JP4339580B2 - Intermittent valve of paint supply device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a valve for completely disconnecting and connecting a paint flow path, which enables electrical insulation of the paint path in electrostatic coating, and is used for reliable switching of the paint path when changing the color of the paint, etc. It is.
[0002]
[Prior art]
When conductive paint typified by water-based, water-based paint or metallic paint is used for electrostatic coating, the high voltage charged in the electrostatic spray gun leaks to the ground potential via the paint supply path, and the specified high voltage Cannot be charged and the effect of electrostatic coating cannot be obtained. For this reason, a method is employed in which the entire coating material supply system is insulated from the ground potential, and the supply system itself is maintained at a high voltage to perform electrostatic coating.
In addition, it is necessary to quickly and surely change the supply paint when supplying the selected paint from a number of paint supply sources to a specific spray gun and applying different colors. A switching valve is used.
[0003]
However, when painting continues, it is essential to replenish the paint supply system, but there is a problem that high voltage leaks to the ground potential through the conductive paint during this replenishment. Has been proposed. As one method, a method of interrupting the painting operation when replenishing the paint and replenishing it during that time is taken. In the case of replenishment, the paint supply system is electrically connected to the ground potential, and is replenished from a separately provided paint replenishment device at the same ground potential. In this case, there is a problem that the painting work is temporarily interrupted, and there are problems in workability, painting efficiency, and the like, which cannot be adopted from the viewpoint of productivity.
[0004]
Another method is to supply paint to the paint container intermittently at a distance interval that can maintain electrical insulation during automatic paint replenishment, and to prevent leakage of high voltage to the paint replenishment system that is at ground potential. Sometimes taken. However, many of these methods use a device that intermittently replenishes in a sealed replenishment route, making it difficult to maintain insulation and ensure reliable insulation and time and amount of replenishment. Depending on the replenishment conditions, stability is lacking and there is a problem in reliability for continuous use.
[0005]
As a method to solve various problems, two paint supply containers are provided, and at least one of the supply containers is configured to always maintain an insulation state between the ground potential and continuous supply is possible. This method has been proposed. Specifically, as seen in Japanese Patent No. 3217394, two supply devices each having a paint container are connected between the paint source and the coating machine, and the supply device connected to the coating machine is a paint. When supplying water, make sure that the supply path to the other supply device is shut off and insulated, and connected to the paint source, and the supply device is pre-supplemented with paint and connected to the coating machine. In the supply of paint to another supply device, a method has been proposed in which the other supply device and the paint source are cut off and insulated so that at least a part of the paint source is always kept in an insulated state. Yes. In order to carry out these methods, an intermittent valve that reliably cuts off the supply of paint and ensures electrical insulation in the paint supply path is required.
[0006]
In the case of the supply device according to the invention, the intermittent valve for cutting off the paint passage of the paint supply path is provided with a check valve at the cut portion, and when the connection end portions are separated, both check valves are Closed to prevent leakage to the outside, and when the connecting end is connected, after the end is connected by the leakage prevention means, one of the check valves is forcibly opened. ing.
Also, in order to prevent the paint from leaking to the outside when the connection end is separated and cut off, a suction part composed of a male / female coupling part is provided on the valve body, and the coupling part is utilized by using the movement at the time of separation. Incorporates a means to suck the paint generated in For this purpose, a stop valve body is provided at the tip of the coupling portion, and a check valve for generating a negative suction pressure is provided.
[0007]
However, in such a conventional technique, the apparatus is complicated in order to prevent mixing of external air generated at the time of connection and disconnection at the connection portion and outflow of the paint to the outside, and the operation is unstable and stable. There was concern about maintenance. In addition, it is inconvenient for maintenance and cleaning due to heavy use of packing and the like, and there is still room for improvement in long-term use.
[0008]
In other words, an air gap remains between the valve body of the connection part and the push pin for opening it, and the paint that enters the gap remains outside when the connection is cut off, resulting in leakage and contamination and poor electrical insulation. Cause. In the next connection, air is trapped and air is mixed into the paint path, resulting in unstable spraying from the spray gun and the cause of poor painting.
