JP2000218196A - Intermediate storage reservior for electrostatic coating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To upgrade the sealing properties between a cylinder and a piston and prevent an accumulation of coating due to its leakage from occurring to enable a high-quality electrostatic coating process to be performed. SOLUTION: A first and a second sealing member 26, 28 are fixed on the end part 14a of a piston 14 through an intermediate press member 22 and a press member 24. The first and the second sealing members 26, 28 have a thin sheet ringlike flange part 52 and a ringlike sliding part 54 which is integrally formed with the flange part 52 bulged in the axial direction and at the same time, slides into contact with the peripheral faces 90, 82 of the inner wall 36 of a cylinder respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paint gun, which is interposed between a paint and a supply source of a cleaning liquid and a coating gun to temporarily store and supply the coating material to the coating gun while cleaning the inside of a cylinder with the cleaning liquid. The present invention relates to an intermediate storage tank of an electrostatic coating device.

[0002]

2. Description of the Related Art Generally, as one form of an electrostatic coating apparatus for conductive paint, an intermediate storage tank is provided between a coating gun and a paint supply source. Various changes have been made to avoid color mixing due to the residual paint remaining in the intermediate storage tank when the color of a newly used paint is changed. An example of this kind of prior art is disclosed in
Japanese Patent Application Publication No. 310671 discloses a “method of sequentially coating a workpiece with a conductive coating material”.

[0003]

In the above prior art,
A sealing ring that slides along the inner wall of the cylinder body is provided on the peripheral surface of the piston. For this reason, at the time of the delivery of the paint accompanying the movement of the piston, the paint injected into the cylinder chamber easily leaks into the sealing ring fitting groove of the piston, and in the sealing ring fitting groove,
There is a possibility that a paint pool may occur before and after the sealing ring.

As a result, the cleanability of the entire cylinder chamber deteriorates remarkably, and the paint remaining on the cylinder chamber and the newly recolored paint cause a mixed color state, so that a genuine color paint is applied to the workpiece. It has been pointed out that the coating cannot be effectively performed.

The present invention solves this kind of problem and reliably prevents the accumulation of paint in the seal between the cylinder and the piston. It is an object of the present invention to provide an intermediate storage tank of an electrostatic coating device capable of performing a proper electrostatic coating operation.

[0006]

In the intermediate storage tank of the electrostatic coating apparatus according to the present invention, a seal member is fixed via a holding member to an end of a piston slidably reciprocated in a cylinder. In addition, the seal member has a ring-shaped flange portion that is in contact with the end surface of the large-diameter portion of the pressing member and is pressed and held by the end portion of the piston, while a ring-shaped sliding portion that swells in the axial direction has the ring-shaped sliding portion. The pressing member is in sliding contact with the peripheral surface of the large diameter portion and the inner wall of the cylinder at the same time.

As described above, the ring-shaped sliding portion is pressed radially outward by the large-diameter portion peripheral surface of the pressing member and slides on the cylinder inner wall, so that the liquid tightness between the piston and the cylinder inner wall is effective. To improve. Therefore, the paint injected into the cylinder does not leak from the sealing portion between the piston and the inner wall of the cylinder, and the paint pool is generated,
This paint is reliably prevented from remaining in the cylinder.

Thus, the cleaning operation can be efficiently performed with a simple structure, and the mixture of the paint before the color change and the paint after the color change is prevented, so that the genuine color paint can be surely applied. And a high quality electrostatic coating operation can be performed.

Further, an annular space is provided inside the ring-shaped sliding portion, and an O-ring is provided in this space. Therefore, the sealing performance between the ring-shaped sliding portion and the inner wall of the cylinder is further improved, and the durability of the ring-shaped sliding portion can be ensured. Further, there is no possibility of electric discharge, and it is possible to prevent the seal member from being damaged as much as possible.

[0010] Furthermore, a plurality of seal members are arranged side by side at the end of the piston via an intermediate pressing member. Thereby, the durability of the seal member is improved, and the sealability can be more reliably maintained.

[0011]

FIG. 1 is an explanatory vertical sectional view of an intermediate storage tank 10 according to an embodiment of the present invention. The intermediate storage tank 10 includes a cylinder 12, a piston 14 slidably reciprocated in the cylinder 12, and a cylinder device wall 16.
An injection hole 18 provided in the cylinder unit and connected to a supply source (described later) of a paint and a cleaning liquid, and a discharge hole 20 provided in the cylinder wall 16 and connected to a coating gun described later and connected to a coating gun. A first material made of a polymer material, for example, a polytetrafluoroethylene (PTFE) resin or a fluorine-based resin disposed on the end portion 14a of the piston 14 with an intermediate pressing member 22 and a pressing member 24 interposed therebetween. And second seal members 26 and 28.

