JP4848185B2 - Painting gun - Google Patents

Description

  The present invention relates to a paint gun.

As a paint gun provided with a needle valve, there is one shown in FIG. This is because the inflow space 103 communicating with the nozzle 102 is formed in the gun body 101 provided with the nozzle 102 at the front end, and the front end side portion of the needle 104 elongated in the front-rear direction is moved back and forth in the inflow space 103. Thus, the valve port 105 provided in the nozzle 102 is opened and closed, and the paint supplied from the inlet 106 opened at the rear end portion of the inflow space 103 is discharged from the nozzle 102.
In addition, there exists a thing described in patent document 1 as an example of the coating gun provided with the needle valve.
JP 2003-087881 A

In the case of a painting gun provided with a needle valve, a drive mechanism 107 for moving the needle 104 back and forth is provided behind the inflow space 103, and the annular space 108 formed on the rear wall of the inflow space 103 is provided with a drive mechanism 107. A packing 109 that is in close contact with the outer peripheral surface of the needle 104 is provided as means for preventing the paint from leaking to the mechanism 107 side.
Now, when cleaning the paint flow path in the paint gun, the cleaning liquid is also flowed along the same path as the paint, but the cleaning liquid that has flowed into the inflow space 103 moves toward the front nozzle 102, and therefore the inflow space 103. In the vicinity of the packing 109 facing the rear wall, the flow rate of the cleaning liquid becomes slow. In particular, the gap between the annular space 108 and the packing 109 is narrow and the cleaning liquid tends to stay. Therefore, the conventional coating gun has a problem that the packing 109 and its vicinity cannot be sufficiently cleaned.
The present invention has been completed based on the above circumstances, and an object thereof is to enable efficient cleaning of the packing and the vicinity thereof.

As means for achieving the above-mentioned object, the invention of claim 1 includes a gun body in which a nozzle is provided at the front end and a circular cross section that is elongated in the front-rear direction and penetrates the gun body in the front- rear direction. Between the outer peripheral surface of the needle and the inner peripheral surface of the through-hole , the needle having a front end corresponding to the valve opening provided in the nozzle And a front end is provided behind the guide passage, and the needle is opened at a position facing the inner peripheral surface of the through hole. A drive mechanism that moves between a retracted position and a forward position to be closed; and a drive mechanism that faces the rear end of the guide path and is installed in an annular space that is substantially concentric with the needle, and is connected to the drive mechanism from the guide path side. Regulating liquid leakage to the side A packing, a ring that is substantially concentric with the needle and surrounds the guide path, has a first annular flow path with a closed front end, a ring that is substantially concentric with the needle, It has a feature in that a second annular channel that communicates the rear end of the one annular channel and the rear end of the guide channel, and an inflow opening that opens to the outer peripheral surface of the first annular channel.

According to a second aspect of the present invention, in the first aspect of the present invention, the inner peripheral surface and the outer peripheral surface of the first annular flow path are configured by different parts, and the front end portion inner peripheral surface of the first annular flow path Is formed with a circumferential mounting groove that is recessed in a substantially “U” shape, and the mounting groove has a front end of the first annular flow path that is in close contact with the outer peripheral surface of the first annular flow path. It is characterized in that a sealing ring for sealing is attached.
The invention of claim 3 is characterized in that, in the invention of claim 2, the seal ring is in close contact with the inner surface of the rear end of the mounting groove.

The invention of claim 4 is the one according to claim 3, wherein the seal ring has a substantially circular cross section,
The radial dimension between the outer circumferential surface and the inner circumferential surface of the first annular channel is approximately 1 of the radial dimension between the outer circumferential surface of the first annular channel and the groove bottom surface of the mounting groove. It is characterized by being / 2.

<Invention of Claim 1>
The cleaning liquid that has flowed into the first annular channel from the inflow port is divided into two hands and flows in a semicircular arc path in the first annular channel, and merges at a position opposite to the inflow port in the first annular channel. To do. Since the front end of the first annular flow path is closed, the merged cleaning liquid turns rearward, splits into the second annular flow path, flows in a semicircular path, and merges in the vicinity of the inlet. . Part of the combined cleaning liquid merges with the cleaning liquid flowing in from the inlet and flows in the guide path toward the front nozzle, and the remaining cleaning liquid collides with the cleaning liquid flowing in from the inlet and turns backward. It flows in a semicircular arc path divided into two in the annular space. Since the packing is provided in the annular space, the object to be removed (for example, pigment) adhering to the gap between the annular space and the packing or the surface of the packing is washed away by the cleaning liquid and removed. And the washing | cleaning liquid which flowed in two parts in the annular space merged, and then flows in the guide path toward the nozzle.

