JPS6217662Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention provides a check valve for a diaphragm pump, in particular, the valve seat is attached to a guide shaft fixed to a valve seat plate that partitions a pump chamber facing the diaphragm from a suction chamber or a discharge chamber. A flexible disc-shaped valve body is loosely fitted into the valve seat plate, and has a pair of annular protrusions protruding concentrically with the guide shaft, which can abut on the plate, and the valve seat plate has a pair of annular protrusions that protrude concentrically with the guide shaft. A plurality of valve holes are bored around the guide shaft, a spring support plate is superimposed on the surface of the valve body opposite to the valve seat plate, and a gap between the spring support plate and the free end of the guide shaft is formed. The present invention relates to a check valve for a diaphragm pump in which a spring is interposed to bias the valve body toward the valve seat plate.

Conventionally, in such check valves, the sealing pressure when a pair of annular protrusions abut against the valve seat plate is determined by applying the spring force of the spring to the center between the two protrusions due to the difference in sealing area due to the difference in diameter. If the sealing pressure is applied only on a virtual circle passing through the outer annular protrusion, the sealing pressure of the outer annular protrusion will be smaller than that of the inner annular protrusion.

However, in the past, such points were not taken into consideration, and fluid leakage could occur due to the difference in sealing pressure between the two protrusions, so the spring force was simply set to a large value to prevent fluid leakage. That's what I do.

The present invention was developed in view of such circumstances, and it makes it possible to make the spring force of the spring relatively small by equalizing the sealing pressure of both annular protrusions, thereby improving responsiveness and sealing performance. An object of the present invention is to provide a check valve for a diaphragm type pump that has the following characteristics.

An embodiment in which the present invention is applied to a diaphragm pump for supplying fuel to an automobile engine will be explained below with reference to the drawings. First, in FIG. The peripheral edge of the diaphragm 4 is sandwiched between the upper body 2 and the lower body 3. This diaphragm 4 repeats suction and discharge operations by an operating shaft 6 connected to a swing arm 5 that swings in conjunction with the rotation of an engine camshaft (not shown). Fluid such as fuel sucked into the pump chamber 9 through the stop valve 7 is discharged from the pump chamber 9 through the discharge check valve 8 during a discharge operation.

A valve seat plate 10 is sandwiched between the upper body 2 and the lower body 3 together with a diaphragm 4 on the upper body 2 side, and a pump chamber 9 is defined between the valve seat plate 10 and the diaphragm 4. . Further, the upper main body 2 is integrally provided with a cylindrical portion 2a that extends toward the valve seat plate 10 and whose end portion abuts against the valve seat plate 10 via the seal member 11.
A suction chamber 12 is defined by a and the valve seat plate 10,
A discharge chamber 13 is defined around the cylindrical portion 2a. The upper body 2 has a suction pipe section 1 that communicates with the suction chamber 12.
4. A discharge pipe part 15 communicating with the discharge chamber 13 and an overflow pipe part 17 communicating with the upper part of the discharge chamber 13 via a throttle 16 are integrally provided in a protruding manner.

A spring chamber 18 is defined between the diaphragm 4 and the lower main body 3, and within the spring chamber 18 is a return spring 1 that biases the diaphragm 4 in the discharge operation direction.
9 is accommodated. The lower body 3 is integrally provided with a guide tube portion 20 that extends downward concentrically with the axis of the diaphragm 4, and the open end of the guide tube portion 20 facing the spring chamber 19 is covered with a flexible shielding member 21. be exposed.

Retainers 22 and 23 are provided on both sides of the diaphragm 4.
The upper end of the actuating shaft 6 passes through both retainers 22 and 23 and the diaphragm 4, and is integrated with the diaphragm 4 by a retaining ring 24. Furthermore, the operating shaft 6 hermetically passes through the shielding member 21 and extends downward within the guide tube 20, and its lower end is connected to one end of the swing arm 5 via the elastic member 25. The swinging arm 5 is pivotally supported by the lower body 3 via a pin 26 perpendicular to the axis of the operating shaft 6, and swings back and forth around the pin 26 as shown by an arrow 27 in conjunction with a camshaft (not shown). move. Furthermore, a return spring 28 is interposed between the swing arm 5 and the lower main body 3 to assist the upward movement of the operating shaft 6 by the return spring 19.

The suction check valve 7 is provided on the valve seat plate 10 to allow fluid to flow only from the suction chamber 12 to the pump chamber 9, and the discharge check valve 8 is provided to allow fluid to flow from the pump chamber 9 to the discharge chamber 1.
The valve seat plate 10 is provided to allow fluid flow only to the valve 3.

In FIG. 2, the discharge check valve 8 has a valve seat plate 1.
The discharge chamber 13 is fixedly installed in the part facing the discharge chamber 13 of 0.
A guide shaft 30 extending to the side, a flexible disk-shaped valve body 31 loosely fitted onto the guide shaft 30, and a valve seat plate 10 bored around the guide shaft 30 at a portion facing the discharge chamber 13. A plurality of valve holes 32 , a spring receiving plate 33 that is in contact with the surface of the valve body 31 opposite to the valve seat plate 10 , and a guide shaft that is interposed between the free end of the guide shaft 30 and the spring receiving plate 33 . 30 and a coiled spring 34 surrounding the coiled spring 30.

