Ball nut pitch diameter measuring device

Abstract

The utility model belongs to the technical field of measuring instruments, and particularly relates to a ball nut pitch diameter measuring device which comprises a measuring device base body, an upper pressing plate, a lower pressing plate and a dial indicator. The upper pressing plate is arranged in the measuring device base body in a sliding mode, the lower pressing plate is arranged in the measuring device base body and is opposite to the upper pressing plate, a spring is arranged between the upper pressing plate and the lower pressing plate, and a measuring head of the dial indicator is connected with the lower pressing plate. Steel ball mounting rods are arranged at the front ends of the upper pressing plate and the lower pressing plate, and steel balls are arranged on the steel ball mounting rods. The upper pressing plate and the lower pressing plate extend into the inner hole of the nut, the steel ball falls into the raceway of the nut, and after loosening, the displacement of the upper pressing plate is measured by the dial indicator, so that the middle diameter of the ball nut can be directly measured. The method for directly measuring the pitch diameter is adopted, online measurement of the pitch diameter of the nut can be simply and conveniently completed, the measuring precision is high, the measuring means cost is low, the testing time is short, and the method is suitable for various working conditions.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of measuring instrument, especially relates to a ball nut middle diameter measuring device. BACKGROUND

[0002] The accurate measurement of nut middle diameter is crucial for ensuring the quality and performance of threaded connection. The current common testing scheme is to use an indirect measurement method of outer diameter micrometer + steel ball, place the steel ball in the nut inner raceway, measure the thickness value of the steel ball and the nut outer diameter with the micrometer, then measure the nut outer diameter, and through calculation, the nut inner thread middle diameter value = (nut outer diameter - measured value + steel ball diameter) / 2, to obtain the middle diameter value data of the nut. This indirect measurement scheme has a complicated measurement process, which needs to measure the nut outer diameter first, measure the wall thickness with the steel ball, and then calculate the actual middle diameter value. The measurement accuracy is not high, which can only reach 0.01, and there are roundness errors and the like in the nut outer diameter, and the calculation result contains the roundness error of the threaded outer circle. The adjustment of the nut assembly gap needs to reach the accuracy requirement of 0.001, which can only be realized through trial assembly and adjustment, and the assembly efficiency is low. It is impossible to evaluate the roundness and cylindricality error of the nut raceway. Since the roundness and cylindricality error of the nut generally needs to be controlled within 0.005, the measurement accuracy of the ordinary measurement method reaches 0.01, which cannot meet the requirement, and affects the adjustment of the grinding machine parameters.

[0003] There is also a three-coordinate detection device with a special probe for detecting the spiral line, mounting the nut on the workbench, aligning the nut outer circle generatrix, and measuring the raceway along the spiral line with the spherical probe. Finally, the coordinate value deviation of each point of the spiral line is compared. However, there are problems of high detection cost and low inspection efficiency, which are not suitable for frequent machine adjustment requirements. Each specification needs a special ball probe, and the grinding dust on the surface and inside of the nut needs to be removed, and the detection time is more than 20 minutes. UTILITY MODEL CONTENT

[0004] UTILITY MODEL OBJECTIVE: In order to overcome the above shortcomings, the utility model provides a middle diameter value measuring device for ball nut, which can realize the measurement of the middle diameter value of the ball nut, evaluate the roundness and cylindricality error of the nut raceway, and has high measurement accuracy.

[0005] TECHNICAL SCHEME: In order to achieve the above objective, the utility model provides a ball nut middle diameter measuring device, which comprises a measuring device base body, an upper pressing plate, a lower pressing plate and a micrometer;

[0006] The upper pressing plate is slidably arranged in the measuring device base body, the lower pressing plate is arranged in the measuring device base body and oppositely arranged with the upper pressing plate, a spring is arranged between the upper pressing plate and the lower pressing plate, and the measuring head of the micrometer is connected with the lower pressing plate;

[0007] The front end of the upper pressing plate and the lower pressing plate is provided with a steel ball mounting rod, and the steel ball mounting rod is provided with a steel ball.

[0008] By extending the upper pressing plate and the lower pressing plate into the inner hole of the nut, the steel ball falls into the inner part of the nut raceway, the displacement of the upper pressing plate after loosening is measured by the micrometer, and the middle diameter of the ball nut is directly measured.

[0009] Further, the middle of the measuring device base body is provided with a rectangular cavity, the upper pressing plate and the lower pressing plate are arranged in the cavity, and the upper end and the lower end of the measuring device base body are provided with threaded holes communicating with the cavity.

[0010] Further, the micrometer is installed on the upper part of the measuring device base body through threaded connection, the threaded hole of the lower part of the measuring device base body is provided with a stop screw, and the stop screw is connected with the bottom surface of the lower pressing plate.

