JPS5938441B2 - Inclined pleated bladder for accumulator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an inclined pleated bladder for an accumulator.

Conventionally, accumulator bladders have been known that have been provided with circumferential folds or axial folds on their circumferential surface, and the performance has been improved by specifying the manner in which the bladder deforms. In the former case, that is, one with diametrical pleats, when pressurized from below, if there is no interference from the pressure vessel, the pleats of the bladder will fold up, greatly shortening the length of the bladder. When the pressure from below is removed,
The bladder returns to the specified length simply by returning the folded folds, and the material such as rubber that makes up the bladder does not expand or contract, and it has the excellent feature of obtaining a large volume change, but in reality, the bladder is opened from below. When pressurized, it also swells in the diametrical direction, brings its outer peripheral surface into close contact with the pressure vessel, and is subject to resistance from the pressure vessel, which has the disadvantage that it cannot be deflated.

In addition, in the case where the pleats are provided in the axial direction, the space between the pleats becomes concave inward due to pressure applied from the outside, and depending on the number of pleats, the bladder is deformed into a delta-shaped or star-shaped cross section. When the pressure is removed, the cross section returns to a circular cross section. In this case as well, there is no expansion or contraction of the material such as rubber that makes up the bladder, and a large change in volume can be achieved. If the shortening of the valve is inhibited, the bladder will contract in the axial direction in addition to the diametrical direction, and the free end of the bladder will move away from the fluid supply/discharge port, preventing valve closing failure and bladder jamming. However, there remains a problem with bladders for accumulators that require

As a result of repeated research aimed at solving the above-described drawbacks of the conventional technology, the present invention has disclosed that if the pleats provided in the axial direction are provided diagonally on the peripheral surface of the conventional bladder, the oblique pleats will cause the folds in the axial direction to The present invention was completed by focusing on the fact that the folds can serve both functions.

In other words, if pleats are formed in a spiral on the circumferential surface of the bladder, and the folds are placed so that they are less likely to deform than other parts, when pressure is applied to the bladder from the outside, the gaps between the folds will Because the folds are recessed, the cross-sectional area of the bladder is reduced by four folds, and the longitudinal cross-sectional area of the bladder is also reduced due to the recess of the folds. It is now possible to deflate the bladder at the same time, and when the pressure from the outside is removed, both the cross-sectional area and the longitudinal cross-sectional area return to their original values due to the return of the recessed folds. Since the material such as rubber must not stretch or contract, and the bladder has excellent durability, it can be used as a bladder for an accumulator to greatly improve the accumulator's volumetric efficiency, pulsation absorption, etc., and guarantee safety and reliability. This has a great effect.

Next, one embodiment of the inclined pleat type plug for an accumulator according to the present invention will be described below with reference to the drawings.

In the figure, 1 is a pressure vessel made of a rigid material such as steel according to the operating pressure. A liquid supply/discharge port 2 is provided at the bottom of the pressure vessel, and this supply/discharge port 2 is opened by a spring 3, and is heated by a bladder (described later). A valve 5 is provided which closes by contacting the valve seat 4 which is pressurized.
The upper part is provided with a mounting opening 6 for a bladder, which will be described later.

7 is the bladder, which is made of natural rubber, synthetic rubber, etc., and is made of pressure vessel 1.
The mounting member 8 is fitted into the mounting port 6 of the pressure vessel 1 and fixed with a screw 9 to be airtightly attached to the pressure vessel 1, and the inside of the pressure vessel 1 is usually
The bladder 6 is divided into a gas chamber a and an external liquid chamber.

Reference numeral 10 denotes a spiral pleat on the circumferential surface of the bladder 6, and as shown in FIG. By recessing the part between the 100 and 100, it can be folded into a lantern shape and contracted in the diametrical and axial directions, or the 10 can be made with three strips as shown in Figure 1 of the drawing. By recessing the portion between the sills 100, the bladder contracts in the diametrical direction as shown in Figure 2 of the drawings and in the axial direction as shown in Figure 3 of the drawings. The number of pleats 8 may further increase to four or more, and in this case, the cross-sectional shape when contracted changes to a cross shape, star shape, etc.