<Invention of Claim 2>
Since the front end of the first annular channel is closed by the seal ring, there is no possibility that the paint or the cleaning liquid may enter the gap between the two parts constituting the inner peripheral surface and the outer peripheral surface of the first annular channel.
<Invention of Claim 3>
The opening edge on the rear side of the mounting groove faces the first annular flow path, but since the seal ring is in close contact with the inner surface of the rear end of the mounting groove, the paint and cleaning liquid in the first annular flow path There is no risk of entering the mounting groove.

<Invention of Claim 4>
The seal ring has a substantially circular cross section, and the radial dimension between the outer circumferential surface and the inner circumferential surface of the first annular channel is a diameter between the outer circumferential surface of the first annular channel and the groove bottom surface of the mounting groove. Since the dimension is approximately ½ of the dimension in the direction, the seal ring and the inner surface of the rear end of the mounting groove abut at the opening edge of the mounting groove. Therefore, there is no gap between the outer peripheral surface forming the arc shape of the seal ring and the opening edge at the rear end surface of the mounting groove, which may clog the object to be removed such as pigment.

<Embodiment 1>
A first embodiment of the present invention will be described below with reference to FIGS. The coating gun of this embodiment is configured to control the discharge of paint or cleaning liquid from a nozzle 12 by a needle valve 11 provided in the gun body 10. The gun body 10 has a cylindrical member 14 having a circular cross section screwed to the front end portion of the block body 13 and coupled thereto, and a head 15 is assembled to the front end of the cylindrical member 14 and fixed by a nut 16. A spring receiving member 17 is screwed into the end and assembled, and a nozzle 12 for discharging paint and cleaning liquid is provided at the front end (the left end in FIG. 1) of the gun body 10. The nozzle 12 has a configuration in which the front end portion of the needle 19 is made to correspond to the valve port 18 at the front end of the cylindrical member 14, and when the needle 19 advances and the valve port 18 is closed, the needle valve 11 is closed. When the discharge of paint or cleaning liquid is stopped, the needle 19 is retracted and the valve port 18 is opened, the needle valve 11 is opened, and the paint or cleaning liquid is discharged from the nozzle 12 through the valve port 18. It has become.

  Inside the block body 13, there are a front hole 20 having a circular cross section opened to the front end face of the block body 13, a rear hole 21 having a circular cross section opened to the rear end face, a front hole 20 and a rear hole 21. A communication space 22 having a circular cross section to be communicated is formed concentrically. A female screw portion 23 is formed in a substantially first half region on the inner peripheral surface of the front hole 20, and a male screw portion 24 on the outer peripheral surface of the rear end portion of the tubular member 14 is concentrically threaded on the female screw portion 23. Are combined. A through-hole 25 having a circular cross section penetrating in the front-rear direction is formed inside the cylindrical member 14, and a needle 19 having a circular cross-section elongated in the front-rear direction is passed through the through-hole 25. A guide path 26 is formed between the outer peripheral surface of the needle 19 and the inner peripheral surface of the through-hole 25 and has a cylindrical shape concentric with the needle 19 and a front end communicating with the valve port 18 (nozzle 12). Yes.

  A drive mechanism 27 for moving the needle 19 in the front-rear direction is provided in the rear hole 21, that is, at a position behind the guide path 26. The drive mechanism 27 includes a piston 28 that moves back and forth while being in sliding contact with the inner peripheral surface of the rear hole 21, and a compression coil spring provided between the rear end surface of the piston 28 and the front surface of the spring receiving member 17. 29, and the rear end of the needle 19 is fixed to the piston 28. The piston 28 and the needle 19 are urged forward by the elastic force of the compression coil spring 29, and the needle valve 11 is always kept closed by this urging force. When operating air is supplied from an air inflow path 30 that opens to the front end of the inner peripheral surface of the rear hole 21, the piston 28 and the needle 19 are retracted to open the needle valve 11.

