Automatic high-precision clamping device special for valve rod

Abstract

The invention relates to the field of valve rod clamping, and discloses an automatic high-precision clamping device special for a valve rod, which comprises a valve rod clamp, a fixing frame, positioning units, an elastic unit and a control unit, the valve rod clamp comprises a fixing groove, a limiting block, an elastic screw hole and at least two positioning holes, and the groove wall of the fixing groove extends out of the limiting block; a loosening and tightening screw is screwed into the loosening and tightening screw hole when a motor of the loosening and tightening unit works so as to fix the valve rod, a positioning pin extends into the positioning hole when a telescopic power source for controlling the positioning unit works so as to fix the position of the valve rod clamp, and the control unit controls the working time of the telescopic power source, the sliding power source and the motor. Through the arrangement of the limiting block, the clamping device not only can control the torque generated by the loosening and tightening screw on the surface of the valve rod by adjusting the number of rotation turns of the motor, but also can fix valve rods of different specifications through cooperation of the limiting block and the loosening and tightening screw, and therefore the problems that in the prior art, a clamp is poor in universality in valve rod accurate grinding machining, and the clamping process depends on artificial experience are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of valve stem clamping, and in particular to an automated high-precision clamping device dedicated to the valve stem. Background Art

[0002] Valve stems, as core components of fluid control systems, are widely used in petrochemical, aerospace, shipbuilding and other industries.

[0003] At present, in the fine grinding process of valve stems, the fixtures used to clamp the valve stems generally have the problem of easy interference with the grinder, and a fixture can only be adapted to one brand of valve stem. When installing the valve stem on the fixture, it is often necessary to rely on the personal experience of the installer to clamp it. Therefore, during the entire installation process, not only is the cost of the fixture itself high, but damage to the valve stem clamping surface due to improper clamping force by personnel also occurs from time to time. These phenomena indirectly lead to problems such as high cost, low product quality consistency, high risk, and low efficiency in the process of fine grinding of the valve stem. Summary of the Invention

[0004] The purpose of the present invention is to provide an automated high-precision clamping device dedicated to valve stems, which solves the problems in the prior art of poor versatility of fixtures in valve stem fine grinding and reliance on manual experience in the clamping process.

[0005] To achieve the above-mentioned object, the technical solution of the present invention is as follows: In a first aspect, the present invention discloses an automated high-precision clamping device dedicated to a valve stem, comprising a valve stem, a valve stem clamp, a fixing frame, a positioning unit, a tensioning unit, and a control unit; The valve stem clamp is provided with a fixing groove running through opposite ends thereof, a limit block extends from the groove wall of the fixing groove, and the side wall of the limit block is in contact with the outer contour of the valve stem, the fixing groove is provided with a tightening screw hole and at least two positioning holes, and the tightening screw hole and the positioning holes both pass through the inner and outer groove walls of the fixing groove; The positioning unit includes a fixed mounting plate, at least two positioning pins and a telescopic power source, wherein the fixed mounting plate is fixedly mounted on the fixed frame, and the telescopic power source is fixedly mounted on the fixed mounting plate, the power end of the telescopic power source is fixedly mounted on the positioning pin, and the telescopic direction of the telescopic power source and the axial direction of the positioning pin are both parallel to the axis of the positioning hole, and the telescopic power end of the telescopic power source drives the positioning pin to slide through the positioning hole; The tensioning unit includes a sliding mounting plate, a sliding power source, a tensioning screw and a motor. The sliding mounting plate is slidably mounted on the fixing frame. The sliding direction of the sliding mounting plate is located on the axis of the tensioning screw hole. The sliding power of the sliding mounting plate is provided by the sliding power source. The motor is fixedly mounted on the sliding mounting plate, and the power end of the motor is detachably mounted on the tensioning screw. The power end of the motor works and drives the tensioning screw to be screwed into the tensioning screw hole until the end surface of the tensioning screw is in contact with the outer contour of the valve stem. The control unit controls the operating timings of the telescopic power source, the sliding power source, and the motor.

[0006] At least two pairs of positioning holes are provided on the groove walls on both sides of the fixing groove, the axes of each pair of positioning holes are collinear, and the axes of each pair of positioning holes are parallel.

