Bellows having tweezers-shaped corrugated portions and method for manufacturing same

Abstract

A bellows having tweezers-shaped corrugated portions for increasing resistance and restoring force against torsion includes: a first flat part having a flat cylindrical shape; a second flat part having a flat cylindrical shape and disposed opposite to the first flat part; and a plurality of corrugated portions, each having a tweezers shape and disposed between the first flat part and the second flat part, wherein each of the plurality of corrugated portions is sequentially connected to each other, so as to increase resistance and restoring force against torsion.

Claims

1. A bellows comprising: a first flat part having a flat cylindrical shape; a second flat part having a flat cylindrical shape and disposed opposite to the first flat part; and a plurality of corrugated portions disposed between the first flat part and the second flat part, wherein the plurality of corrugated portions are sequentially connected to each other, wherein each of the plurality of corrugated portions includes: a protrusion portion having a first surface and a second surface disposed opposite to the first surface in parallel, in which the first surface and the second surface are adjacent to each other, and a connecting portion connecting the first surface with the second surface, wherein the connecting portion has a circular shaped head including a first circumference continuously connected with the first surface and a second circumference continuously connected with the second surface, the first circumference protruding outwardly from the first surface in a direction perpendicular to an extending direction of the first surface, and the second circumference protruding outwardly from the second surface in a direction perpendicular to an extending direction of the second surface; a convex portion having a third surface extending from the first surface and protruding outward in a convex shape and a fourth surface extending from the second surface and protruding outward in a convex shape; and a concave portion having a fifth surface extending from the third surface and recessed inward from the third surface in a concave shape and a sixth surface extending from the fourth surface and recessed inward from the fourth surface in a concave shape, and wherein a shape of each of the plurality of corrugated portions is symmetrical on both sides with respect to a central line extending from a center of the connecting portion, and the plurality of corrugated portions are connected to each other at the respective concave portion, such that the plurality of corrugated portions are prevented from being damaged when external impact is applied thereto due to supporting force of the protrusion portion and restoring force of the convex portion.

2. The bellows of claim 1, wherein an interval between the third surface and the fourth surface is greater than an interval between the fifth surface and the sixth surface.

3. The bellows of claim 1, wherein the plurality of corrugated portions are sequentially formed through a hydro-forming method.

4. A method for manufacturing a bellows, the method comprising: (a) providing a base metal for forming the bellows around a head; (b) supporting the base metal with a support device and a movable device after holding a flat surface with respect to the base metal; (c) applying pressure to the base metal provided between the support device and the movable device; (d) forming a plurality of corrugated portions by moving the movable device toward the support device after the base metal is formed into a predetermined size, wherein the plurality of corrugated portions are sequentially formed through a hydro-forming method, wherein each of the plurality of corrugated portions includes: a protrusion portion having a first surface and a second surface disposed opposite to the first surface in parallel, in which the first surface and the second surface are adjacent to each other, and a connecting portion connecting the first surface with the second surface, wherein the connecting portion has a circular shaped head including a first circumference continuously connected with the first surface and a second circumference continuously connected with the second surface, the first circumference protruding outwardly from the first surface in a direction perpendicular to an extending direction of the first surface, and the second circumference protruding outwardly from the second surface in a direction perpendicular to an extending direction of the second surface; a convex portion having a third surface extending from the first surface and protruding outward in a convex shape and a fourth surface extending from the second surface and protruding outward in a convex shape; and a concave portion having a fifth surface extending from the third surface and recessed inward from the third surface in a concave shape and a sixth surface extending from the fourth surface and recessed inward from the fourth surface in a concave shape, and wherein a shape of each of the plurality of corrugated portions is symmetrical on both sides with respect to a central line extending from a center of the connecting portion, and the plurality of corrugated portions are connected to each other at the respective concave portion, such that the plurality of corrugated portions are prevented from being damaged when external impact is applied thereto due to supporting force of the protrusion portion and restoring force of the convex portion.

5. The method of claim 4, wherein an inner peripheral portion of the support device is formed in a shape corresponding to the first surface of the protrusion portion, the third surface of the convex portion, and the fifth surface of the concave portion, and an inner peripheral portion of the movable device is formed in a shape corresponding to the second surface of the protrusion portion, the fourth surface of the convex portion and the sixth surface of the concave portion.

Description

DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a perspective view showing a configuration of a conventional bellows device.

(2) FIG. 2 is a perspective view of a bellows having tweezers-shaped corrugated portions according to the present invention.

(3) FIG. 3 is a view showing a state in which a double interlock hose is provided in the bellows of FIG. 2.

(4) FIG. 4 is a view for explaining the configuration of the corrugated portion shown in FIG. 2.

(5) FIGS. 5a to 5c are views for explaining a manufacturing process of the bellows according to the present invention.

MODES OF THE INVENTION

(6) These and other objects and novel features of the present invention will become more apparent from the description of the present invention and the accompanying drawings.

(7) First, characteristics of a bellows having tweezers-shaped corrugated portions according to the present invention will be described.

