JPH0551796B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pump device implemented, for example, in a fuel supply system at a gas station.

As is well known, in a pump device, although it is okay for a certain amount of resistance to exist on the discharge side where the head is added by the pump, the presence of large resistance on the suction side will significantly impair pump efficiency. Undesirable. In devices that suck up liquid from underground tanks, such as pumps for refueling machines, there is a large loss head due to piping resistance from the tank to the pump suction port. Therefore, it is desirable to minimize the resistance on the suction side.

However, in conventional pump devices, a check valve is provided at the liquid inlet of the casing, which is biased by a spring in the closing direction. Therefore, since a spring force is applied as resistance to the valve, the resistance on the suction side increases, and as a result, the above-mentioned requirement of reducing the loss head is violated.

For example, a check valve in which a ball is housed in a casing and is opened and closed by the action of gravity and pressure is disclosed in Japanese Utility Model Application Publication No. 126586/1983 and Utility Model Application Publication No. 13830 of 1930, etc.

However, in such known technology, a ball-type check valve is provided in the liquid passage, and if the inlet port opens into the chamber, there is an inconvenience that the hose may jump out of the ball case due to the pressure of the inflow liquid. Further, since the ball and the ball case come into metal contact, leakage occurs and the atmosphere flows into the casing of the pump, which is disadvantageous in a pump device having a gas-liquid separation device.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a pump device that does not leak from the casing when the pump is not in operation and has low resistance on the suction side.

According to the present invention, in the pump device, the pump device includes a pump, a gas-liquid separation device, and a gas-liquid separation chamber in a casing, a check valve is provided at the inlet, and a control valve is provided at the outlet. An inlet is open at the lower surface of the casing, the check valve is closed by gravity, and includes a valve stem and a valve seat, and the inlet is defined in the casing through the check valve. The chamber is connected to a chamber that communicates with the suction side of the pump, and a cover is attached to the side of the chamber so that the casing can be opened and closed, and an opening limiter piece that limits the upward movement of the check valve is attached to the lid. There is.

Therefore, since the valve seat is engaged when the pump is not in operation, the liquid in the casing does not fall from the opening in the lower surface of the casing when the pump is not in operation. When the pump operates to draw up liquid, the pressure in the chamber decreases, and as a result, the check valve moves upward along the valve stem, drawing liquid into the casing. At this time, the only flow resistance is the resistance due to gravity when the check valve is opened, and the loss head is small. Furthermore, after the valve is opened, it can be opened sufficiently by the action of the valve stem, and virtually no resistance is generated. Since the opening limit piece or stopper limits the upward movement of the check valve, the check can operate correctly without the valve stem coming off.

Every time the cover is removed from the casing for inspection, the opening limiter is also removed together with the lid, making it easy to take the check valve in and out.

Embodiments of the present invention will be described below with reference to the drawings.

1 to 4 show the entirety of a pump device U embodying the present invention, and this pump device U is equipped with a casing C. As shown in FIG. The casing C is provided with a liquid inlet I and an outlet O. A check valve 1 is provided at the inner end of the inlet I, and opens into a chamber 2 provided with a strainer 2a on the inlet side. As shown in the figure, the check valve 1 is of a type that closes by gravity, and a stopper 57 is provided above it to prevent the valve from coming off during transportation or operation of the pump device. A pump 3 is provided approximately in the center of the casing C. In the illustrated embodiment, the pump 3 is a known internal gear pump. This pump 3 has a suction port 3a and a discharge port 3b, and a liquid path 10 is formed in the casing C to connect the chamber 2 and the suction port 3a.
The discharge port 3b of the pump 3 is connected to a gas-liquid separator 4, which will be described later.
is connected to. A liquid path is configured such that the liquid flowing outside in the radial direction of the gas-liquid separator 4, that is, the liquid that does not contain bubbles, flows into a chamber 5 provided with a trainer 5a on the outflow side, and a strainer chamber 5 on the outflow side. A control valve 6 is provided between the outlet O and the outlet O. This control valve 6 opens the valve against the spring 6a when the pump is driven, and when the liquid flows out and the pressure in the pipe connected to the outflow port increases due to temperature rise, etc. after the oil supply is stopped, the spring 6b The small valve 6c is opened to allow the liquid to flow backwards. A bypass valve 12 is provided in a liquid passage 11 for liquid flowing radially outward of the gas-liquid separation device 4,
This liquid path 11 communicates with the suction port 3a of the pump 3.

