JPH0128860Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a device for discharging a fixed amount of viscous fluid for adhesive purposes from the mouth of a needle-like thin tube.

Conventionally, valves for devices that discharge a fixed amount of this type of fluid have a structure in which the needle simply approaches and separates from the seat surface, so when the discharge is stopped, the fluid is pushed out to the needle tip. The needle stops and fluid remains on the needle tip, making it difficult to drain the fluid. Other devices have been proposed that draw fluid into the needle tip when the discharge is stopped, but all of them have a structure that uses special packing and sealing, and the amount of fluid drawn in is not uniform due to the structure, so there is a slight difference in the discharge amount. Yes, but it changes and is not constant. In addition, since fluid is discharged from a thin tube, a large pressure is required at the start, and a large drive source must be attached to the fluid pressurized feeder, which makes it difficult to make the entire device compact. Ta.

This proposal has been made with the aim of solving the above-mentioned drawbacks of conventional methods.

The present invention will be explained below with reference to the embodiment shown in the drawings. 1 is a device main body, equipped with an electromagnetic valve 2 at the top, a pressurized fluid feeder 3 for adhesive etc. connected to one side, and a needle at the bottom end. A fluid-accommodating cavity 5 that communicates with the fluid pressurized feeder 3 is provided inside the main body 1 of the device. 6 is the cavity 5
An elevating shaft 8 that is raised and lowered by a solenoid valve is fitted into a vertical hole 7 provided in the center of the upper end of the elevating rod. 9 is a washer 1 made of a coil spring and fixed to the outside of the upper part of the lifting rod 6.
0 and the lower end support step 12 of the inner cavity 11 of the device main body 1, and constantly pushes the lifting rod 6 upward. Reference numeral 5a denotes a cavity wall constituting the fluid accommodation cavity 5, whose inner diameter is appropriately larger from the upper part than the lower part, and a partition seat plate 14 is provided in the upper middle to divide the fluid accommodation cavity 5 into two upper and lower chambers. This partition seat plate is provided with an opening 13 of a required inner diameter in the center.
In the lower fluid storage cavity 5 divided by the partition seat plate 14, a valve seat 15 is formed on the lower surface,
Piston 1 with a vertical hole 16 of the required inner diameter in the center
A valve rod 19 whose upper end is attached to the lifting rod 6 is inserted through the vertical hole 16, and a valve 18 which approaches and separates from the valve seat 15 of the piston 17 is attached to the lower end. An appropriate gap is provided between the inner surface of the vertical hole 16 through which the valve rod 19 is inserted and the valve rod to allow fluid to flow therethrough, and a large inner diameter hole wall 5a is provided above the partition seat plate 14 and the fluid accommodation hole 5. A coil spring 23 for pressing the piston 17 is provided on the outer periphery of the valve rod portion between the upper surface of the piston 17 and the lower end surface of the lifting rod 6, leaving a gap 22 between the lower end inner peripheral edge 21 and the lower end of the piston 17. The outlet of the fluid pressurized feeder 3 is connected to one side of the upper large-diameter cavity wall 5a,
A needle-shaped thin tube 4 is connected to the lower end of the fluid storage cavity 5.

Since the present invention is constructed as described above, after filling the fluid accommodation cavity 5 with fluid (such as adhesive) using the fluid pressurized feeder 3, the solenoid valve 2 is actuated to move the lifting shaft 8. When lowered by a fixed interval, the lifting shaft 8 lowers the lifting rod 6 against the action of the coil spring 9. As a result, the valve rod 19 fixed to the lifting rod 6 moves downward, and the valve 1 attached to the lower end
8 first moves down through the lifting allowance gap 22 together with the piston 17, and the piston 17 is attached to the lower end periphery 21.
reaches. Due to this action, the fluid in the cavity 5 below the piston 17 is pushed out, and a minute amount corresponding to the descending volume of the piston 17 is first pushed out from the needle-shaped thin tube 4 at the lower end. Then, the piston 17 stops, but the valve rod 19 further moves downward, so the valve 18 moves away from the valve seat 15, and the lower end of the vertical hole 16 is opened, so that the inside of the upper cavity 5, which is constantly pressurized, is opened. Since the fluid is forced into the lower cavity 5 through the vertical hole 16, the fluid in the lower cavity 5 is discharged downward in a fixed amount from the mouth of the needle-like thin tube 4 at the lower end. This discharge action is performed by the action of a solenoid valve that operates, and since the time can be set, the discharge amount is determined by that time, and the timer is activated and the lifting rod 6 is compressed at the same time as the solenoid valve stops operating. The normal state is restored by the restoring action of the coil spring 9. Therefore, the valve 18 at the lower end of the valve rod 19, which is integrally attached to the lifting rod, is pressed against the valve seat 15 to close the lower end opening of the vertical hole 16 and stop pressurizing the fluid storage cavity 5 below. Then, the discharge of fluid from the lower end opening of the thin tube 4 is stopped. At the same time, the piston 17 is raised by a predetermined lifting clearance by the valve 18, so that the inside of the lower fluid accommodation cavity 5 temporarily becomes negative pressure, and thus remains at the lower end opening of the thin tube 4. The fluid is sucked into the capillary as illustrated in FIG. 2, and the surface in contact with the outside air is drawn to a surface equal to the inner diameter of the capillary. These operations are to automatically discharge a desired set amount using a switch button (not shown).

