JPH07139469A - Support structure of diaphragm - Google Patents

Abstract

PURPOSE:To provide the highly reliable support structure of a diaphragm having no drag of the diaphragm and which can seal a fluid to be press-fed and an operation oil and not fatigue destroyed by repeating high stress. CONSTITUTION:A support part 201 is arranged on the position apart to the outer periphery side form a diaphragm movable part and the diaphragm is press-contacted in upper/lower direction and held in and supported by making film thickness direction compression amount of the diaphragm 1 in the support 201 large than the film thickness direction compression amount of the diaphragm in an adjacent part to the diaphragm movable part.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art A diaphragm is displaced by hydraulic oil,
In a diaphragm pump that pressure-feeds a fluid to be pressure-fed through a diaphragm, tighten a member with a good bite shape at a high surface pressure to prevent drag of the diaphragm due to displacement of the diaphragm or to seal the fluid to be pressurized and hydraulic oil. , It is necessary to support the diaphragm.

Further, since the diaphragm has its peripheral portion fixed and repeatedly displaced, there is a problem that the stress amplitude in the peripheral portion is large and fatigue fracture occurs. In order to reduce the stress in the peripheral portion, it is effective to provide a stopper having, for example, an R shape, which rises smoothly from the peripheral portion so as to regulate the displacement of the peripheral portion. However, as shown in the unsupported diaphragm support structure in FIG. 3, if it also serves as a support at the end of the R shape, the diaphragm is plastically deformed by tightening at the end of the R shape, and the stress reduction effect of the R shape is halved. However, there is a problem that the reliability of the diaphragm is reduced.

[0004]

DISCLOSURE OF THE INVENTION The present invention is capable of supporting a diaphragm which is free from drag of the diaphragm, can seal the fluid to be pumped and hydraulic oil, and is free from fatigue fracture due to repeated high stress. It is intended to provide a structure.

[0005]

In order to achieve the above-mentioned object, the present invention provides a support portion at a position distant from the diaphragm movable portion on the outer peripheral side, and the amount of compression of the diaphragm in the film thickness direction in the support portion is adjacent to the diaphragm movable portion. A diaphragm support structure is adopted in which the diaphragm is compressed more than the portion in the thickness direction of the diaphragm in the thickness direction and is supported by being pressed and held in the vertical direction of the diaphragm.

[0006]

Since the amount of compression of the diaphragm in the film thickness direction in the support portion is larger than the amount of compression of the diaphragm in the film thickness direction of the portion adjacent to the diaphragm movable portion, the diaphragm is prevented from being dragged and the pressurized fluid and hydraulic oil are sealed. Can be done reliably and satisfactorily. Further, since the compression amount in the film thickness direction of the diaphragm in the portion adjacent to the diaphragm movable portion is smaller than the compression amount in the film thickness direction of the diaphragm in the support portion, the stress of the diaphragm in the portion adjacent to the diaphragm movable portion is reduced. It can be made smaller and fatigue failure of the diaphragm can be eliminated.

[0007]

EXAMPLES Examples of applying the diaphragm support structure of the present invention to a diaphragm pump will be described below. FIG. 1 is a diaphragm pump to which the structure of the diaphragm of the present invention is applied, and FIG. 2 is a detailed view of a diaphragm support portion A in FIG.

Embodiment 1 of the present invention with reference to FIGS. 1 and 2.
The configuration of will be described. The diaphragm 1, which is made of metal and has a plate thickness of 0.1 mm and a movable part diameter of 43 mm, includes an upper housing 2 having a support part 201 and an R-shaped stopper 202, and hydraulic oil 3.
It is sandwiched between the lower stopper 4 having a plurality of return holes 401 and is fixed by being screwed into the upper housing 2 together with the retainer 5. R-shaped stopper 20
No. 2 rises from the movable part diameter φ43 mm of the diaphragm 1 toward the inner side, and the radius of curvature R thereof is 70 mm in this embodiment.

