MXPA06005916A - Accumulator - Google Patents

Abstract

An accumulator where a pressure sealed chamber and a pressure flow-in chamber are formed by an operation member including a metallic bellows, the operation member being provided in a housing constituted of a gas end cover and a bottomed tubular shell. In the accumulator, the volume of a volume-regulating spacer is reduced by eliminating a dead space, processing steps are reduced by simplifying the shape of the end cover, and a margin of weld penetration depth is increased by thickening a backing metal section. The inner outline in a cross-section of a peripheral edge section of the gas end cover is made oval having a recess on the pressure sealed chamber side so as not to produce any dead space.

Description

ACCUMULATOR Technical Field The present invention relates to an accumulator used as an apparatus for accumulating pressure, a pulsation absorber apparatus or the like. The accumulator according to the present invention is used in a hydraulic system of a vehicle braking system and various industrial fluid pressure systems. Background For example, in the hydraulic apparatus the vehicular brake system, with the purpose of dampening pulsation or accumulation of pressure, an accumulator is used in which a pressure sealed chamber and a pressure intake chamber are formed by a chamber of pressure. operation including a flexible metal bellows. The accumulator is structured to cushion and absorb vibration by balancing a pressure in the sealed pressure chamber, determined by the expansion and contraction of the metal bellows and a pressure in the pressure inlet chamber, determined by the input of the fluid flow under pressure from the system side and maintains a sealed high pressure gas inside the pressure sealed chamber and the sealed fluid inside the pressure flow inlet chamber and a gas end cover is installed, so that it closes a Open end pressure and a bottom cover to fix the metal bellows. In recent years, a saving of weight of the vehicular parts has been required for the purpose of improving a specific fuel consumption or the like, and a saving in weight of the accumulator 101, which corresponds to the vehicular part, is attempted by reducing a thickness of the cover of the gas pipe 104 corresponding to a constituent part of a housing 102. However, As shown in Figure 3, since a thickness of the peripheral edge portion 105 of the gas end cover 104 is thin, there is a need for a substantial bending of an end portion of the peripheral edge portion 105 to a side of the inner diameter from a stepped concave portion 111 coupled to the cover 103, to hold a fixing portion 108, for fixing the metal neck 107. Accordingly, a dead space 109 is formed on the inner diameter side of the curved portion and a space for volume adjustment 110 becomes large, such that there is a problem as a weight increases just as the entire accumulator 101 becomes larger in an axial direction. Further, since the manner in which the end portion of the peripheral edge portion 105 curves substantially to the side of the inner diameter is used to hold the application portion 108 as mentioned above, there is a problem in increasing the working steps to produce the gas end cover 104 in the curved form. In addition, since the concave portion of step 111 is formed in the curved portion, as shown in Figure 4, and gas end cover 104 and cover 103 engage in a weld portion 106 aligning the concave portion of stage 111 and a terminal of cover 103 and applying laser welding with carbon dioxide gas, a metal backing structure in which a splash or similar to an internal portion is not dispersed. However, if the peripheral edge portion is formed in the curved structure, a problem occurs that a thickness W1 of the backing metal portion becomes thin and there is a limit to hold a depth of weld penetration. In this case, Japanese Unexamined Patent Publication No. 2002-122101 (Patent Document 1) proposes a structure in which it produces a cross-sectional central portion shape in a convex shape next to the pressure sealed chamber and in a concave shape in the peripheral edge portion so as to ensure strength in a state where the thickness of the gas end cover it is thin, however since the peripheral edge portion constitutes the concave shape next to the pressure sealed chamber, there is dead space, so that the structure can not be effective to make the spacer small for volume adjustment and to make the working stages of the gas end cover easy. Patent Document 1: Japanese Unexamined Patent Publication No. 2002-122101. DESCRIPTION OF THE INVENTION Problem to be Resolved by the Invention The present invention is made by taking the aforementioned points for consideration, the objective of the present invention is to provide an accumulator where a pressure sealed chamber and a pressure flow inlet chamber they are formed by an operation member including a metal bellows which is provided within a housing constituted by a gas end cover and a tubular bottom cover, where a capacity of a spacer for volume adjustment is reduced, eliminating a space dead, the working steps are reduced by simplifying a shape of the gas end cover and a margin of the penetration depth of the weld is improved by increasing a thickness of the backing metal portion. Means for Solving the Problem In order to achieve the aforementioned objective according to a first aspect of the present invention, an accumulator is provided in wherein a pressure sealed chamber and a pressure inlet flow chamber are formed by an operation member including a metal bellows which is provided within a housing constituted by a gas end cover and a bottom tubular cover, wherein an inner cross-sectional profile of a peripheral edge portion of the gas end cap, is an oval shape and is concave to the side of the pressure sealed chamber, and a dead space is not formed. In addition, according to a second aspect of the present invention, an accumulator is provided as described in the first aspect, wherein a pressure loading gate communicating with the pressure sealed chamber is provided on an inner peripheral side of the chamber. a central portion of the gas end cap, and an integrally formed hexagonal nut portion, in the gas end cap, is provided on an outer peripheral side. Effect of the Invention In the accumulator according to the first aspect of the present invention having the aforementioned structure, since the inner cross section profile of the peripheral edge portion of the gas end cover, is the oval shape which is concave next to the pressure sealed chamber, and the dead space is not formed, it is possible to make small the capacity of the spacer for volume adjustment and it is possible to do all the light weight just as it is possible to do all the small accumulator in an axial direction. Further, since the inner cross sectional profile of the peripheral edge portion is the oval shape which is concave next to the pressure sealed chamber, the thickness of the end portion is thick and since it is not necessary employ the manner in which the end portion of the peripheral edge portion is curved to the side of the inner diameter to form the fixing portion for fixing the metal bellows, the gas end cover is easy to work and the working steps can be reduced . Further, since the inner cross sectional profile of the peripheral edge portion is the oval shape that is concave next to the pressure sealed chamber, the thickness of the end portion is thick, it is possible to make the metal portion of thick backing even if the concave portion of the stage joining the end surface of the cover is formed and it is possible to sufficiently hold the depth of weld penetration at a time of welding to the cover. Further, in the invention according to the second aspect, since the hexagonal nut shape corresponding to the position in which a tool such as a spanner or the like is applied to thread the accumulator in a pipe, is formed integrally with the gas end cover, it is possible to reduce the number of parts, it is possible to omit a step to fix a hexagonal nut and it is possible to simplify a stage of assembly of the housing. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a cross-sectional view of an accumulator according to an embodiment of the present invention; Figure 2 is a cross-sectional view in each of the steps of manufacturing a gas end cover in Figure 1; Figure 3 is a cross-sectional view of an accumulator according to the conventional technique; Y Figure 4 is an enlarged cross-sectional view of a portion A in Figure 3. BEST MODE FOR CARRYING OUT THE INVENTION Next, a description will be given of an embodiment according to the present invention, with reference to the accompanying drawings. In this case, the scope of the invention is not limited to the contents described in the mode for carrying out the invention unless there is some specific limited description. An accumulator 1 according to the embodiment corresponds to an accumulator of metal bellows type and structure as follows. First, as shown in Figure 1, a housing 2 is provided such that a gas end cover 4 is fixed to an open end portion of a bottom tubular cover 3, and an operation member 5 is provided with a metal bellows 6 and a bellows cap 7 is housed in an inner portion of the housing 2. The metal bellows 6 is structured such that one end portion is fixed to the gas end cover 4 and the other end portion it is fixed to the bellows cap 7. Accordingly, an inner portion of the housing is sectioned in a pressure-sealed chamber 8 on an inner side of the metal bellows 6 and the bellows cap 7 and an inlet flow chamber pressure 9 on its outer side. A member that is provided with a tubular mounting portion 13, is attached to an end wall portion 11 of the cover 3 that forms a part of the housing 2. The tubular mounting portion 12 is provided with a threaded portion 12 for connecting the accumulator 1 with a pressure pipe on one side of hydraulic system (not shown) or similar on an outer periphery.

