CN112082445A - Detection method and detection device for attenuation change of spiral trajectory of steering screw - Google Patents

Abstract

The invention relates to a detection method and a detection device, in particular to a detection method and a detection device for the change of the helical ballistic attenuation of a steering screw. The detection method includes: cleaning and fixing the workpiece, scanning the workpiece to establish a three-coordinate system, establishing a projection coordinate system and setting calculation rules, evaluating standard lines, and detecting and evaluating the helical trajectory. The detection method and the detection device can precisely control the movement of the three-coordinate probe, and can effectively improve the detection accuracy; can effectively reduce the distance from the origin of the three-coordinate system to the helical trajectory of the steering screw, and correct the three-coordinate system after the initial construction. Thereby, the detection accuracy of the helical trajectory of the steering screw is improved; it can intuitively reflect the curve of the spiral trajectory attenuation change with the change of the spiral trajectory angle, and can intuitively evaluate whether the attenuation trend is qualified or not, and solve the spiral trajectory attenuation of the workpiece in the existing detection method. The change detection accuracy is low and difficult to evaluate, and the detection accuracy of the existing detection device is low.

Description

A detection method and detection device for the change of the helical ballistic attenuation of a steering screw

technical field

The invention relates to a detection method and a detection device, in particular to a detection method and a detection device for the change of the helical ballistic attenuation of a steering screw.

Background technique

The steering gear is an important part in the driving system of the car. The workpiece as its core transmission part will directly affect the driver's feel and safety of steering the steering wheel; the steering screw includes a screw body and an assembly head, and the circumference of the screw body is spirally arranged There is a helical trajectory, and an assembly head is arranged on the end of the screw body above the helical trajectory; the assembly head is in the shape of a variable diameter cylinder, an assembly notch is arranged on the top end face of the assembly head, and a middle circumference is arranged on the assembly head below the assembly notch. The assembling head between the middle circumferential surface and the assembling recess is provided with an upper circumferential surface; the assembling head below the middle circumferential surface is provided with a lower circumferential surface, and an assembling ring groove is arranged between the lower circumferential surface and the middle circumferential surface. The material of the steering screw is: G20CrNi2MoA. It needs to go through the heat treatment carburizing process to make the surface hardness reach 58-63HRC. After the heat treatment of the workpiece, it needs to be finished again, so that it can be assembled with a number of high-precision parts. As the core torque output component of the entire steering gear, its processing accuracy and detection accuracy are particularly important.

At present, the detection of the change of the helical ballistic attenuation of the steering screw mainly uses a three-coordinate detector to detect the trend of the ballistic attenuation of the steering screw. The existing three-coordinate detector uses the air source pressure as the driving force to drive the probe to move, and the probe moves during the movement process. Due to the fluctuation of air source pressure, the displacement distance and displacement speed cannot be accurately controlled, and the three-coordinate system setting of the steering screw (workpiece) during the detection process is unreasonable, and the detection accuracy of the change of the helical ballistic attenuation of the steering screw is low, and at the same time In the evaluation process, it is not easy to intuitively evaluate whether the decay trend of the helical trajectory of the steering screw is qualified or not, so it is necessary to improve it.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a kind of steering screw helical ballistic attenuation change which can improve the detection accuracy and can intuitively evaluate the attenuation change trend of the helical ballistic of the steering screw, so as to solve the problem that the detection accuracy of the helical ballistic attenuation change of the workpiece is low and difficult to evaluate. Detection method and detection device.

The technical scheme of the present invention is:

A detection method and detection device for the change of the helical ballistic attenuation of a steering screw, characterized in that it comprises the following steps:

1), clean and fix the workpiece;

Wipe the workpiece clean with non-woven fabric, install the workpiece on the inspection table of the three-coordinate inspection machine, and clamp it with the fixing fixture of the three-coordinate inspection machine turntable to fix the position of the workpiece;

2) Scan the workpiece to establish a three-coordinate system;

Touch and scan the top end face of the workpiece through the No. 1 probe of the three-coordinate probe of the three-coordinate inspection machine, and upload the data to the PC matched with the three-coordinate inspection machine;

After the top end face is dotted and scanned, the upper and lower circumferential surfaces of the workpiece are touched and scanned by the No. 2 probe of the three-coordinate probe of the three-coordinate inspection machine, and the data is uploaded to the PC matched with the three-coordinate inspection machine. ;

