Clamping force-adjustable clamping tool and method suitable for magnetically soft alloy thin-wall ring sleeve

Abstract

The invention relates to a clamping-force-adjustable clamping tool suitable for a magnetically soft alloy thin-wall ring sleeve and a clamping method. The clamping-force-adjustable clamping tool comprises a chuck assembly located at the front end, a pull rod located in the middle and a pressure adjusting air cylinder located at the tail. The chuck assembly is composed of a pneumatic three-jaw chuck body, a sub-jaw, a clamping force measuring assembly and a force measuring auxiliary jaw. The clamping force measuring assembly comprises a force measuring contact and a force measuring sensor; three clamping jaws at the front end of the pneumatic three-jaw chuck main body form a female clamping jaw; the three sub-clamping jaws are fixedly installed at notches in the front ends of the three main clamping jaws respectively, and the inner side faces of the three sub-clamping jaws define a workpiece clamping face. The inner sides of the three female clamping jaws are respectively provided with a radial insertion hole, a force measuring auxiliary jaw is inserted and fixed in each radial insertion hole, the outer end of at least one force measuring auxiliary jaw is provided with a force measuring contact, and the force measuring contact is electrically connected with the force measuring sensor through a connecting wire; before a workpiece is clamped, the inner side faces of the three auxiliary force measuring claws make contact with the clamping rod in a clamping mode, and the clamping force is measured and adjusted in cooperation with adjustment of the air supply pressure. According to the clamping device, the clamping force can be adjusted.

Description

Technical Field

[0001] The invention belongs to the technical field of mechanical processing, and in particular relates to a clamping tool and method with adjustable clamping force suitable for a soft magnetic alloy thin-walled ring sleeve. Background Art

[0002] Soft magnetic alloys are a type of alloy with high magnetic permeability and extremely low coercive force in weak magnetic fields, and have the mechanical characteristics of low hardness and high plasticity. In the field of navigation, they are used as core workpieces in high-precision instruments such as torque motors, resolver transmitters, missile seeker motors and other precision motors such as stators, rotors, shielding covers, etc. Their structures are mostly thin-walled ring-type workpieces, which have serious clamping deformation and are difficult to process. Since high-precision instruments have high requirements for magnetic properties, and the magnetic properties of high-performance soft magnetic alloys are very sensitive to stress, there are strict requirements on the amount of workpiece clamping deformation during mechanical processing, resulting in extremely high requirements for workpiece clamping in precision machining. In order to solve the problem of clamping deformation of existing soft magnetic alloy workpieces in precision machining, it is very necessary to design a clamping method suitable for soft magnetic alloy thin-walled workpieces, which has controllable and adjustable clamping force, is non-destructive to the workpiece, is fast and convenient, and has strong versatility. Summary of the invention

[0003] In view of the deficiencies of the prior art, the present invention provides a clamping tool and method with adjustable clamping force suitable for a soft magnetic alloy thin-walled ring sleeve.

[0004] One of the above objects of the present invention is achieved by the following technical solution:

[0005] A clamping tool with adjustable clamping force suitable for a soft magnetic alloy thin-walled ring sleeve, comprising a chuck assembly at the front end, a pull rod at the middle part and a pressure regulating cylinder at the rear end; the chuck assembly is fixed to the nose end of a machine tool spindle, the rotary pressure regulating cylinder is installed at the rear end of the machine tool spindle, the pull rod extends into the spindle hole of the machine tool, and the two ends of the pull cylinder are respectively connected to the chuck assembly and the pressure regulating cylinder;

[0006] The chuck assembly is composed of a pneumatic three-jaw chuck body, a sub-jaw, a clamping force measuring assembly, and a force measuring auxiliary jaw; the clamping force measuring assembly includes a force measuring contact and a force measuring sensor; the three jaws at the front end of the pneumatic three-jaw chuck body constitute a mother jaw; the three sub-jaws are detachably fixedly installed in the recesses inside the front ends of the three mother jaws along the circumferential direction, and the inner side surfaces of the three sub-jaws form a workpiece clamping surface, the diameter of the workpiece clamping surface is the same as the outer diameter of the soft magnetic alloy thin-walled ring sleeve to be processed The diameter is straight; a radial plug hole is respectively arranged on the inner side of the three female clamping jaws, and the three force measuring auxiliary jaws are respectively inserted and fixed in the three radial plug holes, and a force measuring contact is installed on the outer end of at least one force measuring auxiliary jaw, and the force measuring contact is electrically connected to the force measuring sensor fixed on one side of the corresponding female jaw through a connecting line; before clamping the soft magnetic alloy thin-walled ring sleeve workpiece, the inner sides of the three force measuring auxiliary jaws are clamped and contacted with the clamping rod, and the air supply pressure of the pressure regulating cylinder is adjusted to realize the measurement and adjustment of the clamping force.

