JPH07227562A - Fixed quantity liquid discharging device - Google Patents

Abstract

PURPOSE:To lower resistance at the time of sucking/discharging liquid and to realize fixed quantity discharge with high accuracy by forming the cylinder of a device for discharging the liquid sucked into the cylinder by simultaneous control with rotation and advance and retreat of a piston from a discharge port to a stepped bore form. CONSTITUTION:The liquid sent from a supply source via a supply pipeline 22 is sucked from the suction hole 1 into the cylinder 3 by rotation of the piston 4 by a rotary actuator and advance and retreat of the piston 4 by a pulse motor. The fixed quantity thereof is supplied from the discharge hole 2 into a dispenser 23. The bore of the deep part 3b is formed to a diameter larger than the bore of the inlet part 3a in such a manner that a difference in level is formed in the position slightly deeper (left side position) than the opening point of the suction hole 1 and discharge hole 2 formed in the opposite position of the cylinder 3 of such fixed quantity discharging device. As a result, the length of the liquid passage 6 formed of the inside surface of the cylinder 3 and the flat surface part 5 of the piston 4 is made short and the fluid resistance is made low even if this passage is narrow.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid quantitative dispensing device.

[0002]

2. Description of the Related Art Conventionally, as one of devices for quantitatively discharging various liquids such as chemical liquids, resin liquids, and adhesives, FIGS.
3, a flat surface portion 5 is formed at one end of a piston 4 that is fitted into a cylinder 3 that is opened with the suction hole 1 and the discharge hole 2 facing each other, and synchronous control of rotation and forward / backward movement of the piston 4 is performed. As a result, a device configured so that a fixed amount of the liquid sucked into the cylinder 3 from the suction hole 1 can be discharged from the discharge hole 2 is widely put into practical use.

[0003]

However, in this discharge device, since the inner diameter of the cylinder 3 into which the piston 4 is inserted is provided to have the same size over the entire length thereof, the inner surface of the cylinder 3 and the flat surface portion 5 of the piston 4 are provided. The liquid passage 6 formed by and becomes narrow, and due to this, the resistance when the piston 4 is retracted in the direction of the arrow to suck the liquid into the cylinder 3 becomes large, and the predetermined amount of liquid can be quickly increased. It was difficult to suck into the cylinder 3. Also,
On the contrary, the same was true when the ink was discharged to the outside of the cylinder 3.

As a result of intensive studies aimed at solving this problem, the present invention has found that the problem can be easily solved by providing the inner diameter of the cylinder in a stepped manner.

[0005]

That is, in a liquid constant quantity discharge device according to the present invention, one end of a piston fitted into a cylinder opened so that a suction hole and a discharge hole face each other is attached to one end of the piston in the longitudinal axis direction. A fixed amount of liquid that is configured to form a flat surface portion extended to and to discharge a fixed amount of the liquid sucked into the cylinder from the suction hole by the synchronous control of rotation and advance / retreat of the piston from the discharge hole. In the discharge device, the inner diameter of the inner part of the cylinder is set so as to form a step at a position slightly deeper than the place where the suction hole and the discharge hole of the cylinder are opened, It is characterized in that it is provided with a diameter larger than the inner diameter.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1 which is a front view and FIG. 2 which is a plan view of this drawing, a bracket 8 fixed on a base 7 is attached to a bracket 8. The pulse motor 9 is fixed, the output shaft of the motor 9 and one end of the ball screw shaft 10 are connected by a shaft joint 11, and the other end of the ball screw shaft 10 is screwed into a nut 13 fixed to a nut bracket 12. Has been done.

The nut bracket 12 is mounted on the bearing portion 15 via the four stays 14. The bearing portion 15 is fixed to the guide 16 on the base 7.
Is mounted so as to be slidable (see FIG. 3, which is a sectional view taken along line XX in FIG. 1). Therefore, by driving the pulse motor 9 and rotating the ball screw shaft 10 in a predetermined direction, it is possible to move the ball screw shaft 10 in a left or right direction by a predetermined distance in FIG. At that time, when the bearing portion 15 is moved to the right side, the tip of the ball screw shaft 10 screwed to the nut 13 passes through a hole (not shown) penetrated by the nut bracket 12 and is projected to the left side. It

In addition, the rotary actuator 17 is fixed to the bearing portion 15.
The shaft 18 of No. 7 is connected to an intermediate shaft 19 rotatably mounted on the bearing portion 15, and the intermediate shaft 19 and the piston 4 are connected via a shaft joint 20. The other end of the piston 4 on which the flat surface portion 5 is formed is
The base 7 is shown enlarged in FIG.
It is fitted and inserted into the inlet portion 3a of the cylinder 3 attached to the cylinder receiver 21 fixed above, that is, the cylinder 3 opens with the suction hole 1 and the discharge hole 2 facing each other. The inner diameter of the inner part 3b is set to be larger than the inner diameter of the inlet part 3a into which the piston 4 is inserted so that a step can be formed at a position on the inner side (left side position) a little from the opened position.