Through the dotted scanning data of the top end face, the upper circumferential surface and the lower circumferential surface of the workpiece, the center axis of the workpiece is the Z axis, the center point of the top end face of the assembly head is the origin, and the line where the center of the assembly notch of the assembly head is located is the X axis. The three-coordinate system of the workpiece is initially established on the PC matched with the coordinate detection machine;

3) Adjust the coordinate axes of the three-coordinate system

The turntable of the three-coordinate inspection machine rotates, and the workpiece is rotated during the rotation of the turntable. During the rotation of the workpiece, the No. 2 probe of the three-coordinate probe abuts on the circumference of the upper circumferential surface of the workpiece to continuously scan the upper circumferential surface. a week;

After the upper circumferential surface is continuously scanned for one week, move the No. 2 probe to the lower circumferential surface of the workpiece and abut against the lower circumferential surface to continuously scan the lower circumferential surface for one week;

After the lower circumferential surface is continuously scanned for one week, move the three-coordinate probe to the top end face of the workpiece. During the rotation of the workpiece, the center of the assembly notch is one of the points through the No. 1 probe of the three-coordinate probe to the top end face of the workpiece. Do a dot scan;

After the top end face scanning is completed, move the three-coordinate probe to the central circumference of the workpiece, and scan the central circumference continuously for one week through the No. 2 probe of the three-coordinate probe;

After the continuous scanning of the mid-circumferential surface is completed, move the three-coordinate probe down to make the No. 3 probe of the three-coordinate probe abut on the assembly ring groove of the workpiece, and continuously scan the assembly ring groove through the No. 3 probe;

Continuously scan the upper circumferential surface, lower circumferential surface, middle circumferential surface and assembly ring groove of the workpiece through the three-coordinate probe, and scan the top end surface of the workpiece 2-3 times to check the centrifugal force and rotation error of the turntable when it rotates. Correct and correct the three-coordinate system of the workpiece, and then accurately adjust the three-coordinate system of the workpiece to determine the precise position of the Z, X and Y axes of the three-coordinate system;

4) Establish a projection coordinate system and set calculation rules and evaluation standard lines;

Set the rotation angle of the three-coordinate probe along the workpiece's spiral ballistic detection process as the Y' axis on the PC matched with the three-coordinate detection machine, and set the distance from the end of the three-coordinate probe to the center axis of the workpiece, namely The radius of the helical trajectory of the steering screw is the X' axis, and then the projected coordinate system is established;

Set the calculation rules of the x-value and y-value of the projected coordinate system on the PC matched with the three-coordinate detector;

Set multiple theoretical drop point values in the projected coordinate system, and connect the theoretical drop point values to establish a theoretical drop standard line;

Set multiple maximum drop point values in the projected coordinate system, and connect the maximum drop point values to establish the maximum drop standard line;

Set multiple minimum drop point values in the projected coordinate system, and connect the minimum drop point values to establish the minimum drop standard line;

5) Detect the spiral trajectory of the workpiece;

The No. 3 probe of the three-coordinate probe continuously scans the spiral trajectory of the workpiece from top to bottom and fills the parameters obtained by scanning into the three-coordinate system, and selects the point values corresponding to the three-coordinate system along the spiral curve corresponding to the spiral trajectory. Calculate the X and Y values of the projected coordinate system according to the set calculation rules and fill them into the projected coordinate system;

Connect the point values filled to the projected coordinate system to establish the decay curve of the helical trajectory of the steering screw;

6), evaluation

The attenuation change curve of the helical trajectory of the steering screw in the projected coordinate system is compared with the standard line of theoretical drop, the standard line of maximum drop and the standard line of minimum drop, so as to evaluate the attenuation change trend of the helical trajectory of the steering screw.

The three-coordinate detection machine is composed of a base, a support frame, a lateral displacement motor and a lift motor. A support frame is installed on the base through a longitudinal transmission belt, and a vertical arm is movably installed on the support frame through a lateral displacement rack. A telescopic rod is installed, and the bottom end of the telescopic rod is equipped with a three-coordinate probe; the vertical arm on one side of the telescopic rod is provided with a lateral displacement motor, and a displacement gear is installed on the output shaft of the lateral displacement motor. The displacement gear and the lateral displacement rack meshing; the vertical arm above the telescopic rod is provided with a lifting motor, the output shaft of the lifting motor is fixed with a lifting screw, and the lifting screw is threadedly connected with the telescopic rod; a turntable is installed on the base under the three-coordinate probe through a turntable motor, and the turntable is The middle part is provided with a fixing clamp.

