Fixture for improving cutting force test stability of ceramic matrix composite material and use method

Abstract

The invention relates to the field of auxiliary tool clamps, in particular to a clamp for improving the cutting force test stability of a ceramic matrix composite and a use method. The device is arranged on a milling machine and comprises a connecting flange, the connecting flange is detachably mounted on the milling machine, the upper surface of the connecting flange is detachably connected with a dynamometer, the upper end part of the dynamometer is connected with a mounting seat, the upper surface of the mounting seat is detachably connected with a positioning platform, and a movable wedge block is arranged on the positioning platform. The positioning platform and the movable wedge-shaped block are matched together to clamp a ceramic matrix composite workpiece; according to the invention, ceramic-based composite material workpieces with different shapes and sizes can be rapidly, accurately and stably clamped, the positions of the workpieces and the dynamometer are ensured to be fixed in the cutting force test process, and the measurement precision and the test efficiency are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of auxiliary tooling fixtures, in particular to a fixture for improving the stability of ceramic matrix composite cutting force testing and a use method thereof. BACKGROUND

[0002] SiCf / SiC ceramic matrix composite is composed of silicon carbide fiber reinforced silicon carbide matrix, has the advantages of low density, high temperature resistance, high specific strength and radiation resistance, and is widely used in fields such as hot end parts of aero-engine and nuclear reactor cladding; and in the SiCf / SiC ceramic matrix composite material processing process, the anisotropy and brittleness of the fiber will cause uneven distribution of cutting force, which is easy to cause matrix cracking, fiber pull-out and interface debonding, and the high hardness of the fiber will cause serious tool wear during processing, and the heat generated by traditional mechanical processing will easily cause micro-cracks and phase change, affecting the service life of the part; therefore, how to improve the processing efficiency and optimize the processing process of the material has been a challenge in the industry.

[0003] The cutting force is an important parameter in the processing optimization process of SiCf / SiC ceramic matrix composite, and it has a key influence on the processing quality and efficiency of SiCf / SiC ceramic matrix composite; understanding the generation mechanism and influencing factors of cutting force is of great significance for optimizing the processing process of SiCf / SiC ceramic matrix composite, improving the processing efficiency and reducing the cost.

[0004] In the cutting force test of SiCf / SiC ceramic matrix composite, the traditional clamping method has many shortcomings and cannot meet the high-precision and high-stability test requirements; in the cutting force test process of SiCf / SiC ceramic matrix composite, the traditional fixture or transition plate may not be able to withstand the high-frequency and high-amplitude cutting force generated during processing, resulting in system deformation and vibration, which seriously affects the accuracy of the force gauge (signal distortion and high noise), and even damages the sensor; and the commonly used electromagnetic chuck clamp is not suitable for SiCf / SiC non-magnetic composite material.

[0005] Therefore, there is an urgent need for a fixture for improving the stability of ceramic matrix composite cutting force testing and a use method thereof to solve the above technical problems. SUMMARY

[0006] The present application aims to solve the above problems, and provides a fixture for improving the stability of ceramic matrix composite cutting force testing and a use method thereof, which can realize rapid, accurate and stable clamping of ceramic matrix composite workpieces of different shapes and sizes, ensure the position of the workpiece and the force gauge fixed during the cutting force test, and improve the measurement accuracy and test efficiency.

[0007] The present application solves the problem by adopting the following technical solution: The utility model provides a kind of fixture for improving the stability of ceramic matrix composite cutting force test, be set on milling machine, including connecting flange, connecting flange is detachably installed on milling machine, force gauge is detachably connected on the upper surface of connecting flange, mounting seat is connected on the upper end of force gauge, positioning platform is detachably connected on the upper surface of mounting seat, movable wedge block is set on positioning platform, and positioning platform and movable wedge block are cooperated to realize clamping to ceramic matrix composite;Positioning platform includes platform plate body, platform plate body is horizontally arranged and detachably installed on mounting seat, fixed rectangular seat is arranged on the left side of the upper surface of platform plate body, fixed wedge seat is arranged on the right side of the upper surface of platform plate body, and fixed rectangular seat and fixed wedge seat both protrude from platform plate body upwards, first inclined surface is arranged on fixed wedge seat, first inclined surface is arranged on the side of fixed wedge seat close to fixed rectangular seat, first inclined surface is inclined from the side away from fixed rectangular seat to the side close to fixed rectangular seat from top to bottom, and movable wedge block is arranged on the upper surface of platform plate body and is in close contact with first inclined surface, clamping portion is arranged between movable wedge block and fixed rectangular seat.

