JPS6019066A - Diaphragm pump for airless painting - Google Patents

Abstract

PURPOSE:To stably supply a paint by reducing the pulsation in emitting pressure, by mounting a check valve as a unit type valve while mounting a spring between a valve body and a holder. CONSTITUTION:A check valve 16 has such a structure that a valve seat 18 is attached to the inflow port side of a cylindrical valve body and a holder 19 is attached to the outflow port side thereof while a valve body 20, which is provided with a valve rod 22 inlaid with the guide orifice of the holder 19 in a freely slidable and protruded state, is mounted to a valve head 21 having a conical surface contacted with and spaced apart from the valve seat 18. In addition, a spring 24 is mounted between the valve body 20 and the holder 19 to bring the valve head 21 into contact with the valve seat 18. As mentioned above, assembling becomes easy by unitization and the pulsation in emitting pressure is reduced and a paint is stably supplied.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a diaphragm pump for airless painting using a tappet type check valve.

A diaphragm separates the hydraulic oil chamber and the pump chamber, and by supplying and discharging hydraulic oil to the hydraulic oil chamber, the diaphragm is driven back and forth to increase and decrease the volume of the pump chamber, allowing liquid paint sucked from the paint tank into the spray gun. In a diaphragm pump for airless painting, which is designed for pressure-feeding, when the volume of the pump chamber decreases and the liquid paint is pressurized, the valve opens to discharge it, and conversely, when the pressure decreases, the valve closes to prevent backflow. A check valve is installed in the discharge path that communicates with the spray gun, but in conventional airless painting diaphragm pumps, a valve element consisting of 31 balls is pushed against the valve seat provided in the discharge path by a spring. This type of check valve is expensive because it requires a high roundness of the valve body, takes time to assemble because it is difficult to make into a unit, and has poor response. Because of this, there was a drawback that the discharge pressure pulsated greatly.

The object of the present invention is to eliminate such drawbacks, to provide a diaphragm pump for airless painting that can be easily assembled by unitization, and has small discharge pressure pulsations. .

Hereinafter, one embodiment of the present invention will be described based on the accompanying drawings.

The recess 2 formed on the upper surface of the lower body 1 has a center hole 4.
A seat plate 3 with a transparent communication hole 5 is fitted therein, and four surfaces 7 corresponding to the recesses 2 are formed on the lower surface of the upper body 6, and between the lower body 1 and the upper body 6, A diaphragm 8 is stretched, a pump chamber 9 is formed on its upper surface, a hydraulic oil chamber 10 is formed on its lower surface, and a spring 14 is attached to the lower surface of the seat plate 3 to urge the diaphragm 8 downward. .

A cylinder 12 is fitted into a device hole 11 formed concentrically on the lower surface of the recess 2 of the lower body 1, and the vertical movement of the piston 13, which is tightly fitted into the cylinder 12, causes an operation υ of the cylinder 12. Oil is pumped into the hydraulic oil chamber lO, and
When the pump is sucked back, the diaphragm 8 moves downward as shown by the chain line and the actual position in the figure, and the volume of the pump chamber 9 alternately increases and decreases accordingly.

A device hole], /] is formed in the side surface of the upper body 6 and communicates with the pump chamber 9 through a discharge hole 15, and a check valve 16 is installed in the device hole 14. In the check valve 16, a valve seat 18 having a conical seat surface 18'a is fixed to the inlet side of a dog-shaped valve body 17, and a boulder 19 is screwed from the outlet side. A valve body 20 in which a valve stem 22 is integrally formed on a valve head 21 having a conical seam 1-surface 21a corresponding to the sea 1-surface 18a.
The valve body 22 of the holder 19 slides freely into the center hole 23 of the holder 19.
1); Spring 24 fitted and installed between the holder 19
The valve head 21 is urged in the direction of contacting the valve seat 18 and closing the valve due to the elasticity of the valve, and the holder 19 is formed with a communication hole 26 that communicates the outflow IJ 25 and the valve body 17 with the outflow port 25. A spray gun is attached to the other end of a pressure hose (not shown) connected to the outlet 25, and a suction pipe 28 is connected to the pump chamber 9 via a foot valve 27, which is connected to a paint tank (not shown). has been done.