The support frame is composed of a positioning rod, an assembling cross rod and a supporting rod. The top end of the positioning rod is fixedly equipped with an assembling cross rod, and the assembling cross rod is fixedly connected with the lateral displacement rack; the end of the assembling cross rod is fixedly installed with The support rod is slidably connected with the base through the roller; the positioning rod is fixedly connected with the longitudinal transmission belt.

The three-coordinate probe is composed of an assembly block, a No. 1 probe, a No. 2 probe and a No. 3 probe. The No. 1 probe is fixed in the center of the bottom of the assembly block, and the No. 2 probe is symmetrically fixed on the side of the assembly block. For the probe, the assembly block on one side of the second probe is symmetrically fixed with the third probe; the three-coordinate probe is fixedly connected with the telescopic rod through the assembly block.

The cross section of the telescopic rod is rectangular.

The fixing fixture is a three-jaw chuck.

The beneficial effects of the present invention are:

The three-coordinate detection machine used in the detection method and the detection device for the change of the helical ballistic attenuation of the steering screw is driven by a longitudinal transmission belt, a lateral displacement motor and a lifting motor, and there is no problem of pressure fluctuation compared with using the air source pressure as the driving power, so It can precisely control the movement of the three-coordinate probe, and can effectively improve the detection accuracy; at the same time, the origin of the three-coordinate system is set on the central axis of the workpiece, which reduces the distance from the origin of the three-coordinate system to the helical trajectory of the steering screw. After the system is initially built, it is corrected again, thereby improving the detection accuracy of the helical trajectory of the steering screw; by projecting the data points scanned by the three-coordinate system to the X-axis and Y-axis of the projected coordinate system according to the calculation rules, it can intuitively reflect the spiral trajectory attenuation. The curve that changes with the change of the spiral trajectory angle can reflect the trajectory attenuation through the theoretical drop standard line, the maximum drop standard line and the minimum drop standard line, and can intuitively evaluate whether the decay trend of the spiral trajectory is qualified. The origin of the coordinate system is associated, which further ensures the accuracy of the detection data, and solves the problems that the detection accuracy of the spiral ballistic attenuation change of the workpiece in the existing detection method is low and difficult to evaluate, and the detection accuracy of the existing detection device is low, especially suitable for steering screw helical Detection of ballistic decay changes.

Description of drawings

Fig. 1 is the schematic diagram of the three-coordinate system of the present invention;

2 is a schematic diagram of the calculation rule of the X value of the projection coordinate system of the present invention;

Fig. 3 is the schematic diagram of the projection coordinate system of the present invention;

Fig. 4 is the scanning result schematic diagram of projection coordinate system of the present invention;

Fig. 5 is the structural representation of the three-coordinate detection machine of the present invention;

Fig. 6 is the right side schematic diagram of Fig. 5;

Fig. 7 is the structural representation of A-A in Fig. 5;

FIG. 8 is a schematic diagram of the structure of the three-coordinate probe of the present invention.

In the picture: 1. Base, 2. Lateral displacement motor, 3. Lifting motor, 4. Longitudinal drive belt, 5. Lateral displacement rack, 6. Vertical arm, 7. Telescopic rod, 8. Displacement gear, 9. Lifting screw, 10. Turntable motor, 11, Turntable, 12, Fixture, 13, Positioning rod, 14, Assembly crossbar, 15, Support rod, 16, Assembly block, 17, No. 1 probe, 18, No. 2 probe, 19 , No. 3 probe, 20, Three coordinate system, 21, Assembly notch, 22, Upper circumference, 23, Lower circumference, 24, Middle circumference, 25, Assembly ring groove, 26, Theoretical drop standard line, 27 , Maximum drop standard line, 28, Minimum drop standard line, 29, Spiral trajectory, 30, Attenuation curve, 31, Longitudinal drive motor.

Detailed ways

The detection method and detection device for the change of the helical ballistic attenuation of the steering screw first wipe the workpiece clean with a non-woven fabric to prevent debris (such as iron filings, hair, etc.) on the surface of the workpiece from affecting the detection accuracy, and dip a small amount through the non-woven fabric Wipe the surface of the workpiece with acetone or alcohol again to remove the oil stains attached to the surface of the workpiece, thoroughly clean the surface of the workpiece, and fix the workpiece on the turntable of the three-coordinate detection machine after wiping.