[0007] As an optional solution, the telescopic power source is a double-finger cylinder, and the double-finger cylinder includes a first telescopic end and a second telescopic end; The at least two positioning pins fixedly mounted on the first telescopic end of the double-finger cylinder constitute a first positioning pin group, wherein the number of positioning pins in the first positioning pin group is the same as the number of positioning holes on the side wall of one side of the fixing groove and the positions of the positioning pins are opposite; The at least two positioning pins fixedly mounted on the second telescopic end of the double-finger cylinder constitute a second positioning pin group, wherein the number of positioning pins in the second positioning pin group is the same as the number of positioning holes on the other side wall of the fixing groove and the positions of the positioning pins are opposite; When the double-finger cylinder is working, both the first positioning pin group and the second positioning pin group move along the axis, and both the positioning pins of the first positioning pin group and the second positioning pin group slide through the corresponding positioning holes.

[0008] As an optional solution, the axis of the tightening screw hole is a, the axis of the positioning hole is b, the axis of the valve stem is c, a⊥b and a⊥c As an optional solution, a positioning V-shaped surface is further provided on the groove wall of the fixing groove, and the positioning V-shaped surface is located on the groove wall on the opposite side of the tightening screw hole.

[0009] As an optional solution, a fastening cylinder and a universal sleeve are provided on the power end of the motor; The universal sleeve is fixedly connected to the motor shaft of the motor, and the fastening cylinder fastens the connection position between the universal sleeve and the motor shaft of the motor; The axes of the motor shaft, the fastening cylinder, the universal sleeve and the loosening screw of the motor are collinear, and the connecting portion of the universal sleeve is connected to the loosening screw.

[0010] As an optional solution, the fixing frame is provided with two guide rail sliders on both sides of the sliding mounting plate; The guide rail parts of the two guide rail sliders are both arranged on the fixed frame, and the two guide rail slider parts are respectively fixedly connected to the two sides of the sliding mounting plate. The sliding direction of the guide rail slider is parallel to the axis of the tightening screw hole, and the two guide rail sliders move synchronously.

[0011] As an optional solution, the control unit includes a torque sensor, a processor and a controller; The signal input terminal of the torque sensor is electrically connected to the signal output terminal of the motor, and the torque sensor collects the real-time torque of the motor; The signal input terminal of the processor is electrically connected to the signal output terminal of the torque sensor, and the signal output terminal of the processor is electrically connected to the signal input terminal of the controller. The processor processes the real-time torque information of the motor detected by the torque sensor into a readable signal and compares it with the manually input rated torque. The processor outputs a control signal to the controller based on the comparison result; The signal output end of the controller is electrically connected to the signal input ends of the telescopic power source, the sliding power source and the motor, and the controller controls the opening and closing of the telescopic power source, the sliding power source and the motor according to the control signal output by the processor.

[0012] The present invention has the following unexpected beneficial effects: 1. The valve stem clamp described in the present invention is provided with a fixing groove, a limit block and a tightening screw hole. Under the control of the control unit, the motor of the tightening unit screws the tightening screw into the tightening screw hole to fix the valve stem in a tight fit, so that the valve stem clamp can adapt to valve stems of different specifications and brands, breaking through the adaptation limitation of existing clamps to a single brand.

[0013] At least two positioning holes are also provided on the valve stem clamp, and the positioning unit sets at least two positioning pins on the power end of the telescopic power source. The power end of the telescopic power source then drives the positioning pins to slide through the positioning holes, and the tightening screws for fixing the valve stem are also screwed in by the motor. During this process, the torque applied to the valve stem is provided by the motor, and its specific value is mechanically controlled. Therefore, the clamping device of the present invention can completely solve the problem of valve stem surface compression caused by improper force, thereby solving the problem of poor versatility of the clamps in the valve stem fine grinding process in the prior art and the reliance on manual experience in the clamping process.

[0014] 2. The valve stem clamp of the present invention adopts an embedded limit block and a side wall slot design (fixing slot, positioning hole, and tightening screw hole), which flattens the overall structure of the clamp, significantly reduces space occupancy, and fundamentally eliminates the risk of interference with the moving parts of the grinder.

