CN87208774U

CN87208774U - Cam shaft tester

Info

Publication number: CN87208774U
Application number: CN 87208774
Authority: CN
Inventors: 李保忠; 陶仲林
Original assignee: NO 2 AUTOMOBILE FACTORY
Current assignee: Dongfeng Motor Corp
Priority date: 1987-05-30
Filing date: 1987-05-30
Publication date: 1988-08-17

Abstract

The utility model relates to a detector which detects the symmetrical cam-lift curve and the asymmetric cam-lift curve of the cam shaft of an internal combustion engine. The detector is composed of a digit index head, a digit abbe head, a detection station which supports an adjustable stand, a detecting computer, an anacom, a printer, a plotter, etc. The utility model is characterized in that the detector adopts two sensors of a length sensor and an angle sensor and two synchronous circuits, and the detector can realize the detection of the cam-lift curve value using the centre of a base circle as the reference.

Description

Cam shaft tester

A kind ofly be used to measure the symmetry of internal combustion (IC) engine camshaft and the detector of asymmetric cam lifting curve.

The utility model belongs to the measuring apparatus that the appliance computer method is a feature.

Measured symmetry and asymmetric cam lifting curve on the internal combustion (IC) engine camshaft in the past, generally be to adopt optical dividing head and Abbe head, and it is contained on the Cam Detection platform, by manually measuring, so that camshaft is rotated, the visual optical read table is noted the value of being surveyed, and the data with survey data and design drawing requirement compare then, draw measurement result.This measuring method, detection efficiency is low, and measuring accuracy is poor.The camshaft detector of computer measurement system appears having in recent years, its measuring method is with the rotation of motor drive cam shaft, spend sampling cam profile lift range value with computing machine by 1 point/1, find out cam profile left and right sides correspondent equal (being similar to) lift range value, determine it and measure axial line, determine cam according to the measurement axial line then and play angle measurement, calculate cam lifting curve by the method for interpolation by computing machine again, promptly think actual cam lifting curve.There is bigger error between cam lifting curve that obtains in this way and the actual cam lifting curve.

For energy measurement goes out actual cam lifting curve, the utility model provides that a kind of function is many, precision is high, the camshaft detector of reliable operation.

Basic design of the present utility model, be that cam profile and generating circle are sampled respectively, determining to measure supporting-point then is the position of the cam axial line and the generating circle garden heart in axle center, calculate cam axial line again by the reality of the generating circle garden heart, on detector, is furnished with simultaneously hardware synchronous circuit, make tested cam and sample count synchronous, thereby cam profile is sampled, and obtain actual cam lifting curve value through the conversion of actual cam axle center line coordinates.

Concrete structure of the present utility model can be illustrated in conjunction with the accompanying drawings

The description of the drawings:

Fig. 1, camshaft detector circuit theory diagrams.

Fig. 2, camshaft detector work synoptic diagram.

Fig. 3, synchronizing circuit block diagram.

As seen, this Cam Detection instrument is by forming with digital dividing head 12, digital Abbe head 1, the monitor station, metering computer 32, anacom 4 and the printer 5 that support adjusting bracket 10, plotter 7 etc. Described detector adopts an angular transducer 13 and linear transducer 14 totally two sensors. And be contained in respectively on digital dividing head 12 and the digital Abbe head 1, in the digital dividing head drive motors 11 being housed simultaneously, monitor station is provided with V-type rail, and digital Abbe head 1 and supporting adjusting bracket 10 can be moved thereon.

Metering computer 32 is single board computer, and it is connected to two cover digital display circuits 2 and 3, respectively is provided with eight-digit number

word display list

19 and 20, trace level pointer on the digital display circuit 2 and 3 and simulates table 15 and 16, dial-up

dish

17 and 18 and the verification K switch₃、K ₄、K ₅And K₆、K ₇、K ₈ Wherein the digital display circuit of a cover is used for recording the cam rotation angle value, another set ofly then is used for recording cam and rises on duty by turns. Digital display circuit 2 and 3 also is connected to synchronous circuit 25 and 26 simultaneously.