[0008] Further, the length of fixed rectangular seat, fixed wedge seat and movable wedge block is consistent with the width of platform plate body.

[0009] Further, second inclined surface is arranged on movable wedge block and is in close contact with first inclined surface, a plurality of lower screw holes are arranged on the platform plate body at the bottom of movable wedge block, the plurality of lower screw holes are sequentially and spacedly arranged along the length direction of movable wedge block, a plurality of upper screw holes are arranged on movable wedge block, the plurality of upper screw holes and the plurality of lower screw holes are one-to-one corresponding, and adjusting bolt is threadedly connected on the corresponding upper screw hole and lower screw hole; the tightness of adjusting bolt is adjusted to make movable wedge block slide up and down along first inclined surface, so that the clamping portion realizes clamping.

[0010] Further, a plurality of connecting screw holes are arranged on the clamping portion of platform plate body and mounting seat, the plurality of connecting screw holes are arranged in annular array on platform plate body and mounting seat, connecting bolt is threadedly connected on each connecting screw hole, and positioning platform and mounting seat are connected together through connecting bolt.

[0011] Further, connecting recess with inverted trapezoidal structure is arranged on the upper end of force gauge, extension protrusion is arranged on the lower bottom surface of mounting seat and is matched with connecting recess, a plurality of fastening screw holes are arranged on connecting recess and extension protrusion, fastening bolt is threadedly connected in each fastening screw hole, and mounting seat is connected with force gauge through fastening bolt;damping washer is clamped between connecting recess and extension protrusion.

[0012] Further, the connecting flange is in the shape of a rectangular plate, three groups of positioning screw holes are uniformly arranged around the center of the connecting flange, and three positioning screw holes are arranged in each group of positioning screw holes.

[0013] Further, two U-shaped open grooves are arranged on the left side of the connecting flange, two U-shaped open grooves are arranged on the right side of the connecting flange, the four U-shaped open grooves are divided into two groups and arranged symmetrically, the two U-shaped open grooves in each group are arranged symmetrically, and the fastening bolts are matched with the U-shaped open grooves.

[0014] Further, a ring-shaped extension is arranged on the lower part of the force gauge, three groups of through screw holes are uniformly arranged on the ring-shaped extension, the three groups of through screw holes and the three groups of positioning screw holes are one-to-one corresponding, and the through screw holes and the positioning screw holes are in communication, and the positioning bolts are threadedly connected in the through screw holes and the positioning screw holes, and the force gauge and the connecting flange are connected together through the positioning bolts.

[0015] Further, a connecting line is connected to the force gauge, and a data acquisition system is connected to the connecting line.

[0016] A method for using a clamp for improving the stability of ceramic matrix composite cutting force testing, comprising the following steps: S1, place the connecting flange on the milling machine, align the positioning screw hole or the U-shaped open groove with the connecting hole on the milling machine, and fix it through the fastening bolt; check the connection gap between the connecting flange and the milling machine to meet the processing requirements; S2, then connect the positioning platform, the mounting seat, the force gauge and the connecting flange in sequence; S3, install the movable wedge-shaped block on the positioning platform, ensure smooth sliding of the movable wedge-shaped block, and adjust the screw bolt to rotate smoothly; S4, place the ceramic matrix composite workpiece on the clamping part, and preliminarily position the ceramic matrix composite workpiece; then gradually tighten the adjusting screw, thereby slowly pushing the movable wedge-shaped block to move downward along the first inclined surface, so that the movable wedge-shaped block and the fixed rectangular seat cooperate to clamp and fix the ceramic matrix composite workpiece; S5, then start the milling machine to cut the ceramic matrix composite workpiece; during the cutting process, the force gauge measures the cutting force size and direction in real time, and transmits the data to the data acquisition system for recording and analysis.

