Basic knowledge of vacuum cleaners
1. Basic structure of vacuum cleaners
The basic structure of vacuum cleaners is divided into five parts according to their functions Parts:
1. Power part: vacuum cleaner motor and governor. The governor is manually controlled and machine controlled.
2. Filtration system: dust bag, front filter, rear filter. According to different filter materials, it is divided into: paper, cloth, SMS, Hypa.
3. Functional part: retracting and releasing mechanism, dust full indicator, button or slide switch.
4. Protection measures: bag-free protection, high vacuum protection, anti-interference protection (soft start), overheating protection, anti-static protection.
5. Accessories: handles and hoses, nozzles, floor brushes, flat suctions, round brushes, sofa suctions, hooks, straps.
Second, working principle
The working principle of the vacuum cleaner is that the vacuum cleaner motor rotates at a high speed, sucking air from the suction port, so that the dust box generates a certain vacuum, dust Enter the dust filter bag in the dust box through the floor brush, connecting pipe, handle, hose and main suction pipe, the dust is left in the dust filter bag, and the filtered air enters the motor through a layer of filter, which is to prevent the dust bag. The cracked dust is sucked into a protective barrier of the motor, and the air entering the motor flows out through the motor. Due to the constant wear and tear of the carbon brushes during the operation of the motor, a filter is added before it flows out of the vacuum cleaner.
The finer the filter material, the cleaner the air can be filtered, but the worse the air permeability, which affects the air volume sucked by the motor and reduces the efficiency of the vacuum cleaner. But for users, comfort and cleanliness is the main thing, so in recent years, filters called “Hypa” have become popular.
Hypa is a foreign name. It is a high-efficiency filter that can block extremely small dust with an efficiency of 99.97%. Its air permeability is low, so it is made into a wave shape to increase the air permeability area. Some of this filter material can also be washed repeatedly. Any filter material has a “life”, that is, the pores of the filter material have been blocked by small particles of dust after long-term use. Therefore, paper dust bags are ideal, which are disposable, hygienic and convenient. The fibers of the cloth filter bag will be hardened after cleaning, which will affect the filtering effect and ventilation effect. The SMS three-layer composite filter material is washable, but the air permeability is slightly lower.
Three. The company’s vacuum cleaner model naming method
In the early stage of the company’s development, it was named JC (Jin Ke) according to three digits.
Handheld 302, 303
Vertical 661, 662
Barrel 981
Horizontal small volume: 861, 862, 863, 865, 866 Larger volume: 871, 872
Some of these products are still being produced by the company, as long as you know it.
By company standard: VC-X-XX XX
Code by structure:
Horizontal vacuum cleaner: represented by the English letter H (horizontal)
Upright vacuum cleaner: represented by the English letter U (upright)
Portable vacuum cleaner: represented by the English letter P (portable)
Special style (cyclone) vacuum cleaner : Indicated by the English letter T (tornado)
Barrel vacuum cleaner: Indicated by the English letter C (container)
Stand type vacuum cleaner: Indicated by the English letter S (stick)
The series code of the horizontal vacuum cleaner is expressed as a common fraction of the total length of the vacuum cleaner, there are 33, 36, 38, 40, 42, 45, 46, 48, 50.
For example: VC-H3301, 3302…3308;
VC-H3601, 3602…3605;
VC-H4801, 4802…4803;
In order to better meet the needs of the market, the company has products that span two structural categories, and the code is represented by two related English
letters, such as: PW: Handheld Cleaning type; PT: handheld with cyclone; UT: vertical with cyclone
4. Main technical indicators of the vacuum cleaner
1. Electrical performance: power supply Voltage: Volts; Frequency: Hertz; Input Power: P1, unit: W.
2. Air performance:
Air volume Q: unit m3/min, hand-held 1.5m3/min, horizontal 2m3/min
vacuum degree Hs unit Pa
Suction power P2 unit W, P2=16.67*10-3HS·Q
efficiency nn=P2/P1*100%
3. Air performance Curve: as shown.
HS: vacuum degree Pa, P1—input power W, P2—input power W
suction efficiency%, Q—air volume m3/min
in air We can see in the performance curve:
HS-Q curve: when the suction air volume (Q value) is getting larger and larger, the vacuum degree (HS value) is getting smaller and smaller, when the HS is small to zero When the air volume reaches the maximum. When the minimum air volume is zero, the vacuum value reaches the maximum value.
It can also be known from the curve that the air volume and the vacuum degree of the vacuum cleaner are a variable during use. The air volume is large and the vacuum degree is small, and vice versa. When the suction port of the vacuum cleaner is completely blocked, the vacuum degree can reach the maximum value. Similarly, when the suction port is unblocked, the maximum air volume is obtained. We usually mean that the vacuum degree and air volume of the technical indicators of the vacuum cleaner should be the maximum value.