(8) A diaphragm bellows is more flexible than necessary so that, for example, a crack may be generated due to resonance during running of a vehicle. Therefore, according to the present invention, a half is made as a diaphragm bellows and the other half is made as a general bellows, thereby providing a bellows having tweezers-shaped corrugated portions capable of obtaining great restoring force.

(9) Hereinafter, the configuration of the present invention will be described with reference to FIGS. 2 to 4.

(10) FIG. 2 is a perspective view of a bellows having tweezers-shaped corrugated portions according to the present invention, FIG. 3 is a view showing a state in which a double interlock hose is provided in the bellows of FIG. 2, and FIG. 4 is a view for explaining the configuration of the corrugated portion shown in FIG. 2.

(11) As shown in FIG. 2, the bellows 100 according to the present invention includes a first flat portion 110 formed in a flat cylindrical shape, a second flat portion 120 formed in a flat cylindrical shape and opposed to the first flat portion 110, and corrugated portions 130 formed between the first flat portion 110 and the second flat portion 120 and having a tweezers shape.

(12) For example, the bellows 100 according to the present invention may be used for vacuum line connection between components of an exhaust pipe connection device for commercial vehicles or components of a semiconductor manufacturing facility. In order to improve mobility of exhaust gas, as shown in FIGS. 2 and 3, a plurality of corrugated portions 130 are sequentially connected to each other to form a corrugated tube having elasticity. That is, the corrugated portions 130 according to the present invention are sequentially formed by a hydro-forming method.

(13) Since the first flat portion 110, for example, can be inserted into a flange to be mounted on an inlet portion of the exhaust gas and the second flat portion 120 can be inserted into a flange to be mounted on an outlet portion of the exhaust gas, the problem that occurs during the cutting and assembling processes in the bellows provided with continuous corrugated portions defined by a spiral hose may be prevented and the bellows can be simply assembled. In addition, since the first flat portion 110 and the second flat portion 120 have no corrugated portions, it is possible to prevent the loss of a base metal, for example stainless steel, as compared with the conventional bellows.

(14) For example, as shown in FIG. 3, a double interlock hose 300 is provided in the bellows 100 according to the present invention, a wire mesh 300 is provided between the bellows 100 and the double interlock hose 300 to attenuate impact caused by contact between bellows 100 and the double interlock hose 300, and the bellows 100, the double interlock hose 200 and the wire mesh 300 are fixed by a coupling ring 400.

(15) As shown in FIG. 4, the corrugated portion 130 formed in the bellows 100 according to the present invention includes a protrusion portion having a first surface 131 and a second surface 132 successively provided next to the first surface 131 in parallel, in which the first surface 131 and the second surface 132 are in close contact with each other, and a connecting portion of the first surface 131 and the second surface 132 protrudes in a circular shape 137; a convex portion having a third surface 133 extending from the first surface 131 and protruding outward in a convex shape and a fourth surface 134 extending from the second surface and protruding outward in a convex shape; and a concave portion having a fifth surface 135 extending from the third surface 133 and recessed inward in a concave shape and a sixth surface 136 extending from the fourth surface 134 and recessed inward in a concave shape.

(16) The corrugated portion 130 has a function of a corrugated tube of the bellows 100 by connecting the fifth surface 135 of one concave portion and the sixth surface 136 of another concave portion adjacent to the one concave portion.

(17) As shown in FIG. 4, in the corrugated portion 130 according to the present invention, an interval between the third surface 133 and the fourth surface of the convex portion is larger than an interval between the fifth surface 135 and the sixth surface 136 of the concave portion so that the corrugated portion 130 may have a shape of a tweezer.

(18) That is, as shown in FIG. 4, since the corrugated portion 130 according to the present invention has a tweezer shape, for example, when the concave portion is subject to an impact caused by sudden discharge of the exhaust gas or an external impact applied to the vehicle, the strength of the corrugated portion 130 may increase due to the supporting force of the protruding portion and the restoring force of the convex portion, thereby preventing the corrugated portion 130 from being damaged even when the impact applied to the bellows 100 is excessive.

(19) In addition, as shown in FIG. 4, since the connecting portion of the protruding portion, which is formed between the first surface 131 and the second surface 132, has the circular shape 137, an edge portion can be prevented from being broken by the impact applied to the corrugated portion 130 of the bellows 100.

(20) Next, the process of forming the corrugated portion 130 as shown in FIG. 4 will be described with reference to FIGS. 5a to 5c.

(21) FIGS. 5a-5c are views for explaining a manufacturing process of the bellows according to the present invention, in which FIG. 5a shows the state where the base metal is in a flat state, FIG. 5b shows the state where pressure is applied the base metal by hydroforming, and FIG. 5c shows the state where the base metal is moved by a movable device.

(22) As shown in FIG. 5a, in order to manufacture the bellows 100 according to the present invention, the base metal 101 formed in a cylindrical shape is supplied along an outer circumference of a cylindrical head 102. The base metal may include, for example, stainless steel, but is not limited thereto. Various materials can be used as the base metal if the hydroforming can be applied to the materials and a mounting target of the bellows. An inner diameter of the cylindrical base metal 101 is, for example, φ103.7 that satisfies the standard of an exhaust pipe of a commercial vehicle, but is not limited thereto. The inner diameter of the base metal 101 may be increased or decreased corresponding to an outer diameter of an exhaust pipe of an apparatus to which the bellows is mounted.