[0011] Further, the measuring device base body is provided with a group of guide positioning pins along the length direction, the upper pressing plate and the lower pressing plate are both provided with a group of guide holes, the upper pressing plate and the lower pressing plate are arranged on the guide positioning pins through the guide holes, and guide copper sleeves are further arranged between the guide holes and the guide positioning pins.

[0012] Further, the steel ball mounting rod is provided with a ball socket, and the steel ball is welded in the ball socket.

[0013] Further, the number of the ball socket is at least three, and the axial spacing of the ball sockets on the upper and lower steel ball mounting rods is same as the lead of the ball nut to be measured.

[0014] Further, the steel ball mounting rod is connected with the upper pressing plate and the lower pressing plate through bolts.

[0015] Further, the rear end of the upper pressing plate and the lower pressing plate extends out of the measuring device base body.

[0016] The above technical scheme can be seen, and the utility model has the following beneficial effects:

[0017] 1. The utility model provides a micro stroke pedal for new energy vehicle adopts direct measurement method, can simply complete the on -line measurement of nut diameter, and the measurement precision is high, and it is much higher than the precision of conventional indirect measurement method, satisfy the measurement requirement of high -precision nut, measurement means cost is low, test time is short, and is suitable for various working conditions.

[0018] 2. The utility model can evaluate the roundness and the cylindricity of the ball nut thread raceway synchronously, is convenient for finding the error of grinding system, and is favorable for improving the processing quality of the nut. DRAWINGS

[0019] Figure 1This is a schematic diagram of the structure of a ball nut pitch diameter measuring device according to the present invention;

[0020] Figure 2 This is a cross-sectional view of a ball nut pitch diameter measuring device according to the present invention;

[0021] Figure 3 This is a schematic diagram illustrating the use of the ball nut pitch diameter measuring device described in this utility model.

[0022] In the diagram: 1- Measuring instrument base, 2- Upper pressure plate, 3- Lower pressure plate, 4- Dial gauge, 5- Steel ball mounting rod, 6- Steel ball, 7- Brake screw, 8- Guide positioning pin, 9- Guide copper sleeve, 10- Spring. Detailed Implementation

[0023] It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0024] like Figures 1-2 As shown: A ball nut pitch diameter measuring device includes a measuring device base 1, an upper pressure plate 2, a lower pressure plate 3, and a dial indicator 4;

[0025] The upper pressure plate 2 is slidably disposed in the measuring instrument base 1, the lower pressure plate 3 is disposed in the measuring instrument base 1 and is disposed opposite to the upper pressure plate 2, a spring 10 is provided between the upper pressure plate 2 and the lower pressure plate 3, and the measuring head of the dial indicator 4 is connected to the lower pressure plate 3.

[0026] The front ends of the upper pressure plate 2 and the lower pressure plate 3 are both provided with steel ball mounting rods 5, and steel balls 6 are provided on the steel ball mounting rods 5.

[0027] The upper pressure plate 2 and lower pressure plate 3 are slidably configured, and can be closed to extend into the nut to be measured. Spring 10 ensures that the upper pressure plate 2 and lower pressure plate 3 can be reset after being released. The measuring head of the dial indicator is connected to the upper pressure plate 2 to directly measure its displacement value. The steel ball can be well inserted into the nut raceway, thus allowing direct measurement of the mean diameter. Users can also select appropriate measuring instruments based on their required accuracy.

[0028] Specifically, the measuring device base 1 has a rectangular cavity in the middle, the upper pressure plate 2 and the lower pressure plate 3 are located in the cavity, and the upper and lower ends of the measuring device base 1 have threaded holes that communicate with the cavity.

[0029] The micrometer 4 is installed on the upper portion of the measuring device base 1 through threaded connection, a threaded hole is arranged in the lower portion of the measuring device base 1, a locking screw 7 is arranged in the threaded hole and connected with the bottom surface of the lower pressing plate 3. The micrometer 4 is convenient to disassemble and replace through threaded connection, the locking screw 7 is connected with the lower pressing plate 3, so that the lower pressing plate 3 is fixed, only the upper pressing plate 2 can slide in the rectangular cavity, so the displacement of the upper pressing plate 2 connected with the micrometer 4 can be measured by the micrometer 4.

[0030] A group of guide positioning pins 8 are arranged on the measuring device base 1 along the length direction, a group of guide holes are arranged on the upper pressing plate 2 and the lower pressing plate 3, the upper pressing plate 2 and the lower pressing plate 3 are arranged on the guide positioning pins 8 through the guide holes, and guide copper sleeves 9 are arranged between the guide holes and the guide positioning pins 8. The guide positioning pins 8 provide good guiding effect for the up-down movement of the upper pressing plate 2, the guide copper sleeves also have good guiding effect and excellent wear resistance.

