Non-contact measuring device for center distance of two holes

Abstract

A non-contact measuring device for the center distance of two holes is characterized in that a large measuring head and a small measuring head are arranged on a gauge base at intervals, and a first nozzle hole and a fourth nozzle hole at the far-diameter end are communicated with a first air inlet joint through a first air joint and a fourth air joint which are correspondingly arranged at the tail end of an air path and are connected with a first air gauge; the second nozzle hole and the third nozzle hole at the near-diameter end are communicated with a second air inlet connector through a second air connector and a third air connector which are correspondingly arranged at the tail end of an air path and are connected with a second air gauge, the indication value of the first air gauge is recorded as 1a, the first nozzle hole and the fourth nozzle hole form a nozzle group I, and 1a is the indication value of the nozzle group I; the second nozzle hole and the third nozzle hole form a nozzle group II, and 1b is the indication value of the nozzle group II, comparative measurement is adopted, the basic amplification factor of the measurement system is adjusted by a standard component and then measurement is performed during use, the measurement result can be obtained by comparing with the standard component, and the measurement precision is high.

Description

Technical Field

[0001] The utility model belongs to the technical field of hole distance measurement, and particularly relates to a non-contact measuring device for the center distance between two holes. Background Art

[0002] The connecting rod is one of the important parts in automotive internal combustion engines and refrigeration compressors. The large hole is connected to the engine crankshaft, and the small hole is connected to the piston pin in the piston to transmit power, so the center distance between the two holes of the connecting rod is an important and necessary inspection item. The well-known high-precision inspection method is three-coordinate, which has sufficient accuracy but extremely low efficiency and high cost. It is only suitable for random inspections, not for 100 inspections. The measured parts are precise and have high surface finish requirements, so non-contact pneumatic measurement is the first choice. The measurement results of the commonly used movable guide structure will include the aperture machining tolerance, which is not accurate enough.

[0003] The utility model with announcement number CN218764957U discloses a two-hole position detection device, the technical solution of which includes a base, a standard part base, and a measuring component. The standard part base is arranged on the base, and the measuring component and the standard part base are spaced apart. The measuring component includes a first positioning element, a measuring element, a moving element, and a second positioning element. The first positioning element is arranged on the base, the measuring element is arranged on the base, the moving element is slidably fitted on the base, a positioning block is provided on the moving element, the positioning block is stopped against the standard part, the measuring element is stopped against the moving element, and the second positioning element is arranged on the moving element. Although the two-hole position measurement device is simple to operate, convenient and fast, and the measurement results are practical and accurate, it is still not suitable for inspection.

[0004] The invention of announcement number CN216482873U discloses a pneumatic inner diameter measuring device, the technical solution of which includes a base and a detection head, a support plate is installed on one side of the base, a rotating shaft is arranged inside the support plate, and a first active bevel gear and a second active bevel gear are installed on the outer surface of the rotating shaft. Through the matching arrangement of the rotating shaft, the first active bevel gear, the second active bevel gear, the first transmission screw, the second transmission screw, the first driven bevel gear and the second driven bevel gear, the first active bevel gear drives the first transmission screw to rotate through the first driven bevel gear, the first transmission screw drives the first transmission block to move up and down along the first guide shaft, and then the first transmission block drives the upper limit arrow to be precisely adjusted through the first L-link rod, and similarly, the lower limit arrow is precisely adjusted. Compared with the manual adjustment method, this adjustment method achieves the purpose of accurate and convenient adjustment; however, the pneumatic inner diameter measuring device has not yet been applied to the detection of the center distance between two holes. Summary of the invention

[0005] The purpose of the utility model is to provide a non-contact measuring device for the center distance between two holes in view of the deficiencies of the above-mentioned prior art, which adopts a non-contact method to measure the hole distance, has high measurement accuracy and precise data processing.

[0006] In order to solve the above technical problems, the technical solution adopted by the utility model is:

[0007] A non-contact measuring device for the center distance between two holes comprises a gauge base, a first air inlet joint and a second air inlet joint arranged on the gauge base, and a large measuring head and a small measuring head of two float-type pneumatic measuring instruments arranged on the gauge base at intervals, and two nozzle holes opened on the column of the large measuring head are defined as a first nozzle hole and a second nozzle hole respectively, and the first nozzle hole is located at the far diameter end of the small measuring head, and the second nozzle hole is located at the near diameter end of the small measuring head.

[0008] The two nozzle holes opened on the cylinder of the small measuring head are defined as the third nozzle hole and the fourth nozzle hole respectively, and the third nozzle hole is located at the near diameter end of the large measuring head, and the fourth nozzle hole is located at the far diameter end of the large measuring head;

[0009] The first nozzle hole and the fourth nozzle hole at the far diameter end are connected to the first air inlet connector through the first air connector and the fourth air connector correspondingly provided at the end of the air path and connected to the first pneumatic measuring instrument.