When the pressure inside the pump chamber 9 increases, the valve body 20 moves back against the elasticity of the spring 24, and the valve head 21 moves from the valve seat 18 to 121[E], as shown by the chain line in FIG. When the valve is opened, the liquid paint that flows from the discharge hole 15 flows into the valve body 17.
When the pressure inside the pump chamber 9 decreases, the valve head 21 comes into contact with the valve seat I8 and closes, as shown by the solid line in the figure. Pump chamber 9 from spray gun 0111 by valve
This is to prevent the liquid paint from flowing back into the interior, but in this embodiment, a tappet 1 type check valve with a valve body protruding from the valve head 21 is used. By retreating, the valve opens sufficiently, and therefore, the valve closes quickly, with little pulsation in the discharge pressure.Also, all parts of the check valve are housed within the valve body, making the unit 1-
It is easy to assemble because it is
Seat surface 2 of valve head 21], since a is conical, 1
'17 There is an advantage that dense additions can be easily performed.

As specifically explained in the above embodiments, the airless painting diaphragm pump of the present invention has a diaphragm that partitions a hydraulic oil chamber and a pump chamber, and a foot valve connected to a suction path that communicates the pump chamber with a paint tank, and a spray gun. A check valve is interposed in each discharge passage communicating with 1.
] The volume of the pump chamber is increased or decreased by driving the diaphragm back and forth by supplying and discharging hydraulic oil to the hydraulic oil chamber;
In the diaphragm pump for airless painting, the foot valve and the check valve are alternately opened and closed to discharge the liquid paint sucked from the suction passage from the discharge passage, and the check valve is connected to the flow of the cylindrical valve body. A valve seat is attached to the inlet side and a holder is attached to the outlet side, and a valve body that automatically fits into the guide hole of the holder is provided protruding from the valve head having a conical seat surface 1171f in contact with the valve seat. The present invention is characterized in that a spring is installed between the valve body and the boulder to bias the valve head in a direction to bring it into contact with the valve seat. Therefore, the pulsation of the discharge pressure is small, the paint can be stably supplied, and it is easy to manufacture and can be provided at low cost.

[Brief explanation of drawings]

The accompanying drawings are cross-sectional views of one embodiment of the invention. 8: Diaphragm 9: Pump chamber jO: Hydraulic oil chamber 1
6: Check valve 17: Valve body 18: Valve seat 19:
Boulder 20: Valve body 21: Valve head 21a: Seat surface
22: Valve stem 24: Spring 27: Two-one valve Applicant Asahi Okuma Sangyo Co., Ltd. Agent Patent attorney Hiroshi Noguchi

Claims (1)

[Claims] A hydraulic oil chamber and a pump chamber are separated by a diaphragm, and a foot valve is interposed in the suction path that communicates the pump chamber with the paint tank, and a check valve is interposed in the discharge path that communicates with the spray gun. The diaphragm is reciprocatingly driven to increase or decrease the volume of the pump chamber by supplying and discharging the liquid, and the foot valve and the check valve are alternately opened and closed to discharge the liquid abrasive sucked from the suction path from the discharge path. In a diaphragm pump for airless painting, the check valve has a valve seat on the inlet side of the cylindrical valve body, a holder on the outlet side, and a conical seat that contacts the valve seat. A valve body having a valve stem protruding from the valve head having a surface and slidably fitting into the guide hole of the holder is provided, and a spring is installed between the valve body and the holder to secure the valve head. A diaphragm pump for airless painting, characterized in that the diaphragm pump is structured such that the pump is biased in the direction of bringing the valve into contact with the valve seat.