15 hexagon socket screws D to insert them into the corresponding screw holes of the movable base No. 8 from above, and install the No. 14 T-block under the two screws.

[0048] Finally, screw the support screw 19 into the threaded hole of the pressure plate 20, adjust it to the appropriate length, press the pressure plate 20 on the appropriate position of the workpiece, and tighten the workpiece with the hexagon socket screw E 18. This forms a component that can preset the tightening force to assist in supporting the clamping mechanism.

[0049] Assembly and use process of the tooling: To assemble the tooling, place the base module with the front side facing up on the platform, connect the three adjustable support and clamping mechanism component modules to the three threaded holes in groups of four on the base module through the hexagon socket screws F24, and adjust the position so that the circle formed by the centers of the three top balls B25 is as concentric as possible with the base module.

[0050] Install the five components of the pre-set pressure and pre-set clamping mechanism (three or four evenly distributed components are also acceptable; considering thin-walled structural components, more pre-set clamping devices are better) into the T-slot of the base module via T-blocks 14. Position the top ball A1 away from the center of the base module. Be careful not to push the movable base 8 all the way to the bottom. Ensure that the limit block 13 on the base module is at a certain distance from the limit surface below the movable base 8 to facilitate workpiece clamping. This completes the assembly of the tooling.

[0051] To use the tooling, place the assembled tooling on the platform, remove one adjustable support and clamping mechanism component module, and place the workpiece on the tooling in an eccentric manner. At this time, the remaining two adjustable support and clamping mechanism component modules are just stuck in the groove of the workpiece cavity, and then adjust the threaded push rod 26 of the removed adjustable support and clamping mechanism component module to the lowest position, install the adjustable support and clamping mechanism component module back to its original position, and adjust the position of the workpiece so that the workpiece is basically concentric with the tooling.

[0052] According to the allowance line drawn in the previous process, by using the height gauge and the up and down adjustment of the threaded push rod 26, the allowance line is calibrated to the horizontal plane, and the pressure plate 20 on the three adjustable support and clamping mechanism component modules is placed at the appropriate position of the workpiece, so that the upper plane of the push ball B 25 on the three adjustable support and clamping mechanism component modules is in stable contact with the workpiece at least 3 points, and the workpiece is clamped by the hexagon socket screw E18. At this time, the main body clamping of the workpiece is completed, and the components of the auxiliary support and clamping mechanism with preset clamping force are clamped.

[0053] Retract the hexagon socket pressure screw 17 on the component of the preset tightening force auxiliary support and clamping mechanism to the end, so that the plane of the top ball A1 on the hydraulic jacking column 3 drops to the lowest surface, and retract the movable base 8 to the bottom, so that the limit block 13 on the base module contacts the limit surface below the movable base 8, and lock the two hexagon socket screws D15 on the component of the preset tightening force auxiliary support and clamping mechanism, fix the component of the preset tightening force auxiliary support and clamping mechanism on the base module, and turn the hexagon socket pressure screw 17 inward. Tighten and push the hydraulic jack 3 upward. When the plane of the jack ball A1 on the hydraulic jack 3 contacts the workpiece, continue to tighten the hexagon socket pressure screw 17 inward until the preset pressure is reached. At this time, lock the two hexagon socket tightening screws A2, place the pressure plate 20 on the assembly of the five preset tightening force auxiliary support clamping mechanism at the appropriate position of the workpiece, and press the workpiece with the hexagon socket screw E18. Check whether all contact surfaces are in contact and whether all screws are tightened. After confirmation, the workpiece clamping is completed.

