Gripping mechanism for a hydrostatic turntable and control method thereof

Abstract

The application discloses a holding mechanism for a static pressure rotary table and a control method thereof. The holding mechanism comprises a hydraulic assembly and a friction assembly. The hydraulic assembly comprises a hydraulic cylinder body and a hydraulic rod. The hydraulic cylinder body has a containing cavity. An elastic piece is arranged at the bottom of the containing cavity. The hydraulic rod is slidably arranged in the containing cavity and abuts against the elastic piece. The friction assembly comprises a first friction plate, a second friction plate and a main friction plate. The first friction plate is fixedly arranged on a base. The second friction plate is connected to the hydraulic rod. The main friction plate is arranged on a workbench and located between the first friction plate and the second friction plate. The second friction plate has a first position in contact with the main friction plate to lock the main friction plate on the first friction plate and lock the workbench. The elastic piece is configured to be pre-pressed when the static pressure rotary table is in an initial state, so that the second friction plate is in the first position. The application can solve the problem that the holding structure in the prior art is difficult to play a safety protection role on the rotary workbench when power is lost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of machining tools, in particular to a clamping mechanism for a hydrostatic rotary table and a control method thereof. BACKGROUND

[0002] As a key functional component of ultra-precision machining tools, the rotary table is responsible for providing precise rotary motion for the tool. When performing angle indexing tasks, the table can drive the workpiece to rotate accurately at a preset indexing angle along the circumferential path. When performing linkage machining, it moves in the circumferential direction and cooperates with other linear feed axes and rotary feed axes to complete high-precision machining of complex surfaces. In the linkage machining mode, the load is relatively small, and the load generated during cutting is mainly overcome by the motor. However, when heavy cutting is performed, the rotary table needs to be firmly locked by a clamping structure to ensure machining accuracy under heavy load.

[0003] The existing clamping structure includes a mouse-tooth disc clamping structure, a radial ring clamping device, and an axial friction plate clamping structure. Among them, the axial friction plate clamping structure has the advantages of simple structure, large clamping torque, and being applicable to rotary tables with arbitrary angle indexing, and is widely used. However, the axial friction plate clamping structure is driven by a hydraulic or pneumatic system to press or loosen the friction plates, and cannot provide safety protection for the rotary table when power is lost. SUMMARY

[0004] The main purpose of the present application is to provide a clamping mechanism for a hydrostatic rotary table and a control method thereof, to solve the problem that the existing clamping structure cannot provide safety protection for the rotary table when power is lost.

[0005] According to one aspect of the present application, a clamping mechanism for a hydrostatic rotary table is provided, the hydrostatic rotary table comprising a table and a base, the table being rotatably arranged on the base, the clamping mechanism comprising:

[0006] a hydraulic assembly arranged on the base, the hydraulic assembly comprising a hydraulic cylinder body and a hydraulic rod, the hydraulic cylinder body having a receiving cavity, the bottom of the receiving cavity being provided with an elastic member, the hydraulic rod being slidably arranged in the receiving cavity and abutting against the elastic member;

[0007] A friction assembly is arranged between the workbench and the base, and comprises a first friction plate, a second friction plate and a main friction plate. The first friction plate is fixedly arranged on the base. The second friction plate is connected to the hydraulic rod at an end away from the elastic member. The main friction plate is arranged on the workbench and located between the first friction plate and the second friction plate.

[0008] The second friction plate has a first position in contact with the main friction plate to lock the main friction plate on the first friction plate and lock the workbench. The elastic member is configured to be pre-pressed when the static pressure turntable is in an initial state, so that the second friction plate is in the first position.

[0009] Further, the holding mechanism further comprises a pre-pressing member movably arranged between the second friction plate and the hydraulic rod. The hydraulic rod is configured to move towards the elastic member under the pre-pressing of the pre-pressing member to pre-press the elastic member and make the second friction plate in the first position.

[0010] Further, an end of the hydraulic rod close to the second friction plate is provided with a threaded hole.

[0011] The second friction plate is provided with a connecting rod on a side close to the hydraulic assembly. The connecting rod extends away from the second friction plate, and an outer surface of the connecting rod is provided with a threaded segment matched with the threaded hole. At least part of the connecting rod is connected to the threaded hole through the threaded segment, so that the second friction plate is connected to the hydraulic rod.

[0012] The pre-pressing member comprises an adjusting nut rotatably sleeved on the connecting rod and reciprocally movable along the length direction of the connecting rod. When the adjusting nut moves along the length direction of the connecting rod towards the hydraulic rod, the hydraulic rod is in the first state.

[0013] Further, the connecting rod has an external segment protruding from the threaded hole. The adjusting nut is located on the external segment and has an adjusting gap with the second friction plate.

[0014] The width of the adjusting gap is smaller than the length of the external segment, and the minimum value A of the width of the adjusting gap satisfies the relationship: 5mm≤A≤10mm.

[0015] Further, the second friction plate further has a second position separated from the main friction plate to rotate the workbench.

[0016] The hydraulic rod is moved towards the elastic member to continuously compress the elastic member, so that the second friction plate is in the second position.

[0017] Further, an outer flange is arranged on the hydraulic rod, the outer flange is arranged on the outer surface of the hydraulic rod along the circumference of the hydraulic rod, and the outer flange is located in the accommodating cavity, and the outer flange has a pre-pressing space between one side close to the second friction plate and the hydraulic cylinder body.

[0018] The hydraulic assembly further comprises a fixing seat arranged on the base, the hydraulic cylinder body is connected to the fixing seat, and an oil inlet channel is arranged on the fixing seat and communicates between the accommodating cavity and a hydraulic station.

[0019] Further, the oil inlet channel is connected to the hydraulic station through an oil supply channel, and a pressure regulating valve is arranged on the oil supply channel, and the pressure regulating valve is used to at least regulate the pressure of the hydraulic oil entering the oil inlet channel.

[0020] Further, the hydraulic assembly comprises a plurality of hydraulic assemblies, and the plurality of hydraulic assemblies are arranged on the base along the circumference of the workbench.

