JP7402036B2 - Syringe pump for paint supply - Google Patents

Description

The present invention relates to a paint supply syringe pump for supplying paint to a spray gun during painting, and more particularly to a paint supply syringe pump that can prevent fluctuations in the initial discharge of paint.

Conventionally, when painting a workpiece, a syringe pump has been used as a method for stably supplying a fixed amount of paint to a spray gun.

This syringe pump has a closed tip, and a piston with a rod is inserted into the cylindrical syringe body with a paint discharge port on the closed tip so that it can move back and forth. At this time, a paint supply hose is connected to the paint outlet, and the paint supply hose is connected to a spray gun.

In addition, the syringe pump has a paint filling port for filling the paint into the syringe body, and the tip side of a paint filling hose equipped with an on-off valve at any location is connected to this paint filling port. , the other end of the paint filling hose is connected to the paint tank.

On the other hand, the spray gun has an internal paint supply path connected to the paint supply hose, and the tip of this paint supply path opens at the tip of the spray gun to serve as a paint discharge port. can be opened and closed by a needle. Accordingly, a paint supply path is constituted by the inside of the syringe body, the inside of the paint supply hose, and the paint supply path of the spray gun.

When discharging paint from the spray gun, with the paint supply route filled with paint, operate the needle to open the paint discharge port of the spray gun, and move the piston of the syringe pump toward the tip of the syringe body. I'm going to push it. Then, the pressure of the piston pushes out the paint inside the syringe body from the paint discharge port, which also pushes the paint in the entire paint supply path, making it possible to discharge the paint from the paint discharge port of the spray gun. . Therefore, when a syringe pump is used, there is an advantage that a fixed amount of paint can be stably discharged compared to when a pressure-feeding pump is used.

By the way, when painting a work using a spray gun, it is necessary to make the discharge pressure of the paint uniform in order to make an even film of paint applied to the work. When the above-mentioned syringe pump is used, it is possible to supply a fixed amount of paint and to discharge the paint at a uniform pressure, compared to the case where a pressure-feeding pump is used.

However, in the method of supplying paint to a spray gun using a syringe pump, it is possible to make the paint discharge pressure uniform when the paint is being continuously discharged, but at the beginning of the discharge, the paint is continuously discharged. There are fluctuations compared to the pressure during discharge. As a result, it has been pointed out that the amount of paint discharged from the spray gun lacks stability, resulting in unevenness in the amount of paint discharged at the initial stage of discharge.

That is, when filling paint into the syringe body of a syringe pump, operate the needle to close the paint discharge port of the spray gun, and in this state, open the on-off valve of the paint filling hose, and open the piston. Pull it toward the side opposite to the paint outlet. This creates a negative pressure inside the syringe body, which causes the paint in the paint tank to be drawn into the syringe body via the paint filling hose, making it possible to fill the body with paint. Then, when the piston is pulled a predetermined distance and filling of the paint into the syringe body is completed, the movement of the piston is stopped and the opening/closing valve of the paint filling hose is closed.

However, at this time, the pressure in the paint supply path changes depending on the viscosity of the paint, and as a result, the paint pressure at the initial stage of dispensing differs from the pressure during continuous dispensing of the paint, and as a result, the spray The amount of paint discharged from the gun lacked stability.

In other words, when the viscosity of the paint is high, the filling speed of the paint into the syringe body is slow, so when the movement of the piston is stopped and the opening/closing valve of the paint filling hose is closed, there is not enough water inside the syringe body. As a result, the pressure inside the syringe body becomes low.

Then, in the initial stage of discharge when the paint discharge port of the spray gun is released for painting, the pressure inside the syringe body is low, so air enters the paint supply path from the paint discharge port side of the spray gun, and the paint supply The paint in the path will momentarily flow backwards, causing a slight delay before the paint is continuously discharged.

