Floating type automatic positioning clamp

Abstract

The floating type automatic positioning clamp comprises a base platform used for bearing a valve block to be machined, and a sinking rectangular groove is formed in the upper surface of the base platform; the main positioning module is used for providing positioning of an XY plane, and the main positioning module is composed of a cylindrical positioning pin and a rhombic positioning pin; the reference supporting module is used for providing Z-direction positioning and comprises equal-height supporting pads arranged at the corners of the sinking rectangular groove respectively; and the floating clamping module is used for carrying out self-adaptive clamping on the valve block. Through the gridding base and the pluggable positioning pin, the main positioning module can be rapidly matched with the positions of auxiliary holes of different valve blocks, the model changing time is greatly shortened, the reference supporting module and the floating clamping module are combined for use, the side face tolerance of the valve blocks can be compensated in a self-adaptive mode, multi-point uniform contact is ensured, deformation caused by rigid clamping is avoided, and the service life of the valve blocks is prolonged. Through combination of flexible positioning and self-adaptive clamping, the problems of positioning precision and clamping stability in multi-variety small-batch production are effectively solved.

Description

Technical Field

[0001] This invention relates to the field of valve block positioning and processing equipment, and in particular to a floating automatic positioning fixture. Background Technology

[0002] Currently, existing valve block fixtures mainly rely on manual alignment and clamping, or employ rigid positioning structures. The former is inefficient, its accuracy is affected by human factors, and its consistency is poor; while the latter, although more efficient, has stringent requirements for the tolerances of the blank parts and is prone to inaccurate positioning due to errors.

[0003] A more prominent problem is that existing fixtures generally suffer from clamping deformation. Rigid clamping forces easily cause stress concentration in local areas of the valve block, leading to minute deformations. After machining, stress release can trigger springback, ultimately causing the parts to exceed tolerances.

[0004] In pursuit of stability, existing technologies often compensate by increasing structural complexity, such as integrating multiple adjustable modules and complex linkage mechanisms. This design is not only costly, but more seriously, the complex clamping arms and locating pins severely interfere with CNC toolpaths, resulting in cumbersome machining processes, poor chip removal, and difficult changeovers, which seriously restricts machining efficiency and flexible production. Summary of the Invention

[0005] To solve the above-mentioned technical problems, the present invention provides a floating automatic positioning fixture.

[0006] To provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. This summary is not intended as a general commentary, nor is it intended to identify key / important components or to describe the scope of protection of these embodiments. Its sole purpose is to present some concepts in a simple form as a prelude to the detailed description that follows.

[0007] The present invention adopts the following technical solution: This invention provides a floating automatic positioning fixture, comprising: A base platform is used to support the valve block to be processed, and a recessed rectangular groove is formed on the upper surface of the base platform; The main positioning module is used to provide positioning in the XY plane. The main positioning module consists of a cylindrical positioning pin and a rhomboid positioning pin set at the bottom of the sunken rectangular groove. A reference support module is used to provide positioning in the Z direction. The reference support module includes: equal-height support pads respectively disposed at the corners of the sunken rectangular groove. A floating clamping module is used to adaptively clamp the valve block. A floating clamping module is provided at the position of each of the support pads. The floating clamping module consists of two sets of floating joints respectively set on the two adjacent walls of the sunken rectangular groove.

[0008] Furthermore, the floating joint includes: a pressing plate, a servo electric cylinder, and a plurality of adaptive pressure components disposed on the front side of the pressing plate, wherein the movable end of the servo electric cylinder is connected to the back side of the pressing plate; the adaptive pressure component includes: a mounting base disposed on the pressing plate, wherein the two ends of the mounting base are bent away from the pressing plate and then extended towards each other to form a pressure-bearing part.

[0009] Furthermore, the end of the pressure-bearing portion is bent towards the direction of the push plate and then extended towards each other to form a guide portion, and the guide portion is attached to the mounting base. The guide portions formed by the tail ends of the two pressure-bearing portions are separated by a certain distance.