[0010] The second nozzle hole and the third nozzle hole at the near-diameter end are connected to the second air inlet connector through the second air connector and the third air connector correspondingly arranged at the end of the air path and are connected to the second pneumatic measuring instrument.

[0011] According to the above-mentioned non-contact measuring device for the center distance between two holes, it is characterized in that: the indication value of the first pneumatic measuring instrument is recorded as 1a, the first nozzle hole and the fourth nozzle hole at the far diameter end are recorded as nozzle group I, and 1a is the indication value of nozzle group I;

[0012] The indication value of the second pneumatic meter is recorded as 1b, the second nozzle hole and the third nozzle hole at the near diameter end are nozzle group II, and 1b is the indication value of nozzle group II.

[0013] The large measuring head and the small measuring head are detachably connected to the inspection body through connecting bolts.

[0014] The top ends of the large measuring head and the small measuring head are both detachably provided with elastic protective caps.

[0015] The elastic protective cap is a soft nylon protective cap and is detachably connected via bolts.

[0016] The distance between the large measuring head and the small measuring head is set according to the minimum value of the object to be measured.

[0017] The beneficial effects of the utility model are:

[0018] (1) The two-hole center distance non-contact measuring device is characterized in that a large measuring head and a small measuring head of two float-type pneumatic measuring instruments are arranged at intervals on a gauge base, and the first nozzle hole and the fourth nozzle hole at the far diameter end are connected to the first air inlet joint through the first air joint and the fourth air joint correspondingly provided at the end of the air path and connected to the first pneumatic measuring instrument, and the second nozzle hole and the third nozzle hole at the near diameter end are connected to the second air inlet joint through the second air joint and the third air joint correspondingly provided at the end of the air path and connected to the second pneumatic measuring instrument, and the indication value of the first pneumatic measuring instrument is recorded as 1a, the first nozzle hole and the fourth nozzle hole are nozzle group I, and 1a is the indication value of nozzle group I; the indication value of the second pneumatic measuring instrument is recorded as 1b, the second nozzle hole and the third nozzle hole are nozzle group II, and 1b is the indication value of nozzle group II, and comparative measurement is adopted. When in use, the basic magnification of the measuring system is first adjusted with a standard part before measurement is performed, and the measurement result can be obtained by comparison with the standard part, and the measurement accuracy is high and the data processing is accurate.

[0019] (2) The non-contact measuring device for the center distance between two holes adopts a pneumatic measurement method. The large and small measuring heads in the device convert the size changes of the parts into changes in the air flow rate. The float-type pneumatic measuring instrument connected to it indicates the change. The device is simple and reliable to operate, with high detection efficiency. It can be placed in the workshop for batch detection of connecting rods and has strong environmental adaptability.

[0020] (3) The measuring device is a non-contact measurement device. There is a gap between the measuring surface and the measured surface, which is not easy to scratch the measured surface. It has a novel design, simple structure, and high measurement accuracy (total measurement accuracy ≤ 0.002 mm); maximum magnification: ≥ 120% of the basic magnification; indication variability: less than one scale value of the matching measuring instrument; simple and reliable operation, high detection efficiency, can be placed in the workshop for batch connecting rod detection, strong environmental adaptability, and can be widely used in the domestic automobile, motorcycle, air conditioning and refrigeration industry, providing reliable detection guarantee for the industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the reference structure of the utility model;

[0022] Figure 2 It is the principle structure diagram of the utility model;

[0023] Figure 3 It is a three-dimensional diagram of the utility model;

[0024] Figure 4 It is a cross-sectional view of the utility model. DETAILED DESCRIPTION

[0025] The following is a description of the implementation of the present invention by means of specific embodiments. People familiar with the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0026] The utility model provides a non-contact measuring device for the center distance between two holes, such as Figures 1 to 4 shown.

[0027] A two-hole center distance non-contact measuring device comprises a gauge base 1, a first air inlet joint 2 and a second air inlet joint 3 arranged on the gauge base, and a large measuring head 4 and a small measuring head 5 of two float-type pneumatic measuring instruments arranged at intervals on the gauge base, and two nozzle holes opened on the column of the large measuring head are respectively defined as a first nozzle hole 41 and a second nozzle hole 42, which are arranged independently, and the first nozzle hole 41 is located at the far diameter end of the small measuring head 5, and the second nozzle hole 42 is located at the near diameter end of the small measuring head 5.

[0028] The two nozzle holes opened on the cylinder of the small measuring head 5 are respectively defined as the third nozzle hole 51 and the fourth nozzle hole 52, which are also independently arranged, and the third nozzle hole 51 is located at the near diameter end of the large measuring head 4, and the fourth nozzle hole 52 is located at the far diameter end of the large measuring head 4; and the distance between the large measuring head 4 and the small measuring head 5 is set according to the minimum value of the workpiece to be measured.