The piston 14 has a piston main body 30 and a piston 32 screwed to the piston main body 30. A stepped hole 3 is formed in the center of the piston main body 30.
4 are formed through. On the outer peripheral surface of the piston body 30,
Seal rings 38a, 38 slidingly contacting the cylinder inner wall 36
b is attached. In the cylinder 12, the first cylinder chamber 40 and the second cylinder chamber 4 sandwich the piston body 30 therebetween.
2 are formed.

In the cylinder wall 16 forming the first cylinder chamber 40, an injection hole 18 and a discharge hole 20 for paint and cleaning liquid are formed. The discharge hole 20 communicates with a coating gun (described later), and the injection hole 18 for introducing the paint and the cleaning liquid into the first cylinder chamber 40 extends to the outer peripheral wall of the cylinder 12 in an inclined state. are doing. The second cylinder chamber 42 is supplied with air as a driving source for sliding the piston 14 in the direction of the arrow X1, and further, the air hole 4 for discharging the supplied air to the outside.
4 are formed.

As shown in FIG. 2, the first and second seal members 26 and 28 have a substantially disk shape, and a hole 50 is formed at the center thereof. The first and second seal members 26 and 28 are formed of a thin ring-shaped flange portion 52 that is pressed and held along the end portion 14a of the piston 14, and are formed integrally with the flange portion 52 and are formed in the axial direction (arrow A). And a ring-shaped sliding portion 54 swelling in the direction.

The sliding portion 54 has a slanted outer peripheral surface 56 and a slanted inner peripheral surface 58 which are inclined in a direction away from the flange portion 52 toward the front in the axial direction (the direction of the arrow A1). And the inclined inner peripheral surface 5
A projection 60 protruding forward is formed at the tip of 8. An annular space 62 is provided inside the sliding portion 54, and an O-ring 64 is provided in the space 62. A ring-shaped insert member 66 is mounted on the opening end side of the space 62, and the insert member 66 has a function of preventing the O-ring 64 from coming off. O-ring 6
4 is formed of, for example, fluorine-based rubber, and the insert member 66 is formed of, for example, PTFE resin.

As shown in FIG. 1, the holding member 24 includes a large-diameter portion 68, a small-diameter portion 70 formed coaxially and integrally with one end of the large-diameter portion 68, and one end of the small-diameter portion 70. A rod portion 72 formed coaxially and inserted into the small-diameter portion side of the stepped hole portion 34 of the piston body 30;
And a screw part 74 formed coaxially on one end side of the nut. A nut 76 is screwed onto the screw part 74.

At the other end of the large diameter portion 68, a conical portion 78 protruding forward toward the center is provided.
The end face 80 of the small diameter portion 70 contacts the flange portion 52 of the second seal member 28. The peripheral surface 82 of the large diameter portion 68 connected to the end surface 80 comes into contact with the inclined inner peripheral surface 58 constituting the sliding portion 54 of the second seal member 28. The diameter of the peripheral surface 82 is set to a size that allows the sliding portion 54 to be pressed and deformed between the peripheral surface 82 and the cylinder inner wall 36 to reliably prevent the paint from leaking.

The sliding portion 54 has an inclined inner peripheral surface 58 having a large diameter portion 6.
When the inclined outer peripheral surface 56 is in contact with the cylinder inner wall 36 and deforms while contacting the peripheral surface 82 of the sliding member 8, the convex portion 60 protrudes forward to absorb the amount of compression of the entire sliding portion 54 in the thickness direction. (See the two-dot chain line in FIG. 2). The small-diameter portion 70 is set to a size that can be inserted into the hole 50 of the first and second seal members 26 and 28. The small-diameter portion 70 fits into the hole 84 of the intermediate holding member 22, and a seal ring 86.
Is interposed.

The intermediate pressing member 22 includes the first sealing member 2
6, an end surface 88 for contacting and holding the flange portion 52 toward the piston main body 30 by contacting the flange portion 52, and an inclined surface which is connected to the end surface 88 and constitutes the sliding portion 54 of the first seal member 26. A peripheral surface 90 that presses the peripheral surface 58 in a radially outward direction, and a protruding portion 92 connected to the peripheral surface 90 are integrally provided.

FIG. 3 is an explanatory view of the overall configuration of the electrostatic coating apparatus 100 in which the intermediate storage tank 10 configured as described above is incorporated. In the electrostatic coating apparatus 100, the intermediate storage tank 1
Numeral 0 designates a color change valve mechanism 102 as a paint supply source and a paint gun 1 provided for selectively supplying a plurality of different paints.
04.