[0010] Furthermore, the adaptive pressure component also includes an attachment pad, which is disposed on the pressure-bearing portion.

[0011] Furthermore, the pressing platform is provided with 3-5 rows of adaptive pressure members, each row having 2-4 adaptive pressure members, and the adaptive pressure members in adjacent rows are arranged alternately.

[0012] Furthermore, a guide groove is formed on the wall of the recessed rectangular groove that is connected to the support pad, and the fixed end of the servo electric cylinder is connected to the bottom of the guide groove; the floating joint also includes a guide mechanism, which is arranged in parallel with the servo electric cylinder in the guide groove, and the guide mechanism is connected to the push plate.

[0013] Furthermore, the bottom of the sunken rectangular groove is provided with a grid plate, and column grooves are opened at the intersection of the grid plates. A lifting mechanism is provided in the column groove, and a positioning platform is provided on the top of the lifting mechanism. A positioning groove is opened on the positioning platform, and a positioning rod adapted to the positioning groove is provided at the bottom of the cylindrical positioning pin and the diamond positioning pin.

[0014] The beneficial effects of this invention are as follows: the gridded base and pluggable positioning pins enable the main positioning module to quickly adapt to the process hole positions of different valve blocks, greatly shortening the changeover time. When used in conjunction with the reference support module and the floating clamping module, it can adaptively compensate for the side tolerances of the valve block, ensuring uniform contact at multiple points and avoiding deformation caused by rigid clamping. The combination of flexible positioning and adaptive clamping in this application effectively solves the problems of positioning accuracy and clamping stability in multi-variety, small-batch production. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a structural schematic diagram of a floating automatic positioning fixture according to the present invention; Figure 2 This is a structural schematic diagram of the main positioning module and the floating clamping module of the present invention; Figure 3 This is a top view of the base platform of the present invention; Figure 4 This is a schematic diagram of the adaptive pressure component of the present invention; Figure 5 This is a schematic diagram of one arrangement of the adaptive pressure component of the present invention. Detailed Implementation

[0017] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be understood that the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0018] like Figure 1-5 As shown in some illustrative embodiments, a floating automatic positioning fixture is provided, which is a special fixture for flexibly clamping valve block-type parts with pre-machined process holes. Specifically, it includes: a base platform 100, a main positioning module 200, a reference support module 300, and a floating clamping module 400.

[0019] The base platform 100, used to support the valve block 500 to be processed, is precision machined from high-strength, low-stress cast iron or steel after aging treatment. A recessed rectangular groove 110 is formed on the upper surface of the base platform 100. The recessed rectangular groove 110 is used for preliminary positioning and guidance; that is, when the valve block 500 is transported to the platform via a conveyor belt or robotic arm, its outline will naturally fall into the groove, achieving rough XY plane positioning and preventing the valve block from sliding freely on the platform. Furthermore, the recessed rectangular groove 110 provides installation space for the subsequent main positioning module 200, reference support module 300, and floating clamping module 400, making the entire fixture structure compact and integrated. Simultaneously, the recessed rectangular groove 110 serves a protective and chip removal function; the groove walls protect the internal precision components from direct impact from cutting fluid and iron filings, while also facilitating the collection and cleaning of machining waste.

[0020] The main positioning module 200 is used to provide XY plane positioning for the valve block 500 to be processed. The main positioning module 200 consists of a cylindrical positioning pin 210 and a diamond-shaped positioning pin 220 set at the bottom of the recessed rectangular groove 110.

[0021] A cylindrical locating pin 210 is inserted into one of the process holes. Because its cross-section is a complete circle, it can simultaneously restrict the movement freedom of the valve block 500 along both the X and Y axes. A rhomboid locating pin 220 is inserted into the other process hole. Its cross-section is rhomboid or oblong, with a gap along its major axis, restricting the rotational freedom of the valve block 500 around the Z axis. Simultaneously, this gap effectively compensates for manufacturing errors in the center distance between the two process holes in the X or Y direction, avoiding over-positioning or installation interference caused by hole spacing deviations. The main positioning module 200 uses two or more pre-machined process holes on the valve block as the first reference, achieving complete positioning of the valve block in the XY plane through the cylindrical locating pin 210 and the rhomboid locating pin 220 on the fixture.