  A cylindrical guide member 31 is fixedly attached to the rear side region excluding the front end portion in the communication space 22, and the needle 19 does not have a radial play in the circular center hole 32 of the guide member 31. And it is penetrated so that the movement to the front-back direction is possible. The clearance between the inner peripheral surface of the communication space 22 and the outer peripheral surface of the guide member 31 and the clearance between the inner peripheral surface of the guide member 31 and the outer peripheral surface of the needle 19 are kept airtight by a ring-shaped seal member 33. Yes.

  Further, the front end portion of the communication space 22 is an annular space 34, and an annular packing 35 concentric with the needle 19 is attached in the annular space 34. The packing 35 is formed by forming a cutout portion 36 in a form cut out in a substantially V shape on the front end surface over the entire circumference. The outer peripheral edge of the front end surface of the packing 35 is brought into contact with a reduced-diameter stopper 37 formed concentrically with the front end edge of the communication space 22, and this contact leads to the front of the packing 35 (to the front hole 20 side). Displacement is regulated. Further, the rear end surface of the packing 35 is in contact with the front end surface of the guide member 31, and displacement of the packing 35 to the rear (rear hole 21 side) is restricted by this contact. The packing 35 regulates leakage of paint and cleaning liquid from the guide path 26 side to the drive mechanism 27 side.

At the rear end of the front hole 20 of the block body 13, a first annular channel 38 and a second annular channel 39 are configured by the rear end of the tubular member 14.
The first annular channel 38 is formed so as to be sandwiched in the radial direction between the rear end inner peripheral surface of the front hole 20 and the rear end outer peripheral surface of the tubular member 14, and is substantially concentric with the needle 19. In this way, an annular shape surrounding the guide path 26 is formed, and the front end is closed. On the inner peripheral surface of the front end portion of the first annular flow path 38 (the outer peripheral surface of the cylindrical member 14), a mounting groove 40 that is recessed in a substantially “U” shape is formed over the entire circumference. Is attached with a seal ring 41 that seals the front end of the first annular flow path 38 in a liquid-tight manner by being in close contact with the outer peripheral face of the first annular flow path 38 (the inner peripheral face of the front hole 20). . The seal ring 41 is in close contact with the front end inner surface and the rear end inner surface of the mounting groove 40. The seal ring 41 has a substantially circular cross section, and the radial dimension between the outer peripheral surface and the inner peripheral surface of the first annular flow path 38 is the groove of the outer peripheral surface of the first annular flow path 38 and the mounting groove 40. Since the radial dimension between the bottom surface and the bottom surface is approximately ½, the close contact position with the seal ring 41 on the rear end inner surface of the mounting groove 40 is a position near the opening edge of the mounting groove 40.

  The second annular channel 39 is formed so as to be sandwiched back and forth between the rear end surface of the tubular member 14 and the rear end surface on the rear side of the front hole 20, and forms a substantially concentric ring with the needle 19. . The second annular flow path 39 communicates the rear end of the first annular flow path 38 and the rear end of the guide path 26. In addition, an annular region near the outer peripheral surface of the needle 19 in the second annular channel 39 communicates with the annular space 34. In other words, the front surface of the annular space 34 and the notch 36 on the front surface of the packing 35 face the second annular flow path 39 and the rear end of the guide path 26.

  An inflow port 42 is opened at a lower end position on the outer peripheral surface of the first annular flow path 38 (inner peripheral surface of the front hole 20). The opening direction of the inflow port 42 is oblique with respect to the moving direction (front-rear direction) of the needle 19, and the coating material or the cleaning liquid is allowed to flow obliquely inwardly from the inflow port 42. The opening area of the inlet 42 faces the inner peripheral surface of the first annular channel 38 and the outer peripheral edge of the second annular channel 39, and the opening dimension in the front-rear direction of the inlet 42 is the first annular channel. The dimension is larger than the longitudinal length of the inner peripheral surface of the flow path 38. That is, the entire first annular channel 38 faces the inlet 42. The front edge of the opening of the inflow port 42 is slightly behind the contact position of the seal ring 41 on the outer peripheral surface of the first annular flow path 38.

