JP7688770B2 - Pump air vent valve - Google Patents

Description

The present invention relates to an air vent valve for a pump.

Conventionally, there is known a pump air vent valve that is connected to the discharge side of a pump and automatically vents air when the pump is started. In the pump air vent valve described in the following Patent Document 1, the valve (valve body) is held open by a biasing member when the pump is started to vent air, and after the air is vented, the force of the liquid pressure acting on the valve automatically switches it to a closed state, preventing leakage of the pumped liquid.

However, with the above air vent valve, after the air is vented, the liquid acts on the valve itself in the closing direction (the main pressure is applied to the side of the valve) as it passes through the gaps around the valve, so there is a problem in that there is a time delay before the valve receives sufficient force in the closing direction to close.

Therefore, the air vent valve in Patent Document 2 below comprises a valve (needle valve) that controls the connection between the pump discharge port and the discharge port, a pressure receiving part that displaces axially together with the valve and receives a force from the pressure of the pump discharge port in a valve closing direction, a biasing member that biases the valve in an opening direction, an upper passage having one end connected to the pump discharge port and the other end connected to the top surface of the pressure receiving part, and a lower passage having one end connected to the pump discharge port and the other end connected to the discharge port. When the pump is started, air remains in the pump discharge port, and although the pressure at the pump discharge port acts from the upper passage through the pressure receiving part in the valve closing direction, the pressure is small, so the valve is held open by the biasing force of the biasing member, and the remaining air in the pump discharge port passes through the lower passage and the valve to the discharge port and is discharged from the discharge port to the outside. After that, when the remaining air in the pump discharge port is almost completely gone, the pump discharge port is almost completely filled with liquid from the pump, and the force acting on the pressure receiving part from the pump discharge port side through the upper passage increases, causing the valve to move against the biasing force of the biasing member and close, resulting in the communication between the pump discharge port and the discharge port being cut off, and the liquid in the pump discharge port being prevented from leaking from the discharge port.

That is, in the air vent valve of Cited Document 2, when air venting at the pump discharge port is completed, sufficient force is applied to the pressure receiving portion to close the valve, so that the air vent valve can be switched to the closed position quickly and smoothly without any time delay.

Japanese Utility Model Application Publication No. 2-92075 Japanese Utility Model Application Publication No. 6-47677

However, the air vent valve for the pump described in Patent Document 2 requires two flow paths (passages) through which liquid flows from the pump discharge port, making the structure complex and large, and therefore there is a demand for a simplified and more compact structure.

The present invention was made to solve these problems, and aims to provide an air vent valve for a pump that is simple in structure and compact, while allowing the valve to be quickly and smoothly switched to a closed state after air venting without any time delay.

The pump air vent valve (100) according to the present invention is an air vent valve (100) for a pump connected to the discharge side of the pump, and comprises a cylindrical valve body (1), a cylindrical valve holder (2) that is attached to the inside of the inlet side of the valve body (1) and has a cylindrical hole (2a) through which liquid flows and is provided at the outlet side end with a notch (2e) that connects the inside and outside of the cylinder, a valve (3) that is inserted axially movably toward the outlet side of the valve holder (2) in the valve body (1) and has a recess (3c) on the inlet side end face that recesses toward the outlet side in the axial direction, and the valve (3) abuts against the valve holder (2) to close the cylindrical hole (2a) and the recess (3c) of the valve (3) and the valve holder (2) The valve (3) is characterized by having a spring means (4) that springs the valve (3) so that the cylindrical hole (2a) of the valve (3) faces the cylindrical hole (2a), an annular packing (5) that is provided on the stepped surface (1a) of the outlet side of the valve body (1) and into which the spring means (4) is inserted and has a hole (5a) through which liquid from the valve holder (2) side can pass to the outlet side, and against which the valve (3) can abut, and a space (1d) that is provided on the inner surface of the valve body (1) and that communicates the notch (2e) of the valve holder (2) with the cylindrical hole (1e, 1f) on the outlet side of the valve body (1) when the valve (3) is spring-loaded by the spring means (4) and abuts against the valve holder (2) to block the cylindrical hole (2a).

