Previously, I introduced the mechanism of operation of gas blowback airsoft guns, specifically the slide and bolt.
This time, we will explain the operation of the remaining parts, from the trigger on the chassis to the hammer mechanism.
These mechanical components are almost identical regardless of the type of gas used, such as HFC-134a or CO2, if it's a gas blowback system, and are basically the same for handguns and rifles.
Well, even with handguns, there are various types such as single-action, double-action, and those with or without a decocking function, but the basic principle of firing a bullet is the same.
For the sake of clarity, this time we will be using the striker-fired system (hammer-fired single-action in gas blowback systems) as an example.
First, before explaining the trigger and hammer, I'll explain the crucial mechanism of the magazine.
*This article aims to provide educational explanations from a mechanical engineering perspective regarding the safe hobby use of airsoft guns.
This does not promote acts of violence, the use of weapons, weapon modification, practical evaluation, or violation of laws and regulations.
Magazine for gas blowback airsoft guns
First, let's look at the operating principle of the magazine from the perspective of its firing function, which is crucial.
This is the back of the magazine.
The golden part at the top of this magazine is called a valve. When you press the valve, gas is released, and when you release it, the gas release stops.
This is what it looks like from the top of the magazine.
The gas outlet is connected to the nozzle hole on the slide that I previously described, and the gas is supplied to the slide.
Let's remove this valve and examine it.
When the valve is pressed, it operates as shown in the following picture and the lid opens.
When you release the pressure, the spring built into the valve moves the lid in the closing direction.
When viewed in a cross-sectional view of the magazine, this operation controls the release of gas using the following mechanism.
Here is something I would like you to understand.Pressing the valve opens the lid and releases the gas; releasing the valve closes the lid and stops the gas release.
This is something that will become important later, but these types of magazines are equipped with a safety device to prevent the muzzle velocity from being too high.
The safety device works as follows: if the gas pressure becomes abnormally high due to some factor, the load required to push the valve that opens the lid increases due to the pressure, so the lid will not open with the normal load and the device will not operate.
By utilizing these characteristics and appropriately setting the force required to press the valve, a mechanism is created to prevent the release of high-pressure gas, thus preventing illegal initial velocities.
If you're interested, you can easily try this experiment with a magazine you already own.
First, try pressing the valve with your finger when there is absolutely no gas inside. You should be able to press it with very little force.
Next, put just a tiny bit of gas into the magazine and press the valve with your finger. You should notice that the valve has more resistance compared to when the magazine is empty.
In other words, the force required to release the magazine valve increases in proportion to the pressure inside the magazine.
Therefore, please rest assured that it is normal for an airsoft gun to malfunction in high summer temperatures, when the magazine becomes too hot, or when improperly compressed gas is used. This is proof that it is functioning correctly.
However, you should absolutely never modify your valve in a way that abnormally increases the force it applies to, resulting in an illegally high muzzle velocity..
Of course, it will function normally once the appropriate gas and temperature are met.
This covers the magazine knowledge necessary to understand how it works.
Required functions around the trigger and hammer
Based on our knowledge of the slide, bolt, and magazine mechanisms so far, let's consider the functions required around the hammer.
The functions required around the hammer are quite simple, consisting of the following two points:
1. Press the magazine valve with the appropriate force at the appropriate time to release the gas.
2. Stop pressing the magazine valve at the appropriate time to stop the gas release.
Let's keep these two functions in mind as we consider this.
Furthermore, airsoft guns have unique and interesting requirements; they also need to have model-like elements, so they must be as similar to the mechanisms of real guns as possible within the limits permitted by law.
With that in mind, let's look at each of the main components and their functions.
Trigger, hammer, and surrounding main components and functions
From here on, let's set aside the overall movement for now and look at the main components and functions.
Trigger, trigger bar
First, the trigger and trigger bar convert the user's intended timing into mechanical movement (converting finger movements into mechanical actions).
This is a simple part that you're probably all familiar with: when you pull the trigger, the trigger bar moves. Conversely, when you release the trigger, the spring returns the trigger to its original position, and the trigger bar returns to its original position as well.
We use the movement of this trigger bar to manage the appropriate timing.
hammer
Next up is the hammer.