[0021] The first friction plate and the second friction plate each comprise a plurality of first friction plates arranged on the base along the circumference of the workbench and corresponding to the plurality of hydraulic assemblies, a plurality of second friction plates corresponding to the plurality of hydraulic assemblies, and the main friction plate is located between the oppositely arranged first friction plate and second friction plate.

[0022] Among the plurality of hydraulic assemblies, the plurality of hydraulic assemblies are communicated through the same oil passing flow channel, and one of the plurality of hydraulic assemblies is communicated with the hydraulic station through the oil supply channel.

[0023] Further, the hydraulic cylinder body comprises a main body and a bottom shell, the bottom shell is detachably connected to the main body and forms the accommodating cavity with the main body, the bottom shell has a mounting column, the mounting column is sleeved with the elastic member, one end of the hydraulic rod close to the bottom shell has a through hole, and the mounting column is arranged in the through hole so that the hydraulic rod and the elastic member abut.

[0024] Further, the elastic member comprises a disc spring, and the disc spring is arranged at the bottom of the accommodating cavity in a superposition or apposition or composite superposition manner.

[0025] In another aspect, the application also provides a control method of the holding mechanism for the hydrostatic rotary table, which comprises the holding mechanism for the hydrostatic rotary table as described above, and the control method of the holding mechanism for the hydrostatic rotary table comprises:

[0026] Step S1: controlling the hydraulic rod to be in a first state by adjusting the nut to pre-press the elastic member so that the second friction plate is in the first position;

[0027] Step S2: controlling the hydraulic rod to be in a second state by the hydraulic oil to continuously compress the elastic member so that the second friction plate is in the second position.

[0028] Further, before the step S1 is performed, the stacking mode of the elastic member is selected, and the step of selecting the stacking mode of the elastic member comprises:

[0029] calculating the maximum load force P of the elastic member C and setting the pre-pressing force P1 of the elastic member, determining the number of the elastic members according to the ratio of P1 to P C , and determining the stacking mode of the elastic members, wherein P C =(4*E*t 2 *h0*K4 2 ) / [(1-μ 2 )*K1*D 2 ], wherein E is the elastic modulus, t is the thickness of the elastic member, h0 is the calculated value of the deformation amount of the elastic member without a supporting surface when being flattened, K4 is a calculation coefficient, μ is the Poisson's ratio, K1 is a calculation coefficient, and D is the outer diameter of the elastic member; and / or,

[0030] In the step S2, when the hydraulic oil controls the hydraulic rod to be in the second state, the predetermined pressure F applied by the hydraulic oil to the hydraulic rod in the pre-pressing space satisfies the relationship F=Ae*B-P1, wherein Ae is the area of the hydraulic oil acting on the outer flange, B is the working pressure of the hydraulic cylinder body, and P1 is the pre-pressing force of the elastic member.

[0031] The application sets the elastic member in the pre-pressing state in the hydraulic cylinder body, so that the elastic member can provide power for the hydraulic rod to approach the main friction plate, thereby locking the main friction plate on the first friction plate to hold the workbench. The whole holding process does not need the participation of the power system or the hydraulic system. Even in the case of power interruption or hydraulic system failure, the holding mechanism in the application can still ensure that the workbench is in the clamped state under the reaction force of the elastic member, effectively preventing the workbench from moving or rotating accidentally, and improving the safety and reliability of the hydrostatic rotary table. BRIEF DESCRIPTION OF DRAWINGS

[0032] The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the application. In the drawings:

[0033] Figure 1 A sectional view of the holding mechanism disclosed by the embodiments of the application;

[0034] Figure 2 A structural schematic view of the holding mechanism disclosed by the embodiments of the application arranged on a base;

[0035] Figure 3 A structural schematic view of the static pressure turntable disclosed by the embodiments of the application;

[0036] Figure 4 A partial structural schematic view of the static pressure turntable disclosed by the embodiments of the application;

[0037] Figure 5 A flow chart of the control method disclosed by the embodiments of the application;

[0038] Figure 6 A relational graph of the elastic deformation amount under different F / P conditions disclosed by the embodiments of the application. C

[0039] In the above drawings, the following reference signs are used:

[0040] 10, hydraulic assembly; 101, accommodating cavity; 102, pre-pressing space; 11, hydraulic cylinder body; 111, main body; 112, bottom shell; 113, mounting column; 12, hydraulic rod; 121, threaded hole; 122, outer flange; 123, through hole; 13, fixed seat; 131, oil inlet channel; 20, elastic member; 30, friction assembly; 31, first friction plate; 32, second friction plate; 33, main friction plate; 34, connecting rod; 341, threaded section; 342, external section; 40, pre-pressing member; 401, adjustment gap; 41, adjusting nut; 50, workbench; 60, base; 70, oil passage; A, minimum value of the width of the adjustment gap. DETAILED DESCRIPTION

[0041] It should be noted that the embodiments and the features in the embodiments in the present application can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0042] ​It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0043] The relative arrangement of parts and steps, numerical expressions, and numerical values set forth in the examples are not intended to limit the scope of the present application unless otherwise specifically stated. It is to be understood that the drawings are not necessarily to scale as the dimensions of the parts shown are for the purpose of illustration and description only. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art can not be discussed in detail, but should be considered as if the techniques, methods, and apparatus were discussed in detail herein. In all examples shown and discussed herein, any specific values are to be interpreted as illustrative only and not limiting. Thus, other examples of the exemplary embodiments can have different values. It is to be noted that like numbers and letters refer to like elements throughout the several views of the drawings and that one or more specific embodiments thereof can be shown in the drawings and described herein.

[0044] As mentioned in the background, the existing holding structures include mouse-tooth disc type holding structure, radial ring holding device and axial friction plate type holding structure. Among them, the axial friction plate type holding structure has the advantages of simple structure, large holding torque and being applicable to rotary workbench with arbitrary angle indexing, and is widely used. However, the axial friction plate type holding structure is driven by a hydraulic or pneumatic system to press or loosen the friction plates, and cannot play a safety protection role on the rotary workbench when power is lost. Therefore, the inventors of the present application design a new holding mechanism, which can solve the problem that the holding structure in the prior art cannot play a safety protection role on the rotary workbench when power is lost. The holding mechanism of the present application will be described in detail below in combination with the drawings.

