JPH0450941Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to an initial flow rate response mechanism for a hand-held flow gun that suppresses a large amount of liquid flowing out immediately after the valve is opened.

[Prior Art] As a hand-held flow gun for applying high viscosity liquids such as sheet materials and adhesives, the ones shown in FIGS. 4 and 5 are conventionally known.

To explain this simply, pressurized high viscosity liquid is supplied from the joint 10 side to the liquid supply path 11 via a conduit (not shown).

When the trigger 9 is pulled in this state, the stem 8 moves to the right,
The right end bent portion 8a moves the adjustment nut 7 to the right,
The needle valve 2, which is integrated with the rod 4, is opened by separating it from the valve seat of the seat member 1 against the biasing force of the spring 3 in the valve closing direction through the stud 6 and the rod 4, which are integrated with the needle valve 4, and The pressurized liquid in the liquid supply path 11 is discharged from the discharge nozzle 12 through the valve gap and applied to the member to be coated.

Note that 5 in FIG. 4 is a gasket that seals the liquid in the liquid supply path 11.

[Problem that the invention attempts to solve]

However, in the case of such a conventional hand-held flow gun, in order to obtain the required flow rate from the illustrated state in which the needle valve 2 is closed, it is necessary to operate the trigger 9 at a constant speed in the direction of arrow A. , the needle valve 2 moves at a substantially constant speed in the valve opening direction via the stem 8, and the valve gap through which the liquid passes increases proportionally.

As a result, immediately after the valve is opened, a large amount of high-pressure liquid is discharged from the discharge nozzle 12 through the opened valve gap, and a pressure loss occurs in proportion to the discharge flow rate. The pressure drops rapidly, and this reduced pressure causes a large change in the flow rate of the liquid.

That is, when trying to apply a high viscosity liquid in the form of a bead of the desired thickness by pulling the trigger 9 at a constant rate, the application area expands into a dumpling shape immediately after the start of ejection, and then
Since the thickness converges to a certain level, the excess enlarged portion of the initial discharge portion had to be removed manually after application.

In addition, to avoid this phenomenon, adjust the operating speed of the trigger 4 depending on the flow rate, and keep the valve gap small when the valve opens and increase the valve gap as the pressure decreases to obtain a constant flow rate. An operating method has also been attempted, but it requires the operator's supervision, and
Even with this method, it is extremely difficult to obtain a constant flow rate throughout.

The purpose of this invention is to provide a mechanism for handling the initial flow rate of a hand-held flow gun that can solve these conventional problems.

[Means for solving problems]

Therefore, the initial flow rate response mechanism of the hand-held flow gun according to this invention is such that the driving member that drives the valve movable part, which is biased in the valve closing direction in conjunction with the trigger, in the valve opening direction against the biasing force, is almost mutually connected. The first and second driving members are divided into first and second driving members that move in parallel, and the first and second driving members are provided at different positions sequentially moving away from the pivot point of the trigger.
The moving amount of the second driving member is made larger than the amount of movement of the first driving member, and the valve movable portion is driven in the valve opening direction by the first driving member at the beginning of the trigger operation. Then, the valve movable portion is driven in the same direction by the second driving member.

[Effect]

With the above configuration, when the trigger is operated at a constant speed, the first driving member, which has a small amount of movement, drives the valve movable part in the valve opening direction due to its initial movement, thereby increasing the initial valve opening speed. After the pressure is lowered, the second driving member with a large travel distance drives the valve moving part in the same direction to increase the valve opening speed and keep the valve opening speed constant. It is possible to secure a flow rate of

[Embodiment] Hereinafter, an embodiment of this invention will be explained with reference to FIGS. 1 to 3 of the attached drawings. Parts corresponding to FIGS. 4 and 5 are designated with the same reference numerals. There is.

1 and 2 show an embodiment of this invention, in which a needle valve 2, which is a valve movable part that blocks or allows the flow of liquid by seating on or separating from a seat member 1, has an axial direction. A rod 4 is screwed onto the side opposite to the valve side, and the other end of the rod 4 is inserted through the packing 5 to protrude to the outside.

Screw the stud 6 onto the protruding rod 4, and tighten the first adjusting nut 17 with a gap between the studs 6 and 6.
and the second adjustment nut 7 to fix it.

On the other hand, as shown in FIG. 2, the trigger 9 is pivotally connected to the gun fixing part by a shaft 13,
First and second connecting portions 14, 15 are provided at different positions successively farther away from the connecting portions 14, 15.
One ends of the first stem 18 and the second stem 8, which are driving members of the needle valve 2, are respectively connected to the stem 18 and the second stem 8, respectively. The driving members 18 and 8 are made to be able to move in the axial direction of the needle valve 2 substantially parallel to each other, and the bent portion 18a of the other end of the first stem 18 is linked to the first adjusting nut 17. let me,
The other end bent portion 8a of the second stem 8 can be linked with the second adjusting nut 7 with a predetermined gap, and the amount of movement of the second stem 8 for the same rotation angle of the trigger 9 can be adjusted. is larger than the amount of movement of the first stem 18. Furthermore, the first stem 18 is engaged with the first adjusting nut 17 at the beginning of rotation of the trigger 9, and the second stem 8 is then engaged with the second adjusting nut 7. Determine the position of the second adjustment nut 7,17.

In this embodiment, the apex angle of the conical portion formed at the tip of the needle valve 2 is reduced to cope with the increase in the amount of movement of the needle valve 2.
The other configurations are the same as the conventional example shown in FIG.

