Clamping tool and method suitable for soft magnetic alloy thin-walled ring sleeve

Abstract

This invention relates to a clamping fixture and method for adjustable clamping force of thin-walled soft magnetic alloy ring sleeves. The fixture includes a chuck assembly at the front end, a pull rod in the middle, and a pressure regulating cylinder at the rear end. The chuck assembly consists of a pneumatic three-jaw chuck body, sub-jaws, a clamping force measuring component, and a force measuring auxiliary jaw. The clamping force measuring component includes a force measuring contact and a force sensor. The three jaws at the front end of the pneumatic three-jaw chuck body form a mother jaw. The three sub-jaws are respectively fixed in the inner recesses at the front ends of the three mother jaws, and the inner surfaces of the three sub-jaws form a workpiece clamping surface. A radial insertion hole is provided on the inner side of each of the three mother jaws, into which a force measuring auxiliary jaw is inserted. A force measuring contact is installed at the outer end of at least one force measuring auxiliary jaw, and the force measuring contact is electrically connected to the force sensor via a connecting wire. Before clamping the workpiece, the inner surfaces of the three force measuring auxiliary jaws are in clamping contact with the clamping rod. By adjusting the air supply pressure, the clamping force can be measured and adjusted. This invention achieves adjustable clamping force.

Description

Technical Field

[0001] This invention belongs to the field of machining technology, specifically relating to a clamping fixture and method with adjustable clamping force suitable for thin-walled ring sleeves made of soft magnetic alloys. Background Technology

[0002] Soft magnetic alloys are a class of alloys that exhibit high permeability and extremely low coercivity in weak magnetic fields, possessing mechanical characteristics of low hardness and high plasticity. In the navigation field, they serve as core components in high-precision instruments such as torque motors, resolver transmitters, and missile seeker motors, including stators, rotors, and shielding covers. These components are often thin-walled, ring-shaped workpieces, prone to severe clamping deformation and difficult to machine. Because high-precision instruments have high requirements for magnetic properties, and the magnetic properties of high-performance soft magnetic alloys are highly sensitive to stress, strict requirements are placed on the amount of workpiece clamping deformation during machining, resulting in extremely high clamping requirements for precision machining. To solve the clamping deformation problem of existing soft magnetic alloy workpieces in precision machining, it is essential to develop a clamping method that is controllable and adjustable in clamping force, non-destructive to the workpiece, fast, convenient, and highly versatile, suitable for thin-walled soft magnetic alloy workpieces. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention proposes a clamping fixture and method with adjustable clamping force suitable for thin-walled ring sleeves made of soft magnetic alloys.

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

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

[0006] The chuck assembly consists of a pneumatic three-jaw chuck body, sub-jaws, a clamping force measuring component, and a force measuring auxiliary jaw. The clamping force measuring component includes a force measuring contact and a force sensor. The three jaws at the front end of the pneumatic three-jaw chuck body form the mother jaw. The three sub-jaws are detachably and fixedly installed in the recesses inside the front ends of the three mother jaws along the circumferential direction. The inner surfaces of the three sub-jaws form a workpiece clamping surface, and the diameter of the workpiece clamping surface is perpendicular to the outer circular surface of the soft magnetic alloy thin-walled ring to be processed. The three female jaws are arranged with a radial insertion hole on the inner side of each of the three female jaws. The three force-measuring secondary jaws are respectively inserted and fixed in the three radial insertion holes. A force-measuring contact is installed on the outer end of at least one force-measuring secondary jaw. The force-measuring contact is electrically connected to a force sensor fixed on one side of the corresponding female jaw through a connecting line. Before clamping the soft magnetic alloy thin-walled ring workpiece, the inner sides of the three force-measuring secondary jaws are in clamping contact with the clamping rod. With the adjustment of the air supply pressure of the pressure regulating cylinder, the clamping force can be measured and adjusted.

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

[0008] Furthermore, the outer side of the notch on the female jaw is an arc surface, and two threaded holes are provided on the bottom surface of the notch, with a round hole between the two threaded holes; a set screw is provided vertically between each radial insertion hole and the round hole on the bottom surface of the notch, and by installing a set screw, the force measuring secondary jaw is pressed into the radial insertion hole; a wire passage hole is provided on the other side of the female jaw relative to the set screw hole, which is perpendicularly connected to the corresponding radial insertion hole, for the connecting wire to pass through.

[0009] Moreover, the sub-jaw adopts a block structure with both inner and outer arc surfaces. The outer arc surface fits into the outer circular surface of the female jaw recess, and the inner arc surface fits into the outer surface of the workpiece. Two screw through holes are provided on the sub-jaw, and the two screw through holes correspond one-to-one with the two threaded holes at the corresponding female jaw recess. By installing screws, the sub-jaw is fixed to the female jaw.