[0029] The first nozzle hole 41 and the fourth nozzle hole 52 at the far-diameter end are connected to the first air inlet connector 2 and the first pneumatic measuring instrument through the first air connector 43 and the fourth air connector 54 respectively provided at the end of the air path.

[0030] The second nozzle hole 42 and the third nozzle hole 51 at the proximal end are respectively connected to the second air inlet connector 3 through the second air connector 44 and the third air connector 53 correspondingly provided at the end of the air path and connected to the second pneumatic measuring instrument.

[0031] In this embodiment, the indication value of the first pneumatic measuring instrument is recorded as 1a, the first nozzle hole and the fourth nozzle hole at the far diameter end are nozzle group I, and 1a is the indication value of nozzle group I; the indication value of the second pneumatic measuring instrument is recorded as 1b, the second nozzle hole and the third nozzle hole at the near diameter end are nozzle group II, and 1b is the indication value of nozzle group II.

[0032] To facilitate installation and disassembly, the large measuring head 4 and the small measuring head 5 are respectively detachably connected to the inspection body 1 by connecting bolts, and the tops of the large measuring head 4 and the small measuring head 5 are detachably provided with elastic protective caps 6. In this embodiment, the elastic protective cap 6 is a soft nylon protective cap and is detachably connected by bolts.

[0033] The measurement principle and calibration process of the device are as follows:

[0034] 1. Device measurement principle

[0035] The working principle of the pneumatic measuring instrument is to insert the pneumatic plug gauge probe into the hole to be measured. When the air flow passes through the nozzle of the pneumatic plug gauge and flows through the gap between the plug gauge and the hole to be measured, the change in the aperture will cause a change in the gas pressure or flow rate. The size of the aperture to be measured can be measured by measuring the change in pressure or flow rate value, and then processed by the sensor, and finally displayed on the display device.

[0036] The non-contact measuring device for the center distance between two holes uses a comparative measurement method. Figure 1 and Figure 2 As shown, the first nozzle hole 41, the second nozzle hole 42, the third nozzle hole 51, and the fourth nozzle hole 52 are arranged on the probe. Figure 2 After the circuit shown is connected, it is connected to two tube measuring instruments respectively, so that the center distance between the two holes can be detected and indicated. Since the nozzles are respectively set in the two holes, the size of the hole diameter affects the calibration range but does not affect the center distance measurement result.

[0037] 2. Calibration

[0038] The size engraved on the side of the substrate in the device is the actual measured value Lbenchmark of the device's datum center distance. When the upper (lower) limit standard parts are placed in the device at the measuring position, the calibration of nozzle group I has the same effect as the internal dimension measurement, and the larger the size, the larger the gap; the calibration of nozzle group II has the same effect as the external dimension measurement, that is, the larger the size, the smaller the gap; after placing the upper and lower limit standard parts respectively to calibrate the basic magnification of the device, the measurement can be started. The calibration range of the two tubes should be distributed in the center of the "0" scale of the measuring instrument.

[0039] 3. Processing of hole center distance measurement results

[0040] If the indication values ​​of the two tube gauges are 1a and 1b respectively, let 1a be the indication value of nozzle group I (i.e. the first nozzle hole and the fourth nozzle hole), and 1b be the indication value of nozzle group II (the second nozzle hole and the third nozzle hole), then half of the difference between the two is the deviation of the center distance of the measured part relative to the reference center distance L of the device. The mathematical expression is:

[0041] L measured = L reference + (1a-1b) / 2 (when the value of tube I is high)

[0042] L measured = L reference - (1a - 1b) / 2 (when the indication of tube II is high)

[0043] If the float of tube I is higher than the float of tube II, the center distance between the two holes of the measured part is greater than the L reference. If the float of tube I is lower than the float of tube II, the center distance between the two holes of the measured part is less than the L reference.

[0044] The non-contact measuring device for the center distance between two holes adopts a pneumatic measurement method. The large and small measuring heads in the device convert the size change of the part into the change of the air flow rate, and the float-type pneumatic measuring instrument connected thereto indicates the change. The device is simple and reliable in operation, with high detection efficiency. It can be placed in the workshop for batch detection of connecting rods, and has strong environmental adaptability. It can be widely used in the domestic automobile, motorcycle, and air conditioning and refrigeration industries, providing reliable detection guarantees for these industries. The device adopts a pneumatic measurement method. The large and small measuring heads in the device convert the size change of the part into the change of the air flow rate, and the float-type pneumatic measuring instrument connected thereto indicates the change. The device has a novel design, simple structure, high measurement accuracy (total measurement accuracy ≤ 0.002 mm), maximum magnification: ≥ 120% of the basic magnification, indication variability: less than one scale value of the matching measuring instrument, simple and reliable in operation, with high detection efficiency. It can be placed in the workshop for batch detection of connecting rods, and has strong environmental adaptability. It can be widely used in the domestic automobile, motorcycle, and air conditioning and refrigeration industries, providing reliable detection guarantees for these industries.

