JP2001003871A - Check valve structure for diaphragm pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide check valve structure for a diaphragm pump capable of keeping a stable flow rate characteristic without degradation in a sealing property. SOLUTION: In a area which blocks an air hole 21a of an open/close plate 22 blocking the air hole 21a of a valve base 21, a bulge portion 22d bulging to the opposite side to the valve base 21 is provided. Since the size of the area covering an end surface opening of the air hole 21a is enlarged, pressure acting on the above mentioned area through the air hole 21a is dispersed, so that generated stress is made to be small. And by providing the bulge portion 22d, the area is also reinforced. Therefore, the check valve resists deforming against the pressure acting on through the air hole 21a to prevent degradation in a sealing property, which can keep a stable flow rate characteristic.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a check valve structure for a diaphragm pump.

[0002]

2. Description of the Related Art A configuration example of a diaphragm pump will be described with reference to FIG. 2 which is an explanatory view of the present invention. In this pump, a diaphragm 5 is provided in a head block including a pump head lower block 3 and a pump head upper block 9 fixed to the pump head from above. It is fixed to a mounting plate 4 that is reciprocated up and down. With such a configuration, the volume of the space between the diaphragm 5 and the pump head upper block 9 (hereinafter, referred to as a pump space) changes, and a pair of through holes formed in the upper wall surface 9a of the pump head upper block 9 are formed. Gas is sucked into the pump space through one of the holes 11 and 11, and the sucked gas is discharged through the other through hole 11.

[0003] Valve bodies 12 and 13 each having a check valve function are mounted in each of the through holes 11 and the intake side valve body 12 on the left side in the figure allows gas to pass therethrough in the suction step. Then, the passage of gas is blocked in the discharging process. Contrary to the above, the right discharge side valve body 13 allows the passage of gas in the discharge step and blocks the passage of gas in the suction step.

Conventionally, as shown in FIG. 3A, a valve body having such a check valve function is provided with a plurality of vertically penetrating vent holes 51a formed at equal intervals along one circle. On the upper surface of the substantially disk-shaped valve base 51, as shown in FIG.
2 is concentrically fixed by a fixing pin 53.
FIG. 3 shows the above-mentioned discharge side valve body. The suction-side valve body has the same structure as this, and functions as a suction-side valve body by being installed upside down in the through hole.

The opening / closing plate 52 has a fixing portion 52a having a through hole through which a fixing pin 53 penetrates at a center portion, and
The valve base 51 is formed in a shape having a donut-shaped opening / closing portion 52b that covers the formation region of each of the ventilation holes 51a, and the opening / closing portion 52b is connected to the fixed portion 52a by three meandering connection portions 52c. Have been.

FIGS. 1C and 1D show through holes 5 on the discharge side.
4 shows an operation state of the valve body attached to the valve body 4.
In the above-mentioned suction step, as shown in FIG. 3C, the opening / closing portion 52b of the opening / closing plate 52 is in close contact with the upper surface of the valve base 51, whereby each air hole 51a is closed and the valve is closed. . On the other hand, in the discharge step, the discharge pressure acts from below through each of the ventilation holes 51a, and as a result, as shown in FIG. The valve 52b is in an open state separated upward from the upper surface of the valve base 51. As a result, gas is discharged upward from below through the ventilation holes 51a as indicated by solid arrows. Such a valve closing state and a valve opening state are automatically generated in accordance with the switching between the intake step and the discharge step, and the operation is continued.

[0007]

However, in the conventional valve body provided with the opening / closing plate 52 as described above, the sealing performance of each valve body when the valve is closed gradually decreases, and the flow characteristics become unstable. Has a problem. That is, for example, in the discharge side valve body, the opening and closing
b is in a valve-closed state in close contact with the upper surface of the valve base 51. At this time, in a region covering each ventilation hole 51a, a downward suction force is applied to each region through each ventilation hole 51a (discharge force in the suction side valve body). As a result, as shown in FIG. 3 (e), permanent deformation deformation occurs such that the area covering the ventilation holes 51 a is depressed downward as shown in FIG.
When the valve is closed, the adhesion to the upper surface of the valve base 51 is impaired, and the sealing performance is reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has as its object to provide a check valve structure of a diaphragm pump capable of maintaining a stable flow rate characteristic without deteriorating sealing performance. Is to provide.