A supply path 106 is provided between the intermediate storage tank 10 and the color changing valve mechanism 102, and at least partly along the supply path 106, an electrically insulating pipe 108 is provided. A block valve mechanism 112 to which switching valves 110a and 110b are connected is disposed on both sides of the block. The color changing valve mechanism 102 includes a first cleaning valve 114 that controls supply of air (A), water (W), a cleaning liquid (S), and the like, and a plurality of paint valves 116a that can supply paint of different colors. ~ 116
e.

The color change valve mechanism 102 and a second cleaning valve 118 for controlling the supply of air (A), water (W), cleaning liquid (S), and the like are controlled by an inlet-side switching valve 110a constituting a block valve mechanism 112. And the block valve mechanism 112 is connected to the supply path 106 from the switching valve 110b on the outlet side.
Is connected to the intermediate storage tank 10. This switching valve 11
Ob is further communicable with a drainage tank 122 via a drainage path 120.

In the second cylinder chamber 42 of the intermediate storage tank 10, an air supply source 124 is provided with a flow path adjustment valve 126, an on-off valve 12
8 and the air hole 44, and the piston 1 is moved by the air pressure supplied from the air supply source 124.
4 is driven. This air supply source 124 is connected to the booster 1
It is connected to a flow path adjuster 132 that adjusts the air pressure via 30, and the flow path adjuster 132 controls the amount of protrusion of the paint.

Between the intermediate storage tank 10 and the coating gun 104, a delivery path 134 in which a flow path adjuster 132 is interposed is provided. The coating gun 104 includes a dump valve 136 and a trigger valve 138. In addition, it is connected to high voltage applying means (not shown).

The electrostatic coating apparatus 100 configured as described above
Will be described below.

At the time of the electrostatic coating, first, as shown in FIG. 3, a paint of a predetermined color is pressure-fed from the paint valve 116a of the color changing valve mechanism 102, and this paint is supplied to the intermediate storage tank 10 through the supply path 106. The first cylinder chamber 40 is filled, and further the coating gun 104 is filled via the delivery path 134.
When the paint is filled, the trigger valve 138 is closed,
The dump valve 136 is opened.
6 is opened.

Therefore, the switching valve 1 of the block valve mechanism 112
The switching operation of 10a and 110b is performed, the block valve mechanism 112 is washed under the driving action of the second washing valve 118, and the washing liquid used for this washing is sent to the drainage tank 122 via the discharge path 120. Is discharged. Next, the block valve mechanism 112 is dried, whereby the color changing valve mechanism 102 is dried.
And the intermediate storage tank 10 are electrically insulated.

Next, the flow control valve 1 is supplied from the air supply source 124.
26 and the second storage tank 10 via the on-off valve 128.
Driving air is supplied to the cylinder chamber 42 and the piston 14
Is displaced toward the first cylinder chamber 40, and a high-voltage applying unit (not shown) is driven. This allows the paint to
In a state where a high voltage is directly applied, the high voltage is applied to a work (not shown) under the opening action of the trigger valve 138.

In this case, in this embodiment, as shown in FIG. 1, the first seal member 26 is attached to the end 14a of the piston 14.
When the second sealing member 28 is disposed with the intermediate pressing member 22 interposed in the first sealing member 26, the pressing member 24
6 is fixed.

For this reason, the first seal member 26 is configured such that the flange portion 52 comes into contact with the end surface 88 of the intermediate holding member 22 to be pressed and held by the end portion 14 a of the piston 14, and the inclined inner peripheral surface of the sliding portion 54. 58 contacts the peripheral surface 90 of the intermediate pressing member 22 and is pressed against the cylinder inner wall 36 side.
Accordingly, the sliding portion 54 is configured such that the inclined outer peripheral surface 56 is pressed and deformed by the cylinder inner wall 36 while the inclined inner peripheral surface 58 is
And is securely slidably supported on the cylinder inner wall 36 and the peripheral surface 90.

Further, the flange portion 52 of the second seal member 28 contacts the end face 80 of the press member 24 and is pressed toward the intermediate press member 22, and the inclined inner peripheral surface 58 of the slide portion 54 has a large diameter. It comes into contact with the peripheral surface 82 of the portion 68 and is pressed toward the cylinder inner wall 36. For this reason, the second seal member 2
8, the sliding portion 54 is securely supported in sliding contact with the cylinder inner wall 36 and the peripheral surface 82 of the large-diameter portion 68, and the paint filled in the first cylinder chamber 40 is filled with the second seal member 28 and the cylinder. There is no leakage to the first seal member 26 side from the sliding contact portion with the inner wall 36 or the large diameter portion 68.