P1 curve: It is the input power change curve of the vacuum cleaner. With the increase of air volume (the suction port of the vacuum cleaner is fully blocked to fully open), the input power is gradually increased. This is because when the suction port is fully blocked, there is no Air can be inhaled, and the fan of the vacuum cleaner motor works in a near-vacuum state, so the input power is minimal. When the suction port is fully open, the suction air volume reaches the maximum, and the input power should also be relatively large. There is a big difference between the two, generally 50-150W, and it varies with different types. Usually, the input power of the vacuum cleaner we mark does not refer to the maximum power (that is, the power when it is fully turned on), nor the minimum power, but the average power.
The input power of the vacuum cleaner = (input power when the suction port is fully opened + input power when the suction port is fully blocked) ÷ 2 The power of the vacuum cleaner marked on the nameplate refers to the average power.
Although the input power of the vacuum cleaner mainly depends on the motor power, there are many factors that affect the input power, that is, a 1500W motor will be lower than 1500W after it is installed in the vacuum cleaner, and the range of change is relatively large. The difference between the fully open and fully closed suction ports is also an uncertain factor. Generally, it can be considered that the entire air duct of the vacuum cleaner is not smooth, there is air leakage, and the inlet and outlet air sections are not enough, etc., which can affect the input power. Therefore, the input power of the same specification and the same batch of vacuum cleaners varies in a certain range due to the process conditions of the motor and the production process of the vacuum cleaner. Our company stipulates that a difference of ±15% is allowed. And countries around the world have also stipulated the range of input power variation in safety rules. For example, UL in the United States is ±1015%, and in Europe, it is +15%, and there is no negative.
According to these regulations, as long as it meets the power tolerance range of the designated countries and regions, it is allowed. For example, the vacuum cleaner sold to the United States with a nameplate power of 1500W, the actual product input power can be between 1650W-1275W.
The P2 curve is the curve of the output power of the vacuum cleaner. The output power of the vacuum cleaner is reflected in the degree of vacuum and air volume. Generally speaking, the higher the degree of vacuum and the larger the air volume, the higher the output power. Its calculation formula is: Output power formula: P2=13.67×10-3HSQ (W)
HS: Vacuum degree of the vacuum cleaner, unit Pa,
Q: Air volume of the vacuum cleaner, unit m3/min
During the use of the vacuum cleaner, The vacuum degree HS and the air volume Q change continuously according to the HS-Q curve, so the output power specified in the technical standard is the maximum power, which is the apex of the P2 curve. It is important to note that the maximum output power is definitely not the product of the maximum vacuum degree and the maximum air volume of the vacuum cleaner. You can observe the air performance curve. When the vacuum degree is the largest, the air volume is zero, and the output power is also zero.
η Efficiency, the efficiency of the vacuum cleaner = (the output power P2 of the vacuum cleaner ÷ the input power P1 of the vacuum cleaner) × 100%
Of course, both P1 and P2 are changing, and the efficiency n should also be The vertex of the curve, the maximum value. The efficiency of vacuum cleaners is generally 28%-32%. This is because the air circulation of the vacuum cleaner has great resistance during use, which reduces the air volume. The resistance is mainly the filter system and the air duct inside the vacuum cleaner, and the efficiency of the vacuum cleaner motor itself is about 40%.
V. The speed controller of the vacuum cleaner
1. Speed regulation and interference: In order to make the “suction power” of the vacuum cleaner change according to the requirements of use, configure the governor. The basic principle of the governor is to change the power input waveform, from a complete AC sine waveform in the figure below, the governor uses the change of the conduction angle of the thyristor to make a part of the sine wave (shaded part) cut off and not conduct. The power input to the motor is reduced, the conduction angle is constantly changed, and the shadow part is increased or decreased to obtain the effect of infinitely variable speed.
This kind of governor is simple and reliable, but it brings harmonic interference. Let’s look at the clipped input waveform in the figure below. The shaded part is cut off, and the waveform is no longer smooth, but intermittent “spikes”. These “spikes” lead to pulse waves, which cause radio interference after multiple harmonics. This is the main source of harmonic interference. source. As the waveform changes, so does the magnitude of the disturbance. This kind of interference has great interference to other electrical appliances, especially to electronic appliances. Countries around the world have made corresponding regulations on harmonic interference. We have also developed measures to suppress this disturbance on the vacuum cleaner governor.