[0015] 3. The valve stem clamp of the present invention is also provided with a positioning V-shaped surface. The V-shaped positioning surface and the tightening screw form a three-point clamping structure, thereby ensuring the clamping effect on the valve stem while dispersing the clamping stress on the valve stem, thereby enhancing the long-term reliability of the valve stem clamp. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 1 is an overall schematic diagram of an automated high-precision clamping device dedicated to a valve stem according to an embodiment of the present invention; Figure 2 1 is a schematic diagram of the operation of an automated high-precision clamping device dedicated to a valve stem according to an embodiment of the present invention; Figure 3 The embodiment of the present invention is Figure 2 A partial enlarged view of point A; Figure 4 Schematic diagram of a positioning unit of an automated high-precision clamping device dedicated to a valve stem according to an embodiment of the present invention; Figure 5 Schematic diagram of a tightening and loosening unit of an automated high-precision clamping device dedicated to a valve stem according to an embodiment of the present invention; Figure 6 Schematic diagram of a valve stem clamp of an automated high-precision clamping device dedicated to a valve stem according to an embodiment of the present invention; Figure 7 This is a schematic diagram of a valve stem clamp provided with multiple pairs of positioning holes in an automated high-precision clamping device dedicated to a valve stem according to an embodiment of the present invention; Figure 8 This is a schematic diagram of the axes of the various components of the valve stem clamp of the automated high-precision clamping device dedicated to the valve stem of an embodiment of the present invention when clamping the valve stem; In the figure, 1. valve stem clamp; 101. fixing groove; 102. limit block; 103. tightening screw hole; 104. positioning hole; 105. positioning V-shaped surface; 2. fixing frame; 3. positioning unit; 301. fixed mounting plate; 302. positioning pin; 303. telescopic power source; 304. pin hole mounting plate; 4. tightening unit; 401. sliding mounting plate; 402. sliding power source; 403. tightening screw; 404. motor; 405. fastening cylinder; 406. universal socket; 407. guide rail slider; 5. valve stem. DETAILED DESCRIPTION

[0017] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0018] In the description of the present application, it should be noted that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0019] In the description of the present application, it should be understood that the terms "connected", "connected", "fixed" and the like used in the present application should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be weldedly connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship of two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0020] In an embodiment, as shown in Figures 1 to 8 The first aspect, the present application provides an automatic high-precision clamping device special for valve rod 5, which comprises valve rod clamp 1, fixing frame 2, positioning unit 3, tension unit 4 and control unit.

[0021] The valve rod clamp 1 is provided with a fixed groove 101 penetrating through the opposite ends thereof, the groove wall of the fixed groove 101 is provided with a limiting block 102, and the side wall of the limiting block 102 is attached to the outer contour of the valve rod 5, the fixed groove 101 is provided with a tension screw hole 103 and at least two positioning holes 104, and the tension screw hole 103 and the positioning hole 104 penetrate the inner and outer groove walls of the fixed groove 101.

[0022] The position and size of the limiting block 102 are not further limited here, when the limiting block 102 is located between the upper and lower end faces of the fixed groove 101, the limiting block 102 is completely located in the fixed groove 101, the groove wall of the fixed groove 101 protects the limiting block 102 from being knocked with parts other than the valve rod 5 during transportation or operation, thereby avoiding damage to the valve rod clamp 1 due to improper operation; when one side end face of the limiting block 102 is flush with the fixed groove 101, the limiting block 102 and the fixed groove 101 can be made at one time through an adaptive mold, thereby reducing the production difficulty of the valve rod clamp 1.

[0023] The positioning unit 3 includes a fixed mounting plate 301, at least two positioning pins 302 and a telescopic power source 303. The fixed mounting plate 301 is fixedly mounted on the fixed frame 2, and the telescopic power source 303 is fixedly mounted on the fixed mounting plate 301. The power end of the telescopic power source 303 is fixedly mounted on the positioning pin 302, and the telescopic direction of the telescopic power source 303 and the axial direction of the positioning pin 302 are both parallel to the axis of the positioning hole 104. The telescopic power end of the telescopic power source 303 drives the positioning pin 302 to slide through the positioning hole 104.

[0024] The side wall of the limit block 102 is only in contact with the outer contour of the valve stem 5. When the diameter of the valve stem 5 is small, the valve stem 5 is in a suspended state. During the process of the motor 404 of the positioning unit 3 screwing in the tightening screw 403, the valve stem 5 is gradually squeezed onto the limit block 102, thereby completing the fixation. Since the limit block 102 of the valve stem clamp 1 does not need to be adapted to a certain model, the length of the limit block 102 extending out of the fixing groove 101 can be appropriately increased or decreased, thereby enabling the clamping device recorded in this application document to design the length of the limit block 102 extending out of the fixing groove 101 according to actual working conditions, so that it can adapt to valve stems 5 of more brands and more specifications.

