JPH1061803A - Abnormal pressure relief valve mechanism for lubrication system - Google Patents

Abstract

(57) [Problem] To provide a constant pressure for releasing abnormal pressure downstream of a check valve regardless of the pressure upstream of the check valve. SOLUTION: In a casing 41 having an inflow port 42 and an outflow port 44, a relief pipe (through hole) 56 for bypassing a check valve 12 is provided, and fitted to a cylinder 57 having an upper chamber 61 opened to the atmosphere. The valve stem 60 extends from the piston 58 to the relief pipe 56, the piston 58 is pushed down by a spring 62 disposed in the cylinder upper chamber 61, and the relief pipe 56 is always closed by the valve rod 60, and The hydraulic pressure in the downstream flow path 45 of the stop valve 12 is introduced into the cylinder lower chamber 65 through the small hole 66, and when the pressure on the downstream side of the check valve 12 becomes abnormal, the spring 6
The piston 58 is slid by the differential pressure with the urging force of 2,
The valve rod 60 is raised, and the abnormal pressure is released into the upstream flow path 43 through the relief pipe 56.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an abnormal pressure relief valve mechanism for a fueling device.

[0002]

2. Description of the Related Art FIG. 2 shows a general system of a refueling device installed in a gas station. An oil liquid 3 pumped by a pump 2 from an underground tank 1 is installed on the ground through an underground pipe 4. It is led to the weighing unit 5 and further sent through a ground pipe 6 to, for example, a teriberi unit 7 suspended from a roof (canopy) of a gas station.
The required oiling is performed by operating the oiling nozzle 9 at the tip of the hose 8 pulled out from the hose, and the amount of oiling at that time is measured by the flow meter 10 in the measuring unit 5. In addition,
In the measuring unit 5, a filter 11 and a check valve 12 are disposed upstream of the flow meter 10.

In such a refueling device, for example, due to a high temperature of the ground pipe 6 in summer, the measuring unit 5
The pressure on the downstream side of the (check valve 12) may abnormally increase. Therefore, conventionally, the check valve 12 in the measuring unit 5 is conventionally used.
In addition, an abnormal pressure relief valve mechanism as shown in FIG. 3 or FIG.
Side).

A check valve 12 A shown in FIG. 3 is provided with an upstream flow path (passage) 15 communicating with the underground pipe 4 and the above-mentioned
And a downstream side flow path (piping) 16 communicating with the casing 17. The check valve 12 </ b> A is provided with a valve body 19 that is separated from and seated on a valve seat body 18 disposed between the upstream flow path 15 and the downstream flow path 16, and that the valve body 19 is always attached to the valve seat body 18 It comprises a valve spring 20 for urging in the seating direction and a valve guide 21 for guiding the valve element 19 in the seating direction. The valve guide 21 has a disk-shaped main body 22 having an annular projection 22 a on the upper surface that contacts the lower surface of the valve element 19, and extends from the lower surface of the main body 22 along the inner wall of the upstream flow path 15. It includes a plurality of leg pieces 23 and a rod 24 extending upward from the upper surface of the main body 22 through the valve element 19 of the check valve 12A. At the upper end of the rod 24,
A spring receiver 26 is fitted and retained by a retaining ring 25, and between the spring receiver 26 and the valve element 19, the valve guide 21 is normally urged upward, and its main body 22
A spring 27 that causes the annular projection 22a to abut on the valve body 19 is interposed. Note that the check valve 12A is
Is inserted into the casing through a hole 17a provided in the valve spring 20. A lid 28 closing the hole 17a is used as a spring receiver for locking one end of the valve spring 20.

In the above-described check valve 12A, the valve guide 21 and the spring 27 constitute an abnormal pressure relief valve mechanism. If the pressure on the downstream side of the check valve 12A becomes abnormally high for some reason, the hydraulic pressure is increased. Acts on the body 22 of the guide 21 to try to push down the valve guide 21. When the oil pressure in the downstream flow path 16 becomes higher than that in the upstream flow path 15 due to the set load of the spring 27, the valve guide 21 is pushed into the upstream flow path 15 due to the pressure difference between the two flow paths. Lowered,
The annular projection 22a is separated from the valve body 19 of the check valve 12A, so that the pressure oil in the downstream flow passage 16 escapes into the upstream flow passage 15.

