JP2002054601A - Accumulator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a seat part 51 of a bladder 5 and a poppet 6 from being seated on an inner surface 22a of a pressure guide port 2, eliminate irregularity of pressure when seated, and improve reliability in performance. SOLUTION: The poppet 6 integrally provided with the seat part 51 of the bladder 5 directed toward the pressure guide port 2 has an engagement protruded surface part 63 which can be engaged with an inner end opening part 7a of a pressure guide hole 7, a seat surface 61a of a main body part 61 extended from an outer circumference and a seat surface 51a of the seat part 51 are continuous with each other to form such a taper form that corresponds to an inner surface 22a of the pressure guide port 2 to make the whole body of the seat part 51 thick. The engagement protruded surface part 63 of the poppet 6 is engaged with the inner opening part 7a in a pressure guide hole 7 to concentrically position the seat part 51 of the bladder 5 to the pressure guide port 2. Since rigidity of the seat part 51 of the bladder 5 is large, it can easily be moved in a concentric direction as a contact area with the inner surface 22a of the pressure guide port 2 is small even when it is eccentrically seated on the pressure guide port 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an accumulator which is provided in a pipe of an apparatus to temporarily store a fluid pressure or absorb a pulsation of a fluid pressure generated by a pump or the like.

[0002]

2. Description of the Related Art Conventionally, there is an accumulator having a structure as shown in FIG. That is, the accumulator 100 includes an outer shell 101, a pressure guiding port 102 provided at one end thereof, and an inner space of the outer shell 101, a pressure guiding chamber 103 on the pressure guiding port 102 side and a gas chamber 104 on the opposite side. Cup-shaped bladder 105
And the bladder 105 facing the pressure guiding port 102 side.
Poppet 106 provided integrally with the seat 105a of the vehicle
And The pressure guiding port 102 is branched and connected to a hydraulic pipe. The pressure guiding port 102 has a pressure guiding hole 102a formed in the inner periphery thereof, and a seat 105a of the bladder 105 and the poppet 10 are provided.
6, the seating surface, which is the lower surface in the figure, is formed in a tapered shape that is continuous with each other, substantially corresponding to the inner surface 102b of the pressure guiding port 102.

That is, this type of accumulator 100
Means that the hydraulic pressure in the piping is
a, the bladder 105 is repeatedly expanded and contracted in a direction in which the oil pressure and the pressure of a gas such as nitrogen gas pressed into the gas chamber 104 are balanced. The hydraulic pressure is temporarily stored, or the pulsation of the hydraulic pressure is absorbed and smoothed. The bladder 105 expands when the introduced oil pressure is lower than the gas pressure in the gas chamber 104 due to the inner peripheral surface of the outer shell 1 and the pressure guiding port 1.
02, the seating portion 105a of the bladder 105 and the poppet 106 are
2 is closely seated on the inner surface 102b.

[0004]

However, according to the accumulator 100 having the conventional structure shown in FIG. 4, when the bladder 105 expands due to a decrease in the hydraulic pressure introduced into the pressure guiding chamber 103, the bladder 105 may be affected by external vibration or the like. Depending on the behavior of the bladder 105, its seat 105a and poppet 106
However, there is a case where the pressure guiding port 102 is eccentrically seated. In this case, as shown in FIG. 5, since the poppet 106 is seated obliquely with respect to the inner surface 102b of the pressure guiding port 102, the seat 105a of the bladder 105 is seated.
In addition, the seating surface of the poppet 106 is not in close contact with the inner surface 102 a of the pressure guiding port 102, and a gap G is generated in a part of the circumference with the pressure guiding port 102. Therefore, the gas pressure in the gas chamber 104 acts as a large deformation force in the direction of reducing the gap G at the joint between the seating portion 105a of the bladder 105 and the outer peripheral edge of the poppet 106, and the durability of the bladder 105 is reduced. There was a risk of being damaged.