[0045] Referring to Figures 1 to 4 As shown in the drawings, according to the embodiments of the present application, a holding mechanism for a hydrostatic rotary table is provided, the hydrostatic rotary table comprising a worktable 50 and a base 60, the worktable 50 being rotatably arranged on the base 60, the holding mechanism comprising a hydraulic assembly 10 and a friction assembly 30.

[0046] Specifically, the hydraulic assembly 10 is arranged on the base 60, the hydraulic assembly 10 comprises a hydraulic cylinder body 11 and a hydraulic rod 12, the hydraulic cylinder body 11 has a containing cavity 101, the bottom of the containing cavity 101 is provided with an elastic piece 20, the hydraulic rod 12 is slidably arranged in the containing cavity 101 and abuts against the elastic piece 20; the friction assembly 30 is arranged between the workbench 50 and the base 60, the friction assembly 30 comprises a first friction plate 31, a second friction plate 32 and a main friction plate 33, the first friction plate 31 is fixedly arranged on the base 60, the second friction plate 32 is connected to one end of the hydraulic rod 12 away from the elastic piece 20, and the main friction plate 33 is arranged on the workbench 50 and located between the first friction plate 31 and the second friction plate 32; wherein the second friction plate 32 has a first position in contact with the main friction plate 33 to lock the main friction plate 33 on the first friction plate 31 so as to lock the workbench 50, and the elastic piece 20 is configured to be pre-pressed when the static pressure turntable is in an initial state so that the second friction plate 32 is in the first position. It should be noted that the "initial state" in the embodiment refers to that the workbench 50 needs to be in a static state.

[0047] In the embodiment, since the main friction plate 33 is arranged on the workbench 50, the main friction plate 33 can be driven to rotate synchronously when the workbench 50 rotates. However, it is difficult to perform heavy cutting and other operations during the rotation of the workbench 50, and the workbench 50 needs to be firmly locked first to ensure that the workbench 50 can still maintain machining precision under heavy load conditions. Therefore, the embodiment is provided with the elastic piece 20 at the bottom of the containing cavity 101 of the hydraulic cylinder body 11, and the hydraulic rod 12 abuts against the elastic piece 20, and the elastic piece 20 is in a pre-pressed state. In this way, the elastic piece 20 will exert a counterforce on the hydraulic rod 12, so that the hydraulic rod 12 moves away from the elastic piece 20. During this process, since the second friction plate 32 is connected to one end of the hydraulic rod 12 away from the elastic piece 20, and the main friction plate 33 is located between the first friction plate 31 and the second friction plate 32, the hydraulic rod 12 will drive the second friction plate 32 to move towards the main friction plate 33, the second friction plate 32 will contact the main friction plate 33 and abut the main friction plate 33 on the first friction plate 31, so as to form the first friction plate 31 and the second friction plate 32 clamping the main friction plate 33, thereby generating a friction force to stop the rotation of the main friction plate 33, and further enabling the workbench 50 to stop rotating, thereby achieving the purpose of holding the workbench 50.

[0048] That is to say, the embodiment sets the elastic member 20 in the hydraulic cylinder body 11, and the elastic member 20 is in a pre-pressing state, so that the elastic member 20 can provide power for the hydraulic rod 12 to approach the main friction plate 33, so as to lock the main friction plate 33 on the first friction plate 31, so as to clamp the workbench 50. The whole clamping process does not need the participation of the power system or the hydraulic system, even in the case of power interruption or hydraulic system failure, the clamping mechanism in the embodiment can still ensure that the workbench 50 is in a clamped state under the reaction force of the elastic member 20, effectively prevent the workbench 50 from moving or rotating accidentally, and improve the safety and reliability of the static pressure turntable.

[0049] Exemplarily, the main friction plate 33 and the workbench 50 in the embodiment, and the first friction plate 31 and the base 60 can be connected together by screws, bolts and the like.

[0050] Further, referring to Figures 1 to 2 The clamping mechanism in the embodiment further comprises a pre-pressing member 40, which is movably arranged between the second friction plate 32 and the hydraulic rod 12. The hydraulic rod 12 is movable towards the elastic member 20 under the pressing action of the pre-pressing member 40 to pre-press the elastic member 20 so that the second friction plate 32 is in the first position. That is to say, when it is needed to make the elastic member 20 in a pre-pressing state, it is only needed to control the pre-pressing member 40 to move towards the direction close to the hydraulic rod 12, so as to drive the hydraulic rod 12 to move towards the elastic member 20. In this process, since the hydraulic rod 12 abuts against the elastic member 20, the movement of the hydraulic rod 12 will compress the elastic member 20, so that the elastic member 20 is pre-pressed.

[0051] Specifically, the pre-pressing member 40 is movably arranged between the second friction plate 32 and the hydraulic rod 12. By adjusting the position of the pre-pressing member 40, the pre-pressing degree of the hydraulic rod 12 to the elastic member 20 can be accurately controlled, so as to adjust the deformation amount of the elastic member 20, and then the reaction force of the elastic member 20 can be controlled to realize the accurate locking of the workbench 50, to a certain extent, avoid the problems that the friction plate is abraded due to the excessive pre-pressing force, and the service life of the friction plate is shortened, or the workbench 50 cannot be effectively locked due to the insufficient pre-pressing force, and the machining precision is affected. At the same time, the pre-pressing member 40 can make the clamping mechanism adapt to various working conditions, and effectively improve the flexibility of the clamping mechanism.

[0052] Further, referring to Figure 1As shown, the hydraulic rod 12 in the embodiment is provided with a threaded hole 121 at one end close to the second friction plate 32; the second friction plate 32 is provided with a connecting rod 34 at one side close to the hydraulic assembly 10, the connecting rod 34 extends away from the second friction plate 32, and the outer surface of the connecting rod 34 is provided with a threaded section 341 matched with the threaded hole 121, at least part of the connecting rod 34 is connected to the threaded hole 121 through the threaded section 341 so as to connect the second friction plate 32 to the hydraulic rod 12; the pre-pressing member 40 comprises an adjusting nut 41, which is rotatably sleeved on the connecting rod 34 and can reciprocate along the length direction of the connecting rod 34, wherein, when the adjusting nut 41 moves along the length direction of the connecting rod 34 towards the hydraulic rod 12, the hydraulic rod 12 can be in the first state. It can be understood that, in the embodiment, "at least part of the connecting rod 34 is connected to the threaded hole 121 through the threaded section 341" means that part of the connecting rod 34 is located in the threaded hole 121, and the other part is located outside the threaded hole 121.