On the other hand, the liquid containing bubbles flowing inside the gas-liquid separator 4 in the radial direction passes through the flow rate restriction valve 7 and flows into the liquid path 13. This liquid path 13 is formed in the cover 16. This liquid path 13 communicates with a gas-liquid separation chamber 8, which will be described later. The gas separated in this gas-liquid separation chamber 8 is released from the air vent 14, and the liquid from which the gas has been separated is released from the liquid path 15.
flows to A check valve 9 is provided in this liquid passage 15, and this liquid passage 15 communicates with the strainer chamber 2 on the inflow side.

A cover 1 is attached to a pair of opposing surfaces of the casing C.
6 is provided. This is so that only one pair of surfaces needs to be opened for repairs after installation.

Therefore, when the pulley 17 is rotated by the motor to rotate the pump 3, the liquid flows from the inlet I to the check valve 1, the strainer chamber 2 on the inflow side, the pump 3, the gas-liquid separator 4, and the strainer chamber 5 on the outflow side. , and is discharged from the outlet O through the control valve 6. Further, a part of the liquid from the gas-liquid separator 4 is bypassed to the pump 3 through the bypass valve 12 . This is because the amount of liquid discharged from the gear pump 3 is determined by the number of revolutions thereof, so that it is possible to cope with changes in the amount of discharged liquid. On the other hand, in the gas-liquid separation device 4, the liquid containing gas flows through the flow rate restriction valve 7 to the gas-liquid separation chamber 8, where the gas is released from the air vent 14.
The liquid flows through the check valve 9 into the strainer chamber 2 on the inflow side.
It will be returned to.

Next, a check valve of a pump device embodying the present invention will be explained with reference to FIG.

The check valve 1 includes a disc-shaped valve body 51 and a valve stem 5.
2. The valve seat 53 has a double circular tubular shape. The valve body 51 and the valve stem 52 are integrally connected, and in the illustrated embodiment, are integrated by a nut 51a. The valve seat 53 has a cylindrical valve seat part 53a with a chamfered upper tip, a valve stem guide part 53b formed in a cylindrical shape inside the valve seat part 53a, and a support that supports the valve stem guide part 53b by the valve seat part 53a. It is composed of a protrusion 53c and a flange 53d. It is preferable that the valve seat portion 53a, the valve stem guide portion 53b, the support protrusion 53c, and the flange 53d are integrally molded. Flange 53d is packing 5
6 interposed therebetween, and contacts the casing C, and the opposite surface contacts the flange 54 of the piping. And casing C, packing 56 and flange 53d
and the flange 54 are connected by bolts 55. The valve stem 52 is loosely fitted into the inner hole of the valve stem guide portion 53b and is guided and supported so as to be freely movable up and down. Since the valve stem 52 is guided by the valve stem guide portion 53b, the vertical movement of the valve body 51, that is, the opening/closing operation of the valve, is accurately performed in a constant vertical axis direction.

In the illustrated example, the opening limiter of the valve is configured as a stopper 57 having an L-shaped cross section.
7 is located directly above the check valve 1, and the distance between the valve body 51 and the stopper 57 is set to a maximum that will prevent the valve stem 52 from coming off the valve stem guide portion 53b. The flange portion 57a of the stopper 57 is connected to the lid body, or cover 16, of the inflow strainer 2 by bolts 58. Since the stopper 57 is located directly above the valve body 51, it can be used when the check valve 1 is placed upside down from the position shown in FIG. 5 when transporting the pump, or when oil fluid suddenly flows in. Even if the valve body moves upward in FIG. 5, the amount of movement is limited by contact with the stopper 57. The distance from the position where the valve body 51 abuts the valve seat 53 to the stopper 57 is shorter than the length of the valve stem 52 inserted into the valve stem guide portion 53b. Even if the valve stem 5 moves (raises) until it touches the
2 will not come off from the valve stem guide portion 53b.

