Ultrasonic Welding Apparatus Including Rotatable Anvil and Welding Method Using the Same

Abstract

The present invention relates to an ultrasonic welding apparatus including a horn unit including a horn wherein the horn is configured to contact a target to be welded and a vibrator configured to apply vibration to the horn; an anvil unit including an anvil having an first flat surface on which the target to be welded is configured to be placed and a support portion configured to support the anvil in a rotatable state; and a welding main body configured to have the horn unit and the anvil unit fixed thereto, wherein the anvil is rotated in a state of being supported by the support portion such that the first flat surface of the anvil is parallel to a welding surface of the horn, whereby parallelism between the horn and the anvil may be easily achieved, and welding quality may be improved.

Claims

1. An ultrasonic welding apparatus comprising: a horn unit including a horn wherein the horn is configured to contact a target to be welded and a vibrator configured to apply vibration to the horn; an anvil unit comprising including: an anvil having a first flat surface on which the target to be welded is configured to be placed, and a support portion configured to support the anvil in a rotatable state; and a welding main body configured to have the horn unit and the anvil unit fixed thereto, wherein the anvil is rotated in a state of being supported by the support portion such that the first flat surface of the anvil is parallel to a welding surface of the horn.

2. The ultrasonic welding apparatus according to claim 1, wherein the anvil is formed in a shape of any one of (1) a cylinder having a section perpendicular to a surface of the anvil, (2) an oval column having a section perpendicular to a surface of the anvil, and (3) a sphere having a section, the section becomes the first flat surface, the support portion is formed in a shape of a container defining an inner space configured to receive a curved surface of the cylinder, the oval column, or the sphere in a rotatable state, and the anvil is disposed such that the first flat surface protrudes outwards from the support portion in an initial state in which the anvil is stopped.

3. The ultrasonic welding apparatus according to claim 2, wherein a lubricant or a bearing is included on contact surfaces of the support portion and the anvil.

4. The ultrasonic welding apparatus according to claim 2, wherein the support portion is fixed to the welding main body.

5. The ultrasonic welding apparatus according to claim 2, wherein a recess or a through-hole is formed in at least a portion of an external surface of the anvil excluding the first flat surface of the anvil.

6. The ultrasonic welding apparatus according to claim 2, wherein the anvil is formed in the shape of the cylinder, and the anvil has a flat section formed by cutting the cylinder perpendicularly to the surface of the anvil such that less than 50% of the cylinder remains, the section becomes the first flat surface, the support portion is formed in a shape of a container defining an inner space configured to receive a curved surface of the cylinder in a rotatable state, and a central axis of the cut cylinder, about which the cut cylinder is rotated, coincides with a central axis of the horn.

7. The ultrasonic welding apparatus according to claim 1, wherein the anvil has a three-dimensional structure in which a section provided at a first part of the anvil becomes the first flat surface, and a fixing shaft of the support portion extends through the anvil so as to be fixed to the welding main body.

8. The ultrasonic welding apparatus according to claim 7, wherein the fixing shaft is parallel to the first flat surface, or is parallel to a portion of a rotating surface of the anvil.

9. The ultrasonic welding apparatus according to claim 1, wherein a protrusion is formed on at least one of surfaces of the horn and the anvil that abut each other.

10. A welding method using the ultrasonic welding apparatus according to claim 1, the welding method comprising: (S1) disposing the target to be welded on the first flat surface of the anvil; (S2) disposing the welding surface of the horn on a surface of the target to be welded; (S3) rotating the anvil to align the anvil such that the first flat surface is parallel to the welding surface of the horn; and (S4) applying ultrasonic waves to perform welding.

11. The welding method according to claim 10, wherein ultrasonic waves are applied to perform welding after rotation of the anvil is stopped.

Description

DESCRIPTION OF DRAWINGS

[0038] FIG. 1 is a view showing a welding process using a conventional ultrasonic welding apparatus.

[0039] FIG. 2 is a perspective view of an ultrasonic welding apparatus according to the present invention.

[0040] FIG. 3 is an exploded perspective view of an anvil unit according to a first embodiment.

[0041] FIG. 4 is a vertical sectional view of the anvil unit of FIG. 3.

[0042] FIG. 5 is a perspective view of an anvil unit according to a second embodiment.

[0043] FIG. 6 is a front view of an anvil according to a third embodiment.

[0044] FIG. 7 is a perspective view of an ultrasonic welding apparatus according to a fourth embodiment.

[0045] FIG. 8 is a front view of an anvil according to a fifth embodiment.

[0046] FIG. 9 is a perspective view showing various shapes of the anvil.

BEST MODE

[0047] Now, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings such that the preferred embodiments of the present invention can be easily implemented by a person having ordinary skill in the art to which the present invention pertains. In describing the principle of operation of the preferred embodiments of the present invention in detail, however, a detailed description of known functions and configurations incorporated herein will be omitted when the same may obscure the subject matter of the present invention.

[0048] In addition, the same reference numbers will be used throughout the drawings to refer to parts that perform similar functions or operations. In the case in which one part is said to be connected to another part throughout the specification, not only may the one part be directly connected to the other part, but also, the one part may be indirectly connected to the other part via a further part. In addition, that a certain element is included does not mean that other elements are excluded, but means that such elements may be further included unless mentioned otherwise.

