JP4072737B2 - Syringe for liquid ejection device - Google Patents

Description

[0001]
[Industrial application fields]
Liquid ejection devices such as adhesives, liquids such as epoxy resins and acrylic resins, and chemical solutions.
[0002]
[Conventional technology]
In the liquid discharge device combining the return syringe and the four-way switching valve, when the piston reciprocates, the syringe is responsible for discharge on one side and the suction on the other side.
In the case of micro discharge, the movement of the piston is small, so there is almost no flow of liquid. The liquid cushioning action causes the liquid to flow out little by little after discharging from the nozzle, resulting in a dripping phenomenon, or discharging larger bubbles, which leads to a deterioration in discharge accuracy.
[0003]
[Problems to be solved by the invention]
The shape of the inner cylinder of the syringe is improved so that the air bubbles that have flowed into the syringe are quickly discharged into the discharge pipe and the air bubbles do not grow in the syringe.
[0004]
[Means for Solving the Problems] On both ends of the syringe inner cylinder, a relief groove is formed with a diameter sufficiently larger than the outer diameter of the piston to discharge the bubbles more quickly and flowing the bubbles along the slope , A liquid inlet / outlet port is provided at the top of the groove, and a syringe is horizontally installed with the inlet / outlet port facing upward to constitute a liquid discharge device.
[0005]
[Action]
The left and right moving ends of the piston move toward the point just before the piston enters the escape groove. During the inhalation of the liquid, bubbles that have flowed into the syringe or generated bubbles are floating in the syringe. Next, when the movement of the piston is switched and the liquid is discharged, the bubbles are pushed into the escape groove and gather at the top along the slope of the escape groove. As the liquid is discharged, the bubbles are discharged into the discharge pipe.
[0006]
[effect]
Since the bubbles do not become large, there is no liquid cushioning action and no dripping occurs. Since large bubbles do not enter the liquid, the discharge accuracy does not deteriorate.
[0007]
[Example 1]
The syringe 1 is formed with ◇ -shaped relief grooves 3 and 3 ′ on both sides of the inner cylinder 2. The piston 4 slides in the inner cylinder 2 and is hermetically sealed with a seal 5.
The piston rod 6 is connected to the right side of the piston 4, passes through the right wall 7 of the syringe 1, protrudes outside, and is hermetically sealed with a seal 8. An entry / exit port 9 is provided at the top of the groove 3, and an entry / exit port 10 is provided at the top of the groove 3 ′.
When the piston rod 6 is pushed leftward, the liquid in the syringe 1 is discharged from the inlet / outlet port 9 and sucked from the inlet / outlet port 10. At this time, the air bubbles flowing in float on the upper side of the right chamber 11 of the syringe 1. When the piston rod 6 is pulled rightward, the liquid in the right chamber 11 is discharged from the access port 10. At this time, the bubbles in the right chamber 11 flow toward the entrance / exit port 10 along the slope of the groove 3 ′. When the piston 4 is placed at the rightmost end of the right chamber 11, all the bubbles are pushed out into the groove 3 ′, floated, and discharged from the inlet / outlet port 10 to the outside of the syringe. Even in the right chamber 12, air bubbles are discharged from the inlet / outlet port 9 by the same action when the piston 4 moves left. If the piston 4 enters the grooves 3 and 3 ', the airtight action of the O-ring 5 is lost, the right chamber 11 and the left chamber 12 communicate with each other, and the liquid can flow between the inlet / outlet ports 9 and 10, thereby cleaning the inside. Can be easily done.
As described above, since bubbles are not retained in the syringe 1 and discharged quickly without affecting the discharge accuracy, high-precision discharge can be measured and no dripping occurs.
[0008]
[Brief description of the drawings]
1 is a cross-sectional view of a syringe according to Embodiment 1 of the present invention.
1, syringe 2, inner cylinder 3, groove 4, piston 5, seal 6, piston rod 7, right wall 8, seal 9, entrance / exit port 10, entrance / exit port

Claims (1)

At both ends of the syringe inner cylinder, an escape groove is formed with a diameter that is large enough to expel bubbles quickly from the outer diameter of the piston, and the bubbles flow along the inclined surface. A syringe for a liquid ejection device, characterized by comprising:

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