A spring receiving portion 35 projecting radially outward for supporting a spring 34 is integrally provided at the free end of the guide shaft 30 . A pair of annular protrusions 36 and 37 are attached to the guide shaft of the valve body 31 so that the positions of contact with the valve seat plate 10 are at the outer and inner positions of each valve hole 32 along the radial direction. Concentric with 30 and valve seat plate 10
Projected towards the side. The spring receiving plate 33 is integrally provided with an annular protrusion 38 that protrudes toward the valve body 31 at a position outward from an imaginary circle passing through the center between the annular protrusions 36 and 37 by bending by press working or the like.

The suction check valve 7 includes a guide shaft 40 that is fixed to a portion of the valve seat plate 10 facing the suction chamber 12 and extends toward the pump chamber 9, and a flexible disc-shaped valve that is loosely fitted onto the guide shaft 40. body 41 and a plurality of valve holes 4 bored around the guide shaft 40 in the portion of the valve seat plate 10 facing the suction chamber 12.
2, a spring receiving plate 43 that comes into contact with the surface of the valve body 41 opposite to the valve seat plate, and is interposed between the free end of the guide shaft 40 and the spring receiving plate 43 and surrounds the guide shaft 40. The discharge check valve 8 includes a coiled spring 44 and is configured similarly to the discharge check valve 8.

Next, the operation of this embodiment will be explained. When the diaphragm 4 is displaced in accordance with the downward movement of the operating shaft 6, that is, when it performs a suction operation, the valve body 41 of the suction check valve 7 moves away from the valve seat plate 10. When they separate, the valve opens, fluid is sucked into the pump chamber 9 from the suction chamber 12, and in the discharge check valve 8, the valve body 31 contacts the valve seat plate 10 and the valve closes. Further, when the diaphragm 4 is displaced in accordance with the upward movement of the operating shaft 6, that is, when the discharge operation is performed, the valve body 41 of the suction check valve 7 contacts the valve seat plate 10 and closes, and the discharge reverse In the stop valve 8, the valve body 31 separates from the valve seat plate 10 to open the valve, and the fluid in the pump chamber 9 is discharged into the discharge chamber 13. In this way, as the diaphragm 4 repeats the suction and discharge operations, both check valves 7 and 8 open alternately, and fluid is sucked and discharged.

By the way, in the discharge check valve 8, the valve body 31
When in contact with the valve seat plate 10, the spring force of the spring 34 is outward from the center between the annular protrusions 36 and 37,
The annular protrusion 38 of the spring receiving plate 10 acts on the valve body 31, and the contact force of both the annular protrusions 36 and 37 to the valve seat plate 10, that is, the sealing force, is almost equal.
Improves sealing performance. This also applies to the suction check valve 7.

As described above, according to the present invention, the spring receiving plate includes:
Since the annular protrusion protrudes toward the valve body outward from the virtual circle passing through the center between both annular protrusions of the valve body, the sealing force of the outer annular protrusion with a large sealing area and the inner annular protrusion with a small sealing area are reduced. The sealing force of the annular protrusion can be made almost equal, thus improving sealing performance, and the spring force of the spring can be set to be relatively small, making it possible to improve responsiveness.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention applied to a diaphragm pump for supplying fuel to an automobile engine. Fig. 1 is an overall longitudinal sectional view, and Fig. 2 is an enlarged sectional view of a discharge check valve. be. 4...Diaphragm, 7...Suction check valve, 8
...Discharge check valve, 9...Pump chamber, 10...Valve seat plate, 12...Suction chamber, 13...Discharge chamber, 30,
40... Guide shaft, 31, 41... Valve body, 32, 4
2... Valve hole, 33, 43... Spring receiving plate, 34, 4
4... Spring, 36, 37... Annular projection, 38...
Annular protrusion, P...Diaphragm pump.

Claims (1)

[Scope of utility model registration request] A guide shaft fixed to a valve seat plate that partitions a pump chamber facing the diaphragm from a suction chamber or a discharge chamber may include a pair of annular protrusions protruding concentrically with the guide shaft and capable of coming into contact with the valve seat plate. A flexible disk-shaped valve body is loosely fitted, and a plurality of valve holes are bored in the valve seat plate around the guide shaft between the contact positions of both the annular projections, and the valve seat of the valve body A spring receiving plate is superimposed on the surface opposite to the plate, and a spring is interposed between the spring receiving plate and the free end of the guide shaft to urge the valve body toward the valve seat plate. In the check valve for a diaphragm pump, the spring receiving plate is provided with an annular protrusion that protrudes toward the valve body outward from a virtual circle passing through the center between the annular protrusions. Check valve for diaphragm pumps.