Hello. I am Terano, a mechanical designer.
In this issue, the "Examples of NG use of shock absorberHere is a note about "The
In the past, when I was designing automation for an NC lathe, we had a problem with frequent damage to the shock absorber of the loader mounted in the machining chamber.
Although shock absorbers are readily available to absorb impact energy, there are actually many restrictions on their use. In this memo,Main NG use cases learned from the above experience for beginners who have completed the selection calculations and for those whose shock absorbers are frequently damaged. The following is a brief description of the process.
Shock absorbers
Basic structure of shock absorber
To begin with, let us review the basic structure of the shock absorber.
Shock absorbers are largely composed of a piston rod and a cylinder. The cylinder is filled with oil, and when the piston rod is pushed in, the oil gradually drains out through a hole (orifice) in the cross section of the piston. ThisEnergy is absorbed by the friction caused by the oil as it exits the hole. The company is now in the process of
2. Major damaged parts and symptoms
There are certain areas and symptoms that are prone to damage,The two main failure points are It is.
- Rod guide → piston rod sliding failure
- Oil seal → Oil pressure drops due to oil loss
Sliding means to move by sliding.
If the lot guide is damaged, the piston rod is pushed in and will not return to normal operation. On the other hand, if the oil seal is damaged, oil loss will occur and it will not be able to absorb the impact sufficiently.
3.NG Example of use
See you then,Environment and examples of use that result in the above conditions Let's take a look.
NG (1) Environment where the rod is loaded vertically
Shock absorbers are,Since energy is absorbed as the rod is pushed in, it can basically only take an impact in the axial direction. Vertical or diagonal impacts can cause damage to the rod guides and oil seals due to unintended loads.
NG (2) Environment exposed to dust
Rods.If the rod is operated with dust or other foreign matter adhering to it, it may cause rubbing against the rod guide when it is pushed in. and if continued for a long period of time, the rod guide and oil seal will be damaged.
If used in an environment exposed to dust, review the following two points
- Adoption of special products with bellows on the rod
- Consideration of protective covers for rods
NG (iii) Environment exposed to chemicals
Oil seals are made of rubber.Deterioration and oil leakage depending on chemical compatibility causes the
If the product is to be used in an environment where it will be exposed to chemicals, review the following two points
- Oil seal compatibility with chemical solutions is confirmed with the manufacturer.
- Downward mounting of shock absorber body
NG④ Shock absorption of heavy or fast workpieces
When stopping a workpiece with large energy, the reaction force of the shock absorber itself should be notedIt is.
If this exceeds the limit, the workpiece itself may be damaged.If this is the case, the shock absorbing stroke needs to be extended However, many shock absorbers on the market are not,Strokes are determined relative to the energy that can be absorbed, making it difficult to find a convenient one It is. Therefore, a practical measure is to review speed and weight.
NG⑤ Structure that cannot be easily maintained
Shock absorbers are consumables Is. Check the operating times of each manufacturer. Even when used in the best environment, they will need to be replaced after a certain period of time. Therefore,Structure must be designed for replacement The first two are the following.
In addition, there are many cases where structural limitations force us to adopt the NG environment and usage described above. In such cases, tooCritical problems can be avoided if maintenance is easily performed.
On the contrary,Structures that are difficult to maintain often require costly and costly downtime for restoration work, which ultimately leads to major problems It is.
Summary
Although we have introduced the main examples of NG use, there are many cases where it is possible to respond by narrowing down the conditions even in applicable cases. First, contact the manufacturer you are considering. They may be able to introduce you to unexpected solutions or products.
Please refer to the following list of typical manufacturers.
- Koganei (https://official.koganei.co.jp/)
- SMC (https://www.smcworld.com/ja-jp/)
- Fuji Latex (https://www.fujilatex.co.jp/)
- Enidine (https://www.enidine.com/ja-JP/Home/)
Please paste the above URL in the address bar to prevent broken links.
That's it.