[0025] The tensioning unit 4 includes a sliding mounting plate 401, a sliding power source 402, a tensioning screw 403 and a motor 404. The sliding mounting plate 401 is slidably mounted on the fixing frame 2. The sliding direction of the sliding mounting plate 401 is located on the axis of the tensioning screw hole 103. The sliding power of the sliding mounting plate 401 is provided by the sliding power source 402. The motor 404 is fixedly mounted on the sliding mounting plate 401, and the power end of the motor 404 is detachably mounted on the tensioning screw 403. The power end of the motor 404 works and drives the tensioning screw 403 to be screwed into the tensioning screw hole 103 until the end face of the tensioning screw 403 is in contact with the outer contour of the valve stem 5.

[0026] There is no further limitation on the style of the fixing frame 2 here. The fixing frame 2 only needs to meet the working requirements of the valve stem clamp 1. Since the valve stem clamp 1 needs to clamp the valve stem 5, the motor 404 of the tension unit 4 is slidably installed in the fixing frame 2, and the positioning pin 302 of the positioning unit 3 slides through the positioning hole 104. Therefore, the length of the fixing frame 2 in the X-axis, Y-axis and Z-axis is positively correlated with the set sliding distance of the motor 404, the telescopic distance of the positioning pin 302 and the length of the valve stem 5 to be clamped. Compared with the prior art, the positioning device recorded in this application document can clamp valve stems 5 of different brands and different lengths. Therefore, the fixing frame 2 can choose a fixing frame 2 type that can adjust the Z-axis length in time.

[0027] During the fine grinding process after the valve stem clamp 1 clamps the valve stem 5, its positioning pin 302 slides out of the positioning hole 104 to release the limit, and the on-site worker takes the valve stem 5 clamped by the valve stem clamp 1 for fine grinding. Since the valve stem clamp 1 only completes the fastening of the valve stem 5 by loosening the screw 403 and the limit block 102 at this time, the space occupied by the valve stem clamp 1 is much smaller than that of the traditional clamp, effectively avoiding the problem of the valve stem clamp 1 easily interfering with the grinder.

[0028] The control unit controls the working timings of the telescopic power source 303 , the sliding power source 402 , and the motor 404 .

[0029] Based on this, the valve stem clamp 1 is provided with a fixing groove 101 running through the opposite ends thereof, and a limit block 102, a tightening screw hole 103 and at least two positioning holes 104 are provided at the corresponding position of the fixing groove 101. A positioning unit 3 provided with a fixed mounting plate 301, at least two positioning pins 302 and a telescopic power source 303 positions the valve stem clamp 1 through the positioning holes 104, and a tightening unit 4 provided with a sliding mounting plate 401, a sliding power source 402, a tightening screw 403 and a motor 404 adjusts the distance between the tightening screw 403 and the tightening screw hole 103 through the sliding mounting plate 401, and tightens the tightening screw 403 through the motor 404. 03 is screwed into the tightening screw hole 103, and the tightening screw 403 passes through the tightening screw hole 103 and contacts the outer contour of the valve stem 5 until the valve stem 5 is pressed against the side wall of the limit block 102 to form a three-point floating clamp for the valve stem 5, thereby completing the fixation of the valve stem 5, so that the clamping device can not only control the torque generated by the tightening screw 403 on the surface of the valve stem 5 by adjusting the number of rotations of the motor 404, but also can fix valve stems 5 of different specifications and brands through the cooperation of the limit block 102 and the tightening screw 403, thereby solving the problems of poor versatility of the fixture in the fine grinding of the valve stem 5 in the prior art and the reliance of the clamping process on manual experience.

[0030] Furthermore, if Figures 1 to 8 As shown, at least two pairs of positioning holes 104 are provided on both side walls of the fixing slot 101 , and the axes of each pair of positioning holes 104 are collinear and parallel.

[0031] The specific position and number of each pair of positioning holes 104 are not further limited here. The more collinear hole pairs are arranged along the radial direction of the valve stem 5 (i.e., the width direction of the clamp), the higher the force balance formed by the positioning pin 302, the smaller the spacing between the hole pairs distributed along the axial direction of the valve stem 5 (i.e., the length direction of the clamp), the denser the selectable discrete axial clamping points, and the wider the range of valve stem 5 lengths covered, thereby breaking through the size limitation of the existing technology that a single clamp can adapt to a single valve stem 5.

