The internal car noise measurement mechanism
Technical field: the present invention relates to a kind of acoustic measurement device, exactly is a kind of internal car noise measurement mechanism.
Background technology: QCT57---1993 " about the automobile internal car noise method of measurement of at the uniform velocity travelling " strict regulations measure used instrument, condition, method and the measuring point of internal car noise.Instrument comprises microphone (microphone, microphone) and sound meter and the towing cable line that is connected both usefulness.Microphone is placed on the measuring point, and the standard code microphone should point to automobile working direction level and put, and the reading of sound meter promptly is the noise of this measuring point.Measuring point is in the space in railway carriage, the point of being determined by three-dimensional dimension.Standard code should be accurate to 2 centimetres, and that the measuring point number requires is abundant, and one of them must measuring point be the operating seat place.
At least need two people at present both at home and abroad when measuring internal car noise, the hand-held microphone of a people is placed on the measuring point, stops for 5 seconds at least, and another people observes sound meter and does the meter record.Yet standard is also advised for M
1Should not comprise chaufeur and landman in the car when measuring, at this moment be fixing microphone, have to build a framework temporarily or draw cross bar, messenger wire rope or the like more than two people with N class car.No matter microphone is hand-held or working fastening, loaded down with trivial details, effort is discussed for the present, waving of microphone, shake is inevitable, and its survey precision can't satisfy standard code, because involved result is not to be certain measuring point noise, but with this point the dry sound of some points in to be that the three dimensional space at center is general enclose, the ball in this space half through definitely greater than 2CM, most of in the practice greater than 5CM even 10CM, so the take off data comparability is poor.
Summary of the invention: problem to be solved by this invention is when measuring internal car noise, with microphone exactly and be to be securely fixed on the measuring point of regulation.
Design of the present invention is to be attachment point with near the fixed beam existing measuring point in the railway carriage (cross bar or vertical rod), but design an energy clamping microphone, its each annex can rotation on the plane separately, and can be on arbitrary position fix and device relative displacement, this device is fixed on the set rod member, by rotation and displacement, microphone just can be like clockwork along automobile working direction horizontal location on measuring point.
The design of this device comprises bracing frame and the retaining element that is made of two interconnective main supporting rods, adjusts element.Two main supporting rods can be in same plane, also can be not in same plane; Two main supporting rods can connect by fixed type, also can movablely connect, and so-called movable connection is meant: when same plane, a main supporting rod can be around another main supporting rod rotation, and not when same plane, a main supporting rod can be around connecting the quarter butt rotation; At least one main supporting rod change length of can stretching wherein.When captive joint, two main supporting rods are preferably vertically basic or antarafacial is vertical substantially.
The effect of two main supporting rods, a main supporting rod is used for fixing, and by two retaining elements this main supporting rod and whole bracing frame is fixed in the railway carriage on the set rod member; Two retaining elements can be fixed blocks, being used for mobilizable set rod member, also can be stationary clamp, can be clamped in fixing promptly deciding on the rod member, wherein at least one retaining element can be on main supporting rod slide displacement so that impose adjusting according to the particular case of set rod member.Another root main supporting rod is by adjusting element and other annexes location microphone.
Described annex mainly comprises pole, carriage and microphone folder etc.
Adjust element and be positioned on another main supporting rod, can rotate around main supporting rod, preferably can also slide displacement, adjust element and can be slide block type, also can be clamp-type.When the slide block mesopore is through hole, just can be equipped with the bolt of rear end plate location at the main supporting rod top offset.Strut fixation is being adjusted on the element.Carriage is positioned on the pole, can rotate around pole, preferably can also slide displacement.
The microphone folder is installed on the carriage, can install by knob, also can install by a pressure pin, and at this moment the microphone folder is positioned on the pressure pin, and can rotate and displacement.
This device is to use like this, near at first selecting to measure in the railway carriage set rod member is as attachment point, fixed pedestal bridge thereon then, by main supporting rod with adjust the element coarse adjustment to determine point position, the last good microphone of clamping, fine setting by carriage and microphone folder just can be positioned at microphone on the measuring point accurately, securely, and its precision definitely satisfies the requirement of standard code.Result of a measurement accurately and reliably, the take off data good comparability
The present invention is simple in structure, and handling ease is carried installation and operation is very convenient.Only need a landman just can finish like a cork.In addition, can also be processed into the supporting use of series of products, can need measure the automotive use of noise in the car for all according to different automobile types and measuring point design.
Description of drawings:
Fig. 1 is a structural representation of the present invention, and two main supporting rods 1 are connected with 2 antarafacials, vertical fixing formula.
Fig. 2 is two main supporting rods 1 and 2 movable connection structure scheme drawings, realizes fixing by captive nut 9 and packing ring 11.
Fig. 3 is retaining element 3 scheme drawings, and A is the fixed block formula, and B is the geometrical clamp formula.
Fig. 4 adjusts element 4 structural representations, and C is a slide block type, and through hole 8 and bolt of rear end plate 9 are arranged, and D is a clamp-type.
To be microphone folder 7 be installed in structural representation on the carriage 6 by pressure pin 10 to Fig. 5.
Concrete implementation: existing to measure noise is example to measure in the travel incognito car driver's seat top, as shown, is attachment point with two pins of seat upper binding head pillow, and in conjunction with the accompanying drawings, non-limiting examples is described below:
As shown in Figure 1, get tubing process support bridge, the main strut 1 that constitutes support is connected with fixed type, and antarafacial is vertical.Main supporting rod 1 has two fixed blocks 3, wherein fix at rod end for one, another can be on bar slide displacement.The effect of fixed block be with bracing frame be fixed on the headrest under two pins on.The structure of fixed block as shown in Figure 3A, two orthogonal through holes 8 mate a bolt of rear end plate 9 separately.
There is the slide block 4 of adjustment the end of main supporting rod 2, and is rotatable, and is furnished with bolt of rear end plate 9 location.Adjust on the slide block 4 and be fixed with pole 5, carriage 6 is arranged on the pole 5, microphone presss from both sides 7 knob formulas and is installed on the carriage 7.