This part's function is similar to a trigger; its main role is to control the timing of striking the magazine valve.
To be precise, it also has the function of pressing the magazine valve, but it's a part that is primarily focused on fulfilling the requirements of a model.
This hammer, as a single component, falls when pressed (like cocking the hammer in a gun), and immediately rises again when released due to spring force (like decocking the hammer in a gun).
There is a component called a shear that allows this movement to be controlled by a trigger.
Sheer
This part called the sear has two functions: it physically holds the hammer in place when it falls (cocking in a gun) to prevent it from immediately rising again (cocking in a gun), and it releases the hammer when the trigger is pulled.
The orientation has been reversed, so the right side of the photo is the front (muzzle side), and the left side is the rear.
This component on the board is called a shear.
To explain how this part works, first, the hammer is held in the down position as follows (the cocked position in a gun).
This works in much the same way as a latch mechanism, with a notched circle on the hammer. A protrusion on the sear catches on this notch, holding the hammer in the cocked position (the cocked position in a gun).
Next is the action when the hammer is released.
By moving the sear backward using the trigger bar, the protrusion that locks the hammer also moves, releasing the lock, and the hammer cocks up due to the force of the spring (in gun terms, the hammer returns to its original position: decock).
To describe the action in words
These five processes work simultaneously, allowing the user to cock the hammer (or return the hammer to its original position, as in a gun) at their preferred timing.
For reference, I've included a video of it in operation. Please pay attention to the moving parts.
A video showing the hammer being locked (the hammer in the cocked position).
A video showing the hammer being released (the hammer returning to its original position: decock).
From the explanation so far, you should understand that it's possible to move the hammer at the right time, but this hammer movement alone cannot press the magazine valve, which is a crucial required function.
Therefore, I will now explain the knocker, or valve knocker, which is an important part for pressing the magazine valve.
Valve knocker
First, the basic function of the knocker is to press the valve in the magazine, so it has the following shape.
The left side of the picture is the front (muzzle side), and the right side is the rear.
A knocker viewed from the back
Let's look at the operating principle of this knocker.
This knocker essentially works by being pushed by the hammer, which in turn pushes the valve in the magazine.
First, when the hammer is down (cocked, in gun terms), the knocker is held in a retracted position by the knocker spring.
In this state, the knocker is in the retracted position and is not touching the magazine valve.
Next is the movement of the knocker when the hammer is released and the knocker is decocked (like the hammer returning to its original position in a gun).
When the hammer rises, the knocker, being in contact with the hammer, is pushed forward by the hammer.
The knocker moves forward, making contact with the magazine's valve, and pressing the valve releases the gas.
In this way, the knocker moves in conjunction with the hammer's movement, striking the magazine's valve and releasing the gas.
A video demonstrating the operation of a hammer and knocker.
UMAREX/VFC VP9 Hammer-driven knocker advancement
As many of you have probably already noticed, the knocker moves forward when pushed by the hammer, so the force that pushes the magazine valve depends roughly on the load of the hammer spring (in reality, the lever ratio due to the shape also plays a role).
SoIf the hammer spring is weakened to improve operability, it may not be able to fully depress the magazine valve and therefore not operate. Conversely, if the hammer spring is made too strong to depress the magazine valve strongly, operability may be compromised, and it may even operate with illegal high-pressure gas.
Therefore, it is necessary to consider the overall balance when determining the strength of the hammer spring.
The components up to this point constitute one of the required functions.It fulfills the function of releasing gas by pressing the magazine valve with the appropriate force at the appropriate time.
With the component configuration described so far, when the hammer falls again (cocking, as in a gun), the knocker returns to its rearward position due to the spring.
This is where a problem unique to gas blowback airsoft guns arises (this is not a problem with real firearms due to the large and rapid burning force of the gunpowder).
I'll explain this in more detail later, but when the blowback is activated, the hammer is pushed down by the slide (this is called the hammer cocking in a gun).
In other words, with only the functions described so far, gas is released only for a short time, from the moment the hammer cocks up (in gun terms, when the hammer returns to its original position: decock) to the moment the hammer is pushed down by the slide (in gun terms, when the hammer cocks up: cock).