The seating portion 105a of the bladder 105 and the seating surface of the poppet 106 correspond to the inner surface 1 of the pressure guiding port 102.
There is also a problem that the pressure at the time of sitting varies depending on whether the seat is seated in an appropriate state closely contacted with 02b or in a state in which the gap G due to eccentricity occurs as described above.

The present invention has been made in view of the above circumstances, and a technical problem thereof is that a seating portion and a poppet of a bladder are eccentrically seated on an inner surface of a pressure guiding port. Another object of the present invention is to improve the reliability of performance by eliminating the variation in pressure at the time of sitting.

[0007]

Means for Solving the Problems As means for effectively solving the above-mentioned technical problems, the accumulator according to the present invention comprises an outer shell and a pressure guiding hole provided at one end of the outer shell and formed on the inner periphery. An opened pressure guiding port, a cup-shaped bladder that partitions the internal space of the outer shell into a pressure guiding chamber on the pressure guiding port side and a gas chamber on the opposite side, and a seating portion of the bladder on the pressure guiding port The poppet has a fitting convex portion that can be fitted into the opening end of the pressure guiding hole, and the seating surface of the main body extending from the outer periphery of the poppet has the pressure guiding hole. The surface corresponding to the inner surface of the pressure guiding port of the hole is continuous with the seating surface of the seating portion.

Further, as another means for effectively solving the above-mentioned technical problem, an accumulator according to the present invention comprises an outer shell and a pressure guide hole provided at one end of the outer shell and formed in an inner periphery. A pressure-guiding port, a cup-shaped bladder that partitions the inner space of the outer shell into a pressure-guiding chamber on the pressure-guiding port side, and a gas chamber on the opposite side; And a seating portion of the bladder, the seating surface of which is continuous with the seating surface of the main body of the poppet which can be separated from and contacted with the inner surface of the pressure guiding port. It is thicker than the cylindrical portion located on the inner peripheral side of the shell.

[0009]

FIG. 1 is a sectional view showing a preferred embodiment of an accumulator according to the present invention. That is, the accumulator according to this embodiment has the outer shell 1
A pressure guiding port 2 for connecting the outer shell 1 to a hydraulic pipe or the like (not shown); and a pressure guiding chamber 3 on the pressure guiding port 2 side and a gas chamber 4 on the opposite side of the inner space of the outer shell 1. And a poppet 6 integrally provided on a seating portion 51 corresponding to the bottom of the bladder 5 facing the pressure guiding port 2 side.

The outer shell 1 comprises a cylindrical shell 11 and a gas port 12 sealed in the inner peripheral surface of the shell 11 near the end opposite to the pressure guiding port 2. Alternatively, it is formed of a metal such as stainless steel.

The gas port 12 has a funnel shape, and has a spherical concave inner surface (lower surface in the figure) 12a.
And a gas pressure inlet 121 extending outward (upward in the figure) along the axis thereof, and the outer peripheral flange 12
2 is a tapered surface 11a formed on the inner peripheral surface of the shell 11.
And is fixed by an annular holding nut 13 which is screwed with a female screw portion 11b formed outside the tapered surface 11a in the axial direction. Reference numeral 14 denotes a spring pin for preventing the holding nut 13 from loosening.

A gas chamber 4 in the outer shell 1 is press-fitted with, for example, nitrogen gas as an inert gas (hereinafter simply referred to as "gas"). The gas is supplied to the gas port 1 in the outer shell 1.
The gas pressure inlet 121 is press-fitted from the second gas pressure inlet 121, and the gas pressure inlet 121 is sealed with the core 15 after the gas is press-fitted. Reference numeral 16 denotes a cap mounted on the gas pressure inlet 121. Further, the amount (pressure) of pressurized gas in the gas chamber 4 is appropriately determined according to the magnitude of the hydraulic pressure introduced into the pressure guiding chamber 3.