The support portion 201 is formed over the entire circumference of the upper housing 2 as shown in FIG. 4 when viewed from below in FIG. 1, and has a width of 0.5 mm and is larger than the R-shaped stopper 202. It projects 0.02 mm downward in No. 2. The retainer 5 has a hydraulic oil chamber 7 and a cylinder 502. A plunger 8 is slidably fitted in the cylinder 502, and the hydraulic oil chamber 7 and the retainer 5 are provided only near the bottom dead center of the plunger 8. A reset port 503 is provided to make the outside electrically conductive.

The plunger 8 is urged downward in the figure by a spring 9 to press the tappet 10 against the cam 11. The inside of the lower housing 13, such as the hydraulic oil chamber 7 and the cam chamber 12, is filled with the same hydraulic oil 3. The inlet 14 communicates with the high pressure chamber 203 via a solenoid valve 15 for metering, and the high pressure chamber 203 communicates with the discharge valve 16.

Next, the operation of the first embodiment will be described. The cam 11 is rotated by a drive source (not shown) to reciprocate the plunger 8 up and down in the figure. When the plunger 8 closes the reset port 503 in the discharge stroke of the plunger 8, the pressure of the hydraulic oil 3 in the hydraulic oil chamber 7 is increased, the pressure of the pressurized fluid in the high pressure chamber 203 is increased via the diaphragm 1, and the discharge valve It discharges from 16. At this time, the solenoid valve 15 is controlled to be closed by a computer (not shown).

On the contrary, at the time of inhalation, the fluid to be pressure-fed from the inlet 14 flows into the high pressure chamber 203 through the electromagnetic valve 15 in the open state. At the same time, the displacement of the diaphragm 1 is reduced, and the hydraulic oil 3 passes through the return hole 401 and returns from the upper portion of the lower stopper 4 in the figure to the hydraulic oil chamber 7. In the above operation, the diaphragm 1 repeats displacement, and its form is shown below.

At the beginning of deformation, the diaphragm 1 gradually contacts the R-shaped stopper 202 from the outer peripheral portion, and the contact surface between the diaphragm 1 and the R-shaped stopper 202 widens as the deformation progresses. At this time, the range in which the diaphragm 1 receives stress also expands. That is, the R-shaped stopper 202
Since the deformation is controlled in a wide range from the central part to the outer peripheral part, the stress is dispersed in a wide range and the fatigue fracture can be prevented from occurring.

On the other hand, in addition to the problem of fatigue fracture due to repeated deformation, in order to prevent drag to the inner peripheral side of the diaphragm 1 caused by repeated deformation and to secure the sealing property of the fluid to be pressurized and the hydraulic oil 3. A high surface pressure is required to support the diaphragm 1, and if the retaining nut 6 is excessively tightened to support the diaphragm 1, a problem that the diaphragm 1 is plastically deformed is applied to the supporting portion of the diaphragm 1. There is.

As shown in FIG. 3, it is conceivable to support the diaphragm 1 at the end of the R-shaped stopper 202, but since the above-mentioned stress reducing effect is halved, in the present embodiment, FIG.
As shown in FIG.
1 was disposed, and the supporting portion 201 was made to project downward from the end portion of the R-shaped stopper 202 by 0.02 mm in FIG. For this reason, the support portion 201 bites into the diaphragm 1 by the tightening for supporting the diaphragm 1 and a large stress is applied, but the movable portion of the diaphragm 1 has an R-shaped stopper 202.
Since it is located at a position distant from the end portion to the inner peripheral side, the stress due to the support of the diaphragm 1 does not affect the fatigue fracture due to repeated displacement.

With the above-mentioned structure and functions, the diaphragm 1 is prevented from being dragged, the sealing property is secured, and the R-shaped stopper 20 is provided.
The stress due to 2 is surely reduced. In this embodiment, the diaphragm 1, the R-shaped stopper 202, the support portion 2
Although the dimensions 01 and the like have been specifically exemplified, the dimensions are not limited to these, and may be arbitrarily changed according to the required discharge amount, physique, and the like.