[0007] Moreover, the sub-claw is made of soft steel.

[0008] Moreover, the outer side surface of the recess on the female jaw is an arc surface, two threaded holes are arranged on the bottom surface of the recess, and a circular hole is arranged between the two threaded holes; a tightening threaded hole is arranged vertically connected between each radial socket and the circular hole on the bottom surface of the recess, and the force measuring jaw is pressed tightly into the radial socket by installing a tightening screw; a wire hole vertically connected to the corresponding radial socket is arranged on the other side of the female jaw relative to the tightening threaded hole for the connecting wire to pass through.

[0009] Moreover, the sub-claw adopts a block structure with both inner and outer sides being arc surfaces. The outer arc surface is in contact with the outer circular surface of the recess of the mother claw, and the inner arc surface is in contact with the outer surface of the workpiece. Two screw holes are provided on the sub-claw, and the two screw holes correspond one-to-one to the two threaded holes at the recess of the corresponding mother claw. The sub-claw is fixed to the mother clamp by installing screws.

[0010] The second objective of the present invention is achieved by the following technical solutions:

[0011] A clamping method based on the above-mentioned clamping tool with adjustable clamping force suitable for the soft magnetic alloy thin-walled ring sleeve comprises the following steps:

[0012] Step 1: Fix the chuck body and the processing equipment used to the nose end of the machine tool spindle through the corresponding accessories and screws, install the rotary pressure regulating cylinder on the tail end of the machine tool spindle, and connect them through the pull rod extending into the spindle hole of the machine tool.

[0013] Step 2, connect and fix the three female claws with the radially movable claws of the chuck through teeth and screws, and control the three female claws to maintain the same position on the circumference of the chuck. After fixing, the three force measuring auxiliary claws are respectively placed in the radial sockets on the three female claws and fixed. The inner ends of the force measuring auxiliary claws extend from the radial sockets, and a force measuring contact is installed at the inner end of a measuring force measuring auxiliary claw. A fixed force measuring sensor is installed on the outer side of the female claw corresponding to the measuring force measuring auxiliary claw, and the force measuring contact and the force measuring sensor are connected with a connecting line;

[0014] Step 3: Select three sub-claws that match the processing environment and fix them to the three mother claws respectively;

[0015] Step 4: Connect the dynamometer display to the external force sensor of the corresponding female claw, insert the clamping rod into the three force measuring auxiliary claws and clamp them, and adjust the pressure of the pressure regulating cylinder according to the data displayed on the display to control the clamping force;

[0016] Step 5. After adjusting the clamping force to an appropriate size, remove the dynamometer display and cover the force sensor with a cover;

[0017] Step 6: Clamp the workpiece to be processed between the inner arc surfaces of the three sub-claws to complete the clamping of the workpiece, and then the workpiece can be processed.

[0018] The advantages and positive effects of the present invention are:

[0019] (1) The clamping jaw of the present invention has a built-in clamping force measuring component and adopts a rear-mounted rotary pressure-regulating cylinder as the power source of the clamping device, so that the clamping force can be adjusted and measured, and is flexible and convenient to use.

[0020] (2) The rotary pressure regulating cylinder of the present invention has a built-in pressure maintaining function, which can make the clamping force constant and the clamping firm and reliable;

[0021] (3) The clamping part of the present invention adopts a split design of parent and child claws. By replacing the child claws, it can be adapted to clamp workpieces of different sizes, and has strong versatility;

[0022] (4) The sub-claws of the present invention are made of trimmable soft steel material and can be appropriately trimmed before precision machining. The contour of the sub-claws can perfectly fit the contour of the workpiece, and the clamping accuracy is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is an overall front schematic diagram of the clamping tool of the present invention;

[0024] Figure 2 It is an overall three-dimensional diagram of the clamping tool of the present invention;