[0009]

Therefore, a check valve structure for a diaphragm pump according to the present invention is characterized in that a valve base having a flow passage opening to a pump space which is increased or decreased by the diaphragm is formed, and the flow passage opening is closed. A check valve of a diaphragm pump which is provided with a thin plate-like opening / closing plate arranged along the end face of the valve base, and wherein the opening / closing plate is bent and deformed according to the pressure of the pump space to open and close the flow passage hole. The valve structure is characterized in that a bulging portion bulging to the side opposite to the valve base is provided in a region of the opening / closing plate that closes the flow path hole.

According to this structure, when the opening / closing plate is in close contact with the end surface of the valve base to close the flow path hole, the area covering the end face opening of the flow path hole is flat. As compared with the shape, the area provided with the above-mentioned bulging portion is widened. As a result, the pressure acting on the region through the flow passage hole is dispersed, and the generated stress is reduced. Further, since the bulging portion as described above has a shape in which a rising portion intersecting a plane area along the end face of the valve base is continuously provided, rigidity against bending deformation in a direction along the rising portion is provided. growing. This also makes it difficult for the pressure acting through the flow path hole to deform. As a result, even if the bending deformation for opening and closing the flow passage hole is repeated, the generation of permanent distortion in the region covering the end face opening of the flow passage hole is suppressed, the deterioration of the sealing property is prevented, and the stable flow characteristic is maintained. can do.

According to a second aspect of the present invention, the check valve structure of the diaphragm pump is characterized in that the bulging portion is formed in an arc-shaped cross section.

As described above, in the configuration in which the bulging portion is formed in an arc shape in cross section, stress concentration when pressure acts through the flow passage hole does not occur as compared with a shape having corner portions such as a triangular cross section. Since a uniform stress distribution state is obtained, it is difficult for the bulging portion itself to be distorted, and the original shape is maintained. Accordingly, this further prevents a decrease in sealing performance, and maintains a stable flow rate characteristic.

According to a third aspect of the present invention, in the check valve structure for a diaphragm pump, when the bulging portion is brought into close contact with the end surface of the valve base, the entire end face opening of the flow passage hole is included inside the bulging portion. It is characterized by forming.

According to this structure, the pressure through the flow passage hole does not act on the flat region outside the bulging portion of the opening / closing plate when the flow passage hole is closed, and the deformation of the flat region is more reliably performed. Is prevented. Therefore, since the flat area is in close contact with the end face of the valve base, a reduction in sealing performance is more reliably prevented, and a stable flow characteristic is maintained.

[0015]

Next, specific embodiments of the present invention will be described in detail with reference to the drawings. FIG. 2 shows a diaphragm pump according to the present embodiment. This pump includes a drive motor 1, a motor head block 2 provided on a front surface of the motor 1, and a pump head lower block 3 fixed on an upper surface of the block 2. The motor head block 2 has a built-in mechanism for converting the rotational motion of the drive motor 1 into a vertical reciprocating motion, and a disk connected to the conversion mechanism and driven up and down in the pump head lower block 3. A mounting plate 4 in a shape of is provided.

A circular thin diaphragm 5 is arranged along the upper surface of the mounting board 4. This diaphragm 5
The Teflon sheet 6 is placed on the lower surface, and the flat flange 7 is placed on the upper surface, and these 5.6.7 are fastened to the mounting plate 4 by mounting screws 8 at the center position. Then, the pump head upper block 9 is fixed to the pump head lower block 3 by inserting a fixing screw 10 from above into the peripheral side thereof so as to cover them. At this time, the peripheral side of the diaphragm 5 is assembled so as to be sandwiched and fixed between the cylindrical side walls of the upper block 9 and the lower block 3 of the pump head.