In addition, the fluid inlet flow gate 14 for introducing a pressurized fluid on the system side to the pressurized inlet flow chamber 9 is provided on an inner peripheral side of the mounting portion 13. Furthermore, a annular sliding member 23 is installed on an outer peripheral side of the other end portion of metal bellows 6 fixed to bellows cap 7 or an outer peripheral side of bellows cap 7 and an outer peripheral side of sliding member 23, is slides to an inner peripheral side of the cover 3 at a time when the metal bellows 6 expands and contracts, and at a time when the bellows cover 7 moves. As the bellows cap 7 moves parallel to the inner peripheral surface of the cover 3 and the metal bellows 6 expands and contracts in parallel with the inner peripheral surface of the cover 3 based on the sliding movement of the sliding member 23, it is possible to prevent the bellows cap 7 and the metal bellows 6 from advancing within the inner peripheral surface of the cover 3. In this case, the sliding member 23 is provided with a coupling portion (not shown) to prevent the pressurized flow inlet chamber 9 is separated to a space 21 on the metal bellows side (an upper side in the drawing) and a space 22 on the side of the flow gate of fluid ingress by the sliding member 23. The annular end cover 4 constituting a part of the housing 2 is structured in such a way that the inner cross-sectional profile 32 of the peripheral edge portion 31 is formed in an oval shape and is pacer for volume adjustment 41 is installed in a space 40 formed with a line connecting both sides of the end portion of the metal bellows 6. A thickness of the peripheral edge portion 31 becomes thicker gradually from an inner peripheral side towards an outer peripheral side, and a portion stage concave 33 is formed on an outer peripheral side at the end surface of the peripheral edge portion 34 and is fixed to an end surface 35 on one side of the open end portion of the cover 3, in accordance with welding carbon dioxide laser. In addition, an inner peripheral side of the end surface of the peripheral edge portion 34 is provided with a fastening portion 30 for securing an end portion of the metal bellows 6. A central portion 38 is provided with a load gate of pressure 36 for charging a gas to the pressure sealed chamber 8 on an inner peripheral side. After the gas is charged to the pressure sealed chamber 8 through the pressure loading gate 36, to obtain predetermined pressure, the pressure loading gate 36 is fixed by a plug member 37 to be closed. An outer peripheral side of the central portion 38 is provided with a hexagonal nut-shaped portion 39 which corresponds to a convenient shape for applying a tool at the time of fixing the thread portion 12 that is provided on the outer periphery of the portion of assembly 13 of accumulator 1 to the pipe by rotation. Accordingly, the hexagonal nut-shaped portion 39 is integrally formed with the gas end cover 4. A method of manufacturing the gas end cover has a method shown in Figure 2. First, as shown in Figure 2 (1), a plate-shaped member convenient in size for the gas end cap is formed in accordance with a pressure mold. Next, die casting to form a hexagonal nut shape is applied to a central portion of the plate-shaped member by a so-called "roll" stage shown in Figure 2 (2). At this time, the pressure loading gate that communicates with the pressure sealed chamber is provided simultaneously.