As described above, according to this invented device, when the fluid is first discharged, a strong pressure higher than the normal pressure of the fluid pressure feeder 3 can be applied to the fluid by the action of the piston 17, and therefore a large driving source is required. The fluid can be easily discharged from the needle-like capillary without using it, and once it has flowed out from the needle-like capillary, the normal pressure of the fluid pressure feeder 3 can be used to sufficiently discharge a fixed amount.

Next, when the valve 18 closes the lower end opening of the vertical hole 16, the piston 17 rises by the vertical allowable clearance as described above, so the inside of the lower fluid accommodation cavity 5 temporarily becomes negative pressure, and the lower end of the thin tube 4 The fluid remaining in the opening is sucked inward, minimizing the contact surface with air, thereby reducing changes caused by contact with air, such as fluid clumping, and
Therefore, this fluid discharge action is performed extremely smoothly, and uneven discharge is eliminated. In conventional outflow devices, when the fluid discharged from the lower end of the capillary stops, the residual fluid flows out from the port of the capillary and remains in a semicircular fluid state, which increases the contact surface with air and easily solidifies. However, if the fluid discharge operation is slow, there is a drawback that the amount of fluid discharged becomes uneven. However, according to the present proposal, as mentioned above, the residual fluid remaining at the lower end of the capillary is always sucked into the capillary, and the contact surface with the outside air is slightly stopped, so there is some difficulty in discharging the fluid. Even at slow speeds, the fluid discharge is always constant and never uneven.
Therefore, it is extremely effective for dispensing a fixed amount of fluid such as adhesive for slide glasses.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a sectional view, and FIGS. 2 and 3 are enlarged sectional explanatory views showing the operation of the main parts. DESCRIPTION OF SYMBOLS 1... Device main body, 2... Solenoid valve, 3... Fluid pressurized feeder, 4... Needle-shaped thin tube, 5... Fluid storage cavity, 6... Lifting rod, 7... Vertical hole, 8 ... Lifting shaft, 13 ... Hole, 14 ... Partition seat plate, 15 ...
Valve seat, 16... Vertical hole, 17... Piston, 18... Valve, 19... Valve rod, 2
1... Bottom inner peripheral edge, 22... Lifting permissible gap.

Claims (1)

[Scope of utility model registration request] A solenoid valve is provided at the top, a pressurized feeder for fluid such as adhesive is connected to one side, and a thin tube for discharging fluid is provided at the lower end.Inside the main body of the device, a fluid communicating with the pressurized fluid feeder is provided. A housing cavity is provided, and an elevating rod that is moved up and down by mutual action of the electromagnetic valve and a coil spring is installed in the upper part of this cavity, and a fluid is pressurized on the wall of the cavity near the lower end of the elevating rod. Open the outlet of the feeder,
A piston having an outer diameter that matches the inner diameter of the wall of the cavity and a vertical hole with a required inner diameter in the longitudinal direction of the center is disposed in the cavity below the outlet portion so as to be able to move up and down at a predetermined interval. A valve for opening and closing the opening at the lower end of the vertical hole of the piston is installed directly below the piston at the lower end of a valve rod whose upper end is attached to the lifting rod and whose lower half extends downward through the vertical hole at the center of the piston. The valve is provided to move up and down together with the piston through the interaction of the lifting rod and the coil spring, and the fluid in the fluid storage cavity is initially pressurized and discharged from the thin tube of the device body;
A device for discharging a fixed amount of fluid from the mouth of a needle-like capillary, characterized in that the device is configured to draw a minute amount into the capillary when discharging is stopped.