Note that the pleats in the bladder are not provided inside the bladder as shown in Figures 1 to 5 of the drawings;
Even if it is provided on the outside as shown in the drawings and FIG. 1, similar effects can be obtained.

Since one embodiment of the inclined pleat type plug for an accumulator according to the present invention is constructed as described above, as shown in FIG. If the bladder 7 is placed so that the pressure is applied from the outside, the bladder 7 is thick at the pleats 10 and has a large resistance to deformation, whereas the resistance between the pleats 10 is small. The section recesses inward, folds up in the same way as a lantern, and contracts in the axial direction as well as in the diametrical direction by the amount of the recess, reducing the bladder to its minimum volume and the liquid chamber to its maximum volume. However, when the pressure is removed from the outside of the bladder 7, the bladder 7 returns to its original shape by returning between the recessed folds 10, and at this time, the material such as rubber that makes up the bladder 7 is It does not expand or contract.

Furthermore, if the aforementioned pleats 10 are provided on the circumferential surface of the three-striped bladder 7 with a gentle slope as shown in FIG. Since the part between the folds 10 is difficult to deform and the part between the folds 10 is easy to deform, the part between the folds 10 which is easy to deform is recessed inward,
The length of the bladder 7 is shortened by the amount of the recess, and the cross-sectional shape of the bladder 7 is contracted into a delta shape as shown by the chain line in Figure 3, and in this case, it is simultaneously contracted in both the diametrical direction and the axial direction. is to be carried out.

As mentioned above, the accumulator bladder according to the present invention is
Folds are formed in a spiral on the circumferential surface of the bladder, and when the bladder is pressurized from the outside, the portion between the pleats is recessed inward, allowing the bladder to contract both in the diametrical and axial directions at the same time. Therefore, compared to a bladder in which the contraction state is specified in either the diametrical direction or the axial direction by pleats, the contraction limit is significantly increased, and the accumulator's volumetric efficiency and pulsation absorbability are significantly improved. In addition to being effective,
The bladder contracts and expands through the deformation of the folds, and the constituent materials do not expand or contract, improving the durability of the bladder.
This has the effect of increasing the reliability and safety of the accumulator.

[Brief explanation of drawings]

The drawings show one embodiment of the inclined pleat type plug for an accumulator according to the present invention, and FIG. 1 is a longitudinal sectional front view showing the state in which a bladder provided with a plurality of spiral pleats is used. FIG. 2 is a longitudinal sectional front view showing the bladder shown in FIG. 1 in a deflated state. FIG. 3 is a plan view taken across the contracted state of FIG. 2. Figure 4 is a longitudinal sectional front view of a bladder provided with one spiral pleat. FIG. 5 is a longitudinal sectional front view showing the bladder shown in FIG. 4 in a deflated state. FIG. 6 is a longitudinal sectional front view of the spiral pleats shown in FIG. 1 provided on the outside of the bladder. FIG. 7 is a longitudinal sectional front view of the spiral pleats shown in FIG. 4 provided on the outside of the bladder. In the figure, 1 is a pressure vessel, a is a gas chamber, b is a liquid chamber, 6 is a bladder, and 8 is a pleat.

Claims (1)

[Claims] 1. A part of the bladder is airtightly attached to a pressure vessel, and pleats are formed in a spiral shape on the circumferential surface of a bladder that divides the inside of the pressure vessel into a gas chamber and a liquid chamber, and the bladder is pressurized from the outside. when the fold is pressed, the part between the folds is recessed,
A slanted pleated bladder for an accumulator, characterized in that the bladder can be contracted simultaneously in both the diametrical direction and the axial direction.