[0053] Specifically, in the embodiment, the connecting rod 34 and the hydraulic rod 12 are connected through threads, and the connecting rod 34 is arranged on the second friction plate 32, when it is needed to disassemble the second friction plate 32 from the hydraulic rod 12, only need to rotate the connecting rod 34 to realize the separation of the second friction plate 32 and the hydraulic rod 12, which is simple in structure, convenient and fast in operation. At the same time, since the threaded connection has adjustability, by rotating the connecting rod 34, the position of the second friction plate 32 relative to the hydraulic rod 12 can be accurately adjusted, so that the distance between the second friction plate 32 and the main friction plate 33 can be controlled, to ensure that the second friction plate 32 can contact the main friction plate 33 under the reaction force of the elastic member 20. In addition, when the adjusting nut 41 moves along the length direction of the connecting rod 34 towards the hydraulic rod 12, it will push the hydraulic rod 12 to press the elastic member 20, so that the elastic member 20 is subjected to a certain pre-pressing force, and then the hydraulic rod 12 can be subjected to a reaction force to make the hydraulic rod 12 drive the second friction plate 32 to move towards the direction close to the main friction plate 33, and finally lock the main friction plate 33 between the first friction plate 31 and the second friction plate 32, to achieve the purpose of holding the workbench 50.

[0054] Further, referring to Figure 1 As shown, the connecting rod 34 in the embodiment has an external section 342 extending out of the threaded hole 121, and the adjusting nut 41 is located on the external section 342 and has an adjusting gap 401 with the second friction plate 32; wherein the width of the adjusting gap 401 is less than the length of the external section 342, and the minimum value A of the width of the adjusting gap 401 satisfies the relationship: 5mm≤A≤10mm, for example, A can be set to 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, 10mm, etc.

[0055] Specifically, when A is less than 5mm, the effective adjustment stroke of the adjusting nut 41 is short, and when the pre-pressing degree of the elastic member 20 needs to be adjusted, the adjusting space of the adjusting nut 41 is limited, and it is difficult to achieve accurate adjustment; when A is greater than 10mm, the adjusting stroke of the adjusting nut 41 is long, and when the pre-pressing force of the hydraulic rod 12 on the elastic member 20 needs to be adjusted through the adjusting nut 41, due to the large adjusting gap 401, the adjusting nut 41 needs to move a large distance to affect the hydraulic rod 12, thereby changing the pre-pressing state of the hydraulic rod 12 on the elastic member 20, which will cause the response time of the adjustment to become longer. That is to say, by making the minimum value A of the width of the adjusting gap 401 satisfy the relationship: 5mm≤A≤10mm in the embodiment, it can be ensured that the rotation of each thread can correspond to a relatively small and controllable displacement change, thereby realizing accurate control of the pre-pressing force.

[0056] Further, referring to Figures 1 to 2 The second friction plate 32 in the embodiment also has a second position separated from the main friction plate 33 to rotate the workbench 50; the hydraulic rod 12 has a second state moving towards the elastic member 20 to continuously compress the elastic member 20 so that the second friction plate 32 is in the second position.

[0057] Specifically, when it is necessary to loosen the workbench 50 to make the workbench 50 continue to rotate, it is only necessary to move the hydraulic rod 12 towards the elastic member 20 to continuously compress the elastic member 20, so as to drive the second friction plate 32 to separate from the main friction plate 33, effectively eliminating the friction between the second friction plate 32 and the main friction plate 33. The hindering effect of the rotation of the workbench 50, so that the workbench 50 can be smoothly rotated under the drive of the motor or other power devices, thereby realizing the machining of the workpiece at different angles.

[0058] Further, referring to Figure 1As shown, the hydraulic rod 12 in the embodiment is provided with an outer flange 122, which is arranged on the outer surface of the hydraulic rod 12 in the circumferential direction of the hydraulic rod 12 and is located in the accommodating cavity 101. The outer flange 122 has a pre-pressing space 102 between the side close to the second friction plate 32 and the hydraulic cylinder body 11. The hydraulic assembly 10 further comprises a fixing seat 13, which is arranged on the base 60 and is connected with the hydraulic cylinder body 11. The fixing seat 13 is provided with an oil inlet channel 131, which is communicated between the accommodating cavity 101 and the hydraulic station. The hydraulic oil in the hydraulic station enters the accommodating cavity 101 through the oil inlet channel 131 and flows to the pre-pressing space 102. The hydraulic oil in the pre-pressing space 102 applies a predetermined pressure to the hydraulic rod 12, so that the hydraulic rod 12 is in the second state. Exemplarily, the hydraulic cylinder body 11 and the fixing seat 13 in the embodiment can be connected by thread connection, screw connection or clamping connection, etc. Other deformation modes under the concept of the present application are also within the protection scope of the present application.

[0059] Specifically, in the embodiment, the oil inlet channel 131 is supplied with oil by the hydraulic station, so that the hydraulic oil enters the accommodating cavity 101 and flows to the pre-pressing space 102. The hydraulic oil is used to apply a predetermined pressure to the hydraulic rod 12, so that the hydraulic rod 12 is accurately in the second state, and then the second friction plate 32 can be separated from the main friction plate 33, thereby effectively improving the reliability and stability of the operation of the holding mechanism. The predetermined pressure applied by the hydraulic oil in the pre-pressing space 102 to the hydraulic rod 12 is stable and adjustable. The design of the outer flange 122 enables the hydraulic oil to form a relatively closed pre-pressing space 102 between the outer flange 122 and the hydraulic cylinder body 11, thereby ensuring the effective transmission of the pressure. That is to say, the separation of the second friction plate 32 and the main friction plate 33 is realized by hydraulic driving. When the hydraulic oil enters the pre-pressing space 102 to apply pressure to the hydraulic rod 12, the outer flange 122 on the hydraulic rod 12 plays a buffering role. The pressure of the hydraulic oil first acts on the outer flange 122, and the outer flange 122 uniformly transmits the force to the hydraulic rod 12, so that the force distribution of the hydraulic rod 12 is more uniform. This helps to avoid damage to the hydraulic rod 12 due to excessive local force, and also better transmits the force to the elastic member 20, thereby realizing stable control of the position of the second friction plate 32.