With this type of pump air vent valve (100), when the pump is started, the air and liquid in the pump and piping flow into the bore (2a) of the valve guard (2) attached inside the inlet side of the cylindrical valve body (1). Here, the valve (3), which is inserted axially movably into the valve guard (2) inside the valve body (1) toward the outlet side and has a recess (3c) on the inlet side end face that recesses axially toward the outlet side, is resiliently spring-loaded by the spring means (4) to block the bore (2a) of the valve guard (2). Therefore, the air and liquid flow from the notch (2e) provided at the outlet end of the valve guard (2) that communicates between the inside and outside of the cylinder, through the space (1d) provided on the inner surface of the valve body (1) that communicates with the notch (2e), to the bore (1e, 1f) on the outlet side of the valve body (1), and are discharged to the outside. Then, almost at the same time that most of the air is discharged, the valve (3) is immediately pushed down against the elastic force of the elastic means (4) by the pressure of the liquid that flows straight through the cylindrical hole (2a) of the valve guard (2) and is received head-on and stored in the recess (3c) of the valve (3). The pushed-down valve (3) comes into contact with an annular packing (5) that is provided on the stepped surface (1a) of reduced diameter on the outlet side of the valve body (1) and has a hole (5a) through which liquid from the valve guard (2) side can pass to the outlet side, and the valve (3) is closed. In other words, the valve (3) is switched to the closed position after the air is vented quickly and smoothly without any time delay by the pressure of the liquid that flows straight through the cylindrical hole (2a) of the valve guard (2) and is stored in the recess (3c) of the valve (3) facing the cylindrical hole (2a). When the pump stops, the pressure in the pump and piping drops from when it is in operation, so the spring force of the spring means (4) pushes up the valve (3), blocking the bore (2a) of the valve holder (2). However, because the notch (2e) of the valve holder (2), the space (1d) on the inner surface of the valve body (1), and the bore (1e, 1f) on the outlet side of the valve body (1) are connected, the liquid is discharged to the outside, and the residual pressure and liquid are eliminated. In this way, the flow path through which the liquid flows is reduced to one, and the structure is simplified and made smaller, and the valve (3) can be switched to the closed position quickly and smoothly after the air is purged without any time delay.

Specific examples of configurations that can best achieve the above-mentioned effect include a configuration in which the valve guard (2) is attached to the valve body (1) by screwing, and the space (1d) in the valve body (1) is a screw relief portion. With such an air vent valve, there is no need to provide a separate space, and the air vent valve (100) can be easily configured.

In this way, the present invention provides a pump air vent valve that can quickly and smoothly close the valve after air venting without any time delay, while simplifying and miniaturizing the structure.

FIG. 2 is a longitudinal cross-sectional view showing the air vent valve according to the embodiment of the present invention, illustrating the valve in an open state. FIG. 2 is a vertical cross-sectional view showing the air vent valve according to the embodiment of the present invention, illustrating a valve closed state. FIG. 3 is a vertical cross-sectional view showing the valve body in FIGS. 1 and 2 . FIG. 3 is a perspective view showing the valve guard in FIGS. 1 and 2 . FIG. 5 is a vertical cross-sectional view of the valve guard shown in FIG. 4 . FIG. 3 is a perspective view of the valve in FIGS. 1 and 2 . FIG. 7 is a longitudinal cross-sectional view of the valve shown in FIG. 6.

A preferred embodiment of the air vent valve for a pump according to the present invention will now be described with reference to the accompanying drawings. Fig. 1 is a vertical cross-sectional view of an air vent valve according to an embodiment of the present invention, showing the valve in an open state, Fig. 2 is a vertical cross-sectional view of the air vent valve in a closed state, Fig. 3 is a vertical cross-sectional view of the valve body, Figs. 4 and 5 are views showing the valve holder, and Figs. 6 and 7 are views showing the valve. The air vent valve for a pump according to this embodiment is used, for example, in a backpack power sprayer.