Further, the pressure molding is applied to the member wherein the hexagonal nut shape is structured, such that an inner profile of a peripheral edge portion is structured in an oval shape and a thickness becomes thicker gradually from the side inner peripheral to the outer peripheral side, by a step called "twisting" shown in Figure 2 (3). Finally, a "cutting step" shown in Figure 2 (4) applies a cutting work to form the concave portion of the stage for attaching to the cover and the fixing portion, for fixing the metal bellows, to the end portion of the outer peripheral side . According to this, it is possible to omit the pressing step to execute a deep drawing which is conventionally executed. In this case, like the metal bellows 6, it is possible to use an electro-deposited bellows, a bellows formed, a bellows joined by welding and the like. However, it is possible to use another bellows material in accordance with a specification and intended use of the accumulator 1. Furthermore, as the gas used in the pressurized chamber 8, nitrogen gas is preferable, however another gas can be used. Since the accumulator 1 having the aforementioned structure is formed in the oval structure wherein the inner cross section profile 32 of the peripheral edge portion 31 of the gas end cover 4 constituting a part of the housing 2, is concave with respect to the side of the pressure sealed chamber 8, the dead space is not formed and it is possible to make the spacer for volume adjustment 41 small. In addition, since the end portion of the peripheral edge portion 31 is sufficiently thick, it is possible to form the fixing portion 30 for fixing the metallic neck 6 even when the concave portion of step 33 for coupling to the cover 3, is formed on the surface end 34. Accordingly, it is not necessary to bend the end portion of the gas end cover 4 to the inner peripheral side, to form the fixing portion 30, and it is possible to easily work the gas end cover 4. Furthermore, even when the concave portion of step 33 for coupling with the cover three is formed on the end surface of the peripheral edge portion 34, it is possible to thicken the thickness of the backing metal portion, because the The thickness of the end portion of the peripheral edge portion is sufficiently thick. Accordingly, it is possible to fasten the depth of weld penetration to the time of welding the cover 3 and the gas end cover 4. Furthermore, since the hexagonal shaped portion 39 is provided integrally in the central portion 38 of the gas end cover 4, it is not necessary to fix the hexagonal nut after fixing the plug member 37 to the loading gate 36 formed in the central portion 38, the number of parts is reduced and it is possible to simplify the work steps .

Claims (1)

1. An accumulator wherein an operation member including a metal bellows fixed to a fastening portion formed in a gas end cap on one end, is installed within a fixed housing according to the weld upon placing a gas surface. end in an open end portion of a bottom tubular cover, in contact with a stage concave portion formed in the gas end cap and a pressure sealed chamber and a pressure inlet flow chamber are formed by the member of operation, wherein an inner cross-sectional profile of a peripheral edge portion of the gas end cap, is an oval shape that is concave next to the pressure sealed chamber and in the case where a spacer in a space formed by a line connecting both sides of an end portion of the metal neck fixed to the fixing portion, no dead space is formed between the outer shell rowing gas and spacer.