[0025] Figure 3 is a front-view stereoscopic view of the chuck assembly of the present invention;

[0026] Figure 4is a rear-view perspective view of the chuck assembly of the present invention;

[0027] Figure 5 It is a three-dimensional exploded schematic diagram of the cooperation between the female jaw and the measuring force measuring auxiliary jaw of the present invention;

[0028] Figure 6 It is a schematic diagram of the structure of the sub-claw of the present invention;

[0029] Figure 7 It is a structural schematic diagram of the pull rod of the present invention;

[0030] Figure 8 It is a structural schematic diagram of the pressure regulating cylinder of the present invention;

[0031] Fig. 9 It is a schematic diagram of the installation of the clamping force measuring assembly of the present invention. DETAILED DESCRIPTION

[0032] The structure of the present invention is further described below with reference to the accompanying drawings and by way of examples. It should be noted that the present examples are descriptive rather than restrictive.

[0033] A clamping fixture with adjustable clamping force suitable for soft magnetic alloy thin-walled ring sleeves, see Figure 1-9 The tooling is mainly composed of three parts: the front end is a chuck assembly 1, the middle part is a pull rod 2, and the rear part is a pressure regulating cylinder 3.

[0034] The chuck assembly is mainly composed of a pneumatic three-jaw chuck body 1.1, a sub-jaw 1.5, a clamping force force measuring assembly, and a force measuring auxiliary jaw 1.4. The three jaws at the front end of the pneumatic three-jaw chuck body constitute the mother jaw 1.2. The mother jaw and the sub-jaw are designed to be split and locked by screws. The clamping force force measuring assembly includes a force measuring contact 1.8 and a force measuring sensor 1.3. The force measuring sensor is fixed to the side of a mother jaw, the force measuring contact is fixed to the outer end of a force measuring auxiliary jaw, and the three force measuring auxiliary jaws are built into the mother jaw. The clamping force is measured by the force measuring contact. The front and rear ends of the pull rod are provided with threads, which are connected to the rear end of the chuck body and the front output end of the pressure regulating cylinder respectively through the threads to perform its axial movement; the rotating pressure regulating cylinder is the power source of the clamping force of the jaws, and the clamping force is controlled by adjusting the gas pressure.

[0035] Figure 3 and Figure 4 The chuck is the main body, and the front end of the chuck is provided with a threaded hole, a threaded through hole and a tooth groove. The tooth groove and the threaded hole are used to match and tighten the female claw, the threaded through hole is used to connect with the nose of the machine tool, and the internal thread 1.6 at the rear end of the chuck is used to connect the pull rod. When the pull rod connected to it makes a corresponding axial movement, the chuck can cooperate with the corresponding structure through the internal bevel to convert the axial movement into a radial movement of clamping and loosening the jaws.

[0036] See also Figure 5 The female claw is a self-designed structure. A notch 1.2.1 is provided inside the front end of the female claw. The outer side of the notch is an arc surface. The matching sub-claw can be positioned and installed at the notch. The teeth at the rear of the female claw cooperate with the tooth grooves of the chuck, which can realize the rapid positioning of the female claw and facilitate the adjustment of the relative positions of the three claws. Two threaded holes 1.2.2 are provided on the bottom surface of the notch, and the sub-claws are pressed and fixed in the axial direction by connecting screws. A circular hole 1.2.3 is provided between the two threaded holes on the bottom surface of the notch. A radial socket 1.2.5 is provided in the middle of the inner side of the female claw for installing the force measuring auxiliary claw. A tightening threaded hole 1.2.4 is provided vertically between each radial socket and the circular hole on the bottom surface of the notch for installing the tightening screw to realize the pressing of the force measuring auxiliary claw into the radial socket. A wire hole vertically connected to the corresponding radial socket is provided on the other side of a female claw relative to the tightening threaded hole, and a force measuring sensor is fixedly installed on the outside of this side of the female claw. The force sensor is electrically connected to the force measuring contact at the outer end of the force measuring claw fixed in the corresponding radial jack through the connecting wire 1.7 passing through the wire hole, and is used to obtain the pressure signal of the force measuring contact. When not in use or after the clamping force is adjusted, the measuring sensor can be covered with a cover to avoid damage. After the force measuring claw with the force measuring contact fixed at the outer end is installed in the radial jack, the force sensor is connected to the force sensor to measure the clamping force.