[0032] Furthermore, if Figures 1 to 8 As shown, the telescopic power source 303 is a double finger air cylinder, which includes a first telescopic end and a second telescopic end. Since it is necessary to ensure that the first telescopic end and the second telescopic end of the double finger air cylinder are synchronous telescopic, the existing double finger air cylinder (such as SC, Festo DHPS, etc.) designed with differential hydraulic cylinder or double ejector rod structure is directly selected here.

[0033] The synchronous telescopic of the first telescopic end and the second telescopic end can ensure that the positioning pins 302 on both sides (the first positioning pin group and the second positioning pin group) can be synchronously penetrated into the positioning holes 104, thereby avoiding the deviation of the valve rod clamp 1 caused by unilateral force, and further eliminating the axis error of the valve rod 5 caused by artificial clamping, so as to ensure that the extrusion force of the elastic screw 403 on the valve rod 5 can act on the axis of the valve rod 5.

[0034] The first telescopic end and the second telescopic end of the double finger air cylinder are both fixedly provided with a pin hole mounting plate 304, and the first telescopic end and the second telescopic end of the double finger air cylinder are both installed with corresponding positioning pins 302 through the pin hole mounting plate 304.

[0035] The at least two positioning pins 302 fixedly installed on the first telescopic end of the double finger air cylinder are a first positioning pin group, and the number of the positioning pins 302 of the first positioning pin group is the same as that of the positioning holes 104 on the side wall of the fixed groove 101 and is opposite in position.

[0036] The at least two positioning pins 302 fixedly installed on the second telescopic end of the double finger air cylinder are a second positioning pin group, and the number of the positioning pins 302 of the second positioning pin group is the same as that of the positioning holes 104 on the side wall of the fixed groove 101 and is opposite in position.

[0037] When the double finger air cylinder works, the first positioning pin group and the second positioning pin group both move along the axis, and the positioning pins 302 of the first positioning pin group and the second positioning pin group are both slidably penetrated into the corresponding positioning holes 104.

[0038] The first positioning pin group and the second positioning pin group arranged opposite to each other form a symmetrical clamping force couple under the driving of the double finger air cylinder, so that the radial forces borne by the surface of the valve rod 5 can be offset to each other, thereby avoiding the micro vibration of the valve rod 5 in the fine grinding process.

[0039] Further, as shown in the figure, Figure 8 The axis of the elastic screw hole 103 is a, the axis of the positioning hole 104 is b, and the axis of the valve rod 5 is c, a⊥b and a⊥c.

[0040] At this time, the axial locking force (along the axial direction of the tightening screw hole 103) applied by the tightening screw 403 to the valve stem 5 and the radial clamping force applied by the limit block 102 to the valve stem 5 form an orthogonal relationship, so that the force on the valve stem 5 can be decomposed into pure radial constraint and pure axial constraint, thereby realizing the limiting function of the valve stem 5 by limiting in two directions, thereby eliminating the clamping slippage that may be caused by using oblique conforming force.

[0041] From the perspective of ergonomics, the tensioning screw 403 and the positioning pin 302 are both separate parts. During maintenance, their assembly relationships do not conflict with each other, and relevant personnel can complete the replacement of the tensioning screw 403 or the positioning pin 302 with only one hand.

[0042] Furthermore, if Figure 6 As shown, a positioning V-shaped surface 105 is further provided on the groove wall of the fixing groove 101 , and the positioning V-shaped surface 105 is located on the groove wall opposite to the tightening screw hole 103 .

[0043] The specific structure of the positioning V-shaped surface 105 is not further limited here. The positioning V-shaped surface 105 can be a "\"-shaped surface and a " / "-shaped surface directly intersecting each other, or the "\"-shaped surface and the " / "-shaped surface can be connected together by a connecting straight surface; the "\"-shaped surface and the " / "-shaped surface of the positioning V-shaped surface 105 are respectively located on both sides of the valve stem 5, and the intersection line or the connecting straight surface of the "\"-shaped surface and the " / "-shaped surface are both located on the axis of the tightening screw hole 103.

[0044] When the tightening screw 403 limits the valve stem 5 to contact with the side wall of the limiting block, the outer contour of the valve stem 5 will also contact the positioning V-shaped surface 105. At this time, the V-shaped double bevel of the positioning V-shaped surface 105 decomposes the locking force into two orthogonal components, thereby expanding the contact stress area on the surface of the valve stem 5, greatly alleviating the indentation caused by the point contact of the tightening screw 403 with the valve stem 5, and further avoiding damage to the clamping surface of the valve stem 5 due to excessive limiting torque.