However, depending on the slide, the blowback may not be completed in the short time it takes for the hammer to cock (or, in airsoft terms, for the hammer to return to its original position: decocking) (most airsoft guns do not complete the blowback in such a short time).
Furthermore, if the knocker fully retracts in conjunction with the hammer, the gas release from the magazine stops, and since the gas power source is not supplied even though the blowback has not finished, the blowback becomes very weak, and the product's marketability is significantly diminished.
Therefore, a mechanism is needed to prevent the knocker from returning to its rearward position when the hammer is cocked (or, in gun terms, when the hammer returns to its original position: decock).
However, if the knocker continues to hold its forward position even after the hammer has been cocked (decocked, as in a gun), the gas will not stop being released, making normal operation impossible.
To put it in extreme terms, if the knocker doesn't return to its original position, a single hammer action will continuously press the gas valve in the magazine, releasing all the gas in the magazine and preventing the blowback from working.
Therefore, a mechanism is needed to prevent the knocker from returning to its rear position when the hammer cocks (decocking, as in a gun), while simultaneously ensuring that the knocker returns to its rearward position at the appropriate time, independent of the hammer's movement.
Knocker lock, knocker lock spring
The parts that perform this function are the knocker lock and the knocker lock spring.
Since it's difficult to understand, if we draw it out in a picture, it will have the following shape.
Let's take a look at how this knocker lock works.
First, let's look at the hammer in the down position (the cocked position in gun terms). When the knocker is in the retracted position, the knocker lock is lowered as shown in the following picture.
The left side of the picture is the front (muzzle side), and the right side is the rear.
Next, as the knocker moves forward, the force of the knocker lock spring lifts the knocker lock, causing the projection to engage with the groove in the knocker, fixing the knocker in the forward position (while gas is being released).
Next, when the hammer is pushed down by the slide (cocked, as in a gun), the knocker will not move backward because it is locked in place by the knocker lock pin (while gas is being released).
So how do you return the knocker to its original position? To do this, press down on the knocker lock from above as shown in the diagram, and the lock will be released. The force of the extended spring will then return the knocker to its original position (gas release stop).
If you put this action into words...
will be important.
When you see the actual movements in the video...
The knocker moves forward and the knocker lock rises.
UMAREX/VFC VP9 Knocker Advance
Even if the hammer falls (or, in gun terms, the hammer cocks up), the knocker does not retract.
Press the knocker lock and the knocker will retract.
UMAREX/VFC VP9 Knocker Lock Release, Knocker Retraction
This is the sequence of events.
Simply put, it's a mechanism that delays the knocker's recoil relative to the hammer's movement.
What I personally find interesting is that it seems to resemble the chamber closing mechanism (barrel recoil delay mechanism) of a real blowback system, which I found fascinating.
The function of releasing the knocker lock by pressing it is controlled on the slide side.
The knocker's retraction timing is controlled by providing a groove of appropriate length and depth in the slide for the knocker, which protrudes from the frame.
The hammer cocks (or, in airsoft terms, the hammer returns to its original position), and blowback begins.
The moment the hammer falls due to the slide's blowback action (in gun terms, the hammer cocks up).
The end of the blowback
This mechanism fulfills the second required function.By stopping pressing the magazine valve at the appropriate time, you can achieve the goal of stopping the gas release.
In other words, The timing of the gas release is left to the hammer (user timing), and the timing of the gas release is controlled by the movement of the slide. This mechanism allows the operation to start at the user's timing and continues to release gas until the blowback, which is unrelated to the user, has completely finished.
Incidentally, when you slowly manually return the slide of a blowback airsoft gun, you may feel a catching or resistance sensation. This is mostly due to the force applied to the slide as it presses down on the knocker lock.
Therefore, the sticking or resistance you feel when slowly moving the slide, which is often a source of concern, is actually a sign of normal operation. In fact, if there is absolutely no sticking or resistance, it is highly likely that the knocker lock and other functions are broken.
Also, during cold winter months or when the gas level is low and the pressure is low, the blowback may be incomplete, and the slide may not fully release the knocker lock, causing all the gas to be released.
The reason is that the slide doesn't move far enough to push in the knocker lock, so the knocker remains protruding and continues to press against the magazine valve, causing all the gas to be expelled.