[0060] Further, the oil inlet channel 131 in the embodiment is connected with the hydraulic station through an oil supply channel (not shown in the drawings). The oil supply channel is provided with a pressure regulating valve (not shown in the drawings), which is used to at least adjust the pressure of the hydraulic oil entering the oil inlet channel 131.

[0061] Specifically, in this embodiment, the pressure regulating valve can precisely regulate the pressure of the hydraulic oil entering the inlet pipe. By changing the valve opening, the flow rate and pressure of the hydraulic oil can be controlled. During the operation of the hydrostatic turntable, different working stages or conditions may require different forces applied by the hydraulic rod 12. For example, during the working stage, higher pressure may be needed to ensure that the hydraulic rod 12 is stably in the second state, so that the second friction plate 32 can reliably separate from the main friction plate 33, ensuring the normal rotation of the worktable 50. At the same time, pressure fluctuations may occur in the hydraulic system. For example, when the pump of the hydraulic station suddenly starts or stops, or when other components in the system experience a brief malfunction, the pressure of the hydraulic oil may rise or fall instantaneously. The pressure regulating valve can act as a buffer to prevent excessive pressure from impacting the hydraulic rod 12 and other hydraulic components 10, thus avoiding equipment damage. Simultaneously, it can also prevent the hydraulic rod 12 from malfunctioning due to excessively low pressure, ensuring the basic functions of the equipment.

[0062] Furthermore, in order to achieve stable control of the worktable 50, the number and position of the clamping mechanisms can be set according to the clamping force required by the heavy-duty hydrostatic rotary table, see [reference]. Figure 4 As shown, the hydraulic components 10 in this embodiment include multiple hydraulic components 10, which are spaced apart on the base 60 along the circumference of the worktable 50. Multiple first friction plates 31 and second friction plates 32 are also included. Multiple first friction plates 31 are spaced apart on the base 60 along the circumference of the worktable 50 and are correspondingly arranged with each of the multiple hydraulic components 10. Multiple second friction plates 32 are correspondingly connected to each of the multiple hydraulic components 10. A main friction plate 33 is located between the opposing first friction plates 31 and second friction plates 32. The multiple hydraulic components 10 are connected through the same oil flow channel 70, and one of the multiple hydraulic components 10 is connected to the hydraulic station through an oil supply channel (not shown in the figures). Exemplarily, the hydraulic components 10, first friction plates 31, and second friction plates 32 in this embodiment can be two, three, or more. The figures of this embodiment show the case where there are eight hydraulic components 10, eight first friction plates 31, and eight second friction plates 32.

[0063] Specifically, in the embodiment, the plurality of hydraulic assemblies 10 are arranged in a circumferential direction of the workbench 50, and the plurality of first friction plates 31 and the plurality of second friction plates 32 are also arranged in the circumferential direction. When the hydraulic assemblies 10 are working, each hydraulic assembly 10 applies a force to the corresponding second friction plate 32, so that the second friction plate 32 is in contact with the main friction plate 33 to generate a friction force. The circumferential arrangement of the friction plates can uniformly distribute the friction force in the circumferential direction of the workbench 50, avoiding uneven force on the workbench 50 due to excessive local friction force. At the same time, since multiple friction plate assemblies are involved in the work, the total friction force is increased. When the workbench 50 needs to be braked, the plurality of hydraulic assemblies 10 act simultaneously, so that the plurality of second friction plates 32 are in close contact with the main friction plate 33, and the large friction force generated can quickly stop the workbench 50 from rotating, effectively improving the reliability and stability of the holding mechanism.

[0064] In addition, since the plurality of hydraulic assemblies 10 in the embodiment are connected through the same oil passage 70, and one of the plurality of hydraulic assemblies 10 is connected to the hydraulic station through the oil supply channel, the hydraulic oil in the hydraulic station flows into the hydraulic assembly 10 through the oil supply channel, and then flows into the other hydraulic assemblies 10 through the oil passage 70, to provide hydraulic oil to each hydraulic assembly 10. That is, the plurality of hydraulic assemblies 10 in the embodiment share the hydraulic oil circuit, and the multi-link hydraulic holding control can be performed through only one oil passage 70, effectively improving the holding efficiency of the plurality of hydraulic assemblies 10.

[0065] Further, as shown in FIG. 1, Figure 1 Further, as shown in FIG. 1,

[0066] Specifically, in the embodiment, the installation column 113 is arranged to achieve the accurate positioning of the elastic member 20 between the hydraulic rod 12 and the bottom shell 112, ensuring that the elastic member 20 does not deviate during operation and always remains in the correct position, thereby ensuring that the elastic force can stably act on the hydraulic rod 12. At the same time, when the hydraulic rod 12 is subjected to the pressure of the hydraulic oil or other external forces, the hydraulic rod 12 will abut against the elastic member 20, and the elastic member 20 can effectively transmit and buffer these forces, preventing the hydraulic assembly 10 from being damaged and prolonging the service life of the hydraulic assembly 10. In addition, since the bottom shell 112 in the embodiment is detachably connected to the main body 111, the installation and disassembly of the elastic member 20 are facilitated. When the elastic member 20 needs to be replaced, the bottom shell 112 is simply detached, and the elastic member 20 sleeved on the installation column 113 can be easily disassembled, reducing the operation difficulty.

[0067] Further, the elastic member 20 in the embodiment includes a disc spring, which is arranged at the bottom of the accommodating cavity 101 in a superimposed or matched or composite superposition manner.

[0068] Specifically, the disc spring can store energy and release it when needed, and it can withstand a large load in a small space, and the deformation is relatively small when a large load is applied, and has a high stiffness.