2. Soft start: In the chapter of the vacuum cleaner motor, we introduce that the starting current of the vacuum cleaner motor is very large, and its starting current is large enough to cause interference to the household power grid, and the sudden start of large appliances in the home in daily life It will affect other electrical appliances. For example, incandescent lamps will be slightly darker. This kind of interference to the power grid is not allowed in Europe. In response to such interference, a control circuit called soft start is added to the vacuum cleaner. Its basic principle is not. Let the vacuum cleaner motor start suddenly (full voltage start), but when the switch is pressed and the power is turned on, a lower voltage is applied first, and the motor is slowly rotated. It is not very big, and then the normal voltage operation is performed again, which is the so-called soft start.
6. Measurement methods of main performance indicators
1. Unit of vacuum degree:
1 atmosphere=101325Pa= Imperial 406.7 inches of water column = old system 760 mm Hg
If the maximum vacuum level of a general vacuum cleaner is 23K Pa
23K Pa = 23000Pa = imperial system 92.336 inches of water column = old system 172.51 mm Hg Column
Among the above three unit systems, Pa or K Pa is a unit that conforms to international and domestic standards, while British and American countries also use inches of water column. Although mmHg is an old system, it is more convenient to measure at the production site, and it is still circulated within the company within a certain range.
1 Pa is read as 1 Pascal=1N/m2 (1 Newton of pressure per square meter)
1inH2O is read as 1 inch of water column=249.1N/m2=249.1 Pa
p>
1mmHg is read as 1 mmHg = 133.32.1N/m2=133.32 Pa
2. Measurement of vacuum degree
The instruments for measuring vacuum degree have been compared There are many methods, such as U-tube method, vacuum meter method, digital measurement, etc. The U-tube method is commonly used in production, which is more convenient and intuitive, and the maintenance cost of the instrument is extremely low. The U-shaped tube method is to use the principle of a connector to pour an appropriate amount of mercury (mercury) into a U-shaped tube to keep the mercury level in the tubes at both ends. Ascent and descent heights can be read off on the scale.
The vacuum degree H=h1+h2=2h2 mmHg Because the vacuum cleaner is connected to the U-shaped tube, it is equivalent to fully closing the suction port, so the vacuum degree measured at this time is the maximum vacuum degree.
3. Air data test
The picture shows the test method specified by the Chinese industry standard vacuum cleaner, which is mainly composed of pressure equalizing container (pressure equalizing box), vacuum pressure gauge, The air volume measurement is composed of a pressure gauge (Pitot tube) and a regulating valve (not shown in the figure) at the tail.
When the power supply of the vacuum cleaner is turned on and the regulating valve is fully opened, the maximum air volume can be measured, and when the regulating valve is fully closed, the maximum vacuum degree can be measured when the air volume is zero. By adjusting the size of the valve step by step, the vacuum degree and air volume of each valve in the open state can be measured point by point. If a power meter is connected to the power input end of the vacuum cleaner, the input power of each turn-on state can be measured at the same time, and we can draw the relevant air data curves from the table below. Obviously, the more points are distributed and the more detailed, the more realistic the curve will be.
Air Curve Measurement Record Sheet
Measurement Data Unit Data Measurement Method Status
HS: Vacuum Degree Pa Reading Meter
Q: Air volume m3/min Meter reading or calculation
P1: Input power W Meter reading
P2: Input power W Calculate P2=13.67×10-3HSQ(W)
n: Inhalation Efficiency % Calculate n= P2÷P1×100%
Where the output power and efficiency are a parabola, and its vertex is the maximum output power and the maximum efficiency. Therefore, in order to measure more accurately, several points are often measured near the vertex.
3. Determination of the cleaning efficiency of floor brushes
An important indicator of the quality of the vacuum cleaner is the level of vacuuming efficiency. The industry standard stipulates this function as follows: The dust capacity is the ratio of the amount of dust removed by the vacuum cleaner to the amount of dust distributed on the test area during the specified cleaning cycle.
98% dust removal capacity on hardwood floors
65% dust removal capacity on carpets
The test method for dust removal capacity on hardwood floors is : On a 0.7×1 meter smooth test floor, evenly distribute 35 grams of test dust. Turn on the vacuum cleaner, push the floor brush at a speed of 0.5±0.02 m/s, use this mode, take a stroke, make the floor brush walk evenly on the test board, absorb the dust on the test board, and carefully test the test board after stopping. The residual dust on the plate is collected and weighed mr. Vacuuming ability Kb=(35g-mr)÷35g×100%
The test method of vacuuming ability on carpet is basically the same as that of wood board, but practice has proved that the specifications and varieties of carpet have a great influence on the test effect Large, such as general short-pile chemical fiber carpets and plush carpets, the same vacuum cleaner test results are different, plush carpets are not easy to be exhausted, and industry standards do not clearly stipulate this.