[0022] The bottom of the sunken rectangular groove 110 is provided with a grid plate 120, which is a grid structure formed by cross-welding of high-strength X-direction and Y-direction crossbeams. Column grooves 130 are formed at the intersections of the grid plates 120, and independent lifting mechanisms 140, such as pneumatic slides, small hydraulic cylinders, or electric push rods, are installed within the column grooves 130. A positioning platform 150 is provided on the top of the lifting mechanism 140, and standardized positioning grooves 160 are formed on the positioning platform 150. Correspondingly, positioning pins 230 that are adapted to the positioning grooves 160 are provided at the bottom of the cylindrical positioning pins 210 and the diamond-shaped positioning pins 220.

[0023] Workflow: Based on the process hole position drawing of the valve block 500 to be processed, the corresponding positioning scheme is selected in the control system; the operator or robot manually or automatically inserts the positioning rods 230 at the bottom of the cylindrical positioning pin 210 and the rhomboid positioning pin 220 into the positioning grooves 160 of the two positioning platforms 150 at the target position on the grid plate 120; after the valve block 500 to be processed falls into the recessed rectangular groove 110, the control system commands the two lifting mechanisms 140 at the corresponding position to start, lifting the positioning platform 150 together with the positioning pins on it upwards; the positioning pins pass through the process holes of the valve block, completing the main positioning. The above structural design allows the position of the cylindrical positioning pin 210 and the rhomboid positioning pin 220 to be adjusted according to the position of the processed process holes on the valve block, and only the positioning rods 230 need to be inserted into the positioning grooves 160, resulting in high adaptability.

[0024] The reference support module 300 is used to provide positioning in the Z direction. The reference support module 300 includes: four support pads 310 at the same height at the corners of the sunken rectangular groove 110; the number of support pads 310 is four, located at the four corners of the sunken rectangular groove 110 respectively, and the non-collinear support pads 310 at the same height provide a positioning reference in the vertical direction.

[0025] The upper surfaces of the four support pads 310 need to be precision ground to ensure they are on the same absolute horizontal plane. This common plane constitutes the positioning reference for the valve block in the Z direction, i.e., the second reference. Simultaneously, the non-collinear layout provides stable and reliable support, effectively preventing the valve block 500 to be processed from warping or deforming under its own weight and clamping force. Workflow: Before the main positioning module 200 operates, the valve block 500's own weight causes it to rest smoothly on the four support pads 310 of equal height, thus determining its zero point in the Z direction.

[0026] By combining the grid plate 120 with the movable positioning pins, the fixture is no longer limited to a single type of valve block. As long as the valve block's shape can fit into the recessed rectangular groove 110 and it has two process holes, it can be adapted by simply moving the position of the positioning pins. For small-batch, multi-variety production models with many product models and rapid product updates, this design can reduce the cost and time of redesigning and manufacturing a dedicated fixture for each new product. When changing production varieties, the operator only needs to pull out the inserts 230 of the two positioning pins according to the drawings and then insert them into the new target positioning groove 160. The entire process can be completed quickly without any tools.

[0027] The fixture utilizes the high-precision process holes pre-machined on the valve block as a positioning reference, which is more reliable and stable compared to positioning using the blank surface. Combined with the four corner equal-height support pads 310 providing a stable Z-axis reference, it ensures the rigidity of the valve block during machining, which is beneficial for improving surface finish and dimensional accuracy. Furthermore, all functional modules are integrated within the recessed rectangular groove 110, making the overall fixture structure very compact and reducing the space occupied by the machine tool table. The recessed design provides a barrier for the internal precision components, effectively resisting the corrosion of cutting fluid and metal shavings, extending the service life and maintenance cycle of the fixture.

