A measuring tongs suitable for various types of conical thin-walled workpieces and a method of using the same

Abstract

The application discloses a kind of measuring tongs suitable for multiple models conical thin-walled workpiece and its using method, belong to precision measuring device field, measuring tongs includes clamping structure and tip measurement structure;Clamping structure is connected with machine tool;Clamping structure includes measuring tong, measuring tong support, limit block and rotating structure;Measuring tong support is fixedly connected with machine tool;Measuring tong is rotationally connected with the front of measuring tong support by rotating structure;Limit block is fixed in measuring tong support one side;Tip measurement structure is located at the tip position of measuring tong, for clamping workpiece measurement wall thickness.When machine tool moves shaft, measuring tong is moved to the workpiece wall, measuring tong inner arm is moved downwards into workpiece, until the top ball of measuring tong contact head contacts workpiece inner wall, that is measurement initial position;When the axis of sensor coincides with the normal line of measured point contour, sensor measures the wall thickness of measured point.The application has the advantages of high measurement accuracy, high compatibility and automatic measurement.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of precision measuring device, more particularly to a measuring clamp suitable for various types of conical thin-walled workpieces and a using method thereof. BACKGROUND

[0002] Conical thin-walled workpieces such as shell of cannonball and antenna cover of missile are widely used in the fields of aviation, aerospace, weapons, etc. With the development of weapon equipment towards light weight, the wall thickness of such components is getting thinner and thinner. Taking the antenna cover as an example, it not only needs to withstand the impact of aerodynamic force and heat in high-speed flight to protect the internal guidance system and realize efficient transmission of microwaves. The geometric thickness is an important factor affecting the wave transmission performance, so the thickness precision of the antenna cover is very high. There are many types of resin-based antenna covers, and the geometric sizes differ greatly, but the wall thickness error is generally required to be not more than 10 microns, so as to ensure the wave transmission performance of such workpieces.

[0003] The existing measurement method is to use a micrometer to measure manually, it is difficult to find the normal direction of the measured point, and it is also difficult to measure the thickness near the tip of the workpiece, and the measurement precision and efficiency are very low. With the mass production of such workpieces, it is necessary to automatically and precisely measure the wall thickness distribution of the antenna cover to screen out qualified products that meet the engineering requirements. Therefore, a new type of measuring clamp is needed to meet the demand of wall thickness measurement of a series of deep cavity conical workpieces. SUMMARY

[0004] Therefore, the present application provides a measuring clamp suitable for various types of conical thin-walled workpieces and a using method thereof, which has the advantages of high measurement precision, high compatibility and automatic measurement.

[0005] In order to achieve the above purpose, the present application adopts the following technical solutions:

[0006] A measuring clamp suitable for various types of conical thin-walled workpieces, comprising a clamping structure and a tip measuring structure; the clamping structure is connected with a machine tool; the clamping structure comprises a measuring clamp, a measuring clamp support, a limiting block and a rotating structure; the measuring clamp support is fixedly connected with the machine tool; the measuring clamp is arranged in front of the measuring clamp support and is rotationally connected with the measuring clamp support through the rotating structure; the limiting block is fixedly arranged on one side of the measuring clamp support and is used for limiting excessive rotation of the measuring clamp; the tip measuring structure is arranged at the tip position of the measuring clamp and is used for clamping the workpiece to measure the wall thickness.

[0007] Further, the rotating structure comprises a bearing seat, a rotating disc, a bearing gland and a fixed bearing; the bearing seat is arranged in the through hole above the measuring tongs support and fixedly connected with the measuring tongs support; the rotating disc is fixedly connected with the measuring tongs; the bearing seat is provided with a through hole in the center, the rotating disc is arranged in the through hole of the bearing seat, and the fixed bearing is arranged between the rotating disc and the bearing seat; the bearing gland is arranged at the end of the bearing seat away from the rotating disc and fixedly connected with the bearing seat.

[0008] Further, the measuring tongs comprise a measuring tongs outer arm and a measuring tongs inner arm; the measuring tongs outer arm and the measuring tongs inner arm are fixedly connected at the blunt end and provided with a gap at the sharp end.

