CN102679939B - Roundness detecting method for eccentric shaft part - Google Patents

Abstract

The invention belongs to mechanical methods, in particular to a roundness detecting method for an eccentric shaft part. The method is characterized in that a turntable and a measurement support are arranged on a base, an eccentric disc is arranged on the measurement support, a telescopic supporting rod is fixed on the eccentric disc through a rotating bearing, a V-shaped reference block is arranged on the telescopic supporting rod, the telescopic supporting rod is fixed on the eccentric disc through the rotating bearing, and the telescopic supporting rod can freely rotate around the rotating bearing. When the eccentric shaft part is driven to rotate by the turntable, the eccentric disc and the turntable rotate synchronously, so that a measurement probe, the V-shaped reference block and the telescopic supporting rod in the roundness detecting process only move in parallel; when the turntable continuously rotates for one circle, the roundness of the measurement probe on the surface of the part in a 360-degree range is measured by a measurement and control system; and the method is simple, convenient, feasible, scientific, reasonable and high in measurement precision.

Description

A method for detecting the roundness of eccentric shaft parts

technical field

The invention belongs to the category of mechanical methods, in particular to a method for detecting the roundness of eccentric shaft parts.

Background technique

In the precision machining process of eccentric shaft parts, such as the grinding process of engine crankshaft pin, it is necessary to measure the roundness deviation of eccentric shaft parts in situ. At present, the method for in situ measurement of the roundness of shaft parts is mainly to use V-shaped The reference block measurement method is to fix the measuring head on the V-shaped reference block. During the roundness measurement process, the two reference planes of the V-shaped reference block are always kept circumscribed with the surface of the measured shaft part by using the support structure, so that by installing on the The measuring probe of the V-shaped reference block obtains the roundness change value of each point on the surface of the measured shaft part. However, there is no scientific, reasonable, simple and easy method to maintain a stable and reliable circumscribed relationship between the two datum planes of the V-shaped datum block and the eccentric shaft part. The patent application with the application number "03813741.0" and titled "Equipment for Checking Pin Dimensions and Geometric Features" discloses a method for measuring the roundness of eccentric pin parts based on a follow-up support. However, the structure of the support is complex and difficult to adjust, which is insufficient Flexible and convenient; the patent application with the application number 201110003560.9 and titled "A Method for Measuring the Roundness of Eccentric Parts" discloses a method for measuring the roundness of eccentric shaft parts based on a telescopic support mechanism, but during the measurement process, the measuring head detects The continuous change of the angle complicates the roundness data acquisition and calculation process.

Contents of the invention

The purpose of the present invention is to provide a scientific and reasonable, simple and easy to implement, high measurement precision roundness detection method for eccentric shaft parts.

Technical scheme of the present invention is as follows:

A method for detecting the roundness of eccentric shaft parts, characterized in that: a turntable and a measuring bracket are installed on the base, an eccentric disk is installed on the measuring bracket, the eccentric disk is located above the turntable, and the eccentric disk and the turntable rotate synchronously, and the The eccentric shaft part is installed on the turntable, and a telescopic support rod is fixed on the eccentric disk through the rotating bearing. The distance between the center of the bearing and the center of the eccentric disk is the same as the eccentric distance of the eccentric shaft part. The telescopic support rod can rotate freely around the rotating bearing; A V-shaped reference block is installed on the support rod. The V-shaped reference block is equipped with a measuring head, and the signal of the measuring probe is connected to the measurement and control system; The V-shaped reference block, measuring probe, and telescopic support rod only move in parallel. Under the action of the internal elastic force of the telescopic support rod, the two reference planes of the V-shaped reference block and the eccentric part remain circumscribed, and the measuring probe can measure the state of the eccentric shaft part. The lower roundness; the eccentric shaft part rotates one circle continuously, the telescopic amount and rotation angle of the telescopic support rod always ensure that the two datum planes of the V-shaped datum block maintain a circumscribed relationship with the eccentric part, and the measurement installed on the V-shaped datum block The probe continuously scans one circle around the surface of the eccentric shaft part, and the measurement and control system can collect the fluctuation signal related to the roundness from the measuring probe, and can obtain the roundness value within 360 degrees of the surface of the eccentric shaft part.

The V-shaped reference block of the present invention is installed on the telescopic support rod, and the telescopic support rod is fixed on the eccentric disk through the rotating bearing, and the telescopic supporting rod can rotate freely around the rotating bearing. When the eccentric shaft part rotates under the drive of the turntable, the eccentric disk and the turntable rotate synchronously, so that the measuring probe, V-shaped reference block and telescopic support rod only move in parallel during the roundness detection process, ensuring that the rotation angle of the turntable is the same as that of the measuring probe at the eccentricity. The scanning angle of the surface of the shaft part remains consistent. When the turntable rotates one circle continuously, the measurement and control system measures the roundness of the measuring probe within 360 degrees on the surface of the part, which is simple, scientific and reasonable, and has high measurement accuracy.