On the other hand, the check valve 12B shown in FIG. 4 is also disposed in the casing 17 similarly to the check valve 12A, and is disposed between the upstream flow path 15 and the downstream flow path 16. It is pressed against the valve seat body 18 by a valve spring 20. The valve guide 21 of the check valve 12B is fixed to the valve body 19 of the check valve 12B by using a support member 30 and a nut 31, omitting the rod 24 (FIG. 3). That is,
The support member 30 extends the small-diameter shaft portion 30b extending from the large-diameter main body portion 30a through the main body 22 of the valve guide 21 and the valve body 19 of the check valve 12B from the upstream flow path 15 to the downstream flow path. The nut 31 is screwed to a male screw provided on the tip side of the shaft portion 30b. The main body 22 of the valve guide 21 and the valve body 19 are clamped between the main body 30a of the support member 30 and the washer (spring receiver) 32 below the nut 31 by tightening the nut 31 to be integrated. .

The main body 30a of the support member 30 is provided with a concave hole 33, and the concave hole 33 has a valve seat body 34 having a conical valve seat as an abnormal pressure relief valve mechanism.
And a valve element (ball) which is detachably seated on the valve seat of the valve element 34
35, and a valve spring 37, one end of which is locked to a lid 36 covered by the open end of the main body 30a, and constantly biases the ball 35 in a direction of sitting on the valve seat. A series of communication passages 38 are formed in the valve seat body 34 and the shaft portion 30b of the support member 30.
When the downstream side of 2B becomes abnormally high pressure, the hydraulic pressure acts on the ball 35, and the hydraulic pressure in the downstream flow path 16 is reduced by the valve spring 37.
In addition to the set load, the ball 35 is pushed down by the pressure difference between the two flow paths when the pressure is higher than in the upstream flow path 15, the communication path 38 is opened, and the pressure oil in the downstream flow path 16 This escapes into the side channel 15.

[0008]

However, according to the abnormal pressure relief valve mechanism incorporated in the check valves 12 (12A, 12B), the difference between the upstream flow path 15 and the downstream flow path 16 is reduced. In a system in which a single pump 2 (FIG. 2) branches and refuels a plurality of metering units 5, a plurality of metering units 5 operate at the same time because the system is operated by the pressure, that is, the differential pressure across the check valve. In this case, there is a problem that the line pressure on the pump 2 side changes and the differential pressure across the check valve 12 in each measuring unit 5 also changes, and the pressure released as abnormal pressure is not constant.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has as its object to operate an abnormal pressure relief valve mechanism without depending on the differential pressure across the check valve. The purpose is to keep the pressure released as abnormal pressure constant.

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a refueling apparatus having a check valve interposed in a passage connecting a pump and a flow meter, wherein the check valve is provided in the passage. A relief passage for bypassing is provided, and one end of a valve stem for opening and closing the relief passage is connected to a piston slidably fitted in a cylinder, and the valve stem is always connected to the cylinder in the cylinder via the piston. A spring for urging the relief passage in a closing direction is provided, and one of two chambers in the cylinder defined by the piston, which is opposite to the side where the valve stem is extended, is opened to the atmosphere. In addition, the other chamber in the cylinder communicates with a downstream passage of the check valve.

In the abnormal pressure relief valve mechanism for an oil supply device configured as described above, when the pressure in the passage downstream of the check valve becomes abnormal, the hydraulic pressure is introduced into the other chamber in the cylinder.
The piston slides due to the differential pressure from the set load of the spring that urges the valve rod in the closing direction via the piston, and the valve rod opens the relief passage to release abnormal pressure downstream of the check valve to the pump side. .