[0010] The second objective of this invention is achieved through the following technical solution:

[0011] A clamping method based on the above-mentioned clamping fixture with adjustable clamping force suitable for thin-walled soft magnetic alloy rings includes the following steps:

[0012] Step 1: Fix the chuck body and the processing equipment to the nose end of the machine tool spindle using appropriate accessories and screws; install the pressure regulating cylinder at the tail end of the machine tool spindle and connect them through a tie rod that extends into the spindle hole.

[0013] Step 2: Connect and fix the three female jaws to the radial moving jaws of the chuck using teeth and screws, and control the three female jaws to keep their positions consistent around the chuck circumference. After fixing, place the three force measuring auxiliary jaws into the radial insertion holes on the three female jaws respectively and fix them. The inner end of the force measuring auxiliary jaw extends out from the radial insertion hole, and a force measuring contact is installed on the inner end of one of the force measuring auxiliary jaws. Install and fix the force measuring sensor on the outer side of the corresponding female jaw of the force measuring auxiliary jaw, and connect the force measuring contact and the force measuring sensor with a connecting wire.

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

[0015] Step 4: Connect the force gauge display to the corresponding external force sensor of the female jaw, and insert the clamping bar into the three force-measuring secondary jaws and clamp them. According to the data displayed on the display, adjust the pressure of the pressure regulating cylinder to control the clamping force.

[0016] Step 5: After adjusting the clamping force to a suitable value, remove the force gauge display and cover the force sensor with the cover;

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

[0018] The advantages and positive effects of this invention are as follows:

[0019] (1) The clamping force measuring component is built into the claw of the present invention, and a rear-mounted pressure regulating cylinder is used as the power source of the clamping device, so that the clamping force is adjustable and measurable, and is flexible and convenient to use.

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

[0021] (3) The clamping part of the present invention adopts a split design of male and female jaws. The female jaws can be replaced to adapt to clamping workpieces of different sizes, which is highly versatile.

[0022] (4) The sub-claw of the present invention is made of trimmable soft steel material, which can be trimmed appropriately before precision machining. The sub-claw contour can perfectly fit the workpiece contour, and the clamping accuracy is high. Attached Figure Description

[0023] Figure 1 This is a front view of the overall clamping fixture of the present invention;

[0024] Figure 2 This is a three-dimensional view of the clamping fixture of the present invention;

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

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

[0027] Figure 5 This is a three-dimensional exploded view of the cooperation between the female jaw and the measuring force secondary jaw of the present invention;

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

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

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

[0031] Figure 9 This is a schematic diagram of the installation of the clamping force measuring component of the present invention. Detailed Implementation

[0032] The structure of the present invention will be further described below with reference to the accompanying drawings and embodiments. It should be noted that these embodiments are descriptive and not limiting.

[0033] For an adjustable clamping fixture suitable for thin-walled ring sleeves made of soft magnetic alloys, please refer to [link / reference]. Figure 1-9 This tooling mainly consists of three parts: the front end is the chuck assembly 1, the middle part is the tie rod 2, and the rear end is the pressure regulating cylinder 3.

[0034] The chuck assembly mainly consists of a pneumatic three-jaw chuck body 1.1, daughter jaws 1.5, a clamping force measuring component, and a force-measuring auxiliary jaw 1.4. The three jaws at the front end of the pneumatic three-jaw chuck body constitute a mother jaw 1.2. The mother jaw and daughter jaws are separate designs, locked together with screws. The clamping force measuring component includes a force-measuring contact 1.8 and a force-measuring sensor 1.3. The force-measuring sensor is fixed to the side of one mother jaw, and the force-measuring contact is fixed to the outer end of one force-measuring auxiliary jaw. The three force-measuring auxiliary jaws are built into the mother jaw, and the clamping force is measured by the force-measuring contact. The pull rod has threads at both ends, connecting to the rear end of the chuck body and the front output end of the pressure regulating cylinder respectively, to perform its axial movement. The pressure regulating cylinder is the power source for the jaw clamping force, controlling the clamping force by adjusting the gas pressure.

[0035] Figure 3 and Figure 4 The chuck body has a threaded hole, a threaded through hole, and a toothed groove at its front end. The toothed groove and threaded hole are used to engage and secure the female jaws, the threaded through hole is used to connect to the machine tool nose, and the internal 1.6 thread at the rear end of the chuck is used to connect a tie rod. When the tie rod makes a corresponding axial movement, the chuck can engage with the corresponding structure through its internal inclined surface to convert the axial movement into a radial movement of clamping and releasing the jaws.