The company’s internal control standards will make clear regulations, and we should also pay attention to the specifications of the test carpet in the communication with customers, otherwise it will cause a large error in the test data.
7. Model and ratio of vacuum cleaner motor
The vacuum cleaner motor is a special motor with a series excitation motor and a special impeller, the technical name is electric fan . The impeller and motor of the electric fan are inseparable, and the motor of the vacuum cleaner without the fan blade cannot run.
In the current domestic standards, the motors of vacuum cleaners are all AC power supply, but in actual use, there are vacuum cleaner motors with DC power supply. Here we are discussing the electric fans of AC power supply.
The technical requirements of the vacuum cleaner motor should include:
Motor dimensions
Using power, voltage, frequency
Input power
Output power
Maximum air volume
Maximum vacuum degree
Efficiency
Insulation class
The company’s motor factory for To meet the needs of different types of vacuum cleaners, we have produced vacuum cleaner motors of various sizes, shapes and performances. For easy identification, the motor models are specified, for example:
The shape and structure of the motor are PG, BG, MG, PM, S, etc. represent different core sizes, impellers, external dimensions and motor structures respectively.
The voltage rating and input power behind the model number are easy to identify.
When the shape and structure of the motor are determined, the number of turns and wire lengths of the motor stator and rotor determine the performance of the motor. Small adjustments to the number of turns of the motor stator and rotor will make the motor performance better. Larger changes, for example:
rotor turns via stator turns via power range
PG23-12 19 0.32 125 0.64 1200W
PG23-13 18 0.35 120 0.67 1300W
Obviously, these two motors are indistinguishable not only in appearance, but also extremely difficult to identify even if the internal windings are different, but they are two types of motors. In the actual production of vacuum cleaners, since vacuum cleaners of different specifications have different air duct structures, customers also have different specific requirements. To meet customer requirements as much as possible, it is necessary to make appropriate adjustments to the number of turns of the stator and rotor of the vacuum cleaner motor, and the wire diameter as required. Therefore, the company introduced the concept of ratio or code, and added a code (proportion ratio) after the model of the vacuum cleaner. ), the performance of the motor can be expressed more specifically.
The motor with the appearance of PG, the operating voltage is 230V, and the input power is 1300W. The complete expression of the production order or requirement should be: PG23-13 code 182067
PG23-13 code 18 The meaning of 20 67 is:
Rotor turns: 18 turns;
Stator turns: 120 turns;
Stator wire diameter: 0.67
In the code representation, there is no rotor wire diameter and no specific number of stator turns, such as PG12-11 code 10 65 85, where 65 represents the number of stator turns with 65 turns, not 165 turns. Will this cause confusion? ? The explanation for the above two questions is:
The code must be a basic data rather than a specific process operation specification and technical requirement, and it is not necessary to write it in great detail. For managers who are familiar with motor manufacturing, the code has been expressed clearly enough, because the motor model, such as PG, has determined the chip slot type of the stator and rotor. For the same slot type, it can only accommodate a certain amount of windings. If the wire diameter is thick, the number of turns must only be small. The above code 106585 has a stator wire diameter of 0.85, which can only accommodate 65 turns, not 165 turns. Similarly, the code 182067 must know that when the stator wire diameter is 0.67, the number of stator turns is 120 turns, not 20 turns.
For the same type of rotor chip, the rotor slot shape has been determined, and the rotor turns and wire diameter are complementary to each other. A certain number of turns and a certain amount of wire diameter can reasonably wrap the rotor. That is, there are only how many turns in a certain diameter. In addition, there is a voltage rating on the model. For a 120V motor with the same power, the current is large and the wire diameter is thick. The corresponding 220V motor has a much smaller current and a thin wire diameter at the same power.
So the code for the production management of vacuum cleaners and the communication between departments has been clearly expressed. Of course, in the process specification book of the motor manufacturing department, there are detailed turns, wire gauges, and even equipment adjustment requirements, etc. , in no way can cause confusion.
In the motor design, on the premise that the external size and model are determined (such as PG, BG), and then according to a series of specific technical requirements such as voltage level, power, efficiency, etc., the stator and rotor turns and wire diameters are determined. The calculation process is relatively complicated. Even if the calculation is completed, a large number of experimental verifications of the calculation results are required due to the constraints of specific process conditions and other factors. There is a lot of experience here, so it is necessary to determine a code motor factory. Efforts, so the code of a specific vacuum cleaner motor is an important technical asset of the company.