[0031] In addition, a ball socket is arranged on the steel ball mounting rod 5, and the steel ball 6 is welded in the ball socket. The number of the ball sockets is at least three, the axial spacing of the ball sockets on the upper and lower steel ball mounting rods 5 is same as the lead of the ball nut to be measured. In the embodiment, the number of the ball sockets is three, a pair of ball sockets are arranged side by side on the upper pressing plate 2, and one ball socket is arranged on the lower pressing plate 3, and the steel balls 6 in the three ball sockets form a stable triangle in space, so that the steel balls 6 can be stably clamped in the ball raceway of the nut.

[0032] In addition, the steel ball mounting rod 5 is connected with the upper pressing plate 2 and the lower pressing plate 3 through bolts. Different steel ball mounting rods 5 can be replaced to adapt to nuts with different leads.

[0033] The rear ends of the upper pressing plate 2 and the lower pressing plate 3 extend out of the measuring device base 1, the extending parts are convenient to hold, and the test personnel can fold the upper pressing plate 2 and the lower pressing plate 3.

[0034] As shown in Figure 3 When the ball nut diameter measuring device is used, first, the micrometer is fixed according to the theoretical value of the nut diameter, the upper pressing plate 2 and the lower pressing plate 3 are folded by hand, the steel ball mounting rod 5 at the front end of the measuring device is put into the micrometer, the micrometer is adjusted to the 0 line, the micrometer is removed, the upper pressing plate 2 and the lower pressing plate 3 are folded by hand, the steel ball mounting rod 5 is deeply put into the nut, the upper pressing plate 2 and the lower pressing plate 3 are gradually loosened, the steel ball 6 is located in the ball raceway of the nut, and the deviation between the pointer of the micrometer and the 0 line is the deviation between the actual diameter value and the theoretical value of the nut.

[0035] When the roundness error value needs to be measured, the nut is rotated, 3-4 point positions on the same circle are measured, and the roundness error value of the spiral surface can be obtained; the indication values at different depths of the same generatrix in the nut are measured, and the cylindricity error value of the thread raceway on the generatrix can be obtained.

[0036] The preferred embodiments of the present application are described above, it should be noted that for those skilled in the art, without departing from the principles of the present application, a number of improvements can be made, which improvements should also be considered as the protection scope of the present application.

Claims

1. A ball nut center finder comprising: It comprises a measuring device base (1), an upper pressing plate (2), a lower pressing plate (3) and a micrometer (4). The upper pressing plate (2) is slidably arranged in the measuring device base (1), the lower pressing plate (3) is arranged in the measuring device base (1) and is arranged opposite to the upper pressing plate (2), a spring (10) is arranged between the upper pressing plate (2) and the lower pressing plate (3), and a measuring head of the micrometer (4) is connected with the lower pressing plate (3). The front ends of the upper pressing plate (2) and the lower pressing plate (3) are provided with steel ball mounting rods (5), and the steel ball mounting rods (5) are provided with steel balls (6).

2. A ball nut center diameter gauge according to claim 1, wherein The measuring device base (1) is provided with a rectangular cavity in the middle, the upper pressing plate (2) and the lower pressing plate (3) are arranged in the cavity, and the measuring device base (1) is provided with threaded holes communicating with the cavity at the upper end and the lower end.

3. A ball nut center finder as set forth in claim 2, wherein, The micrometer (4) is installed on the upper part of the measuring device base (1) through threaded connection, the threaded hole in the lower part of the measuring device base (1) is provided with a stop screw (7), and the stop screw (7) is connected with the bottom surface of the lower pressing plate (3).

4. A ball nut center finder as set forth in claim 1, wherein, The measuring device base (1) is provided with a group of guide positioning pins (8) along the length direction, the upper pressing plate (2) and the lower pressing plate (3) are each provided with a group of guide holes, the upper pressing plate (2) and the lower pressing plate (3) are arranged on the guide positioning pins (8) through the guide holes, and guide copper sleeves (9) are further arranged between the guide holes and the guide positioning pins (8).

5. A ball nut center finder as set forth in claim 1, wherein, The steel ball mounting rod (5) is provided with a ball socket, and the steel ball (6) is welded in the ball socket.

6. A ball nut center diameter gauge according to claim 5, wherein The number of the ball sockets is at least three, the axial spacing of the ball sockets on the upper and lower steel ball mounting rods (5) is the same as the lead of the ball nut to be measured.

7. A ball nut center finder as set forth in claim 1, wherein, The steel ball mounting rod (5) is connected with the upper pressing plate (2) and the lower pressing plate (3) through bolts.

8. A ball nut center finder as defined in claim 1 wherein, The rear ends of the upper pressing plate (2) and the lower pressing plate (3) extend out of the measuring device base (1).

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