[0017] The application adopting the above technical scheme has the following outstanding features compared with the prior art: The application can realize fast, accurate and stable clamping of ceramic matrix composite workpieces of different shapes and sizes, ensure the position of the workpiece and the force gauge fixed during the cutting force test, improve the measurement accuracy and test efficiency; the first inclined surface and the second inclined surface of the movable wedge block and the fixed wedge seat cooperate with each other to have a force increasing effect, can generate a larger clamping force with a smaller operating force, compared with the traditional clamping method, the clamping force is improved, and under the action of the cutting force, the clamping force is more stable, which ensures the stable fixation of the ceramic matrix composite workpiece under complex cutting conditions, effectively avoids the displacement of the ceramic matrix composite workpiece, and greatly improves the reliability of the test data; the positioning platform and the movable wedge block are designed in an integral manner, have high rigidity, short force transmission path and strong vibration resistance, and are suitable for intermittent cutting of the ceramic matrix composite workpiece; in addition, the clamping operation of the clamp can be completed by screwing the adjusting bolt, which is simple and labor-saving, greatly shortens the clamping time, and improves the test efficiency; meanwhile, the adjustable design of the movable wedge block enables it to quickly adapt to various workpieces, and has strong universality. BRIEF DESCRIPTION OF DRAWINGS

[0018] Fig. 1 is a schematic diagram of the main view structure of the application; Fig. 2 is a schematic diagram of the main view structure of the application; Fig. 3 is a schematic diagram of the main view structure of the application; In the figure: 1, connecting flange; 2, force gauge; 3, mounting seat; 4, positioning platform; 5, movable wedge block; 6, platform plate body; 7, fixed rectangular seat; 8, fixed wedge seat; 9, first inclined surface; 10, clamping part; 11, second inclined surface; 12, upper screw hole; 13, connecting screw hole; 14, connecting notch; 15, extension protrusion; 16, fastening bolt; 17, through screw hole; 18, U-shaped open slot; 19, connecting line. DETAILED DESCRIPTION

[0019] The application will be better understood by the following description of the embodiments, but the specific embodiments given by the applicant should not be regarded as limiting the technical solutions of the application, and any change in the definition of components or technical features and / or formal but not substantial change in the overall structure should be regarded as within the protection scope of the technical solutions of the application.

[0020] Referring to Figs. 1 to 3 , the technical solutions of the application are as follows: The utility model provides a kind of fixture for improving the stability of ceramic matrix composite cutting force test, be set to milling machine, including connecting flange 1, connecting flange 1 can be detachably mounted on milling machine, detachably connected with dynamometer 2 on the upper surface of connecting flange 1, connecting line 19 is connected on dynamometer 2, data acquisition system is connected on connecting line 19, mounting seat 3 is connected on the upper end of dynamometer 2, detachably connected with positioning platform 4 on the upper surface of mounting seat 3, movable wedge block 5 is arranged on positioning platform 4, and positioning platform 4 and movable wedge block 5 are clamped to ceramic matrix composite material together with cooperation; Positioning platform 4 includes platform plate body 6, and platform plate body 6 is horizontally arranged, and positioning platform 4 is detachably mounted on mounting seat 3, fixed rectangular seat 7 is arranged on the left side of the upper surface of platform plate body 6, fixed wedge-shaped seat 8 is arranged on the right side of the upper surface of platform plate body 6, and fixed rectangular seat 7 and fixed wedge-shaped seat 8 both protrude upwards from platform plate body 6, first inclined surface 9 is arranged on fixed wedge-shaped seat 8, first inclined surface 9 is arranged on the side of fixed wedge-shaped seat 8 close to fixed rectangular seat 7, first inclined surface 9 is inclined from the side away from fixed rectangular seat 7 to the side close to fixed rectangular seat 7 from top to bottom, movable wedge block 5 is arranged on the upper surface of platform plate body 6 and is in close contact with first inclined surface 9, and clamping part 10 is arranged between movable wedge block 5 and fixed rectangular seat 7;The length of fixed rectangular seat 7, fixed wedge-shaped seat 8 and movable wedge block 5 is consistent with the width of platform plate body 6;Second inclined surface 11 that is in close contact with first inclined surface 9 is arranged on movable wedge block 5, three lower screw holes are machined on platform plate body 6 at the bottom of movable wedge block 5, the three lower screw holes are sequentially and spaced arranged along the length direction of movable wedge block 5, three upper screw holes 12 are machined on movable wedge block 5, the three upper screw holes 12 and the three lower screw holes are one-to-one corresponding, and adjusting bolt is threadedly connected on the corresponding upper screw hole 12 and lower screw hole;By rotating the tightness of adjusting bolt, movable wedge block 5 is slid along first inclined surface 9, so that clamping part 10 is clamped.