The pressure guiding port 2 has a funnel shape, and has a pipe joint portion 21 connected to a hydraulic pipe (not shown) and an inner peripheral surface of the shell 11 near an end on the pressure guiding port 2 side. And a flange portion 22 having a mating surface with the tapered surface 11c formed of the steel material, and is formed of parkerized steel material. A pressure guiding hole 7 penetrating in the axial direction is formed in the inner periphery of the pipe joint portion 21, and the inner surface (the upper surface in FIG. 1) 22 a of the flange portion 22 has a spherical concave surface 221 on the outer peripheral side and a taper on the inner peripheral side. It is formed in a concave shape 222.

The flange portion 22 of the pressure guiding port 2 is fitted with a tapered surface 11c formed on the inner peripheral surface of the shell 11, and is formed with a female screw portion 11d formed axially outside the tapered surface 11c. It is fixed by the annular presser nut 17 that fits. Reference numeral 18 indicates the presser nut 1.
7 is a spring pin for preventing the loosening of 7. The space between the shell 11 and the flange portion 22 is sealed by an O-ring 23 made of an elastomer such as NBR. Reference numeral 24 denotes the O-ring 2 in a seal mounting groove formed continuously on the outer peripheral surface of the flange portion 22 in the circumferential direction.
3, which is a backup ring attached with a synthetic resin material such as PTFE.

The bladder 5 is formed in a cup shape with an elastomer such as NBR. A seating portion 51 corresponding to the bottom of the bladder 5 faces the pressure guiding port 2 side, and an opposite edge portion 52 is formed on the outer side. The shell 1 in the shell 1 is sandwiched and fixed between an inner peripheral surface of the shell 11 and a fitting groove 122a continuously formed in the outer peripheral surface of the flange portion 122 of the gas port 12 in the circumferential direction. The edge 52 also functions as a sealing means between the shell 11 and the flange 122.

The bladder 5 has an outer cylindrical portion 53 extending from the edge portion 52 and is formed relatively thin, and the seating portion 51 is formed thicker than the outer cylindrical portion 53. The seating surface (lower surface in FIG. 1) 51a of the seating portion 51 forms a tapered convex surface corresponding to the tapered concave surface 222 on the inner peripheral side of the inner surface 22a of the flange portion 22 of the pressure guiding port 2, and the inner surface (FIG. The upper surface 51b is formed flat, and the bent portion 54 between the outer peripheral tubular portion 53 and the seating portion 51 is formed in a smooth curved shape. The thickness of the bent portion 54 gradually increases from the outer cylindrical portion 53 toward the seating portion 51.

The poppet 6 is formed of a metal such as parked steel or stainless steel, and is integrally provided in a semi-buried state on an inner peripheral portion of a seating surface 51 a of a seating portion 51 of the bladder 5. This prevents the seating portion 51 of the bladder 5 from biting into the pressure guiding hole 7 when the pressure of the pressure introduced into the pressure guiding chamber 3 becomes lower than the gas pressure of the gas chamber 4.

More specifically, the poppet 6 has a main body 61 joined to the center of the seating surface 51 a of the seating portion 51 of the bladder 5, and protrudes from the center of the large-diameter end (upper surface) of the main body 61. It has a flange-shaped retaining portion 62 embedded in the seating portion 51 of the bladder 5 and a fitting convex portion 63 protruding from the small-diameter end of the main body 61. Further, the outer peripheral edge of the fitting convex portion 63 has substantially the same diameter as the inner end opening 7 a of the pressure guiding hole 7 in the pressure guiding port 2.

The seating surface 61a of the main body 61 of the poppet 6
Has a tapered convex surface corresponding to the tapered concave surface 222 on the inner peripheral side of the inner surface 22a of the flange portion 22 of the pressure guiding port 2, and has a seating surface 51a of the seating portion 51 of the bladder 5.
Is formed so as to form a tapered convex surface that is continuous with the seating surface 61a of the main body 61.