Next, a second embodiment of the present invention will be described. FIG. 5 is an enlarged cross-sectional view of the essential parts of Embodiment 2 of the present invention.
In FIG. 5, the support portion 201 may be provided on the lower stopper 4 as shown in FIG. 5 when it is difficult to process the upper housing 2. In this case, the supporting portion 201 provided on the lower stopper 4 is made to project upward by 0.02 mm from the plate thickness of the portion of the lower stopper 4 adjacent to the diaphragm movable portion.

Next, a third embodiment of the present invention will be described. FIG. 6 is a sectional view of the diaphragm 1 used in the third embodiment of the present invention. Diaphragm 1 as shown in FIG.
May be made of rubber. In this case, since both surfaces of the diaphragm 1 are exposed to different kinds of fluid, for example, if the fluid to be pressure-fed is gasoline and the hydraulic oil 3 is engine oil, as shown in FIG.
Epichlorohydrin rubber with excellent gasoline resistance like 1
No. 01 and a hydrogenated nitrile rubber 102 having excellent oil resistance are welded and bonded to each other, which is advantageous in terms of durability.

Next, a fourth embodiment of the present invention will be described. FIG. 7 is a sectional view of the diaphragm 1 used in the fourth embodiment of the present invention. As shown in FIG. 7, interposing the metal diaphragm 103 between two types of rubber, the epichlorohydrin rubber 101 and the hydrogenated nitrile rubber 102, is also effective in improving reliability.

[0020]

As described above, according to the present invention, it is possible to obtain a highly reliable diaphragm support structure in which the diaphragm is not dragged, the seal is reliable, and the diaphragm is not fatigue-damaged.

[Brief description of drawings]

FIG. 1 is an overall sectional view of a diaphragm pump to which a diaphragm structure according to a first embodiment of the present invention is applied.

FIG. 2 is an enlarged cross-sectional view of part A in FIG.

FIG. 3 is an enlarged cross-sectional view showing a support structure of a diaphragm before improvement at a position corresponding to FIG.

FIG. 4 is a bottom view of the upper housing according to the first embodiment.

FIG. 5 is an enlarged cross-sectional view of a main part at a position corresponding to FIG. 2 of the second embodiment of the present invention.

FIG. 6 is a sectional view of a diaphragm used in a third embodiment of the present invention.

FIG. 7 is a sectional view of a diaphragm used in a fourth embodiment of the present invention.

[Explanation of symbols]

 1 Diaphragm 101 Epichlorohydrin rubber 102 Hydrogenated nitrile rubber 103 Metal diaphragm 2 Upper housing 201 Support part 202 R-shaped stopper 203 High pressure chamber 3 Hydraulic oil 4 Lower stopper 401 Return hole 5 Retainer 502 Cylinder 503 Reset port 6 Retaining nut 7 Hydraulic oil chamber 8 Plunger 9 Spring 10 Tappet 11 Cam 12 Cam chamber 13 Lower housing 14 Inlet 15 Solenoid valve 16 Discharge valve

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuyuki Sakakibara 14 Iwatani, Shimohakaku-cho, Nishio-shi, Aichi Stock Company, Japan Automotive Parts Research Institute (72) Inventor Kazuhide Watanabe 14 Iwatani, Shimohakaku-cho, Nishio-shi, Aichi Stock Association (72) Inventor, Akira Shibata, 1-1, Showa-cho, Kariya, Aichi Prefecture, Nihon Denso Co., Ltd. (72) Inventor, Hiroshi Inoue, 1-1, Showa-cho, Kariya, Aichi Within the corporation

Claims (1)

[Claims] 1. A support part is provided at a position distant from the diaphragm movable part on the outer peripheral side, and a compression amount in the film thickness direction of the diaphragm in the support part is compressed in a film thickness direction of the diaphragm in a part adjacent to the diaphragm movable part. A support structure for a diaphragm, wherein the diaphragm is made larger than the amount to support the diaphragm by pressing it in the vertical direction and sandwiching it.