The three-coordinate detection machine is composed of a base 1, a support frame, a lateral displacement motor 2 and a lifting motor 3. A support frame is installed on the base 1 through a longitudinal transmission belt 4, and a lateral displacement rack 5 is arranged on the support frame. The support frame is composed of a positioning rod 13 , The assembly crossbar 14 and the support rod 15 are formed. The top end of the positioning rod 13 is fixed with the assembly crossbar 14, and the assembly crossbar 14 is fixedly connected with the lateral displacement rack 5; the end of the assembly crossbar 14 is fixed with a support The rod 15 and the support rod 15 are slidably connected with the base 1 through rollers; the positioning rod 13 is fixedly connected with the longitudinal transmission belt 4, and the longitudinal transmission belt 4 is driven by the longitudinal transmission motor 31 set on the base 1, and the longitudinal transmission motor 31 is a servo motor for precise control. The longitudinal displacement of the longitudinal transmission belt 4 can accurately control the displacement distance and displacement speed of the positioning rod 13, thereby accurately controlling the longitudinal displacement of the assembly cross rod 14 and the lateral displacement rack 5. Compared with using the air source pressure as power, the air source The displacement cannot be accurately controlled due to pressure fluctuations. The assembly cross bar 14 and the lateral displacement rack 5 can accurately control the displacement distance and displacement speed when moving; the lateral displacement rack 5 is movably installed with a vertical arm 6, and the lateral displacement rack 5 is assembled together The cross bar 14 can limit the position of the vertical arm 6, so that the vertical arm 6 can only move along the lateral displacement rack 5; the vertical arm 6 is movably inserted with a telescopic rod 7, the cross section of the telescopic rod 7 is rectangular, and the telescopic rod 7 is horizontal. The function of the rectangular section is to prevent the telescopic rod 7 from rotating during the up and down movement of the telescopic rod 7, so that the telescopic rod 7 can only move up and down during operation; the bottom end of the telescopic rod 7 is equipped with a three-coordinate probe, and the three-coordinate probe is The assembly block 16, No. 1 probe 17, No. 2 probe 18 and No. 3 probe 19 are formed. The center of the bottom of the assembly block 16 is fixed with the No. 1 probe 17, and the side of the assembly block 16 is symmetrically fixed with the No. 2 probe. Needle 18, No. 3 probe 19 is symmetrically fixed on the assembly block 16 on one side of No. 2 probe 18; The compound movement makes the end of the second probe 18 or the third probe 19 move in a semicircle along the circumferential surface, that is, the symmetrically arranged second probe 18 or the third probe 19 can be performed when the workpiece is stationary and rotating. Circular detection; when the No. 3 probe 19 detects the helical trajectory, the No. 3 probe 19 can perform a helical motion along the helical trajectory through the composite motion of the longitudinal, lateral and vertical directions in the three-dimensional direction, that is, the symmetrically arranged The No. 2 probe 18 or No. 3 probe 19 can perform circular detection when the workpiece is stationary and rotating; the three-coordinate probe is fixedly connected to the telescopic rod 7 through the assembly block 16; the No. 1 probe 17, the No. 2 probe No. 18 and No. 3 probes 19 are contact probes respectively, that is, when the ends of No. 1 probe 17, No. 2 probe 18 or No. 3 probe 19 are in contact with the workpiece surface, No. 1 probe 17, No. 2 probe No. 18 or No. 3 probe 19 feeds back the generated electrical signal to the controller of the three-coordinate detection machine, and then the controller detects the position parameters of the end of No. 1 probe 17, No. 2 probe 18 or No. 3 probe 19. The size of the workpiece; the vertical arm 6 on one side of the telescopic rod 7 is provided with a lateral displacement motor 2, A displacement gear 8 is installed on the output shaft of the displacement motor 2, and the displacement gear 8 meshes with the lateral displacement rack 5. The lateral displacement motor 2 can drive the vertical arm 6 to move horizontally through the cooperation of the displacement gear 8 and the lateral displacement rack 5. the horizontal movement of the telescopic rod 7, so that the telescopic rod 7 can drive the three-coordinate probe to perform lateral movement in the horizontal direction during the horizontal lateral movement; the lateral displacement motor 2 is a servo motor, In order to accurately control the lateral displacement distance and displacement speed of the vertical arm 6 during operation, and then precisely control the lateral displacement distance and displacement speed of the three-coordinate probe, compared with using the air source pressure as the power, the displacement cannot be caused by the fluctuation of the air source pressure. Precise control, the three-coordinate probe can accurately control the displacement distance and displacement speed when moving laterally; the vertical arm 6 above the telescopic rod 7 is provided with a lift motor 3, and a lift screw 9 is fixed on the output shaft of the lift motor 3 to lift The screw 9 is threadedly connected with the telescopic rod 7. When the lifting motor 3 rotates, the lifting screw 9 drives the telescopic rod 7 to carry out the lifting movement, so that the telescopic rod 7 drives the three-coordinate probe to carry out the lifting movement during the lifting movement; the lifting motor 3 is a servo The motor can precisely control the lifting height and lifting speed of the telescopic rod 7 during operation, and then accurately control the lifting displacement distance and displacement speed of the three-coordinate probe. Compared with using the air source pressure as the power, the fluctuation of the air source pressure causes the displacement Can not be precisely controlled, the three-coordinate probe can accurately control the displacement distance and displacement speed when moving; the base 1 below the three-coordinate probe is provided with a turntable motor 10, the output shaft of the turntable motor 10 is installed with a turntable 11, and the A fixed fixture 12 is arranged in the middle, and the fixed fixture 12 is a three-jaw chuck. The function of the fixed fixture 12 is to fix the workpiece on the fixed turntable 11 during operation, so that the workpiece can rotate together with the turntable 11; the turntable motor 10 is a servo motor, In order to precisely control the rotation speed and rotation angle of the turntable 11, the rotation angle and rotation speed of the workpiece can be precisely controlled (refer to Fig. 5, Fig. 6, Fig. 7 and Fig. 8).