According to the accumulator of the present invention configured as described above, the pressure of the bladder 5 from the hydraulic pipe through the pressure introducing hole 7 is lower than the gas pressure of the gas chamber 4 in the cup-shaped bladder 5. When the system hydraulic pressure introduced into the outer pressure guiding chamber 3 is high, as shown in FIG. 1, the bladder 5 has a seating portion 51 and an outer cylindrical portion 53 which are formed by a flange of the pressure guiding port 2. The pressure guiding chamber 3 is spaced apart from the inner surface 22 a of the portion 22 and the inner peripheral surface 11 e of the shell 11 in the outer shell 1.
Is filled with oil introduced from the hydraulic piping. In this state, when the pulsation of the system hydraulic pressure is introduced into the pressure guiding chamber 3, the bladder 5 is repeatedly displaced in a direction in which the hydraulic pressure and the gas pressure are balanced, thereby causing the pulsation of the system hydraulic pressure. Absorb.

When the system oil pressure on the hydraulic piping side is lower than the gas pressure of the gas chamber 4 in the bladder 5, the bladder 5 is connected to the gas pressure of the gas chamber 4 as shown in FIG. Thereby, the outer cylindrical portion 53 is pressed against the inner peripheral surface of the shell 11 in the outer shell 1 and the seating portion 51 is
It is pressed against the inner surface 22 a of the flange portion 22 of the pressure guiding port 2. At this time, the seating surface 51 of the seating portion 51 of the bladder 5
In the poppet 6 integrally provided on the inner periphery of the pressure guiding port 7, the fitting convex portion 63 is fitted to the inner end opening 7 a of the pressure guiding hole 7. 2 and is seated with its seating surface 51a in close contact with the inner surface 22a of the flange portion 22.

Therefore, in this state, the entire seating portion 51 of the bladder 5 receiving the gas pressure in the gas chamber 4 is supported by the inner surface 22a of the pressure guiding port 2, so that the poppet 6 in the seating portion 51 of the bladder 5 is supported. Bending deformation or the like does not act on the joint with the outer peripheral edge of the main body 61, and the seat 51
Is thick, so that it has excellent durability.
Further, the seating portion 51 is positioned concentrically with the pressure guiding port 2, so that the entire surface of the seating surface 51 a is securely seated in close contact with the inner surface 22 a of the pressure guiding port 2. Pressure does not vary.

Here, it is assumed that the seat 51 of the bladder 5 is eccentric due to vibration or the like in the process of being displaced toward the pressure guiding port 2 by the gas pressure of the gas chamber 4. In this case, as shown in FIG. 3, first, a part of the fitting convex portion 63 of the poppet 6 comes into contact with the edge of the inner end opening 7 a of the pressure guiding hole 7. Since the mating convex portion 63 is formed in a hemispherical shape, it slides on the edge portion toward the inner peripheral side by the pressing force due to the gas pressure, and is fitted into the inner end opening 7 a of the pressure guiding hole 7. , Are automatically positioned to a concentric position.

Further, the seating portion 51 of the bladder 5 is formed in a conical thick wall shape continuous with the main body 61 of the poppet 6 and has a high rigidity. It is not deformed by the gas pressure and adheres to the inner surface 22a of the flange portion 22 of the pressure guiding port 2 as it is. Therefore, in the eccentric state shown in FIG. 3, the seating portion 51 of the bladder 5 and the inner surface 22a of the pressure guiding port 2
The gap G (the pressure guiding chamber 3) remains in a relatively wide range between the two and the contact area of the seating portion 51 with the inner surface 22a of the pressure guiding port 2 is small. The entire seating portion 51 easily moves to a position concentric with the pressure guiding port 2. Accordingly, the seating portion 51 of the bladder 5 is completely concentrically positioned with the pressure guiding port 2, and the entire surface of the seating surface 51 a is the inner surface 22 a of the pressure guiding port 2.
Be closely related to.

The present invention is not limited to the illustrated embodiment, but can be used as a pulsation absorbing means or a pressure storing means for fluid pressure other than hydraulic pressure. Further, the fitting convex portion 63 of the poppet 6 is
As long as it slides on the inner surface of the pressure guiding port 2 by the gas pressure and fits into the pressure guiding hole 7, a conical shape having a round top is used.
Shapes other than hemispherical shapes are also possible.