On the other hand, when the clay content of the paint is low, the syringe body is filled at a high speed, so when the piston stops moving and the paint filling hose on-off valve is closed, more paint than necessary fills into the syringe body. This increases the pressure within the syringe body.

Then, in the initial stage of dispensing when the paint discharge port of the spray gun is released for painting, the pressure inside the syringe body is high, so the amount of paint discharged from the paint discharge port of the spray gun is reduced by the amount of paint being continuously discharged. This results in a large amount compared to when the paint is being dispensed, and there is also a slight delay until the paint is stably and continuously discharged.

For this reason, conventionally, in painting using a syringe pump, a pressure sensor is installed on the discharge side of the syringe pump in order to prevent fluctuations in the paint pressure at the initial stage of paint discharge. A method has been proposed in which the piston is slightly moved to bring the pressure inside the syringe pump closer to the pressure during continuous discharge.

That is, FIG. 5 is a diagram for explaining a paint supply syringe pump 51 equipped with this pressure sensor, and in the figure, 52 is a syringe body. The syringe main body 52 has a cylindrical shape with a closed end and a paint discharge port 53 in the closed portion, and a paint supply hose 58 is connected to the paint discharge port 53. 58 is connected to a spray gun 59.

Further, a piston 54 including a piston rod 55 is inserted into the syringe body 52 so as to be movable forward and backward. A paint filling port 56 is formed in the piston 54, and a paint filling path 57 is formed inside the piston rod 55, communicating with the paint filling port 56 and to which a paint filling hose is connected.

A pressure sensor 60 is provided on the discharge side of the syringe pump, specifically on the paint supply hose 58, so that the pressure inside the syringe body 52 can be detected.

Japanese Patent Application Publication No. 2009-131747

However, in the above-described conventional syringe pump shown in FIG. 5, in order to provide a pressure sensor on the discharge side of the syringe pump, it is necessary to incorporate the sensor into the system, which may be difficult to install depending on the configuration.

Therefore, the present invention provides a paint supply syringe pump in which a pressure sensor can be easily attached without replacing the entire syringe pump and the paint supply hose, thereby making it possible to easily detect the pressure inside the syringe. The challenge is to do so.

The paint supply syringe pump of the present invention includes:
a syringe body having a cylindrical shape with a closed tip side and having a paint discharge port on the closed tip side;
A piston inserted into the syringe body so that it can move forward and backward,
a piston rod connected to the piston;
A paint supply syringe pump equipped with a paint filling port to which a paint filling hose is connected,
It is characterized by having a pressure sensor on the surface of the piston that is exposed inside the syringe body and that comes into contact with the filled paint .

The paint supply syringe pump of the present invention includes a syringe body, a piston inserted into the syringe body so as to be movable back and forth, a piston rod connected to the piston, and a paint filling port to which a paint filling hose is connected. In the syringe pump for supplying paint, a pressure sensor is provided on a surface of the piston exposed within the syringe body and in contact with the filled paint .

For this purpose, the paint supply syringe pump of the present invention can easily detect the pressure during paint filling, and by slightly moving the piston after filling the paint, the pressure in the paint supply path can be adjusted to the pressure during continuous discharge of paint. This makes it possible to prevent fluctuations in the initial stage of ejection.

In addition, the paint supply syringe pump of the present invention is equipped with a pressure sensor on the surface of the piston that is exposed inside the syringe body and comes into contact with the filled paint . A pressure sensor can be installed on the syringe pump of the syringe pump shown in Figure 5. Unlike the case where a pressure sensor is installed on the paint supply hose like the syringe pump shown in Fig. 5, the pressure sensor can be installed without being incorporated into the system, so the installation work is easy. is easy.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure for explaining the Example of the syringe pump for paint supply of this invention. It is a figure for explaining the example of attachment of the Example of the syringe pump for paint supply of this invention. It is a figure for explaining other examples of the syringe pump for paint supply of the present invention. It is a figure for explaining other examples of the syringe pump for paint supply of the present invention. FIG. 2 is a diagram for explaining a conventional paint supply syringe pump.