The workpiece is clamped and fixed at the center of the turntable 11 by the fixing fixture 12 of the three-coordinate detection machine, so as to prevent the detection result from being inaccurate due to the large error in the detection result caused by the position change of the workpiece during the detection process.

After the workpiece is fixed on the turntable of the three-coordinate system testing machine, the three-coordinate probe for three-coordinate detection rotates with the central axis of the workpiece as the center of the circle to scan the workpiece to initially establish the three-coordinate system 20 of the workpiece. The specific process is: through The No. 1 probe 17 of the three-coordinate probe of the three-coordinate detection machine sets the top end face of the workpiece assembly head to the center point of the assembly notch 21 as the starting point, the center point of the top end face is the center of the circle, and the radius of the top end face is the radius of the top end face circumference. Evenly select 4-8 points and touch them during the rotation of the workpiece to perform dot scanning; after the top end face dot scanning is completed, the second probe 18 of the three-coordinate probe of the three-coordinate detection machine is placed on the upper circumferential surface 22 of the assembly head. 4-8 points are evenly selected on the circumference to touch the upper circumferential surface 22 of the workpiece during the rotation of the workpiece to perform dot scanning, and the lower circumferential surface 23 of the workpiece is dotted during the workpiece rotation process through the No. 2 probe 18 Scanning, the three-coordinate probe uploads the scanned data to the PC matched with the three-coordinate testing machine respectively during the dot-scanning process of the top end face, the upper circumferential surface 22 and the lower circumferential surface 23 of the workpiece. The data processing takes the center axis of the workpiece as the Z axis, the center point of the top end face of the assembly head as the origin, and the line where the center of the assembly notch 21 of the assembly head is located is the X axis. Do the initial build (see Figure 1).

After the initial establishment of the three-coordinate system, the turntable of the three-coordinate inspection machine rotates, and the workpiece is rotated during the rotation of the turntable. During the rotation of the workpiece, the No. 2 probe 18 of the three-coordinate probe abuts on the upper circumferential surface 22 of the workpiece. The upper circumferential surface 22 is continuously scanned; after the upper circumferential surface 22 is continuously scanned for one week, the No. 2 probe 18 is moved to the lower circumferential surface 23 of the workpiece, and abuts on the lower circumferential surface 23, and the lower circumferential surface 23 is scanned. Continuous scanning; after the lower circumferential surface 23 is continuously scanned for one week, the three-coordinate probe is moved to the top end face of the workpiece. The center is one of the points for dot scanning; after the top end face dot scanning is completed, move the three-coordinate probe to the mid-circumferential surface of the workpiece, and scan the central circular surface 24 continuously for one week through the No. 2 probe 18 of the three-coordinate probe After the continuous scanning of the central circumferential surface 24 is completed, the three-coordinate probe is moved down to make the No. 3 probe 19 of the three-coordinate probe abut on the assembly ring groove 25 of the workpiece, and the No. 3 probe 19 is used to assemble the ring groove 25. Perform continuous scanning for one week; repeat the continuous scanning of the upper circumferential surface 22, lower circumferential surface 23, middle circumferential surface 24 and assembly ring groove 25 of the workpiece through the three-coordinate probe, and scan the top end face of the workpiece 2-3 times. The scanning results are analyzed to correct the centrifugal force and rotation error when the turntable rotates, and the three-coordinate system 20 of the workpiece is corrected, and then the three-coordinate system 20 of the workpiece is accurately adjusted to determine the Z, X of the three-coordinate system 20 and the precise position of the Y axis.