[0021] And with the movement of movable wedge block 5, first inclined surface 9 and second inclined surface 11 are extruded, a component force in the direction of first inclined surface 9 is generated, and then the component force tightly presses movable wedge block 5 to ceramic matrix composite workpiece, and fixed wedge-shaped seat 8 also generates reverse pressure to ceramic matrix composite workpiece, so that ceramic matrix composite workpiece is clamped;Due to the self-locking characteristics of movable wedge block 5 and fixed wedge-shaped seat 8, the pressure between movable wedge block 5 and fixed wedge-shaped seat 8 will be further increased under the action of cutting force, so as to ensure that ceramic matrix composite workpiece will not be loose.

[0022] It should be noted that connecting flange 1, positioning platform 4 and movable wedge block 5 are integrally formed by using 40Cr material;And the inclination angles of first inclined surface 9 and second inclined surface 11 are the same, and the inclination angle is 5°-20°.

[0023] Eight connecting screw holes 13 are formed on the clamping portion 10 of the platform plate body 6 and the mounting seat 3, and are arranged in a circular array on the platform plate body 6 and the mounting seat 3. A connecting bolt is threadedly connected to each connecting screw hole 13, and the positioning platform 4 and the mounting seat 3 are connected together through the connecting bolt.

[0024] A connecting recess 14 with an inverted trapezoidal structure in cross section is formed on the upper end of the dynamometer 2. An extension protrusion 15 adapted to the connecting recess 14 is formed on the lower bottom surface of the mounting seat 3. Two fastening screw holes are formed on the connecting recess 14 and the extension protrusion 15. A fastening bolt 16 is threadedly connected to each fastening screw hole. The mounting seat 3 is connected to the dynamometer 2 through the fastening bolt 16. A damping gasket is clamped between the connecting recess 14 and the extension protrusion 15.

[0025] The connecting flange 1 has a rectangular plate structure. Three groups of positioning screw holes are uniformly arranged around the center of the connecting flange 1. Each group of positioning screw holes has three positioning screw holes. The centers of the three positioning screw holes are on the same arc and are arranged along the arc line of the arc.

[0026] Two U-shaped open slots 18 are formed on the left side of the connecting flange 1. Two U-shaped open slots 18 are formed on the right side of the connecting flange 1. The four U-shaped open slots 18 are divided into two groups and are arranged symmetrically. The two U-shaped open slots 18 in each group are arranged symmetrically. The fastening bolt 16 is adapted to the U-shaped open slot 18.

[0027] A ring-shaped extension is arranged on the lower part of the dynamometer 2. Three groups of through screw holes 17 are uniformly formed on the ring-shaped extension. The three groups of through screw holes 17 correspond to the three groups of positioning screw holes. Each group of through screw holes 17 has three through screw holes 17. The centers of the three through screw holes 17 are on the same arc and are arranged along the arc line of the arc. The through screw holes 17 and the positioning screw holes are connected. A positioning bolt is threadedly connected to the through screw holes 17 and the positioning screw holes. The dynamometer 2 and the connecting flange 1 are connected together through the positioning bolt.