[0036] See Figure 5 The female jaw has a self-designed structure. A notch 1.2.1 is provided inside the front end of the female jaw, and the outer side of the notch is an arc surface. The notch allows for the positioning and installation of a matching female jaw. The rear teeth of the female jaw engage with the chuck's tooth grooves, enabling rapid positioning of the female jaw and facilitating adjustment of the relative positions of the three jaws. Two threaded holes 1.2.2 are provided on the bottom surface of the notch, allowing for axial clamping and fixing of the female jaw using connecting screws. A circular hole 1.2.3 is provided between the two threaded holes on the bottom surface of the notch. A radial insertion hole 1.2.5 is provided in the center of the inner side of the female jaw for installing a force-measuring auxiliary jaw. A set screw 1.2.4 is vertically connected between each radial insertion hole and the circular hole on the bottom surface of the notch, for installing a set screw to press the force-measuring auxiliary jaw into the radial insertion hole. A wire hole is provided on the opposite side of the female jaw relative to the set threaded hole, perpendicularly communicating with the corresponding radial insertion hole. A force sensor is fixedly mounted on the outside of this side of the female jaw. The force sensor is electrically connected to the force-measuring contact at the outer end of the force-measuring auxiliary jaw fixed in the corresponding radial insertion hole via a connecting wire 1.7 passing through the wire hole, to obtain the pressure signal from the force-measuring contact. When not in use or after the clamping force has been adjusted, the measuring sensor can be covered with a cover to prevent damage. After the force-measuring auxiliary jaw with the force-measuring contact fixed at its outer end is inserted into the radial insertion hole, the force sensor can be connected to the force sensor to measure the clamping force.

[0037] See Figure 6 The female jaw is used for direct clamping contact with the outer surface of the thin-walled ring-shaped workpiece made of soft magnetic alloy. A female jaw and a female jaw work together, forming a female-female jaw system. Three sets of female-female jaws arranged circumferentially achieve the clamping and fixing of the thin-walled ring-shaped workpiece made of soft magnetic alloy. The female jaw adopts a block structure with both inner and outer arc surfaces. It has two screw holes; the outer arc surface 1.5.1 fits against the outer circular surface of the female jaw's recess, and the inner arc surface 1.5.2 fits against the outer surface of the workpiece. The female jaw is fixedly connected to the female jaw by two screws. The female jaw is highly flexible and can be replaced or modified to adjust the clamping width, length, and the curvature of the clamping surface.

[0038] Figure 7 The diagram shows a tie rod used to connect the chuck body and the pressure regulating cylinder. The tie rod is cylindrical in shape, with an external thread 2.1 at the front end connecting to the chuck and an internal thread 2.2 at the rear end connecting to the pressure regulating cylinder, thus transmitting axial tension.

[0039] Figure 8 This is a schematic diagram of a pressure regulating cylinder. It is generally a stepped cylinder with a 3.1 thread at the front end for connecting a pull rod. Two air ports are located on the outer circumference for connecting air hoses and other accessories. This device is the power source for the clamping mechanism and has a built-in pressure-maintaining cylinder to ensure a constant clamping force.

[0040] The clamping method for the adjustable clamping force fixture applicable to thin-walled soft magnetic alloy rings is as follows:

[0041] (1) Fix the chuck and the processing equipment to the nose end of the machine tool spindle with appropriate accessories and bolts, and install the pressure regulating cylinder at the tail end of the machine tool spindle. Connect them with a tie rod that extends into the spindle hole of the machine tool.

[0042] (2) After all components are connected to the processing equipment used, the three female jaws are connected and fixed to the radial moving jaws of the chuck by teeth and screws. The three female jaws can be controlled to keep their positions consistent around the chuck by the teeth and grooves. After fixing, the three force measuring secondary jaws are respectively placed into the radial insertion holes on the three female jaws and fixed. The inner end of the force measuring secondary jaw extends out from the radial insertion hole, and a force measuring contact is installed on the inner end of one of the force measuring secondary jaws. A force measuring sensor is installed and fixed on the outside of the corresponding female jaw of the force measuring secondary jaw. The force measuring contact and the force measuring sensor are connected by a connecting wire.

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

[0044] (4) Connect the force measuring instrument display to the corresponding external force sensor of the female jaw, and insert the clamping bar into the three force measuring secondary jaws and clamp them. 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 a suitable value, remove the force measuring instrument display and cover the force sensor with a cover.

[0046] (6) After operating according to steps (4) and (5), the clamping force has been properly adjusted, and the workpiece can be clamped and processed through the three sub-jaws. If it is necessary to further improve the clamping accuracy, the curvature of the sub-jaws can be adjusted according to the curvature of the workpiece being clamped, so that the curvatures of the two are consistent. If it is necessary to process workpieces with different shapes and rigidities, repeat steps (3) to (6).

