Simple anechoic chamber for hub motor vibration and acoustic signal acquisition

Abstract

The utility model discloses a simple anechoic chamber for hub motor vibration and acoustic signal acquisition. The simple anechoic chamber comprises an outer box; the damping block is arranged at the bottom of the outer box; the aluminum plate is arranged at the bottom in the outer box; the inner box is arranged on the aluminum plate; the bracket is arranged in the inner box, and fixing feet of the bracket penetrate through the inner box and are fixed on the aluminum plate; the clamp is fixed on the bracket; the motor shaft and the hub motor are mounted on the clamp; and the acceleration sensor is arranged on the hub motor. According to the utility model, the abnormal sound of the hub motor of the electric vehicle can be measured without a special anechoic chamber. A common anechoic chamber is transformed, the requirements of experiments for sites are better met, and the cost is reduced on the premise that the sound insulation effect is guaranteed.

Description

Technical Field

[0001] The utility model relates to the field of detection anechoic chambers for isolating internal and external sounds, and in particular to a simple anechoic chamber for collecting vibration and acoustic signals of a hub motor. Background Art

[0002] The anechoic chamber is a non-reflective experimental space. The inner wall is paved with sound-absorbing materials with good sound absorption performance. Therefore, there will be no reflection of sound waves in the space, thus achieving the effect of silencing. The anechoic chamber is specially used to test the acoustic performance of the objects under test such as speakers and speaker units. The sound-absorbing materials used in the anechoic chamber are required to have a high sound absorption coefficient. Generally, a gradient absorption layer is used, and a wedge or cone structure is often used. Glass wool is used as the sound-absorbing material, and soft foam plastics are also used. For example, a 10×10×10m laboratory is laid with a 1m long sound-absorbing wedge on each side, and its low-frequency cutoff frequency can reach 50Hz.

[0003] During the production process of hub motors, unqualified products will produce different types of abnormal noises. In order to more quickly determine whether a motor is qualified through vibration and acoustic signals, it is necessary to collect the vibration and acoustic signals of various abnormal motors for storage, and use algorithms to collect and judge signals from products on the assembly line, so that unqualified motors can be found more quickly during the production process for offline processing, thereby improving the efficiency of the production line and reducing some labor costs.

[0004] When testing and collecting abnormal noises from electric vehicle hub motors, common large anechoic chambers cannot meet the experimental requirements. Testing hub motors requires a relatively small space, and the motors need to be fixed and supported for normal operation. The motors placed in the space need to pass three-phase current to ensure simulated normal operating conditions. Large anechoic chambers cannot meet the above conditions. Utility Model Content

[0005] The utility model provides a simple anechoic chamber for collecting vibration and acoustic signals of a hub motor, which solves the problem of measuring abnormal noise of a hub motor of an electric vehicle without a special anechoic chamber.

[0006] The purpose of this utility model is achieved through the following technical solutions:

[0007] A simple anechoic chamber for collecting vibration and acoustic signals of a hub motor, comprising:

[0008] outer box;

[0009] A damping block arranged at the bottom of the outer box;

[0010] An aluminum plate disposed at the inner bottom of the outer box;

[0011] An inner box disposed on the aluminum plate;

[0012] A bracket installed in the inner box, wherein the fixing legs of the bracket pass through the inner box and are fixed to the aluminum plate;

[0013] a clamp fixed to the bracket;

[0014] A motor shaft and a hub motor mounted on the fixture;

[0015] An acceleration sensor is mounted on the wheel hub motor.

[0016] The inner box is located inside the outer box.

[0017] There are four damping blocks evenly distributed at the bottom of the outer box.

[0018] The outer box includes:

[0019] The outer frame consisting of keels;

[0020] and a panel mounted on the outer frame.

[0021] A sealing strip is attached to the joint of the panel and the outer frame.

[0022] The inner box comprises:

[0023] The inner frame composed of keels;

[0024] and a panel mounted on the inner frame.

[0025] Corner brackets are provided between the panels of the inner box for reinforcement.

[0026] Multiple sound insulation layers are sandwiched between the outer box and the inner box. The multiple sound insulation layers are damping plate layers and sound-absorbing cotton layers.