Description of drawings

Fig. 1 is a schematic diagram of the present invention.

Detailed ways

As shown in Figure 1, a kind of roundness detection method of eccentric shaft part is characterized in that:

A. Install a turntable 2 and a measuring bracket 9 on the base 1, install an eccentric disc 7 on the measuring bracket 9, the eccentric disc 7 is located above the turntable 2, and the eccentric disc 7 and the turntable 2 rotate synchronously; the eccentric shaft part 3 installed on the turntable 2;

B. A telescopic support rod 8 is fixed on the eccentric disc 7 through the rotary bearing 6, the distance between the center of the bearing and the center of the eccentric disc 7 is the same as the eccentric distance of the eccentric shaft part 3, and the telescopic support rod 8 can rotate freely around the rotary bearing 6;

C. Install the V-shaped reference block 4 on the telescopic support rod 8, install the measuring probe 5 on the V-shaped reference block 4, the signal of the measuring probe 5 is connected to the measurement and control system, and the telescopic support rod 8 points downward under the action of gravity to the eccentric shaft part 3;

D. When the eccentric shaft part 3 rotates under the drive of the turntable 2, the eccentric disk 7 and the turntable 2 rotate synchronously, and the V-shaped reference block 4, the measuring probe 5, and the telescopic support rod 8 only move in parallel during the rotation. Under the action of the elastic force inside the telescopic support rod 8, the V-shaped reference block 4 keeps its two reference planes circumscribed with the eccentric shaft part 3, and the measuring probe 5 can measure the roundness of the eccentric shaft part 3 in this state;

E. When the eccentric shaft part 3 rotates continuously under the drive of the turntable 2, the measurement probe 5 installed on the V-shaped reference block 4 scans continuously around the surface of the part, and the measurement and control system can collect the eccentric shaft part that is measured. 3 Fluctuating signals related to roundness, and the roundness within 360 degrees of the surface can be obtained.

The expansion and contraction of the telescopic support rod 8 of the present invention and the angle of rotation must ensure that its two reference planes of the V-shaped reference block 4 and the eccentric shaft part 3 can always maintain a circumscribed relationship when the eccentric shaft part 3 rotates continuously for one week during the measurement process.

During the scanning process of the measuring probe 5 of the present invention, the expansion and contraction amount and rotation angle of the telescopic support rod 8 are automatically generated.

The telescopic support rod 8 of the present invention has a linear guide mechanism, and obtains telescopic elastic force through air pressure, oil pressure and the like.

Claims (3)

1. A method for detecting roundness of eccentric shaft parts, characterized in that: a turntable and a measuring support are installed on the base, an eccentric disc is installed on the measuring support, the eccentric disc is positioned above the turntable, and the eccentric disc and the turntable rotate synchronously ; Install the eccentric shaft part on the turntable, fix a telescopic support rod on the eccentric disk through the rotating bearing, the distance between the center of the bearing and the center of the eccentric disk is the same as the eccentric distance of the eccentric shaft part, and the telescopic support rod can rotate freely around the rotating bearing; Install a V-shaped reference block on the telescopic support rod. The V-shaped reference block is equipped with a measuring head, and the signal of the measuring probe is connected to the measurement and control system; The V-shaped reference block, measuring probe, and telescopic support rod only move in parallel. Under the action of the internal elastic force of the telescopic support rod, the two reference planes of the V-shaped reference block and the eccentric part remain circumscribed, and the measuring probe can measure the eccentric shaft part. Roundness in this state; the eccentric shaft part rotates one circle continuously, and the expansion and contraction and rotation angle of the telescopic support rod always ensure that the two reference planes of the V-shaped reference block maintain a circumscribed relationship with the eccentric part, and are installed on the V-shaped reference block. The measurement probe continuously scans a circle around the surface of the eccentric shaft part, and the measurement and control system can collect the fluctuation signal related to the roundness from the measurement probe, and can obtain the roundness value within 360 degrees of the surface of the eccentric shaft part. 2. The method for detecting the roundness of eccentric shaft parts according to claim 1, characterized in that: during the scanning process of the measuring probe, the expansion and contraction amount and rotation angle of the telescopic support rod are automatically generated. 3. The method for detecting the roundness of eccentric shaft parts according to claim 1, characterized in that: the telescopic support rod has a linear guide mechanism, and the stretching elastic force is obtained by air pressure or oil pressure.

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