[0045] Furthermore, if Figures 1 to 8 As shown, a fastening cylinder 405 and a universal sleeve 406 are provided on the power end of the motor 404 .

[0046] The universal sleeve 406 is fixedly connected to the motor 404 shaft of the motor 404 , and the fastening sleeve 405 fastens the connection position between the universal sleeve 406 and the motor 404 shaft of the motor 404 .

[0047] The fastening cylinder 405 is a cylindrical sleeve and two groups of top screw holes for connecting with top screws are opened on the side wall of the fastening cylinder 405. The top screws of one group of top screw holes are in contact with the output shaft of the motor 404, and the top screws of the other group of top screw holes are in contact with the universal sleeve 406. The output shaft of the motor 404 extends into the fastening cylinder 405 from one end of the fastening cylinder 405 and is fastened by a group of top screws. The installation side of the universal sleeve 406 extends out of the fastening cylinder 405 from the other end of the fastening cylinder 405 and is interference fit with the output shaft of the motor 404. The installation side of the universal sleeve 406 is fastened by another group of top screws. The connecting part of the universal sleeve 406 is a multi-cylindrical elastic structure.

[0048] The top screw design on the fastening cylinder 405 avoids shear damage to the screw hole that may occur due to vibration of the motor 404 when the tightening screw 403 is screwed into the tightening screw hole 103.

[0049] The shape of the head of the tightening screw 403 is not further limited here. The tightening screw 403 can be a hexagonal screw, a round head screw, etc.

[0050] The axes of the motor 404 shaft, the fastening cylinder 405 , the universal sleeve 406 and the loosening screw 403 of the motor 404 are collinear, and the connecting portion of the universal sleeve 406 is connected to the loosening screw 403 .

[0051] The connection part of the universal sleeve 406 is configured as a multi-cylindrical elastic structure, which eliminates the process of aligning the head of the tensioning screw 403 with traditional equipment, and because the multi-cylindrical elastic structure has a certain radial floating ability (can rotate slightly), the sleeve can compensate for part of the axial deviation of the tensioning screw 403, effectively eliminating the thread shear damage caused by the motor 404 shaft and the tensioning screw 403 not being completely coaxial, thereby ensuring that the universal sleeve 406 can stably sleeve the tensioning screw 403 while avoiding the reduction of equipment service life (thread shear damage) due to workpiece production errors.

[0052] Furthermore, if Figures 1 to 8 As shown, the fixing frame 2 is provided with two guide rail sliders 407 on both sides of the sliding mounting plate 401 .

[0053] The guide rail parts of the two guide rail sliders 407 are both set on the fixed frame 2, and the two guide rail sliders 407 are respectively fixedly connected to the two sides of the sliding mounting plate 401. The sliding direction of the guide rail slider 407 is parallel to the axis of the tightening screw hole 103, and the two guide rail sliders 407 move synchronously. The guide rail slider 407 provides guidance for the sliding of the sliding mounting plate 401, so that the motor 404 installed on the sliding mounting plate 401 always moves along the axis direction of the tightening screw hole 103.

[0054] The sliding mounting plate 401 slides to the position where the universal sleeve 406 is connected to the tightening screw 403 only when the motor 404 is required to tighten the tightening screw 403, so that the sliding mounting plate 401 is away from the valve stem clamp 1 most of the time to leave space near the valve stem clamp 1 for on-site operators to use.

[0055] The type of the sliding power source 402 is not further limited here. As shown in 1, the sliding power source 402 is a double-guide rod cylinder, which includes a third telescopic end and a fourth telescopic end. The cylinder body of the double-guide rod cylinder is fixedly arranged on the fixed frame 2.

[0056] The sliding mounting plate 401 is connected to the third telescopic end and the fourth telescopic end of the double guide rod cylinder, and the double guide rod cylinder drives the sliding mounting plate 401 to move. The setting of the double guide rod cylinder avoids the distance accuracy problem between the loosening screw 403 and the universal sleeve 406 that may be caused by manual movement of the sliding mounting plate 401.

[0057] Furthermore, although this embodiment is not shown in the drawings, the control unit includes a torque sensor, a processor, and a controller.

[0058] The signal input terminal of the torque sensor is electrically connected to the signal output terminal of the motor 404 , and the torque sensor collects the real-time torque of the motor 404 .