The valve body 51 is not biased by a spring or the like, but is brought into contact with the valve seat 53 by its own weight. Therefore, the resistance to opening the check valve 1 when liquid flows in, that is, the resistance to moving the valve body 51 upward, is very small. Compared to conventional valve devices, the valve opening resistance is reliably reduced by at least the spring force biasing the valve in the closing direction.

The diameter of the valve body 51 is configured to be slightly larger than the inner diameter of the valve seat portion 53a. This is to reliably prevent liquid from falling (backflow) from the inlet I when the valve body 51 is in contact with the valve seat 53a, ie, when the check valve 1 is closed, such as when the pump is stopped.

6 and 7 show a preferred embodiment of the gas-liquid separation chamber 8 of the pump device implemented in accordance with the present invention.

In the illustrated example, the liquid flowing out from the outlet hole 30 flows into the shelf 31 and flows downward along the wall surface, so that there is no foaming in the gas-liquid separation chamber 8, and malfunction of the float due to foaming is prevented. Further, it is possible to prevent liquid from flowing out from the air vent pipe 14.

When the liquid accumulates in the gas-liquid separation chamber 8, the float 32 rotates counterclockwise about the pivot point 33, the valve body 34 opens, and the liquid in the gas-liquid separation chamber 8 flows out into the liquid path 15. do. Note that 35 in the figure is a stopper.

As shown in FIG. 8, the liquid path 15 from the gas-liquid separation chamber 8 is provided with a check valve 9, so that the liquid in the chamber 2 will not flow back into the gas-liquid separation chamber 8 when the pump is stopped. do not have.

FIG. 9 shows a preferred embodiment of bypass valve 12 implemented in the present invention.

When the pressure in the liquid path 11 on the upstream side of the valve body 40 increases, the valve body 40 opens against the spring 42, and the liquid flows into the chamber 44 on the downstream side of the valve body 40. This chamber 44 communicates with the suction port 3a of the pump 3. spring 42
The spring seat 45 that locks one end has an adjustment screw 46
The valve body 40 can be positioned by adjusting the hydraulic pressure at which the valve body 40 opens.

As described above, the present invention provides the following excellent effects.

(i) Since the check valve is equipped with a valve stem and a valve seat, there is no leakage when the pump is not in operation, and the operation is accurate.

(ii) Since the check valve is closed by gravity, the head loss when the valve is opened during pump operation can be reduced.

(iii) Since the valve stem allows a sufficient opening area, there is little flow loss.

(iv) The opening limiter prevents the check valve from coming off and protruding into the room.

(v) The opening limiter is attached to the cover, so if you remove the cover, you can take out the check valve.
Easy to insert and easy to inspect and repair.

[Brief explanation of drawings]

FIG. 1 is a front view of a pump device embodying the present invention, FIG. 2 is a rear view thereof, and FIG. 3 is a plan view thereof.
Fig. 4 is a sectional view thereof, Fig. 5 is a sectional view showing a casing inlet valve in which the present invention is implemented, Fig. 6 is a longitudinal sectional view showing a part of the gas-liquid separation chamber, and Fig. 7 is a gas-liquid separation FIG. 8 is a cross-sectional view of the chamber, FIG. 8 is a cross-sectional view of the check valve, and FIG. 9 is a cross-sectional view of the bypass valve. 1... Check valve, 2... Strainer on the inflow side, 3... Pump, 4... Gas-liquid separator, 5...
Strainer on the outflow side, 6... Control valve, 7
... Flow rate restriction valve, 8 ... Gas-liquid separation chamber, 9 ... Check valve, 12 ... Bypass valve, S ... Whirlpool chamber, 51 ...
... Valve body, 52 ... Valve stem, 53 ... Valve seat, 53b
... Valve stem guide section, 57 ... Stopper.

Claims (1)

[Claims] 1. A pump device comprising a pump, a gas-liquid separator, and a gas-liquid separation chamber inside a casing, and a check valve is provided at the inlet and a control valve is provided at the outlet; the inlet is connected to the casing. The check valve is open on the lower surface, and is closed by gravity, and includes a valve stem and a valve seat, and the inlet is defined in the casing via the check valve and is connected to the suction side of the pump. The check valve is connected to a chamber that communicates with the check valve, and a cover is attached to the side of the chamber so as to be openable and closable on the casing, and an opening limiter piece for limiting upward movement of the check valve is attached to the cover. pump equipment.