[0037] See also Figure 6 The sub-claw is used to directly clamp and contact with the outer surface of the soft magnetic alloy thin-walled ring sleeve workpiece. A mother claw and a sub-claw are called a mother-and-child claw. The three groups of mother-and-child claws arranged along the circumferential direction can realize the clamping and fixing of the soft magnetic alloy thin-walled ring sleeve workpiece. The sub-claw adopts a block structure with arc surfaces on both the inner and outer sides. Two screw holes are arranged on the sub-claw. The outer arc surface 1.5.1 fits with the outer circular surface of the mother claw notch, and the inner arc surface 1.5.2 fits with the outer surface of the workpiece. The sub-claw is fixedly connected to the mother claw by two screws. The sub-claw is highly flexible and can be replaced or trimmed to adjust the clamping width, length and arc curvature of the clamping surface.

[0038] Figure 7 Schematic diagram of the pull rod, which is used to connect the chuck body and the pressure-regulating cylinder. The pull rod is cylindrical in shape as a whole, with the front end external thread 2.1 connected to the chuck, and the rear end internal thread 2.2 connected to the pressure-regulating cylinder to achieve the transmission of axial tension.

[0039] Figure 8 This is a schematic diagram of a rotary pressure regulating cylinder, which is a stepped cylindrical shape as a whole. The front thread 3.1 is used to connect the pull rod. There are two air hole connection ports on the outside of the circumference for connecting the air pipe and other corresponding accessories. This device is the power source of the clamping device, and has a built-in pressure-maintaining cylinder to keep the clamping force constant.

[0040] The clamping method of the clamping tool with adjustable clamping force applicable to the soft magnetic alloy thin-walled ring sleeve is as follows:

[0041] (1) The chuck and the processing equipment used are fixed to the nose end of the machine tool spindle through the corresponding accessories and bolts, and the rotary pressure regulating cylinder is installed on the tail end of the machine tool spindle and connected through a pull rod extending into the spindle hole of the machine tool.

[0042] (2) After all parts are connected to the processing equipment used, the three female jaws are connected and fixed to the radial movable jaws of the chuck through teeth and screws. The three female jaws can be controlled to maintain consistent positions on the circumference of the chuck through the cooperation of teeth and tooth grooves. After fixation, the three force measuring auxiliary jaws are respectively placed in the radial sockets on the three female jaws and fixed. The inner ends of the force measuring auxiliary jaws extend from the radial sockets, and a force measuring contact is installed at the inner end of a measuring force measuring auxiliary jaw. A fixed force sensor is installed on the outer side of the female jaw corresponding to the measuring force measuring auxiliary jaw, and the force measuring contact and the force sensor are connected with a connecting line.

[0043] (3) Select three sub-claws that match the processing environment and fix them to the three main claws respectively.

[0044] (4) Connect the dynamometer display to the external force sensor of the corresponding female claw, insert the clamping rod into the three force measuring auxiliary claws and clamp them, and adjust the pressure of the pressure regulating cylinder according to the data displayed on the display to control the clamping force.

[0045] (5) After adjusting the clamping force to the appropriate size, remove the force gauge display and cover the force sensor with a cover.

[0046] (6) After following steps (4) and (5), the clamping force has been properly adjusted, and the workpiece can be clamped and subsequently processed through the three sub-clamps. If the clamping accuracy needs to be further improved, the sub-claws can be adjusted according to the curvature of the clamped workpiece to keep the curvatures of the two consistent. If a workpiece with a different shape and rigidity needs to be processed, repeat steps (3) to (6).

[0047] Although the embodiments and drawings of the present invention are disclosed for illustrative purposes, those skilled in the art will appreciate that various substitutions, changes and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the scope of the present invention is not limited to the contents disclosed in the embodiments and drawings.