[0059] The signal input end of the processor is electrically connected to the signal output end of the torque sensor, and the signal output end of the processor is electrically connected to the signal input end of the controller. The processor processes the real-time torque information of the motor 404 detected by the torque sensor into a readable signal and compares it with the rated torque input manually. The processor outputs a control signal to the controller based on the comparison result. When the real-time torque reaches the rated torque, the processor sends a stop signal to the controller, and the controller turns off the motor 404.

[0060] The signal output end of the controller is electrically connected to the signal input ends of the telescopic power source 303, the sliding power source 402 and the motor 404, and the controller controls the opening and closing of the telescopic power source 303, the sliding power source 402 and the motor 404 according to the control signal output by the processor.

[0061] The working process of the present invention is as follows: the on-site operator selects the positioning hole 104 to be used according to the specifications of the valve stem 5, and the on-site operator inputs an instruction into the controller, and the controller controls the telescopic power source 303 to extend and retract so that the positioning pin 302 passes through the corresponding positioning hole 104 to fix the height of the valve stem clamp 1; after the on-site operator puts the tightening screw 403 into the tightening screw hole 103, the valve stem 5 is extended into the fixing groove 101 of the valve stem clamp 1, and then the rated torque calculated in advance is input into the processor, and the processor sends a working instruction to the controller, and the controller controls the sliding power source 402 to start to drive the sliding mounting plate 401 to slide, and the sliding mounting plate 401 is driven by the sliding power source 402. The plate 401 moves together with the motor 404 provided thereon until the tightening screw 403 is connected to the motor 404 shaft of the motor 404 through the universal socket 406 (the sliding distance of the sliding mounting plate 401 is the rated value and does not require sensor calibration). The controller controls the motor 404 to start. At this time, the torque sensor starts working and transmits a signal to the processor in real time until the real-time torque of the motor 404 is equal to the rated torque set by the on-site operator. The processor sends a stop signal to the controller, and the controller controls the motor 404 to stop and starts the sliding power source 402 to drive the sliding mounting plate 401 back to its original position; and the cycle continues.

[0062] In summary, the clamping device redesigns the valve stem clamp 1, and a fixing groove 101 for the valve stem 5 to pass through is provided on the valve stem clamp 1, and a loosening screw hole 103 and a limit block 102 are provided in the fixing groove 101. The loosening unit 4 screws the loosening screw 403 into the loosening screw hole 103 through the motor 404 until the valve stem 5 is against the side wall of the limit block 102. The operating position of the valve stem clamp 1 is adjusted each time by the positioning pin 302 of the positioning unit 3 and the valve stem. The positioning hole 104 on the clamp 1 ensures that the torque of the tightening screw 403 on the valve stem 5 is controlled by the motor 404, so that the clamping device can not only control the torque generated by the tightening screw 403 on the surface of the valve stem 5 by adjusting the number of rotations of the motor 404, but also can fix valve stems 5 of different specifications and brands through the cooperation of the limit block 102 and the tightening screw 403, thereby solving the problem of poor versatility of the clamp in the fine grinding of the valve stem 5 in the prior art and the reliance of the clamping process on manual experience.

[0063] It should be understood that the terms "first", "second", etc. are used in the present invention to describe various information, but such information should not be limited to these terms, which are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present invention, "first" information may also be referred to as "second" information, and similarly, "second" information may also be referred to as "first" information. In addition, the orientations or positional relationships indicated by the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the present invention.

[0064] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. An automated high-precision clamping device for valve stems, characterized by: It comprises a valve stem clamp (1), a fixing frame (2), a positioning unit (3), a tensioning unit (4) and a control unit; The valve stem clamp (1) is provided with a fixing groove (101) passing through two opposite ends thereof, a limiting block (102) extends from the groove wall of the fixing groove (101), and the side wall of the limiting block (102) is in contact with the outer contour of the valve stem (5), the fixing groove (101) is provided with a tightening screw hole (103) and at least two positioning holes (104), and the tightening screw hole (103) and the positioning holes (104) both pass through the inner and outer groove walls of the fixing groove (101); The positioning unit (3) comprises a fixed mounting plate (301), at least two positioning pins (302) and a telescopic power source (303); the fixed mounting plate (301) is fixedly mounted on the fixed frame (2), and the telescopic power source (303) is fixedly mounted on the fixed mounting plate (301); the power end of the telescopic power source (303) is fixedly mounted on the positioning pin (302), and the telescopic direction of the telescopic power source (303) and the axial direction of the positioning pin (302) are both parallel to the axis of the positioning hole (104); the telescopic power end of the telescopic power source (303) drives the positioning pin (302) to slide through the positioning hole (104); The tensioning unit (4) includes a sliding mounting plate (401), a sliding power source (402), a tensioning screw (403) and a motor (404); the sliding mounting plate (401) is slidably mounted on the fixing frame (2); the sliding direction of the sliding mounting plate (401) is located on the axis of the tensioning screw hole (103); the sliding power of the sliding mounting plate (401) is provided by the sliding power source (402); the motor (404) is fixedly mounted on the sliding mounting plate (401), and the power end of the motor (404) is detachably mounted on the tensioning screw (403); the power end of the motor (404) works and drives the tensioning screw (403) to be screwed into the tensioning screw hole (103) until the end face of the tensioning screw (403) is in contact with the outer contour of the valve stem (5); The control unit controls the operating timings of the telescopic power source (303), the sliding power source (402), and the motor (404).