[0069] The disc spring can be arranged at the bottom of the accommodating cavity 101 in a superimposed or matched or composite superposition manner. Among them, superimposed refers to the combination of disc springs stacked one after another in the axial direction. In the superimposed manner, the load (Pz) of the disc spring group is related to the load (P) of a single disc spring as Pz=nP, where n is the number of disc springs. This means that the load that the superimposed disc spring group can withstand is n times the load of a single disc spring. For example, if a single disc spring can withstand a force of 50N, when there are 3 disc springs superimposed, the disc spring group can withstand a force of 150N (3x50N). When superimposed, the deformation (f) of the disc spring group is equal to the deformation (f1) of a single disc spring, because the disc springs are stacked one after another, and their deformations are synchronized.

[0070] Matched is a combination of disc springs placed side by side in the axial direction. The load (Hz) of the disc spring group is related to the load (H) of a single disc spring as Hz=nH, where n is also the number of disc springs. It is worth noting that H here may be different in value from P in superposition, because the load capacity of the disc spring is related to its placement and structure. For example, a single disc spring can withstand a force of 30N when placed in matched, and when there are 4 disc springs matched, the disc spring group can withstand a force of 120N (4x30N). In the matched manner, the deformation of the disc spring group is n times the deformation of a single disc spring, because the disc springs are placed side by side, and their deformations are cumulative.

[0071] The composite is a combination of the two ways of combining and combining the disc spring combination mode. The load of the disc spring group meets Pz=nP (reflected in the stacking part) and Hz=nH (reflected in the combined part). This combination can adjust the load capacity and deformation characteristics of the disc spring group according to actual needs. For example, in a composite disc spring group, there are 2 groups of stacking, each group of stacking has 3 disc springs, and there are 2 groups of combining. The load capacity and deformation of such a composite disc spring group are determined by the stacking and combining parts. The deformation of the composite disc spring group is determined by the deformation of the stacking part and the combining part, which contains the characteristics of synchronous deformation of the stacking part and the characteristics of cumulative deformation of the combining part.

[0072] It can be known from the above that no matter which stacking mode is used, the disc spring has high space utilization. In the limited space at the bottom of the accommodation cavity 101, by reasonably selecting the stacking mode of the disc spring, the space in the accommodation cavity 101 can be used to the maximum extent while meeting the elastic performance requirements.

[0073] On the other hand, referring to Figure 5 The control method for the holding mechanism of the static pressure turntable provided in the embodiment of the present application, and the control method for the holding mechanism of the static pressure turntable comprises the holding mechanism of the static pressure turntable described above, so the control method for the holding mechanism of the static pressure turntable comprises all the technical effects of the holding mechanism of the static pressure turntable described above. Since the technical effects of the holding mechanism of the static pressure turntable have been described in detail in the foregoing, they will not be described here.

[0074] Specifically, referring to Figure 5 The control method for the holding mechanism of the static pressure turntable in the embodiment comprises the following steps:

[0075] Step S1: Control the hydraulic rod 12 to be in the first state by adjusting the nut 41 to pre-press the elastic member 20 so that the second friction plate 32 is in the first position.

[0076] When it is needed to lock the worktable 50, it is only needed to rotate the adjusting nut 41 to move the adjusting nut 41 towards the hydraulic rod 12, so as to move the hydraulic rod 12 towards the elastic member 20, and then the elastic member 20 is pre-pressed. At this time, the elastic member 20 in the pre-pressed state transmits the reaction force to the hydraulic rod 12, so as to drive the hydraulic rod 12 to move towards the main friction plate 33, and then the second friction plate 32 abuts against the main friction plate 33, and the main friction plate 33 is locked between the first friction plate 31 and the second friction plate 32, so as to achieve the purpose of locking the worktable 50. The whole adjusting process does not need the participation of the electric system or the hydraulic system, so that the static pressure turntable can still keep the worktable 50 in the clamped state even in the case of power interruption or hydraulic system failure, effectively prevents the worktable 50 from moving or rotating accidentally, and improves the safety and reliability of the static pressure turntable.

[0077] Step S2: controlling the hydraulic rod 12 to be in the second state by the hydraulic oil to continuously compress the elastic member 20, so that the second friction plate 32 is in the second position.

[0078] Specifically, when it is needed to release the worktable 50, it is only needed to input the hydraulic oil of the hydraulic station into the accommodating cavity 101 through the oil inlet channel 131, and the hydraulic oil flows into the pre-pressing space 102 in the accommodating cavity 101 to contact the outer flange 122. At this time, the outer flange 122 drives the hydraulic rod 12 to move towards the elastic member 20 under the gravity of the hydraulic oil, so as to compress the elastic member 20, and then drive the second friction plate 32 to separate from the main friction plate 33, and finally achieve the purpose of releasing the worktable 50.

[0079] Further, before step S1 is performed, the stacking mode of the elastic member 20 is selected, and the step of selecting the stacking mode of the elastic member 20 includes: calculating the maximum load force P C of the elastic member 20, and setting the pre-pressing force P1 of the elastic member 20, and determining the number of the elastic member 20 according to the ratio of P1 to P C , and determining the stacking mode of the elastic member 20, wherein P C =(4*E*t 2 *h0*K4 2 ) / [(1-μ 2 )*K1*D 2 ], wherein E is the elastic modulus, t is the thickness of the elastic member 20, h0 is the calculated value of the deformation amount of the elastic member 20 without support surface when being flattened, K4 is a calculation coefficient, μ is the Poisson's ratio, K1 is a calculation coefficient, and D is the outer diameter of the elastic member 20. It should be noted that the unit of E is N / mm, and the value of E is 2.06*10 5N / mm, the unit of t is mm, the unit of h0 is mm, the unit of D is mm, and μ=0.3. It should be noted that the number of elastic members 20 is determined according to the installation space of the elastic members 20 at the bottom of the accommodating cavity 101.