In addition, such an intermittent valve is connected and disconnected, and it is necessary to individually control each of the flow paths by using multiple intermittent valves, which complicates the device itself and adjusts the operation and loads of maintenance. Is increasing.
[0009]
[Problems to be solved by the invention]
The present invention is an intermittent valve that reliably connects and disconnects the paint supply path, minimizes the entry of air at the time of connection, eliminates coating defects, and prevents the paint from protruding substantially when disconnected. An object is to provide a device capable of preventing leakage. In addition to simplifying the structure itself, it facilitates cleaning and maintenance, and provides a configuration as an intermittent valve that can switch the flow path with improved durability and certainty of the sealing means used in the switching section. The task is to expand the range of use as a valve . In addition, by providing a device that can handle complicated control of paint passage switching by enabling a plurality of intermittent valves to be operated by a common driving means, a continuous paint supply device in electrostatic painting using water-based paint The purpose is to make it possible to use it in color change devices.
[0010]
[Means for solving problems]
In order to solve the above problems, the present invention provides a movable joint provided in an intermediate portion and piston valves on both sides thereof, and is brought into contact with each piston valve alternately by movement of the movable joint. The basic configuration is an intermittent valve that switches between passages by alternately disconnecting and connecting piston valves. Further, the movable joint is provided with a paint connecting portion in the middle, and a first end portion containing a check valve is formed at both ends facing the piston valve, and the piston valve contacts and separates from the first end portion. 2 is provided with a packing at the end of the paint passage that opens to the end, and is fitted to the packing to be closed, and is a valve that protrudes from the opening end by an operating means from outside. Provide a piston. The shape of the tip of the valve piston is substantially in close contact with the shape of the end of the check valve. After the first end and the second end are hermetically joined, the piston valve is operated to open the valve. The check valve is opened to open the paint passage.
[0011]
Furthermore, in the present invention, a plurality of movable joints are installed on the moving body, and the switching valves are simultaneously operated in a coordinated manner by enabling joining and blocking with a plurality of first end portions provided to face each movable joint. Therefore, it is possible to easily configure complicated paint passage switching control.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below in detail with reference to the drawings.
FIG. 1 shows a switching valve as an embodiment of the present invention.
The movable joint 1 that performs switching operation is configured by incorporating valve bodies 3A and 3B on both sides of the moving body 2. The check valve body 4A is a seat surface 8 A is blocked in close contact with the sealing member 7A inserted into the groove 6 A formed near the tip end portion of the inner sheet 5A formed inside the valve body 3 A The tip surface 9A formed and exposed to the outside has an obtuse angle taper shape.
[0013]
Each of the valve body 3A, a check valve body 4A provided in 3B, 4B are rear end to form a spring receiving is pushed on both sides is fitted to both ends of the spring 13, usually across the sealing member 7 A , 7B is maintained in a closed state. Check valve body 4A of the check valve A on the left side is pressed by the valve piston 22A of the piston valve 21 A, it shows the open state in FIG. The movable joint 1 in which check valves are arranged at both ends is provided with a connection port 12 connected to the internal passage 11.
[0014]
For switching the paint passage, the movement axis of the movable joint 1, the piston valve 21 A is fixed to a support 30 facing the valve body 3 A. The piston valve 21 A is made the valve piston 22A about the movement axis, and configured to close fit the outer diameter 25 A packing 24 A provided at the tip of the cylindrical surface 23 which is formed as a paint passage ing. In the valve piston 22 A, a valve rod 26 provided integrally at the rear part penetrates through an air cylinder 27 disposed at the rear part of the piston valve main body 29 through a packing 31 and is fitted into the air cylinder 27 so as to be moved back and forth by compressed air. It is connected to an operating piston 28 that is slid on the cylinder. When the operating piston is pressed, the valve piston 22A protrudes from the cylindrical surface 23 as shown in FIG. 1, opens the valve, and opens the paint passage on the cylindrical surface 23.