After the adjustment of the three-coordinate system 20 is completed, set the rotation angle of the three-coordinate probe along the workpiece's spiral ballistic detection process as the Y' axis on the PC matched with the three-coordinate detection machine, and set the end of the three-coordinate probe. The drop value of the distance to the central axis of the workpiece, that is, the drop value of the helix ballistic radius of the steering screw is the X' axis, and a projection coordinate system is established (see Figure 3).

，其中x＇为投影坐标系的x值，a为三坐标系的x值，b为三坐标系的y值，m为补偿常数；设定投影坐标系y值的计算规则为

，其中y＇为投影坐标系的y值，k为补偿系数，z为三坐标系的z值，n为补偿常数。After the projection coordinate system is established, the calculation rule for setting the x value of the projection coordinate system on the PC matched with the three-coordinate detector is as follows:

, where x' is the x value of the projected coordinate system, a is the x value of the three coordinate system, b is the y value of the three coordinate system, and m is the compensation constant; the calculation rule for setting the y value of the projected coordinate system is

, where y' is the y value of the projected coordinate system, k is the compensation coefficient, z is the z value of the three-coordinate system, and n is the compensation constant.

A plurality of theoretical drop point values (see Table 1) are set in the projected coordinate system, and a dotted line is used to connect the theoretical drop point values, thereby establishing a theoretical drop standard line 26 (see Figure 3).

Table 1 Drop point value table

After the theoretical drop standard line is established, set multiple maximum drop point values in the projected coordinate system (see Table 1), connect the maximum drop point values, and then establish the maximum drop standard line, and use a solid line to represent the maximum drop standard line 27 (See Figure 3).

After the maximum drop standard line is established, set multiple minimum drop point values in the projected coordinate system (see Table 1), connect the minimum drop point values, and then establish the minimum drop standard line, and use a solid line to represent the minimum drop standard line 28 (See Figure 3).

The No. 3 probe 19 of the three-coordinate probe continuously scans along the spiral trajectory 29 of the workpiece from top to bottom, and the three-coordinate probe fills the scanned value of the spiral trajectory 29 of the workpiece into the three-coordinate system 20, along the spiral trajectory The spiral curve corresponding to 29 selects the X-axis, Y-axis and Z-axis values corresponding to the point values of the three-coordinate system 20 in turn, and calculates the X and Y values of the projected coordinate system according to the set calculation rules and fills them into the projected coordinate system. , using a solid line to connect the point values filled to the projected coordinate system, to establish the decay curve 30 of the helical trajectory of the steering screw (see Figure 4).

After the attenuation variation curve 30 of the helical trajectory of the steering screw is established, the attenuation variation curve 30 of the helical trajectory of the steering screw in the projection coordinate system is compared with the theoretical drop standard line 26, the maximum drop standard line 27 and the minimum drop standard line 28. Attenuation change trend status of the helical trajectory of the steering screw: 1. The attenuation change curve 30 of the helical trajectory of the steering screw exceeds the maximum drop standard line 27 or the minimum drop standard line 28, and the attenuation change trend of the steering screw helical trajectory is evaluated as unqualified and unqualified The workpiece is scrapped, and at the same time, through the analysis of the unqualified curve, the machining center is notified of the unqualified position of the spiral ballistic trajectory, so that the machining center can improve the processing parameters and process to improve the qualification rate of the spiral ballistic processing; 2. Turn to the screw ballistic trajectory The attenuation change curve 30 is between the maximum drop standard line 27 and the minimum drop standard line 28, and the attenuation change trend of the steering screw helical trajectory is evaluated as qualified; 3. The attenuation change curve 30 of the steering screw helical trajectory is between the maximum drop standard line 27 and When it is between the minimum drop standard line 28, and the higher the degree of conformity with the theoretical drop standard line 26, the better the ballistic attenuation change trend of the steering screw is evaluated (see FIG. 4).