[0009] Further, the sharp end measuring structure comprises a measuring tongs contact, a sensor clamp, a sensor and a sensor support; the measuring tongs contact is arranged at the sharp end of the measuring tongs inner arm towards the side of the measuring tongs outer arm; the sensor support is arranged at the sharp end of the measuring tongs outer arm and fixedly connected with the measuring tongs outer arm; the sensor support is provided with a through hole at one end, and the sensor clamp penetrates through the through hole to connect the sensor.

[0010] Further, the sensor is arranged inside the sensor clamp, and a spring is arranged between the sensor and the inner wall of the sensor clamp to support the contact between the sensor and the outer wall of the workpiece.

[0011] Further, the top end of the measuring tongs contact is provided with a self-rotating ball head, and the central axis of the sensor is collinear with the axis of the top end ball head of the measuring tongs contact.

[0012] Further, when the measuring tongs are naturally placed on the limiting block due to self-weight, the central axis of the sensor and the axis of the top end ball head of the measuring tongs contact are horizontally arranged.

[0013] Further, the measuring tongs outer arm and the measuring tongs inner arm are arranged in an elongated shape; one side of the measuring tongs inner arm is provided with a groove with a certain depth.

[0014] A use method of a measuring tongs suitable for various models of conical thin-walled workpieces, the specific steps comprising:

[0015] S1: determining the size model of the workpiece to be measured, selecting a sensor with a suitable wall thickness, and clamping the workpiece in the posture of "sharp end down and blunt end up";

[0016] S2: the measuring tongs are naturally placed on the limiting block, the bottom end of the measuring tongs is higher than the end face of the workpiece, the measuring tongs are moved to above the workpiece by the movement of the machine tool moving shaft, and the workpiece wall is located above the gap between the two sides of the measuring tongs;

[0017] S3: The measuring clamp moves vertically downwards through the movement of the machine tool's moving axis. The inner arm of the measuring clamp enters the workpiece until the ball head at the tip of the measuring clamp contacts the inner wall of the workpiece, which is the initial measurement position.

[0018] S4: According to the outer contour generatrix shape of the workpiece, based on the principle of the clamp measurement method of equal length point traces in the tangent direction of the measured point, the position of the rotating structure moves along the equal length point trace line in the tangent direction of the measured point through the interpolation motion of the machine tool moving axis. The central axis of the sensor coincides with the normal of the measured point of the outer contour, and the sensor measures the wall thickness of the measured point.

[0019] S5: Exit the workpiece; through the interpolation motion of the machine tool's moving axis, the position of the rotating structure moves in the opposite direction of the measurement path. After moving to the initial measurement position, the measuring clamp is lifted vertically upwards and leaves the workpiece range.

[0020] This invention provides a measuring clamp and its usage method applicable to various types of conical thin-walled workpieces. The measuring clamp is designed based on the principle of the clamp-type measurement method using equal-length point traces along the tangent direction of the measured contour. It offers the following advantages: it avoids interference between the measuring clamp arms and the workpiece, and also avoids interference between the clamp jaws equipped with the wall thickness sensor and the inner wall of the workpiece; the measuring force is appropriate, preventing workpiece deformation or damage; the measuring clamp has a suitable weight and sufficient lateral stiffness, preventing deformation from affecting measurement accuracy; and it is compatible with multiple workpiece models (no fewer than 6), enabling automated measurement of the thickness of this type of conical thin-walled workpiece. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the overall structure of the measuring clamp of the present invention, which is applicable to various types of conical thin-walled workpieces.

[0023] Figure 2 for Figure 1 A sectional view.

[0024] Figure 3 This is a schematic diagram of the measuring clamp support of the present invention.

[0025] Figure 4 This is a schematic diagram of the bearing housing of the present invention.

[0026] Figure 5 for Figure 4 A sectional view.

[0027] Figure 6 Structure diagram of the rotating disc provided by the present application.

[0028] Figure 7 For Figure 6 Cross-sectional view.

[0029] In the figure:

[0030] 1-measuring tongs; 2-measuring tongs support; 3-limiting block; 4-bearing seat; 5-rotating disc; 6-bearing gland; 7-bearing; 8-sensor support; 9-measuring tongs contact; 10-sensor clamp; 11-sensor; 12-measuring tongs locking nut; 13-sensor support locking nut; 14-measuring tongs support locking nut; 15-limiting block locking nut; 16-bearing seat locking nut; 17-gland locking nut; 18-measuring tongs inner arm; 19-measuring tongs outer arm. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0032] Please refer to the drawings Figures 1-7 The present application provides a measuring tong suitable for various types of conical thin-walled workpieces, which comprises a clamping structure and a tip measuring structure. The clamping structure is connected to a machine tool, and the machine tool moves the clamping structure above the workpiece to be measured. The tip measuring structure is arranged at the tip of the clamping structure and is used to clamp the workpiece for measuring the wall thickness.