Anacom 4 also is connected to screen display 6 and floppy disk driver 8 except being connected to printer 5.

Measurement operating keys all on this camshaft detector are as detecting cam key J ₁, J ₂, P ₁, P ₂, total power switch key K ₂, operation key K ₁And testing process pilot lamp T ₁～T ₈All be located on the display switch device 9.

Detect the method and the process of cam:, connect total power switch K if when detecting with the symmetry in theoretical cam axle center or asymmetric cam lifting curve ₂Key is pressed and is detected key J ₁Or P ₁, metering computer 32 is opened motor driven switch K automatically by programmed control ₁12 rotations of driven by motor dividing head, drive the rotation of angular transducer 13 and camshaft simultaneously, and promote linear transducer 14 by tested cam and move, at this moment, metering computer 32 in cam rotates a circle to cam profile 300 points of sampling, to 192 points of cam generating circle molded lines sampling, the angle value of sampling and lift range value are respectively by

digital indicator

19 and 20,0.1 second, 0.1 the

micro-pointer gauge outfit

15 and 16 of micron demonstrates, simultaneously through up-down counter 21 and 22, data latches 23 and 24,

level match

27 and 28 and digit buffer 29 and 30 pass through bus, be sent in the metering computer 32 and go.Obtaining to measure supporting-point by the lift range value that allows the measurement minimum error method to find out two correspondent equals with the angle value of being surveyed by it is the cam axial line and the heart position, generating circle garden in axle center.Accurately make actual cam axial line and lift starting point according to the generating circle garden heart, metering computer 32 starts synchronizing circuits 25 and 26 at this moment.Make digital display circuit 2 and 3 up-down counter 21 and 22 and tested cam synchronous.Described synchronizing circuit 25 is identical with 26, form by electronic switch 40, driver 41, level match device 39, its input end is through being connected to IORQ, WR and the address decoding mouth end of the central processing unit of metering computer 32 with door 37 and phase inverter 38, and its output terminal is connected on the up-down counter 21 and 22 of digital display circuit 2 and 3.When cam forwards the lift starting point to, metering computer 32 is sent signal, amplify, drive total clear terminal that electronic switch 40 outputs to up-down counter 21 and 22 through the level match device 39 of synchronizing circuit 25 and 26, driver 41, make total data zero clearing immediately in up-down counter 21 and 22, the digital wash 19 and 20.Metering computer is by the whole lift range value of 4 point/1 degree sampling cam then, and converts through actual cam axle center line coordinates, thereby to obtain with the generating circle garden heart be the actual cam lifting curve value of benchmark.Owing to be solidified with the theoretical cam lift range value in advance in memory under program 31, thereby metering computer compares through the actual lift value of survey cam and theoretical value and calculates cam lift graph of errors value.And process communication interface 35 is delivered to measurement data in the anacom 4, calculate its total error, adjacent poor, keyway to cam angle error, generating circle centering error by anacom 4, and demonstrate at screen display 6, on printer 8, print the Chinese character examining report, can be stored in the floppy disk driver 5 detecting data when needing.

Meanwhile, metering computer 32 can be opened plotting apparatus automatically, and cam lift graph of errors value, delivers to digital to analog converter 33, amplifier 34, converts analog quantity to, drives plotting apparatus 7 and draw out the cam lift graph of errors.

Whole detector is by total power switch K ₂Unified control, testing process is by T ₁～T ₈Pilot lamp indicate successively as: operation, decide to survey zero point, synchronously, survey axial line, the survey generating circle garden heart, communication, drawing, end.It is symmetry or the asymmetric cam lifting curve of benchmark through coordinate transformation that detector can not only be measured with the generating circle garden heart, but also energy measurement is the symmetry and the asymmetric cam lifting curve without coordinate transformation in axle center with the supporting-point, only need press J as requested ₁, J ₂, P ₁, or P ₂Can detect, and detector also can pass through

dial

17 and 18, check key K before detection ₃, K ₄, K ₅And K ₆, K ₇, K ₈Whether the check digit display circuit is working properly.To guarantee to detect the accurate of data.