[0028] A method for using a clamp for improving the stability of ceramic matrix composite cutting force testing, comprising the following steps: S1, place the connecting flange 1 on the milling machine, align the positioning screw hole or the U-shaped open slot 18 with the connecting hole on the milling machine, and fix it through the fastening bolt 16; check the connection gap between the connecting flange 1 and the milling machine to meet the processing requirements, so as to ensure that the connection gap is not more than 0.01 mm; S2, then connect the positioning platform 4, the mounting seat 3, the dynamometer 2 and the connecting flange 1 in sequence; S3, install the movable wedge block 5 on the positioning platform 4, ensure that the movable wedge block 5 slides smoothly, and adjust the bolt to screw smoothly; S4, place the ceramic matrix composite workpiece on the clamping part 10, and preliminarily position the ceramic matrix composite workpiece; then gradually tighten the adjusting bolts, thereby slowly pushing the movable wedge block 5 to move downward along the first inclined surface 9, so that the movable wedge block 5 and the fixed rectangular seat 7 cooperate to realize clamping and fixing of the ceramic matrix composite workpiece; S5, then start the milling machine to cut the ceramic matrix composite workpiece; during cutting, the force measuring instrument 2 measures the cutting force size and direction in real time, and transmits the data to the data acquisition system for recording and analysis.

[0029] The application can realize rapid, accurate and stable clamping of ceramic matrix composite workpieces of different shapes and sizes, ensure that the workpiece and the force measuring instrument 2 are fixed in position during cutting force testing, improve measurement accuracy and testing efficiency; the first inclined surface 9 and the second inclined surface 11 of the movable wedge block 5 and the fixed wedge seat 8 cooperate with each other to have a force amplification effect, can generate a larger clamping force with a smaller operating force, compared with the traditional clamping method, the clamping force is improved, and under the action of the cutting force, the clamping force is more stable, which ensures that the ceramic matrix composite workpiece is stably fixed under complex cutting conditions, effectively avoids displacement of the ceramic matrix composite workpiece, and greatly improves the reliability of test data; the positioning platform 4 and the movable wedge block 5 are designed in an integral manner, have high rigidity, short force transmission path and strong anti-vibration performance, and are suitable for intermittent cutting of ceramic matrix composite workpieces; in addition, the clamping operation of the clamp can be completed by screwing the adjusting bolts, which is simple and labor-saving, greatly shortens the clamping time, and improves the testing efficiency; at the same time, the adjustable design of the movable wedge block 5 enables it to quickly adapt to various workpieces, and has strong universality.

[0030] The above only describes the preferred embodiments of the application, and is not limited to the scope of the application, and any equivalent changes made by applying the content of the application and the drawings are included in the scope of the application.

Claims

1. A fixture for improving the stability of cutting force testing of ceramic matrix composite materials, installed on a milling machine, characterized by: The movable wedge block is arranged on the upper surface of the platform plate and is in contact with the first inclined surface, and the movable wedge block cooperates with the movable wedge block to clamp the ceramic matrix composite workpiece; the positioning platform comprises a platform plate body, the platform plate body is horizontally arranged and detachably mounted on the mounting seat, a fixed rectangular seat is arranged on the left side of the upper surface of the platform plate body, a fixed wedge seat is arranged on the right side of the upper surface of the platform plate body, the fixed rectangular seat and the fixed wedge seat both protrude upward from the platform plate body, a first inclined surface is provided on the fixed wedge seat, the first inclined surface is provided on the side of the fixed wedge seat close to the fixed rectangular seat, the first inclined surface is inclined from top to bottom and from the side away from the fixed rectangular seat to the side close to the fixed rectangular seat, the movable wedge block is arranged on the upper surface of the platform plate body and is in contact with the first inclined surface, and a clamping portion is provided between the movable wedge block and the fixed rectangular seat.

2. The fixture for improving the stability of cutting force testing of ceramic matrix composite materials according to claim 1, characterized in that: The lengths of the fixed rectangular seat, the fixed wedge-shaped seat and the movable wedge-shaped block are all consistent with the width of the platform plate body.