2. The clamping device according to claim 1, characterized in that: At least two pairs of positioning holes (104) are provided on the groove walls on both sides of the fixing groove (101), and the axes of each pair of positioning holes (104) are collinear, and the axes of each pair of positioning holes (104) are parallel.

3. The clamping device according to claim 2, characterized in that: The telescopic power source (303) is a double-finger cylinder, and the double-finger cylinder comprises a first telescopic end and a second telescopic end; At least two positioning pins (302) fixedly mounted on the first telescopic end of the double-finger cylinder constitute a first positioning pin (302) group, wherein the number of positioning pins (302) in the first positioning pin (302) group is the same as the number of positioning holes (104) on the side wall of one side of the fixing slot (101) and the positions thereof are opposite; At least two positioning pins (302) fixedly mounted on the second telescopic end of the double-finger cylinder constitute a second positioning pin (302) group, wherein the number of positioning pins (302) in the second positioning pin (302) group is the same as the number of positioning holes (104) on the other side wall of the fixing slot (101) and the positions thereof are opposite; When the double-finger cylinder is working, the first positioning pin (302) group and the second positioning pin (302) group both move along the axis, and the positioning pins (302) of the first positioning pin (302) group and the second positioning pin (302) group both slide through the corresponding positioning holes (104).

4. The clamping device according to claim 2, characterized in that: The axis of the tightening screw hole (103) is a, the axis of the positioning hole (104) is b, and the axis of the valve stem (5) is c, a⊥b and a⊥c.

5. The clamping device according to claim 4, characterized in that: A positioning V-shaped surface (105) is further provided on the groove wall of the fixing groove (101), and the positioning V-shaped surface (105) is located on the groove wall opposite to the tightening screw hole (103).

6. The clamping device according to claim 1, characterized in that: A fastening cylinder (405) and a universal sleeve (406) are provided on the power end of the motor (404); The universal sleeve (406) is fixedly connected to the motor (404) shaft of the motor (404), and the fastening cylinder (405) fastens the connection position between the universal sleeve (406) and the motor (404) shaft of the motor (404); The axes of the motor (404) shaft, the fastening cylinder (405), the universal sleeve (406) and the loosening screw (403) of the motor (404) are collinear, and the connecting portion of the universal sleeve (406) is connected to the loosening screw (403).

7. The clamping device according to claim 1, characterized in that: The fixing frame (2) is provided with two guide rail sliders (407) on both sides of the sliding mounting plate (401); The guide rail parts of the two guide rail sliders (407) are both arranged on the fixed frame (2), and the two guide rail sliders (407) are fixedly connected to the two sides of the sliding mounting plate (401) respectively. The sliding direction of the guide rail sliders (407) is parallel to the axis of the loosening screw hole (103), and the two guide rail sliders (407) move synchronously.

8. The clamping device according to claim 1, characterized in that: The control unit includes a torque sensor, a processor and a controller; The signal input end of the torque sensor is electrically connected to the signal output end of the motor (404), and the torque sensor collects the real-time torque of the motor (404); The signal input end of the processor is electrically connected to the signal output end of the torque sensor, and the signal output end of the processor is electrically connected to the signal input end of the controller. The processor processes the real-time torque information of the motor (404) detected by the torque sensor into a readable signal and compares it with the rated torque input manually. The processor outputs a control signal to the controller according to the comparison result. The signal output end of the controller is electrically connected to the signal input ends of the telescopic power source (303), the sliding power source (402) and the motor (404), and the controller controls the opening and closing of the telescopic power source (303), the sliding power source (402) and the motor (404) according to the control signal output by the processor.

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