Noise Analysis of Hydraulic Piston Pump

When an engineering machine used in the hydraulic piston pump in operation to issue excessive noise, this is the pump will be damaged symptoms.
Hydraulic piston pump (hereinafter referred to as pump) have the following seven kinds of noise.
⒈ inherent noise pump
The original noise pump is the pump manufacturing technology to the present has not yet reached the “robustness” requirements. On the pump work, the pump spindle every rotation of a week, each pump plunger for a oil to the oil pressure of the cycle. Plunger in the completion of the distribution process of the suction oil, when the cylinder piston hole on the plate from the oil-absorbing plate on the window filled with oil cnc drill after the rotation to the oil discharge area transition, filled with low-pressure oil plunger cavity (See Figure 1, the Kawasaki K3V pump plate with the Japanese plate as an example), high-pressure oil within the oil discharge window from a `secondary pre-booster hole And the triangular throttling groove into the cylinder plunger cavity to increase the chamber oil pressure, the formation of flow intrusion impact (see Figure 2 left). As the plunger pulls out and increases the flow rate of the plunger, the pressure in the cylinder plunger cavity rises to balance the oil pressure in the oil discharge chamber. After the plunger presses the plunger, the plunger starts to move downward Pressure oil into the cylinder with the flow of the window, the plunger discharge oil resistance due to the role of liquid resistance, oil discharge by the system pressure of the anti-impact resistance, cylinder piston cavity pressure overshoot. When the plunger to complete the discharge, the cylinder plunger hole after the spin out of the oil discharge window, into the plate with the flow of the cover area, the cylinder piston cavity is still not part of the emptying of the overshoot pressure Dead volume pressure oil, because the angle of the plate on the angle θ1 obscured area, the plunger still has a compression stroke, so that the cylinder piston cavity of the remaining volume of dead volume pressure oil Steel Beam Drilling Machine more overshoot. When the cylinder plunger bore rotates to the suction window, a pressure relief process (see Figure 2 right) is performed to force the oil pressure in the cylinder piston bore to equalize with the low pressure oil in the suction window. Cylinder piston plunger cavity of the overshoot of the dead volume of high-pressure oil instantaneous pressure release caused by a liquid explosion, this nine plunger cavity of the continuous pressure transient burst is a stable high-pitched sound, each pump There is a high or low liquid waterfall sound. Hydraulic pump manufacturers around the world are in the distribution plate pressure transition area to take various forms of noise reduction unit. From the traditional “triangular throttle slot” to “leak hole” “oblique trench” and other methods, but are still not satisfactorily solve the pump output pressure fluctuations caused by fluid noise. For construction machinery used in the large displacement pressure of the high-pressure pump, dead volume area over-regulation of oil discharge pressure generated when the liquid explosion noise is particularly strong.