[0080] Specifically, in the embodiment, when t=1.75 mm, h0=0.7 mm, D=31.5 mm, K1=0.682, K4=1, E=2.06*10 5 N / mm, μ=0.3, P C =5020 N. At this time, the number of elastic members 20 is set to 3, and the total load value of the elastic members 20 is 3P C =15060 N. It can be known that when F / P Figure 6 =4000 / 15060=0.266, f / h0=0.34, at this time, the deformation amount F0 of the elastic members 20 under load is 0.34*0.7=0.238 mm, and the total deformation amount is 3F0=3*0.238=0.714 mm. C

[0081] Further, in step S2, when the hydraulic oil controls the hydraulic rod 12 to be in the second state, the predetermined pressure F of the hydraulic oil on the hydraulic rod 12 in the pre-pressing space 102 satisfies the relationship F=Ae*B-P1, wherein Ae is the area of the hydraulic oil acting on the outer flange 122, B is the working pressure of the hydraulic cylinder body 11, and P1 is the pre-pressing force of the elastic member 20. It should be noted that the unit of Ae is mm 2 , the unit of B is Pa, and the unit of P1 is N.

[0082] Specifically, since the application controls the clamping mechanism to loosen the workbench 50 through the hydraulic system, a downward force needs to be applied to the hydraulic rod 12 to separate the second friction plate 32 from the main friction plate 33 during the loosening process of the workbench 50. Therefore, the predetermined pressure of the hydraulic rod 12 is set in the embodiment, so that the predetermined pressure F satisfies the relationship F=Ae*B-P1. In this way, the deformation amount of the elastic member 20 can be obtained according to the predetermined pressure, so that the deformation amount of the elastic member 20 can be controlled. According to F / P C , it can be known that the deformation amount of the elastic member 20. Figure 6

[0083] Specifically, in the embodiment, when Ae is 1107 mm 2 , B is 9*10 6 Pa, and P1 is 4000 N, F=1107*10 -6 *9*10 6 -4000=5963 N at this time. Since the deformation amount of the elastic member 20 needs to be determined according to F / P​​C to determine, thus, P C = (4*E*t 2 *h0*K4 2 ) / [(1-μ 2 )*K1*D 2 ] to calculate the specific value of P C , wherein, when t = 1.75 mm, h0 = 0.7 mm, D = 31.5 mm, K1 = 0.682, K4 = 1, E = 2.06*10 5 N / mm, μ = 0.3, P C is 5020 N, at this time, the overlapping number of the elastic member 20 is set to 3, then the total load value of the elastic member 20 is 3P C = 15060 N, F / P C = 5963 / 15060 = 0.396, according to Figure 6 It can be known that f / h0 = 0.44, at this time, the deformation amount f0 of the elastic member 20 under load is 0.44*0.7 = 0.308 mm, and the total deformation amount is 0.308*3 = 0.924 mm.

[0084] It can be known from the above embodiment that the disc spring pre-pressing mode is adopted to realize the clamping of the workbench 50, and even in the case of power interruption or hydraulic system failure, the workbench 50 can still be kept in the clamped state due to the spring force of the disc spring, effectively preventing the workbench 50 from moving or rotating accidentally, and improving the safety and reliability of the static pressure rotary table. At the same time, by changing the relative displacement amount between the adjusting nut 41 and the second friction plate 32, the compression deformation amount of the disc spring can be accurately controlled, so as to realize accurate adjustment of the clamping force. This adjustment mode makes the clamping mechanism adapt to the needs of different working conditions, and ensures that the workbench 50 has sufficient stability and precision in the clamped state. In addition, when the workbench 50 needs to be loosened, the hydraulic oil enters the hydraulic cylinder body 11 through the oil inlet channel 131, pushes the hydraulic rod 12 to move downward and compresses the disc spring, so that the second friction plate 32 is separated from the main friction plate 33, and then the quick and efficient loosening operation is realized, effectively improving the operation efficiency.

[0085] For purposes of the description hereinafter, the terms "upper", "lower", "right", "left", "rear", "front", "vertical", "horizontal", and derivatives thereof shall relate to the application as oriented in the drawing figures. However, it is to be understood that the application can assume various alternative orientations and, accordingly, such terms are not to be taken as limitations of the present application.

[0086] In addition, it should be noted that the use of "first", "second", etc. words to describe various components is only intended to distinguish a certain one to another, and the words do not have special meaning, and therefore cannot be understood as a limitation to the scope of protection of the present application.

[0087] The preferred embodiments of the application are thus described. Changes and modifications can be suggested to one skilled in the art, and it is the intention to encompass such changes and modifications within the scope of the appended claims.

Claims

1. A clamping mechanism for a hydrostatic turntable, the hydrostatic turntable comprising a worktable (50) and a base (60), the worktable (50) being rotatably disposed on the base (60), characterized in that, The clamping mechanism includes: A hydraulic assembly (10) is disposed on the base (60). The hydraulic assembly (10) includes a hydraulic cylinder (11) and a hydraulic rod (12). The hydraulic cylinder (11) has a receiving cavity (101). An elastic element (20) is disposed at the bottom of the receiving cavity (101). The hydraulic rod (12) is slidably disposed in the receiving cavity (101) and abuts against the elastic element (20). Friction assembly (30) is disposed between the worktable (50) and the base (60). The friction assembly (30) includes a first friction plate (31), a second friction plate (32) and a main friction plate (33). The first friction plate (31) is fixedly disposed on the base (60). The second friction plate (32) is connected to the end of the hydraulic rod (12) away from the elastic element (20). The main friction plate (33) is disposed on the worktable (50) and located between the first friction plate (31) and the second friction plate (32). The second friction plate (32) has a first position that contacts the main friction plate (33) to lock the main friction plate (33) onto the first friction plate (31) and lock the worktable (50). The elastic element (20) is configured to be pre-pressed when the hydrostatic turntable is in the initial state so that the second friction plate (32) is in the first position. The clamping mechanism further includes a pre-clamping member (40), which is movably disposed between the second friction plate (32) and the hydraulic rod (12). The hydraulic rod (12) has a first state in which it moves toward the elastic member (20) under the clamping action of the pre-clamping member (40) to pre-clamp the elastic member (20) so that the second friction plate (32) is in the first position. The hydraulic rod (12) has a threaded hole (121) at one end near the second friction plate (32); The second friction plate (32) is provided with a connecting rod (34) on the side near the hydraulic assembly (10). The connecting rod (34) extends in a direction away from the second friction plate (32), and the outer surface of the connecting rod (34) is provided with a threaded section (341) that is adapted to the threaded hole (121). At least part of the connecting rod (34) is connected to the threaded hole (121) through the threaded section (341), so that the second friction plate (32) is connected to the hydraulic rod (12). The pre-tightening component (40) includes an adjusting nut (41), which is rotatably sleeved on the connecting rod (34) and can reciprocate along the length direction of the connecting rod (34). When the adjusting nut (41) moves along the length direction of the connecting rod (34) toward the hydraulic rod (12), the hydraulic rod (12) can be in the first state. The connecting rod (34) has an external section (342) extending out of the threaded hole (121), and the adjusting nut (41) is located on the external section (342) and has an adjusting gap (401) between it and the second friction plate (32). Wherein, the width of the adjustment gap (401) is less than the length of the external segment (342), and the minimum value A of the width of the adjustment gap (401) satisfies the relationship: 5mm≤A≤10mm.