[0027] The inner plate in the inner box is pasted with sound insulation cotton and sound absorbing sponge.

[0028] Further preferred, a simple anechoic chamber for hub motor vibration and acoustic signal collection, including an aluminum plate connected to the motor, an inner bottom plate, two 860mm inner keels, two 680mm inner keels, an inner box composed of two inner box side panels, an inner box top plate, and an inner box rear plate, an outer bottom plate, four 920mm outer keels, three 960mm outer keels, four 830mm outer keels, an outer box composed of two outer box side panels, an outer box top plate, an outer box rear plate, and an outer box front plate, two metal brackets and clamps fixed to the brackets on both sides of the motor shaft with bolts, and four damping blocks; it is characterized in that the anechoic chamber is divided into inner and outer boxes, and the inner and outer boxes are fixed with nails and glue keels to ensure sufficient internal strength, and the middle Multiple layers of sound insulation material are sandwiched between the two boxes to isolate the sound propagation inside and outside the anechoic chamber to the greatest extent possible, ensuring the sealing and sound insulation performance. The openings on the inner and outer box side panels ensure that the wires of the motor and the receiving device can be used normally. The motor shaft fixture and the metal bracket are fixed by bolts and nuts. The motor shaft fixture and the bracket are equipped with several screw holes to ensure that the motor test position can be adjusted in height up and down. The outer box cover adopts an opening and closing design to facilitate the replacement of the experimental motor and deal with various situations during the experiment. The outer box cover is connected to the side panels and the top panel with buckles on all four sides to ensure good connectivity between the cover and the outer box, ensuring the internal sound insulation. There are corner codes between the panels of the inner box to increase the strength of the anechoic chamber. Sound insulation cotton and sound-absorbing sponge are affixed to the inner panel to increase the sound insulation effect of the anechoic chamber. This product retains the sound insulation effect of the basic anechoic chamber, reduces the volume of the anechoic chamber to cope with the situation of testing motors, and makes the experiment more flexible. The inner and outer box design ensures both the strength of the anechoic chamber and the good sound insulation effect of the anechoic chamber. The anechoic chamber and the damping block are fixed with glue. The damping block provides higher shock resistance and dynamic stability for the silent box, thereby improving the measurement accuracy.

[0029] The beneficial effect of the utility model is that it solves the problem of measuring the abnormal noise of the hub motor of an electric vehicle without a special anechoic chamber. The common anechoic chamber is modified to better meet the needs of the experiment for the site, and the cost is reduced under the premise of ensuring the sound insulation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a structural schematic diagram of a simple anechoic chamber for collecting vibration and acoustic signals of a hub motor according to the utility model, wherein 1-outer bottom plate, 2-inner bottom plate, 3-outer box front plate keel, 4-outer box front plate, 5-outer frame, 6-inner box front plate, 7-outer box top plate, 8-outer box rear plate, 9-inner box top plate, 10-inner box rear plate, 11-inner box side plate, 12-through hole, 13-outer box side plate.

[0031] Figure 2This is a schematic diagram of the internal structure of a simple anechoic chamber for collecting vibration and acoustic signals of a hub motor according to the utility model, wherein 14 is an aluminum plate, 15 is a damping plate, 16 is an outer plate, 17 is sound-absorbing cotton, 18 is an inner plate, 19 is a sound-absorbing wedge, 20 is an inner frame, 21 is a detection microphone, 22 is a hub motor, 23 is a motor shaft, 24 is an acceleration sensor, 25 is a fixture, 26 is a bracket, and 27 is a damping block. DETAILED DESCRIPTION

[0032] The simple anechoic chamber for collecting vibration and acoustic signals of a hub motor according to the present invention is further described in detail below in conjunction with the accompanying drawings.