angle straightening machine

⒉ cavitation noise
When the hydraulic oil contains the air bubble, the oil with the bubble is sucked into the cylinder bore, the plunger presses the oil in the cylinder bore to press the oil discharge window in the cylinder flow distribution surface. Under the high pressure, the bubbles in these oil will Sudden collapse, the size of the bubble bevelling machine is almost the same concentration of high pressure and then sudden collapse, causing a strong gas explosion, bubble burst generated by another high-pitched noise, will issue a sharp ear-piercing Of the whistle. This sharp-hitting noise varies with the pressure of the pump. When the pump’s output pressure reaches its maximum, the higher the noise decibel, the lower the noise of the pump when the pump pressure drops.
When the pump inhales a small amount of air generated by the noise sounds like a rattling sound, a bit like bearing damage sound. When the pump pressure rises to high pressure, it produces a very strange blow to blow the noise.
⒊ mechanical noise
Pump the main parts of the mechanical noise ⑴ pump shaft and the engine took place at the damaged. ⑵ pump bearing Department.
If the pump shaft and the engine output shaft is not concentric or top dead, elastic connector damage and connector block loosening of the bolts will produce noise.
If it is bearing the sound of damage will be issued continuously buzzing sound. As the speed of the pump increases, so does the noise. Damage to the bearing, the pump will tremble.
Pump mechanical noise is the human ear can hear out, the best way is to run the pump at low speed, with industrial stethoscope or through the screwdriver in the pump parts of the clinic,
⒋ sudden noise
Once the pump has sudden noise, it must immediately stop the pump operation, this situation is the pump parts have been damaged.
Plunger pump plunger plunger piston plunger or broken off, the return disc disintegration. The noise of this phenomenon is a continuous loud noise with one revolution of the pump Hydraulic punching machines. Like someone in the pump body firecrackers. At the same time with the pump P port pressure hose pulsation phenomenon.
But the sudden emergence of noise, the most critical thing is not to allow the pressure of the hydraulic system increases, because the parts of the pump casing fragments of metal slag will be accompanied by pressure oil into the system. Pump sudden noise is terrible, it is not just the pump damage, broken metal slag block, but into the hydraulic system, can not be removed, the hydraulic system caused by the life-long harm.
⒌ pump maintenance after the noise
After the installation of the pump after the installation of the use of noise than the repair before the pump is even larger, the reasons for this happen:
(1) pump suction hose hardening, the installation of the pump, the suction side of the pump hose was substantially swing, so that hose and hard tube at the junction of loose air leakage occurs.
(2) Another is the improper assembly method, double-pump in front and rear (or left and right) two cylinder bore symmetry, there has been resonance noise.
(3) is the replacement of the bearing clearance excessive, the pump bearings are special models and high-precision level (large bearing capacity), can not use ordinary bearings.
(Iv) is the replacement of parts with quality problems, parts with the accuracy level is low, resulting in operating frequency resonance noise.
(V) is the cylinder and the distribution plate between the pair of friction pairs of arc surface bias, resulting in friction between the leakage of excessive oil noise.
(Vi) is a new valve plate with oblique axis pump and the old pump back cover variable sliding arc bias, resulting in distribution plate disc high pressure port and the back cover of the high pressure area plane leakage, air damage noise. The same fault and noise can be seen on the rear side of the new plate plate and the pressing area of ​​the old pump back cover.
⒍ replace the hydraulic oil pump noise
This noise is the new replacement of oil in the air is not fully escape, when the pump into the bubble of the bubble, the pump at the exit of the high-pressure effect, these bubbles will suddenly burst pressure caused by gas waterfall sound, the other The reason is the new replacement of poor quality hydraulic oil, storage for a long time, the defoaming additives in oil oxidation or oil in a variety of chemical additives are not compatible with the adverse reactions arising from the elimination of oil in the air effect.
Any brand of mineral hydraulic oil contains about 10% of the air. This air is in two ways exist in oil pressure, one is the existence of bubbles in the form of oil, the other is dissolved in the form of molecules in the liquid, is not visible. The volume increase of the liquid is not obvious.
7, the gradual noise
(I) the pump in the long-term use of the process, the noise from small to large. Is the distribution plate and the cylinder with the flow surface of the wear and tear, the flow plate with the cylinder and the cylinder surface is static pressure oil film balance, hydrostatic oil film containing metal particles such as when there will be erosion and erosion, long-term erosion and wear will A certain width worn area is formed on the arc surface of the flow distribution disc, and the curve curve of the inner and outer windows of the flow distribution window is changed, resulting in the process from microleakage to extra large leakage, and the throttle noise is also small to strong.
(2) the pump suction side of the hose aging, the air from the hose and the hard pipe connection was inhaled, air leakage from zero to micro-leakage and then to a process of over-leakage, pump inhaled air caused by “cavitation” This noise is small The noise increases with the extension of the working time.
Some people think that the pump suction port side of the pipeline does not leak, there will be no air infiltration, which is a wrong understanding. From the principles of fluid mechanics and atmospheric pressure, when the pump does not work when the pump suction side and the pressure difference between the atmosphere is zero, the pump suction pipe in the liquid flow is not in balance, no oil leakage. When the “variable pump” in the work, the pump suction pipe in the fluid flow rate is fast time and slow state. When the “variable characteristic” of the pump determines the pump’s swing angle changes instantaneously from zero degrees to the maximum angle, the flow (liquid resistance) in the pump suction pipe can not meet the requirement of the pump in the time difference from the quiescent state to the fast flow state Demand, then produce a very large siphon phenomenon (that is, the civil power). Pump suction mouth occurs when the phenomenon of force, it will be from the hose and the junction of the hard tube into the air and cavitation phenomenon.
When the flow rate in the pump suction port pipe exceeds the standard (the international standard for the steady flow state 0.5m / s, the absolute pressure of not less than 0.8bars [1], the reality of the pump side of the flow rate of up to 2. M / s turbulent flow state). The pump suction side will be below the atmospheric pressure is negative, then there will not be enough pressure to accelerate the flow into the pump rotating components, it will produce siphon phenomenon, the pump as long as the siphon phenomenon, that the life of the pump is to life.
8, cavitation noise hazards
In the operation of the pump, if the local area of ​​the flow-through portion (which is the pressure outlet of the pump) is, for some reason, the absolute pressure of the pumped liquid is reduced to the vaporization pressure of the liquid at that time, the liquid begins to vaporize there, A large amount of steam, the formation of bubbles, when a large number of bubbles of liquid flow through the cylinder outside the high-pressure area of ​​the flow window, the bubble around the high-pressure liquid bubble causes the bubble sharply reduced, these bubbles are suddenly broken pressure, this process will produce high temperature. According to the calculation, when the bubble is compressed from zero pressure to 3000Psi (207Bar), the temperature can be increased to 1149 ℃. [2] The high temperature causes the oil combustion, produces the resinous material, and causes the oil to oxidize quickly the degeneration main reason.
At the same time the bubble collapses, the liquid mass fills the hole at a very high velocity, producing a very strong impact at this instant and striking the metal surface with a high impact frequency drilling machine, the impact stress being several tons per square inch The release of energy from the breakage of a hole would “erode” the metal surface, just as the sculptor used a hammer and a chisel to carve a stone. When such a hydraulic shock occurs in the metal plate side wall, the bubble burst into the cylinder wall when the pressure instantaneous maximum, the resulting local hydraulic impact on the metal surface erosion effect. So that the surface of metal parts gradually formed pockmarks. Serious, it will make the metal surface of small pieces off, there small pits (see Figure 3 Figure 4), this phenomenon is called cavitation. If the long-term cavitation, pump life will be shortened.
Cavitation fault diagnosis method:
(I) When the pump is in a high pressure state, it is used to hold the pump high-pressure glue pipe surface, and sense whether the liquid in the pipeline is vibrating when flowing.
(2) When the pump is in a high-pressure state, in the pump suction port side of the pump shell to hear whether the flap of the explosion noise.
(3) open the hydraulic tank fuel tank cover, the size of the excavator arm stretched flat, the bucket from the ground quickly rise to observe whether the oil inside the tank a large number of bubbles escape.
9, concluding remarks
Any kind of noise, the pump is hazardous. As long as there is excessive noise pump, it is necessary to repair the pump, do not wait until after the failure of the pump completely repaired, then the loss may be too large.