Therefore, for example, it is possible to reliably prevent the accumulation of paint between the first and second seal members 26 and 28, and to clean the inside of the cylinder 12 in order to change colors. The effect that the task is efficiently and reliably performed is obtained. This effectively prevents color mixture between the paint before the color change and the paint after the color change, and makes it possible to apply a genuine color paint after the color change to a work (not shown). There is an advantage that the work is performed with high quality.

Further, an O-ring 64 is disposed in a space 62 in the sliding portion 54 constituting the second seal member 28. Therefore, the inclined inner peripheral surface 58 and the inclined outer peripheral surface 56 of the sliding portion 54 can be reliably brought into sliding contact with the peripheral surface 82 of the large-diameter portion 68 and the cylinder inner wall 36, respectively. Performance can be further improved. In addition, the durability of the sliding portion 54 itself is improved, and since the rubber O-ring 64 is used, there is no risk of electric discharge, and the breakage of the second seal member 28 can be prevented as much as possible.

Further, first and second seal members 26 and 28 are provided side by side with respect to the piston body 30.
Therefore, there is an effect that the durability of the first and second seal members 26 and 28 themselves is improved, and the sealability is further ensured. In the present embodiment, the first and second seal members 26 and 28 are arranged side by side. However, only the first seal member 26 may be used alone, or three or more seal members may be used. May be juxtaposed.

[0035]

In the intermediate storage tank of the electrostatic coating apparatus according to the present invention, the seal member fixed to the end of the piston via the pressing member has a ring-shaped flange portion pressed and held at the end of the piston. And a ring-shaped sliding portion that is formed integrally with the ring-shaped flange portion, swells in the axial direction, and slidably contacts the large-diameter portion peripheral surface of the pressing member and the cylinder inner wall simultaneously. The sealing property between the piston and the inner wall of the cylinder is effectively improved, and the occurrence of paint accumulation due to the leakage of paint from the seal portion can be reliably prevented. This prevents color mixing between the paint before the color change and the paint after the color change, and makes it possible to perform high-quality electrostatic coating work by applying only a genuine color paint.

[Brief description of the drawings]

FIG. 1 is an explanatory longitudinal sectional view of an intermediate storage tank according to an embodiment of the present invention.

FIG. 2 is a partially sectional explanatory view of a seal member constituting the intermediate storage tank.

FIG. 3 is an explanatory view of an entire configuration of an electrostatic coating apparatus in which the intermediate storage tank is incorporated.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Intermediate storage tank 12 ... Cylinder 14 ... Piston 16 ... Cylinder wall 18 ... Injection hole 20 ... Discharge hole 22 ... Intermediate holding member 26, 28 ... Seal member 30 ... Piston body 40, 42 ... Cylinder chamber 52 ... Flange Part 54 Sliding part 56 Slant outer peripheral surface 58 Slant inner peripheral surface 60 Slant part 62 Space part 64 O-ring 66 Insert member 68 Large diameter part 80, 88 End surface 82, 90 Peripheral surface 100 ... Electrostatic coating device 102 ... Color changing valve mechanism 104 ... Coating gun

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Osamu Kageyama 1-10-1 Shinsayama, Sayama City, Saitama Prefecture Honda Engineering Co., Ltd. (72) Inventor Toshiyuki Kubo 1-10-1 Shinsayama, Sayama City, Saitama Prefecture Hondae Engineering F Co., Ltd. F-term (reference) 4F034 AA03 BB04

Claims (3)

[Claims] A cylinder, a piston disposed in the cylinder so as to be reciprocally slidable, an injection hole provided in a cylinder wall, and connected to a supply source of a paint and a cleaning liquid; and a cylinder wall. And a discharge hole for paint and cleaning liquid connected to a coating gun, and a sealing member made of a polymer material fixed to an end of the piston via a pressing member. A ring-shaped flange portion which is in contact with the end surface of the large-diameter portion of the holding member and is pressed and held at the end of the piston; and which is formed integrally with the ring-shaped flange portion and swells in the axial direction, and An intermediate storage tank for an electrostatic coating apparatus, comprising: a ring-shaped sliding portion that simultaneously slides on a large-diameter portion peripheral surface of the member and the cylinder inner wall. 2. The static storage tank according to claim 1, wherein said ring-shaped sliding portion has an annular space inside, and an O-ring is provided in said space. Intermediate storage tank for electrocoating equipment. 3. The electrostatic coating device according to claim 1, wherein a plurality of the seal members are arranged in parallel with an end of the piston with an intermediate pressing member interposed therebetween. Intermediate storage tank.