Next, the operation of the embodiment configured as described above will be explained in the third section.
The explanation will be made with reference to an explanatory diagram showing the principle of operation in the figure.

The trigger 9 rotates by an angle θ ₁ +θ ₂ about the pivot point 13, and its free end moves from point A to point B.
When moving to point _{C via}
5 are points 14a, 14b, 14c and point 1, respectively.
The first and second stems 18 and 8, which have been moved to positions 5a, 15b and 15c and whose ends are connected to the first and second connecting portions 14 and 15, are approximately parallel to each other at a distance u+v as shown in the figure. and w+x respectively.

Now, when the trigger 9 is rotated in the direction of arrow A, the first
The bent portion 18a of the stem 18 presses the stud 6 to the right through the first adjusting nut 17, and the needle valve 2 moves to the right through the rod 4 that is integrated with the stud 6 to open the valve. Become.

When the trigger 9 is rotated by an angle .theta.1 so that its free end is at the point B, the stud 6 moves by a distance u against the spring 3 and is displaced from the position D to the position E.

At this time, the second stem 8 also moves in _the same direction by a distance w=( _2/1 )u, but an initial distance w-u must be provided between the bent portion 8a and the second adjustment nut 7. For example, the movement of the second stem 8 does not contribute to driving the stud 6.

When the trigger 9 is subsequently rotated, the bent portion 8a of the second stem 8 presses the needle valve 2 further to the right via the second adjusting nut 7, stud 6, and rod 4, and the needle valve 2 is pulled. When the free end of metal 9 is at point C, stud 6 moves a distance x to point F.

At this time, the first stem 18 also moves in _the same direction by a distance v, but since v=( _1/2 )x<x,
Movement of the first stem 18 does not contribute to driving the stud 6.

That is, by the initial operation of the trigger 9, the needle valve 2 is driven by the first driving member 18 and opens at a slow speed, and by the subsequent operation of the trigger 9, the needle valve 2 is driven by the second driving member 8. and move at a rapid speed.

As a result, even if the trigger 9 is operated at a constant speed, the initial valve opening speed is slow, and it is possible to suppress the phenomenon in which a large amount of high-pressure, high-viscosity liquid attempts to flow out at once, and the initial outflow causes pressure When the pressure decreases, the valve opening speed becomes rapid, and the required flow rate can be secured despite the low pressure, making it possible to obtain a constant flow rate over the entire area.

Further, according to this invention, a hand-held flow gun has a structure in which the pressure of pressurized liquid acts strongly in the closing direction of the needle valve in addition to the urging force of the spring that biases the needle valve in the closing direction. Even in such cases, the initial operating force for the trigger can be small, reducing operator fatigue.

Furthermore, since the reaction force applied to the trigger clearly changes when switching between the first and second driving members, the operator can easily sense the opening degree of the valve, improving workability.

In the above embodiment, two types of valve opening speeds are obtained using two drive members, but this can be changed by providing three or more drive members to obtain three or more types of valve opening speeds. It is also possible to obtain

[Effect of idea]

As described above, the initial flow response mechanism of the hand-held flow gun according to this invention is a drive that drives the valve movable part, which is urged in the valve closing direction in conjunction with the trigger, in the valve opening direction against the urging force. The member is divided into a first and a second driving member, and one end of each driving member is connected to the first and second connecting portions provided at different positions sequentially away from the pivot point of the trigger. The amount of movement of the driving member is made larger than the amount of movement of the first driving member, and the valve movable part is driven in the valve opening direction by the first driving member at the beginning of the trigger operation, and then the valve movable part is driven by the second driving member. Since the parts are driven in the same direction,
When the trigger is operated at a constant speed, the initial valve opening speed decreases and the initial flow rate that tends to flow out in large quantities can be suppressed, and then when the liquid pressure decreases, the valve opening speed increases and remains constant. can obtain a flow rate of

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of this invention, FIG. 2 is a front view of the main part showing the trigger-linked part, and FIG. 3 is an explanatory diagram showing the principle of operation.
FIG. 4 is a cross-sectional view illustrating a conventional hand-held flow gun, and FIG. 5 is a front view of the main parts similarly showing the trigger-linked part. 1... Seat member, 2... Needle valve (valve movable part), 4... Rod, 6... Stud, 7...
...Second adjustment nut, 8...Second stem (second
(driving member), 9... trigger, 12... discharge nozzle,
13... shaft (trigger pivot point), 14... first connection part, 15... second connection part, 17... first adjustment nut, 18... first stem (first drive member).

Claims (1)

[Scope of utility model registration request] An intermediate portion of a trigger whose one end is pivotally connected to a fixed portion is connected to one end of a driving member that can move in the valve opening/closing direction, and the other end of the driving member is linked to a valve movable portion biased in the valve closing direction; In a hand-held flow gun that opens the valve movable part through the drive member against the urging force of the drive member by operating a trigger, the first and second flow guns move the drive member substantially parallel to each other. The driving member is divided into two parts and connected to first and second connecting parts provided at different positions sequentially away from the pivot point of the trigger, so that the amount of movement of the second driving member can be adjusted by the amount of movement of the first driving member. by driving the valve movable part in the valve opening direction by the first drive member at the beginning of the trigger operation, and subsequently driving the valve movable part in the same direction by the second drive member. , an initial flow rate response mechanism for a hand-held flow gun, characterized in that the initial valve opening speed is slowed to prevent initial large volume discharge.