As shown in FIG. 1, the air vent valve 100 is connected to the discharge side of a pump and comprises a valve body 1 configured as a stepped cylinder, a cylindrical valve retainer 2 attached inside the inlet side of the valve body 1, a valve 3 inserted inside the valve body 1 from the valve retainer 2 to the outlet side so as to be axially movable, a compression coil spring 4 disposed inside the valve body 1 as a spring means for springing the valve 3 so that it abuts against the valve retainer 2, and a packing 5 provided on the stepped surface 1a inside the valve body 1 and capable of abutting against the valve 3 when the valve 3 is pressed down against the spring force of the compression coil spring 4 (when it moves to the left in the figure).

As shown in Figures 1 and 3, the valve body 1 is configured so that the cylindrical portion 1y on the outlet side (left side in the figure) has a smaller inner and outer diameter than the cylindrical portion 1x on the inlet side (right side in the figure), and the stepped surface on the inner side that is reduced in diameter serves as the stepped surface 1a that fixes the above-mentioned packing 5.

The inlet side bore (inner peripheral surface) of the cylindrical portion 1x of the valve body 1 is provided with a screw relief portion (groove) for the female screw 1c, and an O-ring groove 1b for mounting an O-ring 6 is recessed in an annular shape. The bore extending from the O-ring groove 1b to the middle of the axial direction of the valve body 1 is provided with the female screw 1c, which is reduced in diameter from the O-ring groove 1b, for mounting a valve retainer 2. On the outlet side of the female screw 1c of the valve body 1, a screw relief portion (groove) 1d of the female screw 1c, which is an annular space, is provided in the axial direction for a predetermined length. The outlet side bore 1e from the screw relief portion 1d of the valve body 1 is reduced in diameter and reaches the step surface 1a. The bore 1f extending from the stepped surface 1a of the valve body 1 to the outlet side is a bore for accommodating the compression coil spring 4, and the outlet of the bore 1f of the valve body 1 is a reduced-diameter exhaust port 1g. The outer circumferential surface of the small-diameter cylindrical portion 1y on the outlet side of the valve body 1 is configured in a hook shape that continues in the circumferential direction, and the hose 8 inserted on the cylindrical portion 1y engages with the hook shape to connect the hose 8 to the outlet side of the valve body 1.

As shown in Figures 1, 4 and 5, the valve holder 2 is configured in the shape of a hexagonal bolt having a head 2x and a shaft 2y, with a cylindrical hole 2a penetrating in the axial direction at the center. A male screw 2c that screws into the female screw 1c of the valve body 1 is provided on the outer peripheral surface of the shaft 2y of the valve holder 2, and a screw relief portion (groove) 2b of the male screw 2c is provided at the base of the shaft 2y connected to the male screw 2c to accommodate an O-ring 6. In addition, a female screw 2d that screws into a nipple 7 that connects to a pipe from the pump is formed on the inner peripheral surface of the head 2x on the inlet side of the cylindrical hole 2a of the valve holder 2.

In addition, a pair of notches 2e are provided at the outlet end of the valve guard 2, cut in short lengths in the axial direction from the outside of the outlet side and connecting the inside and outside of the cylinder, spaced 180° apart in the circumferential direction. These notches 2e are used to release air from the pump when the pump is started, and to release residual pressure and liquid from the pump when the pump is stopped.

As shown in FIG. 1, the male screw 2c of the valve retainer 2 is screwed into the female screw 1c of the valve body 1 and tightened, so that the valve retainer 2 is attached to the valve body 1. The O-ring 6 is compressed and held between the O-ring groove 1b of the valve body 1 and the screw relief portion 2b of the valve retainer 2, and the inlet end face of the valve body 1 and the outlet end face of the head 2x of the valve retainer 2 are tightly attached to each other, sealing the valve body 1 and the valve retainer 2.