(23) As shown in FIG. 5a, the corrugated tube 130 according to the present invention may be formed after maintaining a length corresponding to a portion of the cylindrical first flat portion 110, for example, a length (23 mm) of the first flat portion 110. To this end, a first support ring 103 and a second support ring 105, which have cylindrical shapes, are fitted around the outer peripheral portion of the head 102 at an interval corresponding to a length suitable for forming the corrugated portion 130 through the hydroforming and a support device 104 and a movable device 106 are mounted on the first support ring 103 and the second support ring 105, respectively. The support device 104 includes a first support device and a second support device in the form of semicircular arcs each of which can move up and down in a state shown in FIG. 5a, and comes into contact with the first support ring 103 with respect to the base metal 101, thereby preventing the movement of the base metal 101. The movable device 106 comes into contact with the second support ring 105 in a state shown in FIG. 5a to prevent the movement of the base metal 101. The movable device 106 can move to the left after the hydroforming is performed on the base metal 101, and can move to the right after the corrugated portion 130 has been formed.

(24) As shown in FIGS. 5a-5e, an outer peripheral side of the support device 104 is formed as a flat surface such that the support device 104 can be withdrawn by vertically moving up and down between the preformed corrugated portions 130, and an inner circumferential side of the support device 104 has a shape corresponding to the first surface 131 of the protruding portion, the third surface 133 of the convex portion, and the fifth surface 135 of the concave portion of the corrugated portion shown in FIG. 4. In addition, an inner peripheral side of the movable device 106 has a shape corresponding to the second surface 132 of the protruding portion, the fourth surface 134 of the convex portion, and the sixth surface 136 of the concave portion of the corrugated portion 130 shown in FIG. 4, and an outer peripheral side of the movable device 106 has a movable structure and is not limited to a particular shape.

(25) Further, the head 102 is formed with a pressure supply hole 107 for applying predetermined pressure, such as pneumatic pressure or hydraulic pressure, to the base metal 101 when the hydroforming is performed.

(26) When manufacturing the bellows 100 according to the present invention, the base metal 101 is kept in a state shown in FIG. 5a, that is, the base metal 101 is kept in a flat state between the first support ring 103 and the second support ring 105, and a gap between the head 102 and the base metal 101 is sealed by the support device 104 and the movable device 106.

(27) In this state, as shown in FIG. 5b, when the predetermined pressure (arrow direction) is applied to the pressure supply hole 107 of the head 102, the forming of the base metal 101 is generated in the outer circumferential direction of the head 102 due to the applied pressure. That is, the hydroforming is performed with respect to the base metal 101. The hydroforming is performed to the extent that the corrugated portions 130 can be formed only in forming portions formed when the movable device 106 moves to the left.

(28) Next, in the state shown in FIG. 5b, the movable device 106 moves to the left to maintain the state shown in FIG. 5c for a predetermined time.

(29) The movement of the base metal 101, the pressurization through the head 102, the up/down movement of the support device 104, and the left/right movement of the movable device 106 are automatically performed according to preset shape information and material information of the bellows. In addition, the holding time of the state shown in FIG. 5c is defined according to the metallic property of the base metal 101, and is not particularly limited to the specific time.

(30) After one corrugated portion 130 has been formed as shown in FIG. 5c, the first support device and the second support device respectively move up and down from the state shown in FIG. 5c, the base metal 101 is supplied by a predetermined length and the movable device 106 moves to the right. Then, the first support device and the second support device move up and down to come into contact with the first support ring 103, and the movable device 106 comes into contact with the second support ring 105 as shown in FIG. 5a. After that, as described above, the states shown in FIGS. 5b and 5c are progressed so that the corrugated portions 130 can be formed sequentially.

(31) That is, different from the conventional bellows which is formed continuously, the corrugated portions 130 according to the present invention are formed sequentially.

(32) After forming a predetermined number of corrugated portions corresponding to the mounting target of the bellows according to the present invention, the base metal 101 is simply supplied to form the second flat portion 120, thereby forming the bellows according to the present invention as shown in FIG. 2.

(33) According to the present invention, after forming a predetermined number of the corrugated portions 130, the base metal 101 is simply supplied corresponding to the lengths of the second flat portion 120 and the first flat portion 110 to sequentially form the corrugated portions so that a plurality of bellows can be continuously produced. Accordingly, the bellows having the first flat portion 110, the corrugated portion 130, and the second flat portion 120 can be easily manufactured by simply cutting a portion between the second flat portion 120 and the first flat portion 110.

(34) Although the present invention has been described in detail with reference to the above embodiments, the present invention is not limited to the above-described embodiments, and various modifications may be made without departing from the scope of the present invention.

INDUSTRIAL APPLICABILITY

(35) According to the bellows having tweezers-shaped corrugated portions and the method for manufacturing the bellows, resistance and restoring force against torsion applied to the corrugated portions can be increased.