The three-coordinate detection machine used in the detection method and detection device for the change of the helical ballistic attenuation of the steering screw is driven by the longitudinal transmission belt 4, the lateral displacement motor 2 and the lifting motor 3, and there is no pressure fluctuation compared with the use of the air source pressure as the driving power. Therefore, the movement of the three-coordinate probe can be accurately controlled, and the detection accuracy can be effectively improved; at the same time, the origin of the three-coordinate system is set on the central axis of the workpiece, which reduces the distance from the origin of the three-coordinate system to the helical trajectory of the steering screw, and After the initial construction of the three-coordinate system, it is corrected again, thereby improving the detection accuracy of the helical trajectory of the steering screw; by projecting the data points scanned by the three-coordinate system to the X-axis and Y-axis of the projected coordinate system according to the calculation rules, it can intuitively reflect The curve of the change of the spiral ballistic decay with the change of the spiral ballistic angle, through the theoretical drop standard line 26, the maximum drop standard line 27 and the minimum drop standard line 28 to reflect the ballistic attenuation and can intuitively evaluate whether the attenuation change trend of the spiral trajectory is qualified or not, At the same time, the data is directly associated with the origin of the three-coordinate system, which further ensures the accuracy of the detection data, and solves the problems that the detection accuracy of the spiral ballistic attenuation change of the workpiece in the existing detection method is low and difficult to evaluate, and the detection accuracy of the existing detection device is low. It is especially suitable for the detection of the change of the ballistic attenuation of the steering screw helix.

Claims (5)

1. A detection method and a detection device for attenuation change of a spiral trajectory of a steering screw are characterized in that: it comprises the following steps:

1) cleaning and fixing the workpiece;

wiping a workpiece with non-woven fabric, mounting the workpiece on a detection table of a three-coordinate detection machine, and clamping with a fixing clamp of a turntable of the three-coordinate detection machine to fix the position of the workpiece;

2) scanning the workpiece to establish a three-coordinate system;

a first probe (17) of a three-coordinate probe of a three-coordinate detecting machine is used for performing touch dotting scanning on the top end face of the workpiece, and data are uploaded to a PC (personal computer) matched with the three-coordinate detecting machine;

after the top end face is subjected to dotting scanning, the upper circumferential surface (22) and the lower circumferential surface (23) of the workpiece are subjected to touch dotting scanning through a second probe (18) of a three-coordinate probe of a three-coordinate detecting machine, and data are uploaded to a PC (personal computer) matched with the three-coordinate detecting machine;

the method comprises the steps that a three-coordinate system (20) of a workpiece is initially established on a PC (personal computer) matched with a three-coordinate detector by using dotting scanning data of the top end face, the upper circumferential face (22) and the lower circumferential face (23) of the workpiece and taking the central axis of the workpiece as a Z axis, the central point of the top end face of an assembly head as an origin, and the straight line where the center of an assembly notch (21) of the assembly head is located as an X axis;

3) adjusting coordinate axes of the three-coordinate system

The rotary table of the three-coordinate detecting machine rotates, the workpiece is driven to rotate in the rotating process of the rotary table, and a second probe (18) of the three-coordinate probe abuts against the circumference of the upper circumferential surface (22) of the workpiece to continuously scan the upper circumferential surface (22) for one circle in the rotating process of the workpiece;

after the upper circumferential surface (22) continuously scans for one circle, the second probe (18) is moved to the lower circumferential surface (23) of the workpiece and is abutted against the lower circumferential surface (23), and the lower circumferential surface (23) is continuously scanned for one circle;

after the lower circumferential surface (23) continuously scans for a circle, the three-coordinate probe is moved to the top end surface of the workpiece, and in the rotating process of the workpiece, the center of the assembly notch (21) is used as one point for dotting scanning on the top end surface of the workpiece through a first probe (17) of the three-coordinate probe;

after the dotting scanning of the top end face is finished, moving the three-coordinate probe to the middle circumferential surface (24) of the workpiece, and continuously scanning the middle circumferential surface (24) for one circle through a second probe (18) of the three-coordinate probe;

after the continuous scanning of the middle circumferential surface (24) is finished, the three-coordinate probe is moved downwards to enable a third probe (19) of the three-coordinate probe to abut against an assembly ring groove (25) of the workpiece, and the assembly ring groove (25) is continuously scanned through the third probe (19);

continuously scanning the upper circumferential surface (22), the lower circumferential surface (23), the middle circumferential surface (24) and the assembly ring groove (25) of the workpiece and dotting the top end surface of the workpiece for 2-3 times by a three-coordinate probe repeatedly, correcting the centrifugal force and the rotation error when the turntable rotates, correcting the three-coordinate system (20) of the workpiece, accurately adjusting the three-coordinate system (20) of the workpiece, and determining Z, X of the three-coordinate system (20) and the accurate position of the Y axis;