A pair of circular through holes 11 are formed in the upper wall 9a of the upper block 9 of the pump head at the center thereof. Disc-shaped valve bodies 12 and 13 to be described later are mounted in these through holes, respectively. The pump head upper block 9 is provided with a block 14 for covering the through holes 11 from above. Between the lower surface of the block 14 and the valve bodies 12 and 13, O With the ring 15, the ring-shaped adapter 16 and the gasket 17 interposed, the respective valve bodies 12 and 13 are fixed in the circular through holes 11 and 11.

Each of the valve bodies 12 and 13 has a check valve function, and the left valve body 12 (hereinafter also referred to as an intake side valve body) in the figure allows gas to pass from above to below. It blocks the passage of gas from below to above. Right valve body 13 (hereinafter also referred to as discharge side valve body)
Conversely, permits the passage of gas from below to above and blocks the passage of gas from above to below.

In such a configuration, when the drive motor 1 is operated, the diaphragm 5 is fixed between the upper block 9 and the lower block 3 of the pump head at the peripheral side, and the mounting plate 4 is positioned at the center side. Together move up and down.
As a result, the volume of the space between the diaphragm 5 and the upper wall surface 9a of the upper pump head block 9 (hereinafter referred to as a pump space) changes, and a pumping action occurs.

That is, in the suction step in which the diaphragm 5 descends, the suction force of the gas into the pump space is generated as the pump space increases, thereby forming a block 14 as shown by a solid line arrow. Gas is sucked into the pump space through a suction passage (not shown) and the intake side valve body 12. At this time, the discharge side valve body 13 is held in a closed state.

Next, in the discharge step in which the diaphragm 5 rises, the gas that has been sucked into the pump space is reduced by the decrease in the pump space, and the discharge passage (not shown) formed in the discharge side valve body 13 and the block 14. Is discharged from this block 14 to the outside as shown by the broken line arrow in the figure. At this time, the intake side valve body 12 is held in a closed state. With the repetition of the suction step and the discharge step, the gas is sequentially sucked, and the pressure is increased to be discharged.

Next, the specific structure of the valve bodies 12 and 13 having the above-described check valve function will be described. Note that these valve bodies 12 and 13 are formed in the same structure as each other, and the only difference is that they are mounted in the respective through holes 11 and 11 with the front and rear sides changed. 13 will be described as an example.

As shown in FIG. 1 (a), the valve body 13 has a substantially disc-shaped valve base 21 and
A flexible thin plate-shaped opening / closing plate 22 attached along the upper surface of the base plate, and a fixing pin 23 for fixing the valve base 21 and the opening / closing plate 22 concentrically with each other and fixing them at a center position.
And is constituted by.

As shown in FIG. 2B, the valve base 21 is provided with a plurality of vent holes (flow passage holes) 21a penetrating vertically, in the case of FIG. These ventilation holes 21a are formed at equal intervals along one circle.

The opening / closing plate 22 is made of, for example, a stainless steel plate having a thickness of about 120 μm. The opening / closing plate 22 in the present embodiment has a doughnut-shaped portion that has a fixed portion 22a formed with a through hole through which the fixed pin 23 penetrates in the center portion, and a donut-shaped portion that covers the formation region of each of the vent holes 21a of the valve base 21 on the outer periphery. It is formed in a shape having an opening / closing portion 22b,
The opening / closing portion 22b is connected to the fixed portion 22a by three meandering connection portions 22c. A swelling portion 2 swelling upward over the entire circumference is provided on the opening / closing portion 22b.
2d is provided.

The bulging portion 22d has a semicircular cross-sectional shape as shown in FIG. The width of the lower end of the bulging portion 22d is set so that the entire upper end opening of each of the vent holes 21a is included in the space surrounded by the bulging portion 22d. Have been.

In the above-described valve body 13, the downward suction force acts on the opening / closing portion 22b through each vent hole 21a in the above-described intake process, and as a result, as shown in FIG. The plane area excluding the protruding portion 22d is in close contact with the upper surface of the valve base 21, whereby the valve is in a valve-closed state in which the flow path through each vent hole 21a is shut off.