[0054] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A tool with controllable pre-tightening force, characterized by: It consists of three parts: a base module, an adjustable support and clamping mechanism module, and an auxiliary support and clamping mechanism module with preset top clamping force; The base module comprises a base (21), a hexagon socket screw C and a limit block (13); on the circular base, three groups of threaded holes for fixing the adjustable support and clamping mechanism are distributed; there are also three to five T-slots for installing the auxiliary support and clamping mechanism with a preset top tightening force; a limit block fixed by the hexagon socket screw C is provided on the notch of each T-slot; forming the base module; The adjustable support and clamping module includes a fixed base, a top ball B (25), a threaded push rod, an inner hexagon screw E, and a support screw. The fixed base is fixed to the base (21) by the inner hexagon screw F24. Three sets of threaded holes for fixing the adjustable support and clamping mechanism are used. The convex spherical surface of the top ball B is inserted into the concave spherical surface of the threaded push rod (26). The external thread of the threaded push rod is engaged with the threaded pin hole provided on the fixed base. The threaded push rod moves up and down in the matching threaded pin hole in the fixed base (23), so that the plane part of the top ball B can always maintain a surface or at least three points of contact when it contacts the plane of the workpiece or a surface that is not very flat; then the support screw (19) is screwed into the threaded hole of the pressure plate (20) and adjusted to a suitable length. One end of the pressure plate (20) is screwed onto the support screw. The pressure plate is pressed on a suitable position of the workpiece. The upper end of the inner hexagon screw E is passed through the hole on the pressure plate and the lower end of the inner hexagon screw E (18) is screwed to the screw hole on the fixed base to fix the center of the pressure plate to clamp the workpiece; The auxiliary support and clamping mechanism with preset tightening force includes a top ball A, a hydraulic top column (3), a sealing ring B (16), a hexagonal pressure screw, a movable base (8), a T-block, a hexagonal top screw A, a steel ball (4) and a spring (5), a hexagonal top screw B (11), and a sealing pressure relief seat (10); the hexagonal screw D for fixing is inserted into the corresponding screw hole of the movable base from above, and a T-block (14) is installed below the hexagonal screw D; the T-block is installed in the T-slot on the base module; The hydraulic ejector column (3) is installed on the movable base. The ejector ball A is located above the hydraulic ejector column. The hydraulic ejector column can move up and down so that the flat part of the ejector ball A can always maintain a surface or at least three points of contact when it contacts the plane of the workpiece or a surface that is not very flat. Then, the support screw (19) is screwed into the threaded hole of the pressure plate and adjusted to a suitable length. One end of the pressure plate is screwed onto the support screw. The pressure plate is pressed on a suitable position of the workpiece. The upper end of the hexagon socket screw E (18) is passed through the hole on the pressure plate and the lower end of the hexagon socket screw E is screwed into the screw hole on the fixed base to fix the center of the pressure plate to press the workpiece. Insert the steel ball and spring into the inner hole of the sealing pressure relief seat in sequence, screw the hexagon socket set screw B (11) into the sealing pressure relief seat to form a new assembly, insert this new assembly into the inner hole of the hydraulic jack, and use the hexagon socket screw B (9) to fix the new assembly on the movable base; A threaded hole is provided at the rear end of the movable base. An appropriate amount of hydraulic oil is injected into the inner cavity of the movable base 8. The cylindrical end of the hexagonal pressure screw (17) with the sealing ring B (16) installed on the cylindrical end is inserted into the corresponding hole at the rear end of the movable base (8) and the thread of the hexagonal pressure screw (17) is screwed into the movable base.

2. The tooling with controllable pre-tightening force according to claim 1 is characterized in that: Install the convex spherical surface of the jack ball A into the concave spherical surface of the hydraulic jack column, insert the assembly into the movable base with the sealing ring A installed, and adjust the direction so that the cylindrical surfaces of the two hexagon socket set screws A are vertically inserted into the two long grooves on the side of the hydraulic jack column.

3. The tooling with controllable pre-tightening force according to claim 1, characterized in that: The upper conical surface of the sealing pressure relief seat inner hole contacts the steel ball.

4. The tooling with controllable pre-tightening force according to any one of claims 1 to 3 is used for processing thin-walled cylindrical or disc-shaped parts of cavity stabilizers.

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