3. The fixture for improving the stability of cutting force testing of ceramic matrix composite materials according to claim 1, characterized in that: The movable wedge block is provided with a second inclined surface that is in contact with the first inclined surface. A plurality of lower screw holes are provided on the platform plate at the bottom of the movable wedge block. The plurality of lower screw holes are arranged in sequence and spaced apart along the length direction of the movable wedge block. The movable wedge block is provided with a plurality of upper screw holes. The plurality of upper screw holes and the plurality of lower screw holes correspond to each other one by one. Adjustment bolts are threadedly connected to the corresponding upper and lower screw holes. By tightening the tightness of the adjustment bolts, the movable wedge block is tilted and slid up and down along the first inclined surface, so that the clamping part is clamped.

4. The fixture for improving the stability of cutting force testing of ceramic matrix composite materials according to claim 3, characterized in that: A plurality of connecting screw holes are provided on the clamping portion of the platform plate and the mounting seat. The connecting screw holes are arranged in a circular array on the platform plate and the mounting seat. A connecting bolt is threadedly connected to each connecting screw hole, and the positioning platform and the mounting seat are connected together by the connecting bolts.

5. The fixture for improving the stability of cutting force testing of ceramic matrix composite materials according to claim 1, characterized in that: A connecting recess with an inverted trapezoidal cross-section is provided at the upper end of the dynamometer, an extending protrusion adapted to the connecting recess is provided on the lower bottom surface of the mounting seat, a plurality of fastening screw holes are provided on the connecting recess and the extending protrusion, and a fastening bolt is threadedly connected in each fastening screw hole, and the mounting seat and the dynamometer are connected together through the fastening bolts; a shock-absorbing gasket is sandwiched between the connecting recess and the extending protrusion.

6. The fixture for improving the stability of cutting force testing of ceramic matrix composite materials according to claim 1, characterized in that: The connecting flange has a rectangular plate structure. Three groups of positioning screw holes are evenly arranged around the center of the connecting flange. Each group of positioning screw holes has three positioning screw holes. The centers of the three positioning screw holes are all on the same minor arc and are arranged at intervals along the arc line of the minor arc.

7. The fixture for improving the stability of cutting force testing of ceramic matrix composite materials according to claim 6, characterized in that: Two U-shaped opening grooves are provided on the left side of the connecting flange, and two U-shaped opening grooves are provided on the right side of the connecting flange. The four U-shaped opening grooves are divided into two groups, and the two groups of U-shaped opening grooves are symmetrically arranged up and down. The two U-shaped opening grooves in each group are symmetrically arranged left and right, and the fastening bolts and the U-shaped opening grooves are adapted to each other.

8. The fixture for improving the stability of cutting force testing of ceramic matrix composite materials according to claim 7, characterized in that: An annular extension is provided at the lower part of the dynamometer, and three groups of through screw holes are evenly provided on the annular extension. The three groups of through screw holes correspond to the three groups of positioning screw holes one by one, and the through screw holes and the positioning screw holes are connected. Positioning bolts are threadedly connected in the through screw holes and the positioning screw holes, and the dynamometer and the connecting flange are connected together by the positioning bolts.

9. The fixture for improving the stability of cutting force testing of ceramic matrix composite materials according to claim 8, characterized in that: The dynamometer is connected with a connection line, and the connection line is connected with a data acquisition system.

10. A method for using the fixture for improving the stability of cutting force testing of ceramic matrix composite materials according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. Place the connecting flange on the milling machine, align the positioning screw holes or U-shaped opening slots with the connecting holes on the milling machine, and secure them with the tightening bolts; check the connection clearance between the connecting flange and the milling machine to ensure that it meets the processing requirements; S2. Then, the positioning platform, the mounting base, the dynamometer and the connecting flange are connected together in sequence; S3. Install the movable wedge block on the positioning platform to ensure that the movable wedge block slides smoothly and the adjusting bolt is screwed smoothly; S4. Placing the ceramic matrix composite workpiece on the clamping portion to preliminarily position the ceramic matrix composite workpiece; then gradually tightening the adjusting bolt to slowly push the movable wedge block downward along the first inclined surface, so that the movable wedge block and the fixed rectangular seat cooperate to clamp and fix the ceramic matrix composite workpiece; S5. The milling machine is then started to cut the ceramic matrix composite workpiece. During the cutting process, the dynamometer measures the magnitude and direction of the cutting force in real time and transmits the data to the data acquisition system for recording and analysis.

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