Next, the operation of this embodiment will be described.
The paint supplied from the inlet 42 into the front hole 20 reaches the valve port 18 through the second annular channel 39 and the guide channel 26. When the drive mechanism 27 is operated in this state to retract the needle 19, the needle valve 11 is opened, the valve port 18 is opened, and the paint is discharged from the nozzle 12. When the paint is supplied into the front hole 20, the paint is filled not only in the second annular flow path 39 and the guide path 26 but also in the first annular flow path 38 and the annular space 34. The paint adheres to the front surface of the packing 35 (the surface of the notch 36) and the inner wall of the annular space 34.

  Next, a process of cleaning the paint flow path for color change or the like will be described. At the time of cleaning, the cleaning liquid is supplied from the inlet 42 into the front hole 20 with the needle valve 11 opened. Since the inlet 42 faces the first annular channel 38, the supplied cleaning liquid is divided into left and right hands in the first annular channel 38 as shown by the arrow a in FIG. It flows upward along the path and merges at the upper end of the first annular channel 38 (the end opposite to the inlet 42). Since the front end of the first annular channel 38 is closed by the seal ring 41, the merged cleaning liquid turns backward as indicated by the arrow b in FIG. 2, and is indicated by the arrow c in FIGS. As shown, the second annular channel 39 is divided into left and right hands, flows downward along a semicircular arc path, and merges in the vicinity of the inlet 42. A part of the combined cleaning liquid merges with the cleaning liquid flowing in from the inlet 42 and flows in the guide path 26 toward the front nozzle 12 as shown by an arrow d in FIG. The rest collides with the cleaning liquid flowing in from the inlet 42 and turns backward as shown by an arrow e in FIG. 2, and in the annular space 34 as shown by an arrow f in FIG. Divides and flows upward through a semicircular arc path. Since the packing 35 is provided in the inner part of the annular space 34, an object to be removed (for example, a paint pigment) adhering to the gap between the annular space 34 and the packing 35 or the surface of the packing 35 is removed from the annular space 34. It is washed away by the washing liquid flowing through the inside 34 and removed. Then, the cleaning liquid that has flowed in the left and right hands in the annular space 34 joins at the upper end portion of the annular flow path, and then moves in the guide path 26 toward the front nozzle 12 as indicated by an arrow g in FIG. The liquid is discharged from the nozzle 12.

  As described above, in this embodiment, since the flow of the cleaning liquid is formed in the annular space 34 in which the packing 35 is accommodated, the cleaning liquid does not stay inside the annular space 34, and the annular space 34. Therefore, it is possible to reliably remove the object to be removed adhering to the inner wall of the steel and the surface of the packing 35.

  In addition, the inner peripheral surface and the outer peripheral surface of the first annular flow path 38 are configured by different parts (the cylindrical member 14 and the block body 13), but on the inner peripheral surface of the front end portion of the first annular flow path 38. A mounting groove 40 having a substantially “U” shape is formed, and the first annular ring is formed in close contact with the outer circumferential surface of the first annular flow path 38 (the inner circumferential surface of the block body 13). Since the seal ring 41 for sealing the front end of the flow path 38 is attached and sealed in a liquid-tight manner, there is no possibility that the paint or the cleaning liquid may enter the gap between the block body 13 and the cylindrical member 14.