Summary of parts introductions
The rear chassis is responsible for holding the necessary parts for the gas blowback system, as described above, in the correct positions.
The actual object has the following shape.
The left side of the photo is the front (muzzle side), and the right side is the rear.
Other side
By assembling the components into this rear chassis, each component will be able to operate in a way that fulfills its required function.
It's on the opposite side.
This is a view from above.
This is what it looks like from below.
This rear chassis assembly is the part that fulfills all the functions I've explained so far.
If you're interested, it might be fun to imagine how each part moves while looking at the rear chassis assembly.
Summary
Now that you understand the movement of each major component, let's look at the overall movement of the trigger and hammer assembly step by step.
This state is equivalent to a "cocked" state in firearms (the hammer is down). It's almost the same as what's known as "cock and lock."
The right side of the picture is the front.
The left side of the picture is the front (it is a reversed version of the picture above).
The image is reversed again, so the right side is now the front.
This time, the left is the front.
In the actual operation described so far, each component operates almost simultaneously, completing the task in an instant.
The slide's blowback action begins at approximately this point.
This is how the trigger and hammer work.
This article has become quite long, but I wrote it this way because I thought reading it all in one go would deepen your understanding.
The operating time is only a moment, but in that brief moment, a variety of functions are packed in by many mechanisms.
It's difficult to understand because it has so many functions, but using systems engineering methods, I've carefully broken down each function, even those that actually operate simultaneously, and arranged them in the order they run.
Incidentally, the shapes of the parts introduced here are just examples, and not all bookbinding is the same, but there are always parts with similar shapes that perform the same function, so it can be fun to think about them while looking at long parts as a way to practice your thinking.
Also, although this is unrelated to airsoft, one advantage of machinery is that even with a small number of parts, many functions can be performed simultaneously by combining them.
In some cases, they may possess useful functions that humans are unaware of.
This is one of the advantages of machines, or analog systems.
However, a drawback of machines and analog systems is that it can be difficult to add new functions to a machine once it has been designed.
Conversely, popular programs and AI, unlike machines, will produce errors unless every single action, no matter how minute, is programmed (this makes the programs long and tedious to write, and also makes them prone to omissions and errors, making it difficult to find and fix mistakes (bugs) compared to machines).
Furthermore, due to its design, it can run multiple programs simultaneously, but since it basically processes step by step, its operating speed is inferior to that of a machine (increasing the speed would require a more powerful CPU).
On the other hand, adding extra features is relatively easy.
Don't be fooled by the government and media's one-sided focus on AI; machines also have their appropriate roles, so don't be deceived. Both are important and absolutely necessary for civilized life.
AI and programs alone are merely instruction manuals; they will never function without the actual machinery to operate the objects.
In this way, I found myself lost in thought about machines, programs, and AI while gazing at a gas blowback handgun.
If you'd likeI've included some gas blowback airsoft guns, so please take a look.
Finally, if there is any interest, I will provide a summary of how gas blowback guns work and some tuning tips.
Thank you for your association until the end.
Comment:
Comment list (10)
I've read many articles about the mechanism of gas blowback guns, but this is the first one that explains it in such detail and in such an easy-to-understand way. After reading this article, I finally feel like I understand how it works.
All of your other articles are also detailed and easy to understand, setting them apart from what others write. I look forward to your new articles in the future.
Tagusari-san
thank you for your comment.
Thank you for your kind words.
I will continue to explain various mechanisms in the future.
I found the article very interesting.
The explanation of the structure and operation was very detailed, easy to understand, and accurate, which was extremely helpful in understanding gas guns.
There are no other articles that cover this topic, including its operation, in such a comprehensive way, so I'm truly grateful.
There's one thing that bothered me. The terms "raise" and "knock down" are used in reverse order to describe the state of the hammer.
Please note that the following expressions are commonly used.
Putting the hammer back down = "decock", returning to its original position = "rest"
Cocking a hammer = "to raise" or "cock", and being in a cocked state = "cocked".
I look forward to your future articles.
Mr. Iruka
thank you for your comment.
I'm glad you enjoyed the article.
Thank you for the advice. As you pointed out, I simply described it as being knocked over based on how the hammer appeared in the image.