[0033] The clamping structure comprises a measuring tong 1, a measuring tong support 2, a limiting block 3 and a rotating structure. The measuring tong support 2 is fixedly connected to the machine tool through a measuring tong support locking nut 14. The measuring tong 1 is arranged in front of the measuring tong support 2 and is rotationally connected to the measuring tong support 2 through a rotating structure. The limiting block 3 is arranged on one side of the measuring tong support 2 and is fixedly connected through a limiting block locking nut 15, which is used to limit the excessive rotation of the measuring tong 1. The measuring tong 1 rotates along the rotating structure under the influence of its own weight and leans against one side of the limiting block 3. The limiting block 3 limits the counterclockwise rotation of the measuring tong 1.

[0034] The rotating structure comprises a bearing seat 4, a rotating disc 5, a bearing gland 6 and a fixed bearing 7; the bearing seat 4 is arranged in a through hole above the measuring tongs support 2 and is fixedly connected with the measuring tongs support 2 through a bearing seat locking nut 16; the rotating disc 5 is fixedly connected with the measuring tongs 1 through a measuring tongs locking nut 12; the bearing seat 4 and the rotating disc 5 are arranged between the measuring tongs support 2 and the measuring tongs 1; the bearing seat 4 is provided with a through hole in the center, the rotating disc 5 is arranged in the through hole of the bearing seat 4, and the fixed bearing 7 is arranged between the rotating disc 5 and the bearing seat 4; the bearing gland 6 is arranged at one end of the bearing seat 4 away from the rotating disc 5 and is fixedly connected with the bearing seat 4 through a gland locking nut 17. The measuring tongs 1 and the measuring tongs support 2 are rotatably connected through the cooperation of the bearing seat 4 and the rotating disc 5.

[0035] The measuring tongs 1 comprise a measuring tongs outer arm 19 and a measuring tongs inner arm 18, the blunt ends of the measuring tongs outer arm 19 and the measuring tongs inner arm 18 are fixedly connected, and the tips are provided with a gap. The measuring tongs outer arm 19 and the measuring tongs inner arm 18 are arranged in an elongated shape; during measurement, the measuring tongs inner arm 18 is located inside the workpiece, the measuring tongs outer arm 19 is located outside the workpiece, and the workpiece wall position is between the measuring tongs outer arm 19 and the measuring tongs inner arm 18.

[0036] The tip measuring structure is arranged at the tip of the measuring tongs 1, and the tip measuring structure comprises a measuring tongs contact 9, a sensor clamp 10, a sensor 11 and a sensor support 8; the measuring tongs contact 9 is arranged at the tip of the measuring tongs inner arm 18 towards one side of the measuring tongs outer arm 19; the sensor support 8 is arranged at the tip of the measuring tongs outer arm 19 and is fixedly connected with the measuring tongs outer arm 19 through a sensor support locking nut 13; one end of the sensor support 8 is provided with a through hole, the sensor clamp 10 penetrates through the through hole to connect the sensor 11; the sensor 11 is arranged inside the sensor clamp 10, and a spring is arranged between the sensor 11 and the inner wall of the sensor clamp 10 for supporting the contact between the sensor 11 and the outer wall of the workpiece. The top end of the measuring tongs contact 9 is provided with a self-rotating ball head, the central axis of the sensor 11 is collinear with the axis of the top end ball head of the measuring tongs contact 9; the sensor 11 can move along the axial direction in the through hole through the cooperation of the sensor clamp 10 and the through hole, that is, the sensor 11 can move in position to adjust the distance between the sensor 11 and the measuring tongs contact 9, so as to adjust the measurement range.