4) establishing a projection coordinate system and setting a calculation rule and an evaluation standard line;

setting a rotation angle of a three-coordinate probe along a spiral trajectory detection process of a workpiece as a Y 'axis on a PC (personal computer) matched with the three-coordinate detector, and setting a distance from the end head of the three-coordinate probe to the central axis of the workpiece, namely setting the radius of a spiral trajectory of a steering screw as an X' axis, so as to establish a projection coordinate system;

setting calculation rules of an x value and a y value of a projection coordinate system on a PC (personal computer) matched with a three-coordinate detector;

setting a plurality of theoretical fall point values in the projection coordinate system, and connecting the theoretical fall point values to establish a theoretical fall standard line (26);

setting a plurality of maximum fall point values in a projection coordinate system, connecting the maximum fall point values, and establishing a maximum fall standard line (27);

setting a plurality of minimum fall point values in the projection coordinate system, connecting the minimum fall point values, and establishing a minimum fall standard line (28);

5) detecting the spiral trajectory of the workpiece;

continuously scanning a spiral trajectory (29) of a workpiece from top to bottom through a third probe (19) of the three-coordinate probe, filling scanned parameters into a three-coordinate system (20), sequentially selecting X-axis and Y-axis numerical values corresponding to point values of the three-coordinate system (20) along a spiral curve corresponding to the spiral trajectory (29), calculating an X value and a Y value of a projection coordinate system according to a set calculation rule, and filling the X value and the Y value into the projection coordinate system;

connecting the point values filled into the projection coordinate system to establish a damping change curve (30) of the spiral trajectory of the steering screw;

6) evaluation of the test specimen

And comparing the attenuation change curve (30) of the spiral trajectory of the steering screw of the projection coordinate system with a theoretical fall standard line (26), a maximum fall standard line (27) and a minimum fall standard line (28), thereby evaluating the attenuation change trend of the spiral trajectory of the steering screw.

2. The method and device for detecting the attenuation change of the spiral trajectory of the steering screw according to claim 1, wherein: the three-coordinate detection machine is composed of a base (1), a support frame, a transverse displacement motor (2) and a lifting motor (3), wherein the support frame is installed on the base (1) through a longitudinal transmission belt (4), a vertical arm (6) is movably installed on the support frame through a transverse displacement rack (5), a telescopic rod (7) is movably inserted on the vertical arm (6), and a three-coordinate probe is installed at the bottom end of the telescopic rod (7); a transverse displacement motor (2) is arranged on a vertical arm (6) on one side of the telescopic rod (7), a displacement gear (8) is mounted on an output shaft of the transverse displacement motor (2), and the displacement gear (8) is meshed with a transverse displacement rack (5); a lifting motor (3) is arranged in a vertical arm (6) above the telescopic rod (7), a lifting screw (9) is fixedly arranged on an output shaft of the lifting motor (3), and the lifting screw (9) is in threaded connection with the telescopic rod (7); a turntable (11) is installed on the base (1) below the three-coordinate probe through a turntable motor (10), and a fixing clamp (12) is arranged in the middle of the turntable (11).

3. The method and device for detecting the attenuation change of the spiral trajectory of the steering screw according to claim 2, wherein: the supporting frame consists of a positioning rod (13), an assembly cross rod (14) and a supporting rod (15), the assembly cross rod (14) is fixedly arranged at the top end of the positioning rod (13), and the assembly cross rod (14) is fixedly connected with the transverse displacement rack (5); a supporting rod (15) is fixedly arranged at the end of the assembling cross rod (14), and the supporting rod (15) is connected with the base (1) in a sliding manner through a roller; the positioning rod (13) is fixedly connected with the longitudinal transmission belt (4).

4. The method and device for detecting the attenuation change of the spiral trajectory of the steering screw according to claim 2, wherein: the three-coordinate probe is composed of an assembly block (16), a first probe (17), a second probe (18) and a third probe (19), the first probe (17) is fixedly installed at the center of the bottom of the assembly block (16), the second probe (18) is symmetrically and fixedly installed on the side face of the assembly block (16), and the third probe (19) is symmetrically and fixedly installed on the assembly block (16) on one side of the second probe (18); the three-coordinate probe is fixedly connected with the telescopic rod (7) through an assembling block (16).

5. The method and device for detecting the attenuation change of the spiral trajectory of the steering screw according to claim 2, wherein: the cross section of the telescopic rod (7) is rectangular.

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