[0033] like Figure 1 and Figure 2 As shown, a simple anechoic chamber for collecting vibration and acoustic signals of a hub motor comprises an inner box, an outer box, two metal brackets 26, and a clamp 25 bolted to the metal bracket 26 on both sides of the motor shaft, and four damping blocks 27. The inner box comprises an aluminum plate 14 connected to the hub motor, an inner bottom plate 2, an inner frame 20 (two 860 mm inner keels, two 680 mm inner keels), two inner box side plates 11, an inner box top plate 9, and an inner box rear plate 10. The outer box comprises an outer bottom plate 1, an outer frame 5 (four 920 mm outer keels, three 960 mm outer keels, and four 830 mm outer keels), two outer box side plates 13, an outer box top plate 7, an outer box rear plate 8, and an outer box front plate 4, wherein the outer box front plate keel 3 is a keel in the outer frame 5.

[0034] The anechoic chamber is divided into an inner and outer box, which are fixed and supported by nails and glue keels to ensure sufficient internal strength. Multiple layers of sound insulation materials (damping plate 15 and sound-absorbing cotton 17) are sandwiched in the middle to isolate the sound propagation inside and outside the anechoic chamber to the maximum effect, ensuring sealing and sound insulation performance. The openings (through holes 12) on the side panels of the inner and outer boxes ensure that the wires of the motor and the receiving device can be used normally. The fixture 25 (motor shaft fixture) and the bracket 26 (i.e., the metal bracket) are fixed by bolts and nuts. The motor shaft fixture and the bracket 26 are both equipped with a number of screw holes to ensure that the motor test position can be adjusted up and down in height. The outer box cover The board is designed to be openable and closable, which is convenient for replacing the experimental motor and dealing with various situations during the experiment. The outer box cover is connected to the side panels with buckles on all four sides, and a sealing strip is affixed to the cover to ensure good connectivity between the cover and the outer box, thereby ensuring internal sound insulation. Corner codes are reinforced between the boards of the inner box to increase the strength of the anechoic chamber. Sound insulation cotton and sound-absorbing sponge are affixed to the inner panels, specifically sound-absorbing wedges 19, to increase the sound insulation effect of the anechoic chamber. The anechoic chamber and the damping block 27 are fixed with glue. The damping block 27 provides the silent box with higher shock resistance and dynamic stability, thereby improving measurement accuracy.

[0035] The aluminum plate 14 of the anechoic chamber is 600mm long, 300mm wide and 30mm thick. Four M10 threaded holes are punched at the four corners of the plate at 240mm and 120mm from the length and width centerline, and 28 M6 threaded holes are punched at 100mm and 20mm from the length and width centerline of the plate and at intervals of 30mm in the long direction.

[0036] The inner bottom plate 2 of the anechoic chamber is 1080 mm long, 980 mm wide and 30 mm thick, and a rectangle of 600 mm long and 300 mm wide is opened in the middle of the plate.

[0037] The two inner keels in the anechoic chamber are 860mm long, 30mm wide and 30mm thick, and the two inner keels are 680mm long, 30mm wide and 30mm thick.

[0038] The two inner box side plates 11 in the anechoic chamber are 860 mm long, 950 mm wide and 10 mm thick, and a through hole with a diameter of 30 mm is opened in the plate at 350 mm and 490 mm from the length and width.

[0039] The length of the top plate 9 in the anechoic chamber is 960 mm, the width is 860 mm, and the thickness is 10 mm, and the length of the inner box rear plate is 940 mm, the width is 850 mm, and the thickness is 10 mm.

[0040] The outer bottom plate 1 of the anechoic chamber is 1080 mm long, 980 mm wide and 30 mm thick, and M12 threaded holes are opened in the plate at 240 mm and 120 mm from the length and width centerline.

[0041] The four inner keels in the anechoic chamber are 920mm long, 30mm wide and 30mm thick; the three inner keels are 960mm long, 30mm wide and 30mm thick; the four inner keels are 830mm long, 30mm wide and 30mm thick.

[0042] The length of the outer box side plate 13 of the muffler is 950mm, the width is 920mm, and the thickness is 30mm. A through hole with a diameter of 30mm is provided in the plate at a distance of 475mm and 350mm from the length and width.

[0043] The length of the outer box top plate 7 of the muffler is 1020mm, the width is 950mm, and the thickness is 30mm. The length of the outer box rear plate 8 is 1020mm, the width is 890mm, and the thickness is 30mm. The length of the outer box positive plate 4 is 1080mm, the width is 920mm, and the thickness is 30mm.