2. The clamping mechanism for a hydrostatic turntable according to claim 1, characterized in that, The second friction plate (32) also has a second position that is separated from the main friction plate (33) to allow the worktable (50) to rotate; The hydraulic rod (12) has a second state in which it moves toward the elastic member (20) to continuously compress the elastic member (20) so that the second friction piece (32) is in the second position.

3. The clamping mechanism for a hydrostatic turntable according to claim 2, characterized in that, The hydraulic rod (12) is provided with an outer flange (122), which surrounds the outer surface of the hydraulic rod (12) in the circumferential direction and is located in the accommodating cavity (101). There is a pre-compression space (102) between the side of the outer flange (122) near the second friction plate (32) and the hydraulic cylinder body (11). The hydraulic assembly (10) further includes a fixed seat (13), which is disposed on the base (60). The hydraulic cylinder (11) is connected to the fixed seat (13). The fixed seat (13) is provided with an oil inlet channel (131), which is connected between the accommodating cavity (101) and the hydraulic station. The hydraulic oil of the hydraulic station enters the accommodating cavity (101) through the oil inlet channel (131) and flows to the pre-pressurization space (102). The hydraulic oil in the pre-pressurization space (102) applies a predetermined pressure to the hydraulic rod (12) so that the hydraulic rod (12) is in the second state.

4. The clamping mechanism for a hydrostatic turntable according to claim 3, characterized in that, The oil inlet channel (131) is connected to the hydraulic station through the oil supply channel. A pressure regulating valve is provided on the oil supply channel. The pressure regulating valve is used to regulate the pressure of the hydraulic oil entering the oil inlet channel (131).

5. The clamping mechanism for a hydrostatic turntable according to claim 1, characterized in that, The hydraulic components (10) include a plurality of hydraulic components (10) which are arranged at intervals along the circumference of the worktable (50) on the base (60); The first friction plate (31) and the second friction plate (32) each include multiple ones. Multiple first friction plates (31) are arranged at intervals along the circumference of the worktable (50) on the base (60) and are arranged one-to-one with multiple hydraulic components (10). Multiple second friction plates (32) are connected one-to-one with multiple hydraulic components (10). The main friction plate (33) is located between the oppositely arranged first friction plates (31) and second friction plates (32). The plurality of hydraulic components (10) are connected to each other through the same oil passage (70), and one of the plurality of hydraulic components (10) is connected to the hydraulic station through the oil supply channel.

6. The clamping mechanism for a hydrostatic turntable according to claim 1, characterized in that, The hydraulic cylinder body (11) includes a main body (111) and a bottom shell (112). The bottom shell (112) is detachably connected to the main body (111) and forms the accommodating cavity (101) with the main body (111). The bottom shell (112) has a mounting post (113). The elastic element (20) is sleeved on the mounting post (113). The hydraulic rod (12) has a through hole (123) at one end near the bottom shell (112). The mounting post (113) passes through the through hole (123) so that the hydraulic rod (12) abuts against the elastic element (20).

7. The clamping mechanism for a hydrostatic turntable according to any one of claims 1 to 6, characterized in that, The elastic element (20) includes a disc spring, which is disposed at the bottom of the accommodating cavity (101) in a stacked, paired, or compound manner.

8. A control method for a clamping mechanism used in a hydrostatic rotary table, characterized in that, The control method for the clamping mechanism of the hydrostatic turntable includes the clamping mechanism for the hydrostatic turntable as described in any one of claims 1 to 7, wherein the control method for the clamping mechanism of the hydrostatic turntable includes: Step S1: Control the hydraulic rod (12) to the first state by adjusting the nut (41) to pre-tighten the elastic element (20) so that the second friction plate (32) is in the first position; Step S2: Control the hydraulic rod (12) to be in the second state by hydraulic oil to continuously compress the elastic element (20) so that the second friction plate (32) is in the second position.

9. The control method for the clamping mechanism of a hydrostatic turntable according to claim 8, characterized in that, Before performing step S1, the stacking method of the elastic element (20) is selected. The step of selecting the stacking method of the elastic element (20) includes: Calculate the maximum load force P of the elastic element (20). C The preload P1 of the elastic element (20) is set according to the relationship between P1 and P. C The ratio determines the number of the elastic elements (20), and the stacking method of the elastic elements (20) is determined, wherein P C =(4*E*t 2 *h0*K4 2 ) / [(1-μ 2 )*K1*D 2 ], where E is the elastic modulus, t is the thickness of the elastic element (20), h0 is the calculated value of the deformation of the elastic element (20) under compression without a support surface, K4 is the calculation coefficient, μ is Poisson's ratio, K1 is the calculation coefficient, and D is the outer diameter of the elastic element (20); and / or, In step S2, when the hydraulic oil controls the hydraulic rod (12) to be in the second state, the predetermined pressure F applied by the hydraulic oil to the hydraulic rod (12) in the pre-pressure space (102) satisfies the following relationship: F=Ae*B-P1, where Ae is the area of ​​the hydraulic oil acting on the outer flange (122), B is the working pressure of the hydraulic cylinder (11), and P1 is the pre-pressure of the elastic element (20).

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