Toughness and Wear Resistance of High Speed ​​Steel Cutters

High-speed steel milling cutter generally do not do tensile strength testing bevel machine, and to metallographic, hardness test-based. Tungsten and molybdenum high-speed steel milling cutter after the correct heat treatment, Rockwell hardness can reach 63 or more, high-speed steel cobalt in more than 65. Acid leaching of steel should not be visible macroscopic shrinkage, turning the skin. Center loose, generally loose should be less than 1 level. Metallographic examination includes the decarburization layer drilling machine company, microstructure and carbide non-uniformity of the three projects.

1.High speed steel milling cutter should not have obvious decarburization. Microstructure must not have bone-like eutectic lathite exist.

2. High-speed steel milling cutter in the uneven impact on the quality of the largest carbide, the current metallurgical and mechanical sectors of the degree of uneven carbide attaches great importance iron worker tools. According to the different uses of steel carbide unevenness can be put forward different levels of requirements, usually less than 3 levels.

3. The use of high-speed steel cutting tools, in addition to its high hardness, high wear resistance and adequate toughness, there is an important factor is the red hardness.

Characteristics of co – closed closed precision punch machine

1. Superior plan, high-rigidity three-stage punch body, 4 2 times the nominal force of the pre-tightening rod, locking by the high-pressure oil lock, stable shape, high precision control of the bottom dead center precision, and as long as the custody Department of hydraulic pressure can play card mode. 2. 4 points support the crankshaft, the support point near to avoid the crankshaft force deformation, and precision can be adhered to, the fulcrum and connecting rod are applied to import heavy duty fine rolling bearings, the gap is minimal, argue that force is very small, Block not only the death of the shock and greatly reduce the debate that fever, reduce deformation energy consumption.

3. Equalization of audio equipment, set aside the weight of the weight of the audio balance display can be low consumption back and forth movement produced Hongyuan inertia angle drill machine, vibration is minimal, 4. Slide guide system, take the above large double guide column, the top four circular static pressure guide column, large guide column can suck rod movement lateral force and can withstand a larger mold upward preference load, 4 round static guide column High precision, good orientation, strong anti-bias technology and can be symmetrical row of stamping produced by lateral anti-induced force. 5. Stress cycle smooth furnishings, after a strong motor smooth all the movement of machine parts, to avoid wear. In order to avoid heat on the impact of product quality, configuration cooling oil circulation equipment. 6. Preferred axis plan, adopt high-strength alloy steel, heat treatment hydraulic busbar cutter, grinding, far more than the general crankshaft plan, CNC punch presses can withstand greater technical output and stable shape. 7. Rib hydraulic locking device beveling machine, the application of high-pressure oil lock, remove the mold-rib clearance, guarantee the accuracy of movement back and forth.