Further, the opening edge on the rear side of the mounting groove 40 faces the first annular channel 38, but the seal ring 41 is in close contact with the inner surface of the rear end (right end in FIG. 2) of the mounting groove 40. There is no possibility that the paint or the cleaning liquid in the first annular flow path 38 enters the inside of the mounting groove 40 (the gap between the mounting groove 40 and the seal ring 41).
Further, the seal ring 41 has a substantially circular cross section, and the dimension in the radial direction (vertical direction in FIG. 2) between the outer circumferential surface and the inner circumferential surface of the first annular channel 38 is the outer circumference of the first annular channel 38. The seal ring 41 and the inner surface of the rear end of the mounting groove 40 are brought into contact with each other at the opening edge of the mounting groove 40 since the size in the radial direction between the surface and the groove bottom surface of the mounting groove 40 is approximately ½. become. Therefore, there is no possibility of forming a narrow gap between the outer peripheral surface forming the arc shape of the seal ring 41 and the opening edge portion of the rear end surface of the mounting groove 40 that may clog the object to be removed such as pigment.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.
(1) In the above embodiment, the front end of the first annular channel is sealed by the seal ring. However, according to the present invention, the seal ring may not be used.
(2) In the above embodiment, the seal ring is in close contact with the inner surface of the rear end of the mounting groove. However, according to the present invention, a gap may be formed between the seal ring and the inner surface of the rear end of the mounting groove. .
(3) In the above embodiment, the seal ring has a substantially circular cross section. However, according to the present invention, the seal ring may have a non-circular cross section.
(4) In the above embodiment, the radial dimension between the outer peripheral surface and the inner peripheral surface of the first annular flow path is the radial dimension between the outer peripheral surface of the first annular flow path and the groove bottom surface of the mounting groove. According to the present invention, the radial dimension between the outer peripheral surface and the inner peripheral surface of the first annular flow path is set to be equal to that of the outer peripheral surface of the first annular flow path and the mounting groove. It is good also as a dimension larger than about 1/2 of the radial dimension between groove bottoms, or a dimension smaller than 1/2.
(5) In the above embodiment, the entire first annular channel faces the inflow port. However, according to the present invention, a part of the first annular channel may be removed from the opening region of the inflow port. .
(6) In the above embodiment, the opening size of the inlet in the front-rear direction is made larger than the front-rear length of the first annular flow path. However, according to the present invention, the opening size of the inlet in the front-rear direction is The dimension may be the same as or smaller than the length of one annular channel.
(7) In the above-described embodiment, the opening direction of the inflow port on the outer peripheral surface of the first annular flow path is the diagonally forward direction. However, according to the present invention, the opening direction of the inflow port is A perpendicular direction (radial direction) may be used.

Sectional drawing of Embodiment 1 Partial enlarged sectional view XX line end view of FIG. YY line end view of FIG. Cross section of conventional example

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Gun body 12 ... Nozzle 18 ... Valve port 19 ... Needle 26 ... Guideway 27 ... Drive mechanism 34 ... Annular space 35 ... Packing 38 ... First annular channel 39 ... Second annular channel 40 ... Mounting groove 41 ... Seal Ring 42 ... Inlet

Claims (4)

Inside the gun body with a nozzle at the front end,
A configuration that is elongated in the front-rear direction and is movable in the front-rear direction in a through hole having a circular cross-section provided through the gun body in the front- rear direction, with the front end corresponding to the valve port provided in the nozzle Needle of
A guide path formed between an outer peripheral surface of the needle and an inner peripheral surface of the through-hole, and a front end connected to the valve port;
The needle is provided behind the guide path, and the needle is positioned between a retracted position in which the valve port is opened at a position facing the inner peripheral surface of the through hole and an advanced position in which the valve is closed. A drive mechanism to be moved;
A packing that faces the rear end of the guide path and is attached in an annular space that is substantially concentric with the needle, and that can regulate leakage of liquid from the guide path side to the drive mechanism side;
A first annular flow path that is substantially concentric with the needle and surrounds the guide path, the front end of which is closed;
A second annular flow path that is substantially concentric with the needle and that communicates the rear end of the first annular flow path and the rear end of the guide path;
A coating gun comprising: an inlet opening on an outer peripheral surface of the first annular channel. The inner circumferential surface and the outer circumferential surface of the first annular channel are configured by different parts,
On the inner peripheral surface of the front end portion of the first annular channel, a circumferential mounting groove is formed that is recessed in a substantially “U” shape,
The coating gun according to claim 1, wherein a seal ring that seals a front end of the first annular flow path by being in close contact with an outer peripheral surface of the first annular flow path is attached to the mounting groove. . The coating gun according to claim 2, wherein the seal ring is in close contact with an inner surface of a rear end of the mounting groove. The seal ring has a substantially circular cross section;
The radial dimension between the outer circumferential surface and the inner circumferential surface of the first annular channel is approximately 1 of the radial dimension between the outer circumferential surface of the first annular channel and the groove bottom surface of the mounting groove. The paint gun according to claim 3, wherein the paint gun is set to / 2.

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