Claims

1. A clamping tool with adjustable clamping force suitable for a soft magnetic alloy thin-walled ring sleeve, characterized in that: It includes a chuck assembly at the front end, a pull rod at the middle part and a pressure regulating cylinder at the rear end; the chuck assembly is fixed to the nose end of the machine tool spindle, the rotary pressure regulating cylinder is installed at the rear end of the machine tool spindle, the pull rod extends into the spindle hole of the machine tool, and the two ends of the pull cylinder are respectively connected to the chuck assembly and the pressure regulating cylinder; The chuck assembly is composed of a pneumatic three-jaw chuck body, a sub-jaw, a clamping force measuring assembly, and a force measuring auxiliary jaw; the clamping force measuring assembly includes a force measuring contact and a force measuring sensor; the three jaws at the front end of the pneumatic three-jaw chuck body constitute a mother jaw; the three sub-jaws are detachably fixedly installed in the recesses inside the front ends of the three mother jaws along the circumferential direction, and the inner side surfaces of the three sub-jaws form a workpiece clamping surface, the diameter of the workpiece clamping surface is the same as the outer diameter of the soft magnetic alloy thin-walled ring sleeve to be processed The diameter is straight; a radial plug hole is respectively arranged on the inner side of the three female clamping jaws, and the three force measuring auxiliary jaws are respectively inserted and fixed in the three radial plug holes, and a force measuring contact is installed on the outer end of at least one force measuring auxiliary jaw, and the force measuring contact is electrically connected to the force measuring sensor fixed on one side of the corresponding female jaw through a connecting line; before clamping the soft magnetic alloy thin-walled ring sleeve workpiece, the inner sides of the three force measuring auxiliary jaws are clamped and contacted with the clamping rod, and the air supply pressure of the pressure regulating cylinder is adjusted to realize the measurement and adjustment of the clamping force.

2. The clamping tool with adjustable clamping force suitable for a soft magnetic alloy thin-walled ring sleeve according to claim 1, characterized in that: The sub-claw is made of soft steel.

3. The clamping tool with adjustable clamping force suitable for a soft magnetic alloy thin-walled ring sleeve according to claim 1, characterized in that: The outer side surface of the recess on the female jaw is an arc surface, two threaded holes are arranged on the bottom surface of the recess, and a round hole is arranged between the two threaded holes; a tightening threaded hole is arranged vertically connected between each radial socket and the round hole on the bottom surface of the recess, and the force measuring jaw is pressed tightly into the radial socket by installing a tightening screw; a wire hole vertically connected to the corresponding radial socket is arranged on the other side of the female jaw relative to the tightening threaded hole for the connecting wire to pass through.

4. The clamping tool with adjustable clamping force suitable for a soft magnetic alloy thin-walled ring sleeve according to claim 1, characterized in that: The sub-claw adopts a block structure with both inner and outer sides being arc surfaces. The outer arc surface fits with the outer circular surface of the recess of the mother claw, and the inner arc surface fits with the outer surface of the workpiece. Two screw holes are provided on the sub-claw, and the two screw holes correspond one-to-one with the two threaded holes at the recess of the corresponding mother claw. The sub-claw is fixed to the mother clamp by installing screws.

5. A workpiece clamping method based on the clamping tool with adjustable clamping force suitable for the soft magnetic alloy thin-walled ring sleeve according to any one of claims 1 to 4, characterized in that: The steps include: Step 1: Fix the chuck body and the processing equipment used to the nose end of the machine tool spindle through the corresponding accessories and screws, install the rotary pressure regulating cylinder on the tail end of the machine tool spindle, and connect them through the pull rod extending into the spindle hole of the machine tool. Step 2, connect and fix the three female claws with the radially movable claws of the chuck through teeth and screws, and control the three female claws to maintain the same position on the circumference of the chuck. After fixing, the three force measuring auxiliary claws are respectively placed in the radial sockets on the three female claws and fixed. The inner ends of the force measuring auxiliary claws extend from the radial sockets, and a force measuring contact is installed at the inner end of a measuring force measuring auxiliary claw. A fixed force measuring sensor is installed on the outer side of the female claw corresponding to the measuring force measuring auxiliary claw, and the force measuring contact and the force measuring sensor are connected with a connecting line; Step 3: Select three sub-claws that match the processing environment and fix them to the three mother claws respectively; Step 4: Connect the dynamometer display to the external force sensor of the corresponding female claw, insert the clamping rod into the three force measuring auxiliary claws and clamp them, and adjust the pressure of the pressure regulating cylinder according to the data displayed on the display to control the clamping force; Step 5. After adjusting the clamping force to an appropriate size, remove the dynamometer display and cover the force sensor with a cover; Step 6: Clamp the workpiece to be processed between the inner arc surfaces of the three sub-claws to complete the clamping of the workpiece, and then the workpiece can be processed.

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