[0028] The floating clamping module 400 is used to adaptively clamp the valve block, solving problems such as workpiece deformation, unstable clamping, or damage to the machined surface that may be caused by traditional rigid clamping. A floating clamping module 400 is provided at the position of each support pad 310. The floating clamping module 400 consists of two sets of floating joints respectively set on the two adjacent groove walls of the recessed rectangular groove 110.

[0029] At each corner of the recessed rectangular groove 110, corresponding to the positions of the four support pads 310, a set of floating clamping modules 400 is installed. Each set of floating clamping modules 400 consists of two sets of floating joints, which are respectively installed on two adjacent groove walls of the recessed rectangular groove 110. The diagonal layout allows pressure to be applied to the sides of the valve block from two directions simultaneously, forming a stable, torsion-free clamping force system.

[0030] The floating joint includes: a pressing plate 410, a servo electric cylinder 420, a guide mechanism 440, and several adaptive pressure components disposed on the front side of the pressing plate 410.

[0031] The movable end of the servo cylinder 420 is connected to the back of the pressing plate 410. A guide groove 430 is formed in the groove wall of the recessed rectangular groove 110 that connects to the support pad 310. The fixed end of the servo cylinder 420 is connected to the bottom of the guide groove 430. The guide mechanism 440 is arranged side by side with the servo cylinder 420 in the guide groove 430 and is connected to the pressing plate 410. The guide mechanism 440 consists of a linear bearing and a guide rail. Its function is to ensure that the pressing plate 410 can move linearly in a parallel and stable manner under the drive of the servo cylinder 420.

[0032] The adaptive pressure component includes a mounting base 450 and an attachment gasket 460. The adaptive pressure component is made of spring steel plate with a certain degree of elasticity and strength.

[0033] The mounting substrate 450 is disposed on the pressing plate 410. Both ends of the mounting substrate 450 are bent away from the pressing plate 410 and then extended towards each other to form a pressure bearing part 451. The pressure bearing part 451 contacts the valve block 500 to be processed.

[0034] The end of the pressure-bearing part 451 is bent toward the push plate 410 and then extended toward each other to form a guide part 452. The guide part 452 is in contact with the mounting base 450. The guide parts 452 formed by the tail ends of the two pressure-bearing parts 451 are separated by a certain distance. The head end of the pressure-bearing part 451 is the end connected to the mounting base 450.

[0035] When the servo cylinder 420 pushes the pressing plate 410 forward, the pressure-bearing part 451 first contacts the side of the valve block 500 to be processed. If the side of the valve block 500 to be processed is an ideal plane, all pressure-bearing parts 451 will be evenly stressed and undergo slight elastic deformation, providing a stable and gentle clamping force. If it is not an ideal plane, the side of the valve block may have slight unevenness or casting camber. When a pressure-bearing part 451 first contacts the highest point, it will begin to deform and move towards the mounting base 450. During this process, the guide part 452 at the end will slide along the inner side of the mounting base 450. The sliding plays an internal guiding and limiting role, ensuring that the pressure-bearing part 451 does not become laterally unstable during deformation and always maintains an effective pressure perpendicular to the pressing plate 410. Since each adaptive pressure component deforms independently, when the workpiece surface is uneven, the pressure component at the higher contact point will deform more, while the pressure component at the lower contact point will continue to move forward until all pressure components reach a certain preload, so that the clamping force can be evenly distributed on the contact surface, rather than concentrated on a few points.

[0036] An attachment gasket 460 is disposed on the pressure-bearing part 451. The attachment gasket 460 is typically made of polyurethane, rubber, or a composite material with a soft coating. Its function is to: increase the coefficient of friction and prevent the valve block from lateral slippage during machining, especially when subjected to large cutting forces; and protect the workpiece surface. For machined surfaces or surfaces requiring high surface finish, the soft gasket can effectively prevent scratches, indentations, and other defects during clamping.