The syringe pump for supplying paint according to the present invention has a syringe body, and the syringe body has a cylindrical shape with a closed tip, and a paint supply hose is connected to the closed tip side. Equipped with an outlet.

Further, a piston is inserted into the syringe main body so as to be movable forward and backward, and a piston rod is connected to the side of the piston opposite to the paint discharge port.

Furthermore, the syringe pump of the present invention is provided with a paint filling port for filling paint into the syringe body, and a paint filling hose is connected to this paint filling port.

A pressure sensor is provided on the surface of the piston that is exposed inside the syringe body and comes into contact with the filled paint , thereby making it possible to detect the pressure of the paint inside the syringe body.

Here, the paint filling port may be provided at any location as long as the paint can be filled into the syringe body, but the paint filling port is formed in the piston and communicates with the paint filling port. It is preferable to form a paint filling path inside the piston rod and connect a paint filling hose to this paint filling path. According to this, paint can be filled into the syringe body simply by pulling the piston toward the side opposite to the paint discharge port. This makes it easier to fill the paint into the syringe body.

In addition, a paint filling port to which a paint filling hose is connected may be formed in the syringe body, and by this as well, paint can be filled into the syringe body simply by pulling the piston toward the side opposite to the paint discharge port. Therefore, it becomes easy to fill the paint into the syringe body.

An embodiment of the paint supply syringe pump (hereinafter simply referred to as "syringe pump") of the present invention will be described with reference to the drawings. FIG. 1 is a diagram for explaining the configuration of the syringe pump of the present embodiment. 1 in the figure is the syringe pump of this example.

The syringe pump 1 of this embodiment has a syringe body, and the syringe body is filled with paint. That is, in the figure, 2 is a syringe body, and the syringe body 2 has a cylindrical shape and is closed at the distal end, and a paint discharge port 3 is formed in this closed part. The base end of a paint hose whose one end is connected to the paint supply path of the spray gun is connected to this paint outlet 3, thereby supplying the paint inside the syringe body 2 to the spray gun. It is possible.

Next, in the figure, 4 is a piston. That is, a piston 4 is inserted into the syringe body 2 so as to be movable forward and backward, and a piston rod 5 is connected to the side of the piston 4 opposite to the paint discharge port.

Further, a paint filling port 6 is formed in the piston 4 and passes through the piston rod 5 in the forward and backward directions.On the other hand, a paint filling port 6 is formed in the piston 4 and passes through the piston rod 5 in the axial direction. A paint filling path 7 is formed which is continuous with the paint filling port 6. One end of a paint filling hose is connected to the paint filling path 7, the base end of the paint filling hose is connected to a paint tank, and an on-off valve is disposed in the middle of the path. In the figure, 10 is an O-ring.

Next, in the figure, 8 is a pressure sensor. That is, in the syringe pump 1 of this embodiment, the pressure sensor 8 is arranged on the surface of the piston 4 that is exposed inside the syringe body 2, and the lead wire 21 of the pressure sensor 8 passes through the inside of the piston rod 5. It is connected to a control device for moving the piston 5 forward and backward. Thus, when filling the inside of the syringe body 2 with paint, the pressure of the paint filled into the syringe body 2 can be detected.

Therefore, in the syringe pump 1 of this embodiment, when filling the inside of the syringe body 2 with paint, the pressure of the paint can be easily detected, and by slightly moving the piston 4 after filling the syringe body 2, the syringe body 2 Since the pressure of the paint inside can be made the same as the pressure during continuous discharge of paint, fluctuations in the initial stage of discharge can be prevented.

Furthermore, in the syringe pump 1 of this embodiment, the pressure sensor 8 is provided on the surface of the piston 4 that is exposed inside the syringe body 2. Therefore, the pressure sensor can be installed in an existing syringe pump by simply replacing the piston. Unlike the conventional syringe pump described above, a pressure sensor can be provided without being incorporated into the system, making installation work easy and reducing installation costs.