[0044] Four keels are nailed on the inner side of the outer box cover of the anechoic chamber, sound insulation cotton is pasted inside, and sealing strips are added around the keels to increase the sound insulation effect of the anechoic chamber.

[0045] The left end connecting wire of the hub motor 22 in the anechoic chamber passes through the through hole to connect the motor mobile power supply and the motor speed controller, and the right through hole is connected to the detection microphone 21 and the acceleration sensor 24 installed on the hub motor 22.

[0046] The four damping blocks 27 at the bottom of the anechoic chamber bottom plate are 60 mm long, 30 mm wide and 10 mm thick, and the center points of the damping blocks are placed 510 mm and 460 mm away from the length and width center lines of the plates.

[0047] When it is necessary to detect a motor with abnormal noise, open the four-sided buckles on the outer box plate, remove the outer box main plate 4, put the hub motor 22 on the bracket 26 in the inner box, extend the wires out of the box through the through holes 12 on both sides, connect the corresponding motor power supply, extend the detection microphone 21 into the inner box from the through hole 12 on the other side and fix it, turn on the detection microphone 21, and check whether the sound signal can be received. After the equipment is normal, cover the outer box main plate 4, start the hub motor 22, start the computer to connect the output end of the detection microphone 21, start the computer detection software, gradually increase the motor speed to the motor working speed, maintain it for a period of time, then record the signal received by the detection microphone 21, repeat the switch experiment five times, and record the rotation noise of the hub motor 22 under abnormal conditions.

[0048] The specific implementation methods described above provide a detailed description of the technical solutions and beneficial effects of the utility model. It should be understood that the above is only the most preferred embodiment of the utility model and is not intended to limit the utility model. Any modifications, supplements and equivalent substitutions made within the scope of the principles of the utility model should be included in the protection scope of the utility model.

Claims

1. A simple anechoic chamber for collecting vibration and acoustic signals of a hub motor, characterized in that: include outer box; A damping block arranged at the bottom of the outer box; An aluminum plate disposed at the inner bottom of the outer box; An inner box disposed on the aluminum plate; A bracket installed in the inner box, wherein the fixing legs of the bracket pass through the inner box and are fixed to the aluminum plate; a clamp fixed to the bracket; A motor shaft and a hub motor mounted on the fixture; An acceleration sensor is mounted on the wheel hub motor.

2. The simple anechoic chamber for collecting vibration and acoustic signals of a hub motor according to claim 1, characterized in that: The inner box is located inside the outer box.

3. The simple anechoic chamber for collecting vibration and acoustic signals of a hub motor according to claim 1, characterized in that: There are four damping blocks evenly distributed at the bottom of the outer box.

4. The simple anechoic chamber for collecting vibration and acoustic signals of a hub motor according to claim 1, characterized in that: The outer box includes: The outer frame consisting of keels; and a panel mounted on the outer frame.

5. The simple anechoic chamber for collecting vibration and acoustic signals of a hub motor according to claim 4, characterized in that: A sealing strip is attached to the joint of the panel and the outer frame.

6. The simple anechoic chamber for collecting vibration and acoustic signals of a hub motor according to claim 1, characterized in that: The inner box comprises: The inner frame composed of keels; and a panel mounted on the inner frame.

7. The simple anechoic chamber for collecting vibration and acoustic signals of a hub motor according to claim 1, characterized in that: Corner brackets are provided between the panels of the inner box for reinforcement.

8. The simple anechoic chamber for collecting vibration and acoustic signals of a hub motor according to claim 1, characterized in that: Multiple sound insulation layers are sandwiched between the outer box and the inner box.

9. The simple anechoic chamber for collecting vibration and acoustic signals of a hub motor according to claim 8, characterized in that: The multi-layer sound insulation layer is a damping plate layer and a sound-absorbing cotton layer.

10. The simple anechoic chamber for collecting vibration and acoustic signals of a hub motor according to claim 1, characterized in that: The inner plate in the inner box is pasted with sound insulation cotton and sound absorbing sponge.

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