[0037] The sensor 11 at the measuring tongs 1 jaw is used for wall thickness measurement with the measuring tongs contact 9, in order to increase the measurement area as much as possible to adapt to deep cavity workpieces, the tongs arm of the measuring tongs 1 is designed in an elongated shape, in order to avoid the interference between the inner arm 18 of the measuring tongs and the inner wall of the workpiece, the measuring tongs contact 9 is arranged at the top of the inner arm 18 of the measuring tongs, in order to avoid the interference between the outer arm 19 of the measuring tongs and the outer wall of the workpiece, the profile shape of the outer arm 19 of the measuring tongs is designed with reference to the typical workpiece outer profile generatrix, so as to adapt to the requirements of multiple models of workpieces, the measuring tongs 1 has an elongated tongs arm, and the spatial posture of the measuring tongs 1 needs to be adjusted during the measurement to meet the measurement requirements, therefore, the influence of the weight of the measuring tongs 1 on the force at the contact point between the inner wall of the workpiece and the measuring tongs contact 9, the deformation of the measuring tongs 1 due to its own weight and the lateral stiffness of the measuring tongs 1 are comprehensively considered, and a groove with a certain depth is arranged on one side of the inner arm 18 of the measuring tongs, so that the measurement force, the self-weight working condition and the lateral stiffness working condition are balanced.

[0038] When measuring the wall thickness of the workpiece, the wall of the workpiece is located between the inner arm 18 of the measuring tongs and the outer arm 19 of the measuring tongs, the top ball head of the measuring tongs contact 9 is in contact with the inner wall of the workpiece, when the posture of the measuring tongs 1 changes, the top ball head of the measuring tongs contact 9 rolls on the inner wall of the workpiece, avoiding the interference between the inner arm 18 of the measuring tongs and the inner wall of the workpiece, and preventing the measuring tongs 1 from damaging the inner wall of the workpiece, when reaching the measured point, the sensor 11 is in contact with the outer wall of the workpiece by the spring force, avoiding damage to the outer wall of the workpiece, and the sensor 11 measures the wall thickness of the measured point of the workpiece. The measuring tongs 1 naturally rests on the limiting block 3 due to its own weight, at this time, the central axis of the sensor 11 and the top ball head axis of the measuring tongs contact 9 can be kept horizontal, facilitating the measuring tongs to vertically enter the workpiece from the large end opening of the clamped workpiece.

[0039] The application provides a method for using a measuring tongs suitable for various models of conical thin-walled workpieces, and the specific steps are as follows:

[0040] S1: Determine the size and model of the workpiece to be measured, select a suitable wall thickness sensor 11, and clamp the workpiece in the posture of "point end down and blunt end up";

[0041] S2: The measuring tongs 1 naturally rests on the limiting block 3, the bottom end of the measuring tongs 1 is higher than the end face of the workpiece, the measuring tongs 1 is driven to move transversely above the workpiece by the movement of the machine tool moving shaft, and the wall of the workpiece enters the gap between the two tongs arms of the measuring tongs 1;

[0042] S3: The measuring tongs 1 is driven to move vertically downward by the movement of the machine tool moving shaft, the inner arm 18 of the measuring tongs enters the inside of the workpiece, and the top ball head of the measuring tongs contact 9 contacts the inner wall of the workpiece, which is the initial measurement position;

[0043] S4: According to the outer contour of the workpiece, the contour measured point tangent direction equal length point trace line clamp type measurement principle, through the interpolation movement of the machine tool moving axis, the rotating structure is in the position along the measured point tangent direction equal length point trace line movement, the sensor 11 axis coincides with the outer contour measured point normal, the sensor 11 can measure the measured point wall thickness;

[0044] S5: Exit the workpiece; through the interpolation movement of the machine tool moving axis, the rotating structure is in the position along the measurement path in the opposite direction movement, movement to the measurement initial position, the measurement clamp 1 is lifted vertically upward, leaving the workpiece range.

[0045] The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the difference from other embodiments. The same or similar parts between the various embodiments can be referred to each other. For the device disclosed by the embodiments, since it corresponds to the method disclosed by the embodiments, the description is relatively simple, and the related parts can be referred to the method part.