[0037] The pressing plate 410 has 3-5 rows of adaptive pressure elements, with 2-4 adaptive pressure elements in each row, and the adaptive pressure elements in adjacent rows are staggered. Compared with a simple grid arrangement, the staggered arrangement can provide denser support points in a smaller area, allowing pressure to be applied more evenly to the entire side of the workpiece, effectively avoiding local stress concentration. For sides with local grooves, bosses, or arcs, the staggered layout has a higher probability of avoiding these obstacles and finding effective clamping points. The dense and evenly distributed clamping points work together to greatly improve the overall rigidity of the clamping system, effectively resisting cutting vibrations and impacts from all directions.

[0038] Regardless of dimensional deviations in the cast blank or minor unevenness on the machined surface, the structural design of this application achieves adaptive fitting through elastic deformation, ensuring effective contact and avoiding clamping force concentration and workpiece deformation caused by point or line contact. Elastic clamping avoids rigid impacts, providing excellent protection for the precision valve block. The design of the guide section 452 ensures controllability of the deformation process, keeping the clamping force perpendicular to the workpiece surface, resulting in extremely high stability. The entire structure is integrally formed from spring steel, with no moving parts, resulting in an extremely low failure rate. The elastic deformation remains within the material's yield limit, allowing it to withstand millions of cycles, far exceeding the lifespan of mechanical floating joints.

[0039] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A floating automatic positioning fixture, characterized in that, include: A base platform is used to support the valve block to be processed, and a recessed rectangular groove is formed on the upper surface of the base platform; The main positioning module is used to provide positioning in the XY plane. The main positioning module consists of a cylindrical positioning pin and a rhomboid positioning pin set at the bottom of the sunken rectangular groove. A reference support module is used to provide positioning in the Z direction. The reference support module includes: equal-height support pads respectively disposed at the corners of the sunken rectangular groove. A floating clamping module is used to adaptively clamp the valve block. A floating clamping module is provided at the position of each of the support pads. The floating clamping module consists of two sets of floating joints respectively set on the two adjacent walls of the sunken rectangular groove.

2. The floating automatic positioning fixture according to claim 1, characterized in that, The floating joint includes: a pressing plate, a servo electric cylinder, and a plurality of adaptive pressure components disposed on the front side of the pressing plate, wherein the movable end of the servo electric cylinder is connected to the back side of the pressing plate. The adaptive pressure component includes: a mounting base plate disposed on the push plate, wherein both ends of the mounting base plate are bent away from the push plate and then extended towards each other to form a pressure-bearing portion.

3. A floating automatic positioning fixture according to claim 2, characterized in that, The end of the pressure-bearing part is bent toward the direction of the push plate and then extends toward each other to form a guide part, and the guide part is attached to the mounting base. The guide parts formed by the tail ends of the two pressure-bearing parts are separated by a certain distance.

4. A floating automatic positioning fixture according to claim 3, characterized in that, The adaptive pressure component further includes an attachment pad, which is disposed on the pressure-bearing part.

5. A floating automatic positioning fixture according to claim 4, characterized in that, The pressing platform is provided with 3-5 rows of adaptive pressure components, each row having 2-4 adaptive pressure components, and the adaptive pressure components in adjacent rows are arranged alternately.

6. A floating automatic positioning fixture according to claim 5, characterized in that, A guide groove is formed on the wall of the recessed rectangular groove that is connected to the support pad, and the fixed end of the servo electric cylinder is connected to the bottom of the guide groove; the floating joint also includes a guide mechanism, which is arranged in parallel with the servo electric cylinder in the guide groove, and the guide mechanism is connected to the push plate.

7. A floating automatic positioning fixture according to claim 6, characterized in that, The bottom of the sunken rectangular groove is provided with a grid plate, and column grooves are opened at the intersection of the grid plates. A lifting mechanism is provided in the column groove, and a positioning platform is provided on the top of the lifting mechanism. A positioning groove is opened on the positioning platform, and a positioning rod adapted to the positioning groove is provided at the bottom of the cylindrical positioning pin and the diamond positioning pin.

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