Next, the operation of the syringe pump 1 of this embodiment will be explained with reference to FIG. A spray gun, 12 is a paint supply hose connected to a paint supply path of the spray gun to supply paint to the spray gun, and 13 is a paint supply valve provided on the paint supply hose 12.

When incorporating the syringe pump 1 into a coating system, connect the base end of a paint supply hose 12, one end of which is connected to the paint supply path of the spray gun 11, to the paint discharge port 3 of the syringe body 2, and A paint supply valve 13 is installed at an arbitrary location on the paint supply hose 12.

On the other hand, in the figure, reference numeral 14 denotes a paint filling hose, and one end of the paint filling hose 14 is connected to the paint filling path 7 formed inside the piston rod 5, and the base end is connected to the paint tank 16. Furthermore, a paint filling side valve 15 is installed in the middle of the route.

Here, the mechanism for moving the piston 4 forward and backward will be explained. In FIG. This ball screw 18 is connected to the shaft of a motor 19 serving as a driving means. With this configuration, by driving the motor 19 and rotating the ball screw 18, the actuating plate 17 is reciprocated at a constant speed along the ball screw 18, thereby moving the piston 4 through the piston rod 5. It is movable back and forth inside the syringe body 2.

Next, in FIG. 2, reference numeral 20 denotes a control device composed of a computer or the like, and the motor 19, the paint supply side valve 13, and the paint filling side valve 15 are connected to this control device 20. Although omitted, an air supply means for supplying air to the spray gun 11 is connected. Further, the lead wire of the pressure sensor 8 is connected to the control device 20 after passing through the inside of the piston rod 5 and extending to the outside. As a result, the control device 20 controls the drive of the motor 20 to slightly move the piston 4 in the forward and backward directions based on the detection result of the pressure sensor 20, thereby controlling the pressure of the paint inside the syringe body 2 and the pressure during continuous discharge of the paint. This makes it possible to prevent fluctuations in the initial stage of ejection. In other words, when the pressure inside the syringe body is low, the pressure of the paint inside the syringe body 2 is reduced by slightly moving it toward the paint discharge port side, and when the pressure inside the syringe body is high, by slightly moving it toward the side opposite to the paint discharge port. It is possible to keep the pressure the same as the pressure during continuous discharge of paint and prevent fluctuations at the beginning of discharge. In addition, the parts indicated by 21 in the figure are electric wires connecting the motor 19, the paint supply side valve 13, the paint filling side valve 15, and the pressure sensor 8 to the control device 20.

When filling the interior of the syringe body 2 with paint in the coating system configured as described above, the paint supply valve 13 is closed, the paint filling valve 15 is opened, and the motor 20 is driven. and pull the piston 4 toward the side opposite to the paint discharge port. Then, since the inside of the syringe body 2 becomes negative pressure, the paint in the paint tank 16 is filled into the inside of the syringe body 2 through the paint filling hose 14, the paint filling path 7, and the paint filling port 6.

Then, when the piston 4 has been pulled a predetermined distance, the piston 4 is stopped being pulled and the paint filling side valve 15 is closed. This makes it possible to fill the inside of the syringe body 2 with the required amount of paint.

On the other hand, as mentioned above, immediately after filling the inside of the syringe body 2 with paint, the pressure of the paint filled inside the syringe body 2 varies depending on the clay of the paint, which releases the paint discharge port of the spray gun. At the initial stage of discharge, fluctuations in paint pressure occur.

Therefore, in the syringe pump 1 of this embodiment, the pressure sensor 8 detects the paint pressure inside the syringe body 2, and after filling the inside of the syringe body 2 with the necessary amount of paint, the pressure inside the syringe pump is adjusted. In order to bring the pressure close to that during continuous discharge, the control device 20 slightly moves the piston 4 in the forward or backward direction based on the detection result of the pressure sensor 8.