The rotation of the piston 4 by the rotary actuator 17 and the advance / retreat of the piston 4 by the pulse motor 9 sucks the liquid sent from a supply source (not shown) through the supply conduit 22. It is possible to suck from 1 into the cylinder 3, and to discharge a certain amount from the discharge hole 2 to supply it to the dispenser 23. At that time, the rotation and advance / retreat of the piston 4 are synchronously controlled, and one rotation of the piston 4 completes one cycle of suctioning and discharging of the liquid.

In FIG. 6, at the suction position shown in FIG. 6B, the flat surface portion 5 of the piston 4 is located at the suction hole 1, and the liquid is sucked from the suction hole 1 into the cylinder 3 when the piston 4 retracts. It At the switching position of (C), the flat surface portion 5 is located at a position different from the opening portions of the suction hole 1 and the discharge hole 2, so that the liquid remains retained in the cylinder 3. . At the ejection position of (E), the flat surface portion 5 is located at the ejection hole 2,
The liquid is discharged from the discharge hole 2 as the piston 4 advances.

In this way, a fixed amount of liquid can be discharged, but the inner diameter of the inner portion 3b of the cylinder 3 is larger than the inner diameter of the inlet portion 3a into which the piston 4 is inserted so as to form a step. Since the diameter of the liquid passage 6 (see FIG. 5) formed by the inner surface of the cylinder 3 and the flat surface portion 5 of the piston 4 is narrow, since it is short, suction and suction into the cylinder 3 The resistance at the time of discharging the liquid to the outside of the cylinder 3 can be reduced, and a predetermined amount of liquid can be sucked and discharged more rapidly.

In order to enlarge the liquid passage 6, it is conceivable to provide a concave groove such as a key groove in place of the flat surface portion 5 of the piston 4, but the piston 4 is made of a ceramic material (cylinder). 3 is also the same),
It is troublesome to process, and if it is provided in such a manner, the strength is significantly deteriorated, and it is not preferable to increase the width of the flat surface portion 5 from the viewpoint of strength. Therefore, there is a problem in solving this point. However, in the present invention, the problem is solved by increasing the inner diameter of the inner portion of the cylinder 3 as described above.

FIG. 5 shows the discharge mode of (E) in FIG. 6, and one end of the supply pipeline 22 is screwed to the cylinder 3 to the piping adapter 2.
It is fixed to 4. To control the piston 4 by the pulse motor 9, the light shielding plate 25 fixed to the nut 13 (see FIG. 4, which is a sectional view taken along the line Y-Y of FIG. 1) is mounted at a predetermined position on the base 7. It is carried out by moving to a pair of photoelectric tube type proximity switches 26 (see FIG. 1).

[0014]

As described above, according to the present invention, a flat end extending in the longitudinal axis direction of the piston is attached to one end of the piston which is inserted into the cylinder having the suction hole and the discharge hole facing each other. A liquid constant-quantity discharge device configured to form a surface portion and to discharge a fixed amount of the liquid sucked into the cylinder from the suction hole from the discharge hole by synchronous control of rotation and advance / retreat of the piston, The resistance at the time of sucking in and discharging to the outside of the cylinder can be reduced, and a predetermined amount of liquid can be sucked and discharged more rapidly.

[Brief description of drawings]

FIG. 1 is a front view of a liquid dispensing device.

FIG. 2 is a plan view of FIG.

3 is a sectional view taken along line XX of FIG.

FIG. 4 is a sectional view taken along line YY of FIG.

FIG. 5 is an enlarged view of a cylinder portion.

FIG. 6 is a control process diagram of a piston.

FIG. 7 is an enlarged view of a cylinder portion of a conventional liquid constant-volume discharge device.

FIG. 8 is a vertical cross-sectional view of FIG.

[Explanation of symbols]

 1 Suction Hole 2 Discharge Hole 3 Cylinder 3a Inlet 3b Inner Part 4 Piston 5 Flat Surface 6 Liquid Passage 9 Pulse Motor 17 Rotary Actuator

Claims (1)

[Claims] 1. A flat surface portion extending in the longitudinal axis direction of the piston is formed at one end of a piston fitted into a cylinder opened so that the suction hole and the discharge hole are opposed to each other, and the piston is rotated and reciprocated. In the liquid constant-volume discharge device configured to discharge a fixed amount of the liquid sucked into the cylinder from the suction hole through the discharge hole by synchronous control with the suction hole and the discharge hole of the cylinder. A fixed amount liquid discharge characterized in that the inner diameter of the inner part of the cylinder is set to be larger than the inner diameter of the inlet part into which the piston is inserted so as to form a step at a position a little behind the position where the piston is inserted. apparatus.