Co-forging precision forging press, spinning Spinning

Co-forging precision forging press, spinning Spinning is the common rotation of the slab and mandrel drilling machine manufacturers, the pressure from the roll wheel and the pressure, so that slabs close to the local deformation of the core point by point of the stamping process. Spinning principle Spinning can produce a variety of axisymmetric rotating parts cnc plate drilling machine, such as loudspeakers ﹑ ﹑ ﹑ pressure vessel head closure gongs; can also be used for closing the cylinder ﹑ ﹑ tube forming angle steel open. Spinning is characterized by: small deformation force can be formed with a large workpiece; use of equipment is relatively simple, small and medium size sheet metal parts can be used ordinary lathe spinning; mold is simple, only a core mold, material requirements low.

Spinning applies to small batch production, because it can only rotate parts of the body, the limitations of large, low productivity. Spinning can be used special machinery, the use of copy spinning and digital control spinning. Spinning at the same time the thickness of the thinning process known as thinning spinning, also known as strong spinning, used for processing cone-shaped pieces of thin-walled, etc., can also be used to spin a large diameter deep Tube, and then cut open after the plate.

Co-forging precision punch use IPM precision punching equipment

Co-forging precision punch use IPM precision punching equipment is widely used in home appliance manufacturing, automobile manufacturing, electrical and electronic manufacturing, medical equipment, lighting, connectors, terminals, shrapnel and all kinds of hardware products. Using high-grade, high-strength cast iron to create. To ensure the accuracy of the product drilling equipment companies, we are applying for a patent, I believe in the near future, we can artificially limit the maximum natural mechanical wear and tear.

IPM PRECISION PUNCH As the manufacturer of punch press Angle Steel Punching Machine, we aim at improving the stamping technology capacity, customer first and sincere service as our business tenet. We are adhering to the meticulous and meticulous work requirements of fine workmanship, strict quality and continuous improvement. Each IPM machine cnc drill machine. To innovation, sincerity of the business philosophy, service to our customers.

professional punch manufacturer sieve plate machine

Co-forging precision presses, high-quality presses, Foshan Punch IPM insists on the quality policy of ‘quality and service’ automatic punching machine, continuously improves the quality consciousness and quality level of the whole staff, confirms the quality target and the principle of compliance, and ensures the advanced position and reliability of IPM precision punching machine in the market competition busbar machine. The company produces high-quality presses, low-cost presses, IPM – Foshan punch is your trusted professional punch manufacturer sieve plate machine, please call to discuss:

On the domestic punch technology to be improved 10 years in the world

On the domestic punch technology to be improved 10 years in the world is still in the bubble burst after the false alarm, our country has won two consecutive ‘world first’. First, the car yield reached 13.7 million cnc drill, the ‘world first’ is usually considered to be the symbol of access to industrial countries. Second, China’s punch industry output value of 401 hydraulic press.4 billion yuan, the first time the world’s first big punch into the country. The car went down the assembly line of the factory. Those used to polish the parts, assembly of various colors of the car is a great machine, is the punch. Punch also known as machine tools.

Marx once said that the machine tool is the starting point of the eighteenth industrial revolution. The industry has this argument, saying that China’s manufacturing is ‘polished goods’, made in Germany or Japan, is known as ‘manufacturing plant’. The implication, the level of industrialization progress and occlusion, in the punch of this industry ‘machine’ production capacity Beam Sawing Machine, who holds the bull? 2002 so far, China’s first 10 years of light for the first punch and the largest importer of large countries, punch into the super-business there are billions of dollars. This means that, despite the large capacity of our industry, but in fact or ‘armed themselves’. Today, China’s ‘world polishing factory’ has been to upgrade the final restructuring of the teeth, not only to be able to polish the goods, but also must be able to ‘manufacturing plant’. The first demand to climb the ‘threshold’, is the punch.