[0015]
At this time, the check valve body 4A pushed by the valve piston 22A is separated from the inner surface sheet 5A and the seal member 7A, and the internal passage 11 and the container side passage 32 of the cylindrical surface 23 communicate with each other. The intermittent valve of the present invention has the configuration of the above-described intermittent valve on the left and right, and the other piston valve 21B is provided on the opposite side of the movable joint 1 as shown in FIG. In this embodiment, the check valve body is an example of a ball valve, but there is no substantial difference within the scope of the present invention.
[0016]
Operation of the switching, the working piston 28 is returned first, the piston valve 21 becomes closed state by the packing 24 A as the valve piston 22 A is seen in Figure 3 becomes a position of the cylindrical surface 23. At the same time, the check valve A closes when the check valve body 4A is in close contact with the seal member 7A of the check valve body 3A. Thereafter the movable joint 1 is moved in the right direction as shown in FIG. 3, away from the packing 24A to first end 10A of the check valve A-side is provided on the second end of the piston valve 21 A side The piston valve 21 A and the check valve A are completely separated.
[0017]
Further moving unit 2 is in contact with the valve piston 22B of the front end surface 9 B is the piston valve 21B of the check valve body 4 B of Moving to the right the other check valve B person, without a gap in close contact, leaving no air gaps It is like that. At the same time in contact with the packing 24B provided in the second end portion of the first end portion 10B is a piston valve 21B, the valve piston 22B of the distal end surface 9 B and the piston valve 21B of the check valve body 4 B as shown in FIG. 4 The tip surface 19B is in close contact. The distal end of the Tokiben piston 22B is to match the opening exposing the check valve body 4 B, is connected passage periphery is filled without gaps by the check valve body 4 B and the valve piston 22B.
[0018]
Piston 22B from this state is pushed to the left, the check valve body 4 B away from the sealing member 7B, the valve piston 22B projects into the interior passageway 11 away from the packing 24B, the interior passage 11 without aerating The communication with the container side passage of the piston valve 21B completes the switching of the paint passage.
Since the piston valves are provided on both sides of the movable joint in this way, one valve is cut by one operation, and is reliably cut off to form electrical insulation, and the other valve is connected. be able to. Therefore, it is possible to switch the flow path while maintaining insulation by connecting the paint path to each piston valve and movable joint.
[0019]
FIG. 5 shows an example of a paint flow path switching valve system in which this intermittent valve is actually used. This device is a system that enables continuous supply of a paint supply system to a spray gun while maintaining an electrical insulation state when electrostatic coating is performed using a water-based paint, and is disclosed in the aforementioned Japanese Patent No. 3217394. Used for the same purpose.
The switching valve has check valves at both ends, and movable joints 71 and 72 having connection ports connected to the spray gun 75 and the replenishment pump 73 in the middle, and piston valves 55, 65 and 56 provided on both sides thereof. , 66 are provided in two sets, and the movable joints 71 and 72 are simultaneously operated by the operating means such as the air cylinder 40 and are reciprocally driven between the opposed piston valves. It is the composition which becomes.
[0020]
The piston valve side is connected to each inlet side and outlet side. That is, the outlet side 52 of the paint container 51 is connected to the piston valve 55, and the inlet side 53 is connected to the piston valve 66. The outlet side 62 of the paint container 61 is connected to the piston valve 65, and the inlet side 63 is connected to the piston valve 56. At this time, the connection port of the movable joint 71 is connected to the spray gun 75 via the supply pump 74, and the other movable joint 72 is connected to the supply pump 73.
In this state, the paint fed from the replenishing pump 73 enters and is replenished from the inlet side 63 of the paint container 61 via the piston valve 56 connected to the movable joint 72. In this case, the paint supply path is shut off by the piston valve 65 connected via the outlet side 62, and is completely cut off from the supply path on the side of supplying the paint to the spray gun. The ground potential is.
[0021]
On the other hand, the spray gun 75 charged to a high potential is fed with paint through a supply pump 74 from a movable joint 71 connected to the piston valve 55 connected to the outlet side 52 of the paint container 51. At this time, the inlet side 53 of the paint container 51 is connected to the piston valve 66, but is completely isolated from the movable joint 72, and the high voltage is also cut off here. Therefore, high voltage insulation on the spray gun side is maintained.