[0045] At the same time, you need to pay attention to maintenance during daily use. The precautions are as follows:

[0046] (1) The working surfaces of the device and standard parts should be kept clean and rust-proof treatment should be performed when they are not in use;

[0047] (2) Compressed air should be dry and clean, and the filter should be drained and discharged regularly;

[0048] (3) The basic magnification of the measuring instrument should be recalibrated each time it is used;

[0049] (4) The parts to be measured should be clean before measurement;

[0050] (5) The probe and related dimensions in the device are designed according to the minimum conditions. When the measured part cannot be placed in the measuring position, it should not be pressed in hard (out-of-tolerance parts) to avoid damaging the device. When the measured part cannot be placed in the measuring position (not counting the phenomenon of misalignment and skewness), other detection methods can be used to verify whether the measured dimension is too out of tolerance;

[0051] (6) When calibrating, the operator should place the center of the standard part on one side of the large head hole and then insert it smoothly;

[0052] (7) Operators should handle equipment with care and adhere to civilized operation when working;

[0053] (8) For ease of use, the standard size takes into account the calibration of multiple tubes. Tube I is calibrated at the full value, and tube II is calibrated at only a section of the tolerance range. During the measurement process, the float of tube II will exceed the upper and lower limit marks. This is normal and does not affect the measurement results.

[0054] If the words "first", "second" and so on are used in this patent to limit components, those skilled in the art should know that the use of "first" and "second" is only for the convenience of describing the utility model and simplifying the description, and the above words have no special meaning.

[0055] The above shows and describes the basic principle, main features and advantages of the utility model. Those skilled in the art should understand that the utility model is not limited by the above embodiments. The above embodiments and descriptions are only for explaining the principle of the utility model. The utility model may have various changes and improvements without departing from the spirit and scope of the utility model. These changes and improvements fall within the scope of the utility model to be protected. The scope of protection claimed by the utility model is defined by the attached claims and their equivalents.

[0056] In the description of the present invention, it is necessary to understand that the terms "front", "rear", "left", "right", "center", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the protection content of the present invention.

Claims

1. A non-contact measuring device for the center distance between two holes, characterized in that: The invention comprises a gauge base, a first air inlet joint and a second air inlet joint arranged on the gauge base, and a large measuring head and a small measuring head of two float-type pneumatic measuring instruments arranged on the gauge base at intervals, and two nozzle holes opened on the column of the large measuring head are defined as a first nozzle hole and a second nozzle hole respectively, and the first nozzle hole is located at the far diameter end of the small measuring head, and the second nozzle hole is located at the near diameter end of the small measuring head. The two nozzle holes opened on the cylinder of the small measuring head are defined as the third nozzle hole and the fourth nozzle hole respectively, and the third nozzle hole is located at the near diameter end of the large measuring head, and the fourth nozzle hole is located at the far diameter end of the large measuring head; The first nozzle hole and the fourth nozzle hole at the far diameter end are connected to the first air inlet connector through the first air connector and the fourth air connector correspondingly provided at the end of the air path and connected to the first pneumatic measuring instrument. The second nozzle hole and the third nozzle hole at the near-diameter end are connected to the second air inlet connector through the second air connector and the third air connector correspondingly arranged at the end of the air path and are connected to the second pneumatic measuring instrument.

2. A non-contact measuring device for the center distance between two holes according to claim 1, characterized in that: The indication value of the first pneumatic meter is recorded as 1a, the first nozzle hole and the fourth nozzle hole at the far diameter end are recorded as nozzle group I, and 1a is the indication value of nozzle group I; The indication value of the second pneumatic meter is recorded as 1b, the second nozzle hole and the third nozzle hole at the near diameter end are nozzle group II, and 1b is the indication value of nozzle group II.

3. The non-contact measuring device for the center distance between two holes according to claim 1, characterized in that: The large measuring head and the small measuring head are detachably connected to the inspection body through connecting bolts.

4. A non-contact measuring device for the center distance between two holes according to any one of claims 1 to 3, characterized in that: The top ends of the large measuring head and the small measuring head are both detachably provided with elastic protective caps.

5. A non-contact measuring device for the center distance between two holes according to claim 4, characterized in that: The elastic protective cap is a soft nylon protective cap and is detachably connected via bolts.

6. The non-contact measuring device for the center distance between two holes according to claim 4, characterized in that: The distance between the large measuring head and the small measuring head is set according to the minimum value of the object to be measured.

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