[0012]

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

FIG. 1 shows an abnormal pressure relief valve mechanism for an oil supply device according to the present invention. This abnormal pressure relief valve mechanism 40
Is installed in the metering unit 5 of the oil supply device shown in FIG. 2 described above, and is unitized together with the check valve 12 in one casing 41. In the casing 41, an upstream flow path (passage) 43 continuing from an inlet 42 provided at one end thereof, and a downstream flow path (passage) 45 continuing to an outlet 44 provided at the other end are formed. At the inlet 42, an underground pipe 4 extending from the pump 2 is provided.
The above-mentioned pipes 6 are connected to the outlets 44 via the flow meters 10 in the measuring unit 5, respectively. The oil liquid 3 pumped by the pump 2 from the underground tank 1 shown in FIG. Channels 43 and 45 in this casing 41
Then, the oil is sent to the refueling nozzle 9 through the flow meter 10.

The check valve 12 is disposed between the upstream passage 43 and the downstream passage 45 in the casing 41. The check valve 12 includes a valve body 47 that is detachably seated on a ring-shaped valve seat body 46 disposed between an upstream flow path 43 and a downstream flow path 45, and that the valve body 47 is always the valve seat body. A valve spring 48 biases the seat 46 in a seating direction, and a valve guide 49 for guiding the valve body 47 in the seating direction. The valve guide 49 includes a disk-shaped main body 50, a plurality of leg pieces 51 extending from the lower surface of the main body 50 along the inner wall of the upstream flow path 43, and a check valve from the upper surface of the main body 50. And a shaft portion 52 that extends upward through the twelve valve bodies 47, and is fixedly fastened to the valve body 47 by a nut 53 screwed into a male screw provided on the shaft section 52. ing. The valve body 47 has a composite structure in which a reinforcing plate 47a is embedded in an elastic body such as rubber. Also, this check valve 12
Is inserted into the casing through a hole 41a provided in the casing 41. A lid 55 fixed to the casing 41 by a bolt 54 so as to close the hole 41a is connected to one end of the valve spring 48. It is used as a locking spring receiver.

The upstream flow path 43 and the downstream flow path 4
A through-hole (relief passage) 56 that bypasses the check valve 12 is provided in a partition wall 41 b in the casing 41 that separates the check valve 5 from the check valve 5. On the other hand, the partition wall 41 provided with the through hole 56
Above b, a bottomed cylindrical cylinder 57 whose upper part is open to the outside of the casing 41 is arranged. Cylinder 57
A piston 58 is slidably fitted therein via a seal member 59, and a valve stem 60 extends downward from the piston 58 through the bottom of a cylinder 57. The valve stem 60 extends on the axis of the through hole 56 serving as the relief passage, and has a conical tip portion 60 a formed at the opening end of the through hole 56. The valve seat 45a is configured to be separated from and seated on the frusto-conical valve seat 45a.

Cylinder 5 partitioned by piston 58
A spring 62 for urging the valve rod 60 downward through the piston 58 is provided in an upper chamber (one chamber) 61 in the inside 7. The spring 62 is interposed between a piston receiver 58 and a spring receiver 64 which is secured to the open end of the cylinder 57 by a retaining ring 63 and pushes down the piston 58 at a predetermined pressure. A vent hole 64a is formed in the spring receiver 64, and the cylinder upper chamber 61 is always open to the atmosphere. On the other hand, a lower chamber (the other chamber) 65 in the cylinder 57 defined by the piston 58 communicates with the downstream flow path 45 through a small hole 66 formed in a wall of the cylinder 57. That is, a small hole 66 is provided in the cylinder lower chamber 65.
The oil liquid in the downstream side flow path 45 can freely enter and exit through. The hydraulic pressure in the downstream flow passage 45 is maintained at the set pressure of the pump 2 while the pump 2 is stopped as well as during the operation of the pump 2 (during refueling). A set pressure will be introduced.

