Today, we are going to discuss the "Shock Absorber Selection Formula and Selection Considerations [RB SeriesA note on "The
In mechanical design, we often use shock absorbers to absorb impact energy. Since the selection of such shock absorbers can be a bit time-consuming, in this article, I will use SMC's shock absorbers [RB series] as an example and write down the Excel formula and peripheral information that can be used. You can also find the basic calculations of the energy for a collision, so please use it not only for SMC shock absorbers.
Shock absorber selection formula
Here, I would like to explain the formula for shock absorber selection, but there are several shock absorber selection formulas,It was difficult to see if we wrote everything down, so here is a rough flow summary of the selection process, and please see the full calculations in the calculation excel at the end.
Selection sequence for shock absorbers
The same is true for air cylinders, etc,Selection method in which shock absorbers are also evaluated for a hypothetically selected model.The first two are the following.In addition, the selection process for all patterns follows the same flow, which is described below.
- Gather design requirements
- Shock absorbers.tentative selection be just about to
- Calculate impact energy
- Calculate equivalent mass
- Check the graph to see if the tentatively selected model is OK.
The above is the process.The following is a summary of points to be considered when selecting a shock absorber.
Points to note in shock absorber selection
Here.Necessary keywords in shock absorber selection and points to note for themThe following table summarizes the
Maximum absorbed energy (very important matter)
of the collision object.The selection is made so that the total energy does not exceed the maximum absorption energy indicated. And the maximum energy absorbed will be the energy absorbed when the entire stroke is used,Since the capacity of shock absorbers decreases due to wear and deterioration as they are used more and more, it is recommended to select a size with a margin of about 30% of the maximum absorbed energy. It is.
Conversely, if the impact energy is less than 5% of the maximum absorbed energy, the model should be selected one class lower.
Highest frequency of use
The maximum frequency of use set for each model must not be exceeded.
equivalent mass
Selection should be made so that the equivalent mass does not exceed the allowable range due to pulsation in buffer force and deceleration.
impact velocity
Selection is made under the condition that the collision speed does not exceed the specification range, as this will cause changes in cushioning characteristics and damage to the shock absorber.
Cautions when using multiple bottles (items to be checked)
When multiple shock absorbers are used, parallel use does not apply energy evenly.The total energy expended divided by the number of units usedApproximately 1.7 times more energy is applied per unit.Yes, it does. (It seems to take less energy)
![https://mechanical-engineer48.com/wp-content/uploads/2017/06/ショックアブソーバの選定計算式と選定の注意点[RB Series] 1.png](https://mechanical-engineer48.com/wp-content/uploads/2017/06/ショックアブソーバの選定計算式と選定の注意点[RB Series] 1.png)
About collision objects (confirmation required)
When using uncapped absorbers, the hardness of the object impacting the shock absorber is HRC 35 or higher.Also, the collision angle should be less than 3 degrees.
Download Calculation Excel
As explained at the beginning of this article, the shock absorber selection excel is exclusively for the SMC-made absorber model RB series.For other models, only the basic calculation section can be used. In addition, only the horizontal use is currently available as a stand-alone file, while the other files are combined into a single set, so please delete unnecessary items.
*Image may be out of date. Please confirm with the latest calculation sheet.
Shock absorber selection calculation sheet_load cylinder horizontal_191111
RELATED:Shock absorbers
That's it.