On the other hand, in the above-described discharge step, each air hole 2
The discharge pressure acts on the opening / closing portion 22b from below through 1a,
As a result, as shown in FIG. 4D, the opening / closing plate 22 undergoes a bending deformation such that the outer peripheral side is warped upward, and the opening / closing portion 22 b
Is in an open state separated from the upper surface of the valve base 21 or upward. Thereby, the gas is discharged upward from below through each ventilation hole 21a as shown by the solid arrow. The valve closing state and the valve opening state are automatically generated in accordance with the switching between the intake step and the discharge step, and the operation is continued.

By the way, in the valve closed state shown in FIG. 2C, a downward suction force acts on the opening / closing portion 22b through each air hole 21a. The same applies to the intake side valve body 12 described above. In this case, the intake side valve body 1
When the valve 2 is in a closed state, the discharge pressure generated in the pump space acts. As a result of intermittent repetition of the state in which such suction force and discharge pressure act, in the conventional valve body, permanent distortion deformation occurs in the opening / closing portion as described above, and the sealing performance at the time of valve closing decreases. Problem had arisen.

On the other hand, in the present embodiment, the opening / closing section 22
b is provided with an upwardly bulging portion 22d,
The area of the region covering the end face opening of 1a increases. As a result, the pressure acting on the region through the air holes 21a is dispersed, and the generated stress is reduced. In addition, by providing the above-described bulging portion 22d, the above-mentioned region is reinforced, and thereby, it is difficult to be deformed by the pressure acting through the ventilation hole 21a. As a result, the ventilation holes 2
Even if the bending deformation caused by the opening and closing of 1a is repeated, the ventilation holes 21
The generation of permanent distortion in the area covering the end face opening of “a” is suppressed, the deterioration of sealing performance is prevented, and stable flow characteristics are maintained.

Since the bulging portion 22d is formed in an arcuate cross section, substantially uniform stress is not generated in the bulging portion 22d when a pressure is applied through the vent hole 21a. It becomes a distribution state. As a result, the bulging portion 22d itself is unlikely to be distorted, and the initial shape is maintained. This also prevents a decrease in sealing performance and maintains a stable flow rate characteristic.

Further, the bulging portion 22d is formed such that the entire end face opening of the ventilation hole 21a is included inside the bulging portion 22d when the bulging portion 22d is in close contact with the end face of the valve base 21. For this reason, the bulging part 2 in the opening / closing part 22b
No pressure is applied to the flat area outside the 2d when the air hole 21a is closed when the air hole 21a is closed, so that the deformation of the flat area is more reliably prevented. Therefore, since the flat region adheres tightly along the end face of the valve base 21, a decrease in sealing performance is more reliably prevented, and a stable flow characteristic is maintained.

Although the specific embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various changes can be made within the scope of the present invention. For example, in the above embodiment, the bulging portion 22d is
Although an example has been described in which the protrusions 1a are formed in a circumferential shape along a circle in which they are arranged, it is also possible to adopt a configuration in which bulging portions are discretely formed in a region corresponding to each of the ventilation holes 21a. In the above description, the example in which the bulging portion 22d is formed in an arc shape in cross section has been described. It can be provided and configured.

Further, in the above description, when the opening / closing plate 22 is in close contact with the end face of the valve base 21, the width dimension of the bulging portion 22d is so set that the entire end face opening of the vent hole 21a is included inside the bulging portion 22d. Although the example of setting and forming was given,
In the scope of claims 1 and 2, the width of the bulging portion 22d may be reduced so that a part of the end face opening of the ventilation hole 21a is located outside the bulging portion 22d. It is. Even with the bulging portion 22d having such a shape, the area of the region covering the end face opening of the ventilation hole 21a is increased,
In addition, since this region is reinforced by the bulging portion 22d, distortion and deformation of the plane region outside the bulging portion 22 are unlikely to occur, and a decrease in sealing performance is suppressed, and a stable flow rate characteristic is obtained. Will be maintained.