[0026]

According to the accumulator according to the first aspect of the present invention, even if the seating portion of the bladder is eccentric in the process of being displaced toward the pressure guiding port by the gas pressure of the gas chamber, the fitting formed on the poppet is achieved. Since the mating convex portion is fitted into the inner end opening of the dynamic pressure hole in the pressure guiding port, the seating portion of the bladder is concentrically positioned with respect to the pressure guiding port. In the joint portion, it is possible to effectively prevent a decrease in durability due to the action of bending deformation and the like, and moreover, the entire seating surface of the seating portion is securely seated in a state of being in close contact with the inner surface of the pressure guiding port. The pressure at the time of sitting does not vary, and the reliability can be improved.

According to the accumulator according to the second aspect of the present invention, the seating surface of the seating portion of the bladder forms a surface continuous with the seating surface of the body portion of the poppet, and the entirety of the accumulator is formed thick to increase rigidity. When the seat is eccentrically seated on the pressure guiding port, the contact area with the inner surface of the pressure guiding port is small. At the junction with the poppet at the bladder seat,
This effectively prevents a decrease in durability due to the action of bending deformation and the like, and furthermore, the entire seating surface of the seating portion is securely seated in a state of being in close contact with the inner surface of the pressure guiding port. Variations can be effectively prevented and reliability can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a preferred embodiment of an accumulator according to the present invention.

FIG. 2 is a cross-sectional view showing a state in which a seating portion of a bladder is seated on an inner surface of a pressure guiding port in the embodiment.

FIG. 3 is a partially enlarged cross-sectional view showing a state in which the seating portion of the bladder is eccentric in the process of seating on the inner surface of the pressure guiding port in the embodiment.

FIG. 4 is a cross-sectional view showing an accumulator according to the related art.

FIG. 5 is a partially enlarged cross-sectional view showing a state in which the seating portion of the bladder is eccentrically seated on the inner surface of the pressure guiding port in the conventional accumulator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Outer shell 11 Shell 12 Gas port 2 Pressure port 21 Ring joint part 22 Flange part 22a Inner surface 3 Pressure guiding chamber 4 Gas chamber 5 Bladder 51 Seating part 51a, 61a Seating surface 52 Edge 53 53 Cylindrical part 6 Poppet 61 Main body 62 Retaining portion 63 Fitted convex surface 7 Pressure guiding hole

Claims (2)

[Claims] 1. An outer shell (1), a pressure guiding port (2) provided at one end of the outer shell (1) and having a pressure guiding hole (7) opened in the inner periphery, and the outer shell (1). A bladder (5) for partitioning an internal space of the bladder into a pressure guiding chamber (3) on the pressure guiding port (2) side and a gas chamber (4) on the opposite side; and a bladder (5) to the pressure guiding port (2). And a poppet (6) provided integrally with a seating portion (51), wherein the poppet (6) can be fitted into an inner end opening (7a) of the pressure guiding hole (7). The seating surface (61a) of the main body (61) having a convex portion (63) and extending from the outer periphery thereof,
The inner surface (22a) of the pressure guiding port (2) of the pressure guiding hole (7)
An accumulator characterized in that the accumulator has a surface continuous with the seating surface (51a) of the seating portion (51). 2. An outer shell (1), a pressure-guiding port (2) provided at one end of the outer shell (1) and having a pressure-guiding hole (7) formed in an inner periphery thereof, and the outer shell (1). A bladder (5) for partitioning an internal space of the bladder into a pressure guiding chamber (3) on the pressure guiding port (2) side and a gas chamber (4) on the opposite side; and a bladder (5) to the pressure guiding port (2). And a poppet (6) provided integrally with a seating part (51) of the bladder (5), wherein the seating part (51) of the bladder (5) has a seating surface (51).
a) is a seating surface (6) of the main body (61) of the poppet (6) which can be brought into contact with and separated from the inner surface (22a) of the pressure guiding port (2).
An accumulator characterized by having a surface continuous with 1a) and being entirely thicker than a cylindrical portion (53) located on the inner peripheral side of the outer shell (1).