Therefore, I have included the correct terminology for gun mechanisms in parentheses.
If you'd like, I'd be happy if you could take another look.
Hello.
I loaded the gas-filled magazine into the airsoft gun.
When you cock the hammer and pull the trigger, the sequence of movements you described occurs, resulting in blowback.
However, if you tighten the knocker spring just a little, the blowback will not occur even if you perform the above steps.
I replaced the knocker springs in all five of my M1911A1s, including Marui and copy versions, with slightly thicker springs that are one and a half turns longer.
(We also applied this to other guns.)
Then, even if you insert a gas-filled magazine and cock the hammer, there will be no blowback.
However, if you pull the slide to charge and then pull the trigger, it will fire as usual.
Once fired, the initial velocity has no effect, and you can continue firing until the magazine stops.
Is the reason it won't fire unless the slide is pulled back because the pressure in the knocker spring has slightly increased, causing the knocker to disperse the force of the hammer?
(When the hammer is raised, the knocker is extended forward.)
I disliked the blowback that occurred when I pushed down the hammer even though I wasn't loading anything, so I modified all seven of my airsoft guns that I could. I've never had an accidental discharge.
Even if you load a gas-filled magazine with ammunition, if the slide doesn't move, no matter how much you cock the hammer and pull the trigger, it will only make a "click!" sound.
It's realistic and good, but I'm struggling to understand where the force is distributed so that the knocker doesn't hit the valve.
Do you understand?
I apologize for the sudden and lengthy message.
Umenyan-sama
Thank you for visiting the site and leaving a comment.
Unfortunately, I don't own any Tokyo Marui models with external hammers, so I can't confirm this, but I did try it with a KSC STi2011 Edge, and when I simply pushed down the hammer, the knocker only retracted a little.
I believe the problem stems from the fact that the knocker needs to strike the valve with a small amount of retraction and a short knocker stroke, so even a slight decrease in striking force prevents the knocker from fully pushing the valve (the increased spring load should have slightly reduced the striking force).
Therefore, by moving the slide and fully retracting the knocker, there is sufficient distance to apply enough striking force, and it should function without any problems.
This is just my personal speculation, but I think it reflects Marui's design philosophy of wanting the slide to move fully before it can be activated.
By the way, I share the same philosophy as Umenyan, so I basically only own KSC's Live Operation type airsoft guns with exposed hammers.
The mechanism of operation of a gas blowback gun
Was funny
But sometimes left and right get reversed.
My mind is a jumbled mess and I can't understand anything anymore.
Take it again
7 steps: The hammer decocks (like the hammer returning to its original position in a gun), and the knocker is pushed forward by the hammer (releasing gas).
What's unclear from the illustration is that normally you hit it with the tip of the hammer, but
Does this one have a cam-like structure at the base that pushes it out?
In that case, the idea of making the hammer lighter doesn't apply.
Especially since the blowback is coming.
So, see you later!
Nekomaru-sama
Thank you for your comment. (I apologize for the very late reply.)
I apologize for the frequent horizontal flipping of the images and photos. I've made a slight adjustment.
Regarding the 7-step hammer, the cam at the base of the hammer pushes the knocker, and the knocker strikes the valve in the magazine.
In a real firearm, the hammer strikes the firing pin, so the middle to tip of the hammer is used. However, in a gas gun, it seems the base of the hammer is used to strike the magazine valve.
Therefore, the hammer's weight contributes little to the operation of the gas blowback mechanism, and the force of impact on the valve is almost entirely dependent on the load of the hammer spring.
I hope this is helpful. I'm also planning to explain the mechanism of the external hammer type (1911 series) in the near future, so please check it out if you're interested.
Hello!
This blog is very helpful; it was a great opportunity to review structural analysis.
If possible, I would appreciate it if you could re-examine this using the widely available Marui model as a reference. Although I have disassembled and studied 1911-type pistols, when a malfunction occurs, I lack sufficient knowledge to determine if it's the sear, the hammer area, or the disconnector.
I would really appreciate it if you could teach me in this way.
Hidede-sama
thank you for your comment.
I'll try to explain the hammer-action single-action mechanism of the Marui M1911 series.
Please wait.