[0022]
When the paint in the paint container 51 is used, the moving body 30 is moved rightward by the air cylinder 40, the movable joints 71 and 72 are separated from the piston valves 55 and 56, and are connected to the piston valves 65 and 66. The paint from 73 is supplied to the paint container 51 through the piston valve 66, and the paint in the paint container 61 is connected to the supply pump 74 through the movable joint 71 from the piston valve 65 and supplied to the spray gun 75. In the case of continuous supply, the operation timing is set and these operations are repeated.
[0023]
In this embodiment, two paint containers are provided in parallel, and the paint is alternately supplied from one of the paint containers to the coating machine. In this way, a plurality of flow paths are simultaneously switched. However, since it can be reliably cut off and switched, it can be used without any problem even when electrical insulation is required in particular in the electrostatic coating.
[0024]
【The invention's effect】
As can be seen from the above-described embodiments, the connection and disconnection structure of the movable joint and the piston valve is closely attached to the check valve provided in the movable joint as shown in FIG. A piston valve is arranged in a shape, and the piston valve is projected and opened, and the check valve is opened away from the valve seat as a seal member, and the piston valve can eliminate a gap with the periphery of the valve body. Therefore, the air gap at the time of connection can be made as close to zero as possible, and air can be prevented from being mixed.
[0025]
Further, even when cutting, there is no space where the paint remains outside the blocking portion, so that the paint hardly remains outside, and it is possible to prevent the paint from dripping and poor electrical insulation. Therefore, it is possible to obtain a paint supply system that enables electrical insulation. In addition, since there is no gap, cleaning becomes easy.
[0026]
In addition, the present invention is a combination of a piston valve and a check valve, so that the timing of opening and closing the valve can be freely controlled in order to control the operation of the piston valve by the operation of the air cylinder. Maintenance can be facilitated by reducing instability factors such as packing and the like.
[0027]
In addition, by installing multiple movable joints on the support and disposing piston valves facing each other, it is possible to reliably and easily synchronize control, while reliably controlling the timing of supply and insulation from multiple supply devices Complex control that alternately controls the supply can be easily performed.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of the main part of an intermittent valve showing an embodiment of the present invention. FIG. 2 is a cross-sectional view of a switching valve provided with intermittent valves on both sides. FIG. 4 is a cross-sectional view when the piston valve of the intermittent valve and the check valve are connected and the passage is closed. FIG. 5 is a cross-sectional view of the switching valve system using the intermittent valve of the present invention. Schematic diagram showing one embodiment 【Explanation of symbols】
1, 71, 72, movable joints 2, 30, moving body 3, body 4, check valve body 5, inner surface sheet
6, groove 7, seal member 9, front end face 10A, 10B, first end 20A , 20B , second end 21A , 21B , 55, 56, 65, 66, piston valve 22A , 22B , valve piston 24A , 24B , packing 27, air cylinders 51, 61, paint container 73, replenishment pump 74, supply pump

Claims (2)

A movable joint provided in an intermediate portion and piston valves are arranged on both sides thereof, and the movable joint and the respective piston valves are alternately cut off and connected to each other by the movement of the movable joint. Each of the movable joints has a paint connecting portion in the middle and a first end portion containing a check valve at each end facing the piston valve. A second end portion that contacts and separates from the first end portion, and is fitted and closed by a packing provided at an end portion of the paint passage that opens to the end portion, and the opening end is operated by an external operating means. protruding from parts provided a valve piston opens, a shape tip shape of the valve piston is substantially close contact with the edge shape of the check valve, said first end and said second end is the packing After hermetically sealed through Intermittent valve of the paint supply device for opening the paint passage opening the check valve with opened by actuating the piston valve. More movable joints are installed in the mobile, intermittent valve of each mobile opposed to respective piston valves and junctions provided, enabling and blocking the paint supply apparatus according to claim 1.

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