The set load of the spring 62 in the cylinder upper chamber 61 is adjusted so as to generate an urging force higher than the set pressure of the pump. As a result, during normal operation of the refueling device, the piston 58 is pushed down by the urging force of the spring 62, and the valve rod 60 maintains the valve closed state in which the distal end portion 60a is seated on the valve seat 45a of the through hole 45. It is supposed to. In addition, the above-mentioned through-hole (release passage) 56, cylinder 57, piston 58,
The valve rod 60, spring 62, small hole 66, etc.
0.

Abnormal pressure relief valve mechanism 4 configured as described above
At zero, while the hydraulic pressure in the downstream flow passage 45 of the check valve 12 is at a normal pressure (set pressure of the pump), the valve rod 60 closes the through hole 56 as a relief passage. The oil liquid pressure-fed to the inlet 42 of the casing 41 opens the check valve 12 and
From 4, it is sent to the refueling nozzle 9 via the flow meter 10.

If, for some reason, the downstream side of the check valve 12 becomes abnormally high in pressure, the high-pressure oil flows into the cylinder lower chamber 65 through a small hole 66 provided in the cylinder 57. When the oil pressure becomes larger than the set load of the spring 62, the piston 58 is pushed up against the urging force of the spring 62, and the distal end portion 60a of the valve rod 60 is correspondingly released.
6, the high-pressure oil in the downstream flow passage 45 flows into the upstream flow passage 43. That is, the abnormal pressure on the downstream side of the check valve 12 is released to the upstream side (the pump 2 side) of the check valve 12. At this time, since the inside of the cylinder upper chamber 61 is open to the atmosphere, the force for pushing up the piston 58 is equal to the pressure of the cylinder lower chamber 65 (the pressure on the downstream side of the check valve 12) and the spring 62 except for its own weight. Therefore, the pressure released as abnormal pressure is constant irrespective of the pressure fluctuation on the upstream side of the check valve 12.

In the above-described embodiment, the abnormal pressure relief valve mechanism 40 and the check valve 12 are housed in a single casing 41 to form a unit.
May be separated from the check valve 12 and provided separately.

[0021]

According to the abnormal pressure relief valve mechanism for a lubricating device according to the present invention, the relief passage is opened by the differential pressure between the pressure on the downstream side of the check valve and the set load of the spring. The pressure at which the abnormal pressure on the downstream side is released is constant irrespective of the pressure on the upstream side of the check valve, and the reliability of the device is improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a structure of an abnormal pressure relief valve mechanism for a fueling device according to the present invention.

FIG. 2 is a schematic diagram showing a general system of an oil supply device that provides the abnormal pressure relief valve mechanism.

FIG. 3 is a cross-sectional view showing one structure of a conventional abnormal pressure relief valve mechanism.

FIG. 4 is a sectional view showing another structure of the conventional abnormal pressure relief valve mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Underground tank 2 Pump 4 Underground piping 5 Metering unit 6 Above-ground piping 9 Refueling nozzle 10 Flow meter 12 Check valve 40 Abnormal pressure relief valve mechanism 43 Upstream flow path (passage) 45 Downstream flow path (passage) 56 Through hole ( (Relief passage) 57 cylinder 58 piston 60 valve rod 61 one chamber in cylinder 62 spring 65 other chamber in cylinder 66 small hole

Claims (1)

[Claims] 1. A refueling system having a check valve interposed in a passage connecting a pump and a flow meter, wherein a relief passage bypassing the check valve is provided in the pipeline, and a valve for opening and closing the relief passage is provided. One end of a rod is connected to a piston slidably fitted in a cylinder, and a spring is provided in the cylinder to normally bias the valve rod through the piston in a direction to close the relief passage. Further, one of two chambers in the cylinder partitioned by the piston, which is opposite to the side where the valve rod is extended, is opened to the atmosphere, and the other chamber in the cylinder is connected to the check valve. An abnormal pressure relief valve mechanism for a lubrication device, characterized in that the valve communicates with a downstream passage of the oil supply device.