In the above description, the gas diaphragm pump has been described as an example. However, the present invention can be applied to a liquid diaphragm pump.

[0036]

As described above, in the check valve structure of the diaphragm pump according to the first aspect of the present invention, the opening / closing plate for closing the passage hole of the valve base is provided with the valve base in the region for closing the passage hole. Has a bulging part that bulges out on the opposite side,
The area of the region covering the end face opening of the flow path hole is increased. As a result, the pressure acting on the region through the flow path hole is dispersed, and the generated stress is reduced. In addition, by providing the above-described bulging portion, the above-mentioned region is reinforced, and thus, it becomes difficult to be deformed by the pressure acting through the flow passage hole. As a result, even if the bending deformation for opening and closing the flow passage hole is repeated, the generation of permanent distortion in the region covering the end face opening of the flow passage hole is suppressed, the deterioration of the sealing property is prevented, and the stable flow characteristic is maintained. can do.

In the check valve structure for a diaphragm pump according to the second aspect, since the bulging portion is formed in an arcuate cross section, stress concentration when pressure acts through the flow passage hole in the bulging portion. Is not generated, and a substantially uniform stress distribution state is obtained, so that the swelling portion itself is hardly distorted and the original shape is maintained, so that the sealing property is further prevented from lowering and stable. Flow characteristics are maintained.

In the check valve structure for a diaphragm pump according to the third aspect, when the bulging portion is in close contact with the end surface of the valve base, the entire end face opening of the flow passage hole is included inside the bulging portion. Since the pressure is not applied to the flat area outside the bulging portion of the opening / closing plate when the flow path hole is closed, the deformation of the flat area is more reliably prevented. Is done. Therefore, since the flat area is in close contact with the end face of the valve base, a reduction in sealing performance is more reliably prevented, and a stable flow characteristic is maintained.

[Brief description of the drawings]

FIGS. 1A and 1B show a main configuration of a diaphragm pump according to an embodiment of the present invention. FIG. 1A is a perspective view of a valve body incorporated in the diaphragm pump, and FIG. FIG. 3C is an exploded perspective view of the valve body, and FIG. 4C is a cross-sectional view showing an operation state when the valve body is closed, and FIG.
FIG. 4 is a cross-sectional view showing an operation state when the valve body is opened.

FIG. 2 is an exploded perspective view showing a configuration of the diaphragm pump.

FIGS. 3A and 3B show a main part configuration of a conventional diaphragm pump. FIG. 3A is a perspective view showing a valve base of a valve body incorporated in the diaphragm pump, and FIG. 3B is a view showing the valve base. (C) is a cross-sectional view showing an operation state when the valve body is closed, and FIG. (D) is a cross-sectional view showing an operation state when the valve body is opened. FIG. 4E is a cross-sectional view showing an operation state, and FIG. 4E is a cross-sectional view showing a state in which the opening / closing plate is deformed.

[Explanation of symbols]

 5 Diaphragm 12 Intake side valve body 13 Discharge side valve body 21 Valve base 21a Vent hole (flow path hole) 22 Opening / closing plate 22d Swelling part

Claims (3)

[Claims] 1. A valve base in which a flow passage hole communicating with a pump space which is increased and decreased by a diaphragm is formed, and a thin plate-shaped opening / closing plate arranged along an end face of the valve base so as to close the flow passage hole. A check valve structure of a diaphragm pump formed so that the opening / closing plate is bent and deformed in response to the pressure of the pump space to open and close the flow passage hole, and in a region for closing the flow passage hole in the opening / closing plate, A check valve structure for a diaphragm pump, wherein a bulging portion bulging out on the opposite side to the valve base is provided. 2. The check valve structure for a diaphragm pump according to claim 1, wherein said bulging portion is formed in an arc shape in cross section. 3. The swelling portion is formed such that the entire end face opening of the flow passage hole is included inside the swelling portion when the swelling portion is in close contact with the end face of the valve base. The check valve structure of the diaphragm pump of 1 or 2.