Therefore, according to the syringe pump 1 of this embodiment, the pressure of the paint after being filled with the paint can be made the same as the pressure during continuous discharge, and fluctuations in the initial stage of discharge can be prevented.

Furthermore, in the paint supply syringe pump 1 of this embodiment, the pressure sensor 8 is provided on the surface of the piston 4 that is exposed inside the syringe body 2, so there is no need to incorporate a pressure sensor into the system, and the piston 4 Installation is easy because the pressure sensor can be installed by simply replacing the pressure sensor.

In this way, the syringe pump 1 of this embodiment can prevent fluctuations in the initial stage of discharge, and can be equipped with a pressure sensor by replacing only the piston 4, making installation work easy.

In the above description, the paint filling port 6 is formed in the piston 4, and the paint filling path 7 is formed inside the piston rod 5, which is continuous with the paint filling port 6 formed in the piston 4. Although the configuration for filling the inside of the syringe body 2 with paint has been described, the location where the paint filling port 6 is formed in the syringe pump of the present invention is not particularly limited. For example, FIG. 3 is a diagram showing the configuration of a syringe pump 1b having another configuration. In this syringe pump 1b, a manifold 9 is provided on the distal end side of the syringe body 2. A paint discharge port 3 and a paint filling port 6 which are continuous to each other are formed.

Further, FIG. 4 is a diagram showing the configuration of a syringe pump 1c having still another configuration. In this syringe pump 1c, a paint filling port 6 is formed in the piston 4, similar to the syringe pump 1 shown in FIG. A paint filling path 7 continuous with the paint filling port 6 is formed in the piston rod 5, but unlike the piston 4 shown in FIG. 1, the paint filling port 6 does not extend through the piston in the forward and backward directions. That is, in the piston 4 shown in FIG. 4, the diameter of the upper part of the piston 4 is made smaller than the other parts, and the openings of the paint filling ports 6 are arranged at multiple locations on the side surface of this small diameter part. The paint is filled into the syringe body 2 from the side. The part indicated by 21 in FIGS. 4 and 5 is a lead wire that connects the pressure sensor 8 and the control device 20. Also in the syringe pump shown in FIGS. 4 and 5, the lead wire 21 of the pressure sensor 8 is It is connected to a control device through the inside of the piston rod 5. However, the wire connecting the pressure sensor and the control device 20 does not necessarily need to pass through the inside of the piston rod 5, and may be installed at any location.

The paint supplying syringe pump of the present invention is capable of detecting and adjusting the paint pressure inside the syringe body after filling the syringe body with paint, and is therefore applicable to all syringe pumps.

1, 1b, 1c Syringe pump 2 Syringe body 3 Paint discharge port 4 Piston 5 Piston rod 6 Paint filling port 7 Paint filling path 8 Pressure sensor 9 Manifold 10 O-ring 11 Spray gun 12 Paint supply hose 13 Paint supply side valve 14 Paint filling Hose 15 Paint filling valve 16 Paint tank 17 Operating plate 18 Ball screw 19 Motor 20 Control device 21 Electric wires

Claims (3)

a syringe body (2) having a cylindrical shape with a closed tip side and having a paint discharge port (3) on the closed tip side;
a piston (4) inserted into the syringe body (2) so as to be movable forward and backward;
a piston rod (5) connected to the piston (4);
A paint supply syringe pump equipped with a paint filling port (6) to which a paint filling hose is connected,
A syringe pump for supplying paint, characterized in that a pressure sensor (8) is provided on a surface of the piston (4) that is exposed inside the syringe body (2) and comes into contact with the filled paint . A paint filling port (6) is formed in the piston (4), and a paint filling path (7) that communicates with the paint filling port (6) and to which a paint filling hose is connected is formed in the piston rod (5). The syringe pump for supplying paint according to claim 1, characterized in that: The syringe pump for supplying paint according to claim 1, wherein the syringe body (2) is formed with a paint filling port (6) to which a paint filling hose is connected.

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