As shown in Figures 1, 6 and 7, the valve 3 has a columnar or cylindrical shaft 3b connected to the center of the rear end surface of the disk-shaped head 3a on the inlet side. The head 3a is movable between the outlet end surface of the valve guard 2 and the packing 5 inside the valve body 1, and the inlet end surface is provided with a recess 3c that faces the cylindrical hole 2a of the valve guard 2 and has a circular cross-sectional recess on the axial outlet side. By forming the recess 3c in this way in the head 3a, the peripheral portion that forms the recess 3c becomes an annular portion 3d that protrudes toward the inlet side. The shaft 3b is for guiding the compression coil spring 4 that is inserted externally, and is movable across the cylindrical holes 1e and 1f.

As shown in FIG. 1, the packing 5 is made of flexible resin and is configured in a circular shape with a hole 5a in the center of a thin disk. The packing 5 is fixed to the step surface 1a of the valve body 1 by, for example, gluing, so that the hole 5a communicates with the cylindrical hole 1f of the valve body 1.

The compression coil spring 4 is fitted onto the shaft 3b of the valve 3 and is fitted into the bore 1f of the valve body 1 and the hole 5a of the packing 5, and is interposed between the outlet end face of the head 3a of the valve 3 and the inner part of the periphery that forms the discharge port 1g of the valve body 1, and springs the head 3a of the valve 3 towards the valve retainer 2.

In the air vent valve 100 of the pump of this embodiment having such a configuration, when the pump is not operating, as shown in Figure 1, the valve 3 is resiliently pushed up by the compression coil spring 4 (moving to the right in the figure), and the inlet end of the head 3a of the valve 3, specifically the end face of the annular portion 3d of the head 3a, abuts against the outlet end face of the valve holder 2, blocking the cylindrical hole 2a of the valve holder 2. In this state, the notch 2e of the valve holder 2 is in communication with the cylindrical holes 1e and 1f on the outlet side of the valve body 1 via the screw relief portion 1d of the valve body 1.

When the pump is started, the air and liquid (e.g. water) in the pump and piping flow into the bore 2a of the valve retainer 2. Here, the valve 3 is resilient to the compression coil spring 4, blocking the bore 2a of the valve retainer 2, so the air and liquid flow from the notch 2e of the valve retainer 2 through the screw relief portion 1d on the inner surface of the valve body 1 to the bores 1e and 1f on the outlet side of the valve body 1, and are discharged to the outside through the exhaust port 1g. In other words, the air on the pump side can be bled when the pump is started.

Then, at almost the same time that most of the air is discharged (escaped), the liquid moving straight through the bore 2a of the valve retainer 2 is received head-on by the recess 3c of the valve 3 facing the bore 2a of the valve retainer 2 and is stored there, and the pressure of the liquid immediately pushes the valve 3 down (moves to the left in the figure) against the elastic force of the compression coil spring 4, as shown in Figure 2. The pushed-down valve 3 comes into contact with the packing 5, closing the valve 3 and blocking the discharge of liquid.

In other words, the valve 3 is switched to the closed position after the air is removed quickly and smoothly without any time delay due to the pressure of the liquid that flows linearly through the cylindrical hole 2a of the valve holder 2 and accumulates in the recess 3c of the opposing valve 3.

When the pump stops, the pressure in the pump and piping drops below that when it is in operation. As a result, as shown in Figure 1, the elastic force of the compression coil spring 4 pushes up the valve 3, blocking the cylindrical hole 2a of the valve holder 2. In this state, the notch 2e of the valve holder 2, the screw relief portion 1d on the inner surface of the valve body 1, and the cylindrical holes 1e and 1f on the outlet side of the valve body 1 are connected, so the liquid is discharged to the outside, and the residual pressure and liquid are eliminated.

In this way, the air vent valve 100 of the pump of this embodiment has a single flow path through which the liquid flows, simplifying and miniaturizing the structure, while allowing the valve 3 to be switched to closed quickly and smoothly after air venting without any time delay.

In addition, the valve retainer 2 is attached to the valve body 1 by screwing, and the vent space of the valve body 1 is formed by the screw relief portion 1d, so there is no need to provide a separate space, and the air vent valve 100 can be easily constructed.