Talking about the Development Trend of Press In the severe economic environment

Talking about the Development Trend of Press In the severe economic environment, non-cutting forming is a powerful means to win the competition and distance between enterprises and competitors, and environmental protection is the theme of the 21st century, as environmental protection processing methods will be the main direction of development. High-precision, high-value form-free forming is essential for cutting angle iron drill. In order to achieve these requirements, it is necessary to understand the overall process from material to finished product. Punch on one of the important technical elements. Punch the basic characteristics and developed in recent years applicable to a variety of forming technology, high-precision multi-function punch direction of development. There are two main characteristics of a punch, one is rigid, which includes the longitudinal stiffness of the slider and table arch and the elastic elongation of the frame; and lateral stiffness under the influence of the eccentric load of the horizontal displacement of the slider. The second is the movement of the slider characteristics, including the vertical, parallelism, straightness, etc., have a great impact on the accuracy of the product.

The accuracy of the product is not only with the punch, and materials, molds, lubrication and so on custom processing machine, can not only consider a certain factor. The accuracy of the thickness direction of the product is related to the longitudinal rigidity, while the deviation, bending or parallelism is related to the transverse rigidity and the characteristics of the motion profile. So to improve these characteristics, product accuracy can be improved, die life extension, production stability can be improved. Universal punch high rigidity, high performance: the original general-purpose machine C-shaped punch is also the pursuit of high-precision, high performance, which developed an integrated gantry punch; with AIDA connecting rod drive mechanism and near the bottom dead center speed Slow and SPM unaffected rod presses. The connecting rod presses the two eccentric connecting rods between the drive gear and the crankshaft hydraulic punching machine. When the driving gear rotates, the crankshaft does not move at a constant speed due to the change of the connection angle of the connecting rod. Unlike the other link mechanisms, the link mechanism has a small number of connection points of the pressure receiving portion and a small integrated gap. As shown in Fig. 8, the connecting rod mechanism has a higher torque capacity than the toggle mechanism, and can be formed at a higher dead center position.

IPM pneumatic punch, the mold should be safe operation

IPM pneumatic punch, the mold should be safe operation First, the work before the pneumatic punch press the power button to open the first off, not a sudden start, stop 5 minutes check the content: 1), check the punch health iron Marking Machines, table clean no debris. Hydraulic press, pneumatic presses, hydraulic presses, C-hydraulic machine 2), check the machine lubrication system, mechanical system is normal shearing machine. Hydraulic press, pneumatic presses, hydraulic presses, C-hydraulic machine 3), check the clutch, the brake is flexible and easy to use, foot pedals, rods, pressure plate, screws and the operation of the device without loosening.

Hydraulic press, pneumatic presses, hydraulic presses, C-hydraulic machine 4), check whether the mold head fracture, die is bang bite, limit column is loose. Hydraulic press, pneumatic presses, hydraulic presses, C-hydraulic machine 5), clean mold chest. Hydraulic press, pneumatic presses, hydraulic presses, C-hydraulic machine 6), check whether the stamping die and the pressure plate is installed firmly marking machine, punch whether the batter situation. Hydraulic press, pneumatic presses, hydraulic presses, C-hydraulic machine 7), check the electrical grounding line intact, tubing smooth without clogging, no rupture. Hydraulic press, pneumatic presses, hydraulic presses, C-hydraulic machine

The future market demand of punch press and the development direction of punch press manufacturer

The future market demand of punch press and the development direction of punch press manufacturer China’s largest punch as one of the countries machinery manufacturing, but most of our factories are produced by the equipment are some no-name products, technical content and other brands of punch equipment compared to a relatively large difference, not in the same level , Fortunately, as China’s technology matures, the gold content of the equipment is also getting higher and higher, such as China’s Taiwan region, such as punch Jinfeng punch, in terms of performance and price has been an international leader, with some of the traditional Punch the gap between enterprises is also growing.


Some middle and low-end enterprises in order to survive in the fierce competition which should be more equipment to upgrade the processing Steel Punching, the latter part of the development of enterprises and equipment needs not only by a certain aspect (such as price) decision, more enterprises Procurement of equipment will be conducted when an integrated study, cost-effective products is the focus of future business direction of choice. For precision punching production enterprises, to enhance their product accuracy and equipment life and the quality of products stamping out is the focus of future development steel straightening machine. The ability to grasp the needs of market customers to carry out product sales Companies specializing in the provision of high-quality precision punching equipment bus bar bender, products widely used in the manufacturing industry, machinery industry, and so on a number of areas. High-quality products and perfect after-sales service is fundamental to our survival, the punch press recently in a series of international press exhibition and the corresponding press appraisal activities have gained a good reputation and market influence.

Changes in the market demand for change in customer interest points are also changes in time, the company believes that we provide the equipment can be targeted to meet the needs of all sectors of the customer. We will provide the latest and highest development technology; accurate and precise production technology; accurate and rapid sales? Services, to improve the world’s customers the production capacity and production efficiency and make unremitting efforts.