[0047] Although embodiments and drawings of the present invention have been disclosed for illustrative purposes, those skilled in the art will understand that various substitutions, variations 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 fixture with adjustable clamping force suitable for thin-walled ring sleeves made of soft magnetic alloys, characterized in that: It includes a chuck assembly at the front end, a tie rod in the middle, and a pressure regulating cylinder at the rear end; the chuck assembly is fixed to the nose end of the machine tool spindle, the pressure regulating cylinder is installed at the tail end of the machine tool spindle, and the tie rod extends into the machine tool spindle hole, with the two ends of the tie rod connected to the chuck assembly and the pressure regulating cylinder, respectively. The chuck assembly consists of a pneumatic three-jaw chuck body, sub-jaws, a clamping force measuring component, and a force measuring auxiliary jaw. The clamping force measuring component includes a force measuring contact and a force sensor. The three jaws at the front end of the pneumatic three-jaw chuck body form the mother jaw. The three sub-jaws are detachably and fixedly installed in the recesses inside the front ends of the three mother jaws along the circumferential direction. The inner surfaces of the three sub-jaws form a workpiece clamping surface, and the diameter of the workpiece clamping surface is perpendicular to the outer circular surface of the soft magnetic alloy thin-walled ring to be processed. The three female jaws are arranged with a radial insertion hole on the inner side of each of the three female jaws. The three force-measuring secondary jaws are respectively inserted and fixed in the three radial insertion holes. A force-measuring contact is installed on the outer end of at least one force-measuring secondary jaw. The force-measuring contact is electrically connected to a force sensor fixed on one side of the corresponding female jaw through a connecting line. Before clamping the soft magnetic alloy thin-walled ring workpiece, the inner sides of the three force-measuring secondary jaws are in clamping contact with the clamping rod. With the adjustment of the air supply pressure of the pressure regulating cylinder, the clamping force can be measured and adjusted.

2. The clamping fixture with adjustable clamping force for thin-walled soft magnetic alloy rings according to claim 1, characterized in that: The sub-claw is made of mild steel.

3. The clamping fixture with adjustable clamping force for thin-walled soft magnetic alloy rings according to claim 1, characterized in that: The outer surface of the notch on the female jaw is an arc surface. Two threaded holes are provided on the bottom surface of the notch, and a round hole is provided between the two threaded holes. A set screw is provided vertically between each radial insertion hole and the round hole on the bottom surface of the notch. By installing a set screw, the force measuring secondary jaw is pressed into the radial insertion hole. On the other side of the female jaw opposite to the set screw, a wire passage hole is provided vertically connected to the corresponding radial insertion hole for the connecting wire to pass through.

4. The clamping fixture with adjustable clamping force for thin-walled soft magnetic alloy rings according to claim 1, characterized in that: The sub-jaw adopts a block structure with both inner and outer arc surfaces. The outer arc surface fits into the outer circular surface of the female jaw recess, and the inner arc surface fits into the outer surface of the workpiece. Two screw holes are provided on the sub-jaw, and the two screw holes correspond one-to-one with the two threaded holes at the corresponding female jaw recess. By installing screws, the sub-jaw is fixed to the female jaw.

5. A workpiece clamping method based on the adjustable clamping force clamping fixture for thin-walled soft magnetic alloy rings according to any one of claims 1-4, characterized in that, Includes the following steps: Step 1: Fix the chuck body and the processing equipment to the nose end of the machine tool spindle using appropriate accessories and screws; install the pressure regulating cylinder at the tail end of the machine tool spindle and connect them through a tie rod that extends into the spindle hole. Step 2: Connect and fix the three female jaws to the radial moving jaws of the chuck using teeth and screws, and control the three female jaws to keep their positions consistent around the chuck circumference. After fixing, place the three force measuring auxiliary jaws into the radial insertion holes on the three female jaws respectively and fix them. The inner end of the force measuring auxiliary jaw extends out from the radial insertion hole, and a force measuring contact is installed on the inner end of one of the force measuring auxiliary jaws. Install and fix the force measuring sensor on the outer side of the corresponding female jaw of the force measuring auxiliary jaw, and connect the force measuring contact and the force measuring sensor with a connecting wire. Step 3: Select three sub-jaws that match the processing environment and fix them to the three female jaws respectively; Step 4: Connect the force gauge display to the corresponding external force sensor of the female jaw, and insert the clamping bar into the three force-measuring secondary jaws and clamp them. According to the data displayed on the display, adjust the pressure of the pressure regulating cylinder to control the clamping force. Step 5: After adjusting the clamping force to a suitable value, remove the force gauge display and cover the force sensor with the cover; Step 6: Clamp the workpiece to be processed between the inner arc surfaces of the three sub-jaws to complete the workpiece clamping, and then proceed with the processing of the workpiece.

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