In addition, according to this embodiment, the following actions and effects are also achieved. That is, since there is no residual pressure, there is no unnecessary load on the motor when the pump is started, making it easy to start. In addition, when connecting a nozzle for spraying mist, a check valve is attached to prevent water droplets from dripping from the nozzle when the pump is stopped. When connecting multiple nozzles, the closing pressure varies due to the variation in the check valve spring of each nozzle, and if a nozzle with high closing pressure is located close to the pump, the time when the residual pressure is high increases, and if the pump is stopped for a short time, the motor will not restart. However, since the residual pressure is released regardless of the variation in the check valve spring, motor start-up problems can be prevented. In addition, if the internal pressure is high when the pump is stopped, there is a risk that it will flow back to the suction side and damage the low-pressure packing, but since there is no residual pressure, the low-pressure packing will not be damaged.

The present invention has been specifically described above based on its embodiments, but the present invention is not limited to the above embodiments. For example, in the above embodiment, which is particularly suitable, the valve guard 2 is attached to the valve body 1 by screwing, and the space on the inner surface of the valve body 1 is used as the screw relief portion 1d, but the connection between the valve guard 2 and the valve body 1 may be by means other than screwing, and therefore the space on the inner surface of the valve body 1 does not have to be a screw relief portion.

In addition, in the above embodiment, the spring means is a compression coil spring 4, but other springs may be used as long as they have the same spring performance as the compression coil spring 4.

In addition, in the above embodiment, a pair of notches 2e are provided facing each other, but the number is not limited to two and may be three or more. In this case, it is preferable to provide them at equal intervals along the circumferential direction. The number of notches 2e is not limited to multiple.

In addition, in the above embodiment, the application to the pump of a backpack power sprayer, for example, is described, but the invention can also be applied to pumps of boom sprayers, for example, and in short, can be applied to pumps in general.

1... valve body, 1a... stepped surface, 1d... screw relief portion (space), 1e, 1f... outlet side bore, 2... valve holder, 2a... bore, 2e... notch, 3... valve, 3c... recess, 4... compression coil spring (spring mechanism), 5... packing, 5a... hole, 100... air vent valve.

Claims (2)

In the pump air vent valve (100) connected to the discharge side of the pump,
A cylindrical valve body (1),
a cylindrical valve guard (2) that is attached to the inside of the inlet side of the valve body (1), has a cylindrical hole (2a) through which liquid flows, and has a notch (2e) at an outlet side end that communicates between the inside and outside of the cylinder;
a valve (3) that is inserted into the valve body (1) so as to be axially movable toward the outlet side from the valve retainer (2), and has an annular portion (3d) that protrudes toward the inlet side on an end face of the inlet side, thereby providing a recess (3c) that is recessed toward the outlet side in the axial direction;
a spring means (4) for springing the valve (3) such that an inlet end surface of the annular portion (3d) of the valve (3) abuts against an outlet end surface of the valve guard (2) to close the cylindrical hole (2a) and the recess (3c) of the valve (3) faces the cylindrical hole (2a) of the valve guard (2);
an annular packing (5) that is provided on a stepped surface (1a) of a reduced diameter on the outlet side of the valve body (1), into which the spring means (4) is inserted, and that has a hole (5a) through which liquid from the valve holder (2) side can pass to the outlet side, and against which the valve (3) can abut;
a space (1d) provided on an inner surface of the valve body (1), the space (1d) communicating between the notch (2e) of the valve guard (2) and the cylindrical holes (1e, 1f) on the outlet side of the valve body (1) when the valve (3) is elastically biased by the elastic means (4) to abut against the valve guard (2) and close the cylindrical hole (2a),
The annular portion is formed on the periphery of the end face on the inlet side of the valve (3). The valve guard (2) is attached to the valve body (1) by screwing.
The air vent valve (100) for a pump according to claim 1, wherein the space (1d) of the valve body (1) is a screw relief portion.

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