In order to improve the reliability of camshaft detector, this instrument has been taked strict interference protection measure, whole switching values adopts photoelectricity, the relay two-stage is isolated, promptly the input end at signal display switch device 9 has added photoisolator 36, all transmit signal wire, data line all adopts the shielding line transmission, simultaneously in order to prevent the load current of public power internal resistance, voltage drop is disturbed each circuit, power supply is taked three grades of power supplies of branch, the computing machine external circuits is by a senior stabilized voltage supply power supply, drive motor directly gets access to grid, computing machine and peripherals are then by special-purpose stabilized voltage supply power supply, in addition, on printed circuit board (PCB), be provided with the electric capacity that absorbs undesired signal.And in AC power, be provided with alternating current filter, make the detector can not only be in office work, and can also be under more bad environment operate as normal.

The utility model characteristics:

1, circuit compactness, reliable operation, function is many, detection efficiency is high.

2, the software of detector adopts the modular mode to work out, and metering computer adopts assembly language, and anacom adopts higher level lanquage.Assembly language is solidificated in the memory of single card microcomputer, thereby accounts for that memory headroom is little, logicality is strong.

3, measuring accuracy height.

Detect camshaft maximum length 1000mm

Detect camshaft maximum weight 40kg

Numeral Abbe head axial stroke 60mm

The horizontal process 1000mm of numeral Abbe head

1 micron of numeral Abbe head resolution

Numeral dividing head resolution 1 second

Measuring accuracy:

Length numeral Abbe head accuracy ± 2 microns.

Angle numeral dividing head accuracy ± 4 seconds.

Generating circle misalignment measurement error ± 1 micron.

Keyway is to cam angle error ± 4 minute.

3 microns of repetitive errors.

Graph of errors plotting error ± 1.5 microns.

Most preferred embodiment of the present utility model:

Metering computer 32 is the TP801 single card microcomputer, anacom 4 is the BCM-3 microcomputer, described angular transducer 13 and rectilinear transducer 14 are respectively garden inductosyn and linear inductosyn, electronic switch 40 in the described synchronizing circuit 25 and 26 selects for use MC14066 chip, driver 41 to select the 74LS04 chip for use, and level match device 39 is selected the MC14504 chip for use.

Claims

1, a kind ofly is used to detect the symmetry of internal combustion (IC) engine camshaft and the detector of asymmetric cam lifting curve, form by the monitor station, metering computer 32, anacom 4 and the printer 5 that have digital dividing head 12, digital Abbe head 1, supporting adjusting bracket 10, plotting apparatus 7 etc., it is characterized in that, described detector only adopts an angular transducer 13 and linear transducer 14 totally two sensors, and the digital display circuit 2 and 3 of described metering computer 32 is connected to synchronizing circuit 25 and 26 respectively.

2, detector according to claim 1, it is characterized in that, wherein said synchronizing circuit 25 and 26, form by electronic switch 40, driver 41 and level match device 39, its input end is through being connected to IORQ, WR and the address decoding mouth end of metering computer 32 central processing units with door 38 and phase inverter 37, and its output terminal is connected on the up-down counter 21 and 22 of digital display circuit 2 and 3.

3, detector according to claim 2 is characterized in that, described angular transducer 13 and linear transducer 14 are respectively garden inductosyn and linear inductosyn.

4, detector according to claim 3 is characterized in that, described anacom 4 also is connected to screen display 6 and floppy disk driver 8.

5, detector according to claim 4, it is characterized in that, metering computer 32 is the TP801 single card microcomputer, anacom 4 is the BCM-3 microcomputer, described synchronizing circuit 25 and 26 electronic switch 40 are selected the MC14066 chip for use, driver 41 is selected the 74LSO4 chip for use, and level match device 39 is selected the MC14504 chip for use.