[0046] The above description of the disclosed embodiments enables a person skilled in the art to implement or use the present application. Various modifications to the embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A measuring clamp suitable for various types of conical thin-walled workpieces, characterized in that, The device includes a clamping structure and a tip measuring structure; the clamping structure is connected to the machine tool; the clamping structure includes a measuring clamp (1), a measuring clamp support (2), a limiting block (3), and a rotating structure; the measuring clamp support (2) is fixedly connected to the machine tool; the measuring clamp (1) is located in front of the measuring clamp support (2) and is rotatably connected to the measuring clamp support (2) through the rotating structure; the limiting block (3) is fixed to one side of the measuring clamp support (2) to limit excessive rotation of the measuring clamp (1); the tip measuring structure is located at the tip of the measuring clamp (1) and is used to clamp the workpiece to measure the wall thickness; the tip measuring structure includes a measuring clamp... The measuring clamp (9), sensor clamp (10), sensor (11), and sensor bracket (8) are provided. The measuring clamp contact (9) is located on the side of the inner arm (18) of the measuring clamp facing the outer arm (19). The sensor bracket (8) is located on the tip of the outer arm (19) of the measuring clamp and is fixedly connected to the outer arm (19). One end of the sensor bracket (8) is provided with a through hole, and the sensor clamp (10) passes through the through hole to connect to the sensor (11). The top of the measuring clamp contact (9) is provided with a rotatable ball head, and the central axis of the sensor (11) is collinear with the axis of the ball head at the top of the measuring clamp contact (9).

2. The measuring clamp applicable to various types of conical thin-walled workpieces according to claim 1, characterized in that, The rotating structure includes a bearing housing (4), a rotating disk (5), a bearing cap (6), and a fixed bearing (7); the bearing housing (4) is disposed in the through hole above the measuring clamp bracket (2) and is fixedly connected to the measuring clamp bracket (2); the rotating disk (5) is fixedly connected to the measuring clamp (1); the bearing housing (4) has a through hole in the center, the rotating disk (5) is placed in the through hole of the bearing housing (4), and a fixed bearing (7) is disposed between the rotating disk (5) and the bearing housing (4); the bearing cap (6) is disposed at the end of the bearing housing (4) away from the rotating disk (5) and is fixedly connected to the bearing housing (4).

3. The measuring clamp applicable to various types of conical thin-walled workpieces according to claim 1, characterized in that, The measuring clamp (1) includes an outer arm (19) and an inner arm (18); the blunt ends of the outer arm (19) and the inner arm (18) are fixedly connected, and the tips are provided with a certain gap.

4. The measuring clamp applicable to various types of conical thin-walled workpieces according to claim 1, characterized in that, The sensor (11) is disposed inside the sensor fixture (10), and a spring is provided between the sensor (11) and the inner wall of the sensor fixture (10) to support the contact between the sensor (11) and the outer wall of the workpiece.

5. The measuring clamp applicable to various types of conical thin-walled workpieces according to claim 1, characterized in that, When the measuring clamp (1) rests against the limit block (3) under its own weight in its natural state, the central axis of the sensor (11) and the axis of the ball head at the top of the measuring clamp contact (9) are set horizontally.

6. The measuring clamp for various types of conical thin-walled workpieces according to claim 3, characterized in that, The outer arm (19) and inner arm (18) of the measuring clamp are designed to be elongated; a groove of a certain depth is provided on one side of the inner arm (18).

7. A method for using a measuring clamp suitable for various types of conical thin-walled workpieces, characterized in that, The specific steps include: S1: Determine the size and model of the workpiece to be measured, select a sensor with appropriate wall thickness (11), and clamp the workpiece with the "point down and blunt end up" in the clamping structure. S2: The measuring clamp (1) rests against the limit block (3) in its natural state. The bottom of the measuring clamp (1) is higher than the end face of the workpiece. The measuring clamp (1) is moved laterally to the top of the workpiece by the movement of the machine tool moving axis. The workpiece wall is located above the gap between the clamp arms on both sides of the measuring clamp (1). S3: The measuring clamp (1) moves vertically downward through the movement of the machine tool's moving axis. The inner arm (18) of the measuring clamp enters the workpiece until the ball head at the top of the measuring clamp contact (9) contacts the inner wall of the workpiece, which is the initial measurement position. S4: According to the outer contour generatrix of the workpiece, based on the principle of clamp measurement method of equal length point trace line in the tangent direction of the measured point, the position of the rotating structure moves along the equal length point trace line in the tangent direction of the measured point through the interpolation motion of the machine tool moving axis. The central axis of the sensor (11) coincides with the normal of the outer contour measured point, and the sensor (11) measures the wall thickness of the measured point. S5: Exit the workpiece; by interpolating the machine tool's moving axis, the position of the rotating structure moves in the opposite direction of the measurement path. After moving to the initial measurement position, the measuring clamp (1) is lifted vertically upwards and leaves the workpiece range.

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