[0049] In addition, a description to embody elements through limitation or addition may be applied to all inventions, unless particularly restricted, and does not limit a specific invention.

[0050] Also, in the description of the invention and the claims of the present application, singular forms are intended to include plural forms unless mentioned otherwise.

[0051] Also, in the description of the invention and the claims of the present application, “or” includes “and” unless mentioned otherwise. Therefore, “including A or B” means three cases, namely, the case including A, the case including B, and the case including A and B.

[0052] In addition, all numeric ranges include the lowest value, the highest value, and all intermediate values therebetween unless the context clearly indicates otherwise.

[0053] Embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0054] FIG. 2 is a perspective view of an ultrasonic welding apparatus according to the present invention.

[0055] Referring to FIG. 2, the ultrasonic welding apparatus according to the present invention includes a horn unit 100 including a horn 110 configured to be vibrated in a state of being in contact with a target to be welded and a vibrator 120 configured to apply vibration to the horn 110; an anvil unit 200 including an anvil 210 having an upper flat surface on which the target to be welded is placed and a support portion 220 configured to support the anvil in a rotatable state; and a welding main body 300 configured to allow the horn unit 100 and the anvil unit 200 to be fixed thereto, wherein the anvil 210 is rotated in a state of being supported by the support portion 220 such that the upper flat surface of the anvil is parallel to a welding surface 111 of the horn 110.

[0056] In general, before ultrasonic waves are applied after the horn 110 is mounted to a horn holder 130, a process of aligning the horn 110 is required such that the welding surface 111 of the horn 110 and the upper flat surface of the anvil 210 are parallel to each other.

[0057] Conventionally, in the process of aligning the horn 110, the direction of the horn is visually checked and fixed, a welded state of a weld result is determined, and the horn 110 is realigned. Slight deviation in parallelism between the welding surface 111 of the horn 110 and the upper flat surface of the anvil 210 may occur, and therefore, there is a problem in that pre-adjustment of the slight deviation in parallelism is difficult.

[0058] In the present invention, however, the rotatable anvil 210 is used. Even though the welding surface 111 of the horn is disposed so as not to be parallel to the upper surface of the target to be welded, therefore, the anvil 210 on which the target to be welded is placed is rotatable so as to be parallel to the welding surface 111 of the horn 110.

[0059] Since the horn 110 is vibrated in an x-axis direction by ultrasonic vibration, the anvil 210 must be fixed in place in the support portion 220.

[0060] In addition, the support portion 220 is fixed to the welding main body 300, whereby movement of the anvil 210 in the x-axis direction is prevented.

[0061] FIG. 3 is an exploded perspective view of an anvil unit according to a first embodiment.

[0062] Referring to FIG. 3, the anvil 210 is configured to have a section formed by cutting a cylinder perpendicularly to a circular lower surface thereof, wherein the section becomes an upper flat surface 211 of the anvil 210. The support portion 220 is configured to have a structure provided with an inner space 222 configured to receive the anvil 210 in a rotatable state. The support portion 220 of FIG. 3 is configured to have a structure in which two separable members are coupled to each other.

[0063] A protrusion is formed on the upper flat surface 211 of the anvil 210. When the horn rubs against the upper surface of the target to be welded while being vibrated and the anvil rubs against the lower surface of the target to be welded, weldability may be further improved by the protrusion.

[0064] The protrusion may be formed on the welding surface of the horn. The size of the protrusion formed on the welding surface of the horn and the size of the protrusion formed on the upper flat surface of the anvil may be equal to each other, or may be different from each other.

[0065] FIG. 4 is a vertical sectional view of the anvil unit of FIG. 3.

[0066] Referring to FIG. 4, although FIG. 4 shows the state in which a space is formed between the anvil 210 and the support portion 220 for convenience of understanding, it may be understood that there is actually little space between the anvil 210 and the support portion 220 such that the anvil cannot move in the support portion. In addition, a lubricant or a bearing may be added to the entire contact surfaces of the support portion 220 and the anvil 210, and therefore there may be almost no friction therebetween when the anvil is rotated in directions indicated by arrows.

[0067] The anvil 210 of FIG. 4 has a semicircular side surface, wherein the lengths of line (a), line (b), and line (c) are equal to each other. Alternatively, the lengths of line (a) and line (c) may be less than or greater than the length of line (b) within a range within which the lengths of line (a) and line (c) are equal to each other such that the side surface of the anvil is oval.

[0068] In an initial state in which the anvil is stopped while being parallel to the welding surface of the horn, however, the upper end 230 of the support portion must not protrude further than the upper flat surface 211 of the anvil, irrespective of the shape of the side surface of the anvil.

[0069] Even though the anvil mounted in the inner space 222 of the support portion 220 is rotated in directions indicated by arrows, therefore, it is preferable for the upper flat surface 211 of the anvil to protrude further than the upper end 230 of the support portion.

[0070] FIG. 5 is a perspective view of an anvil unit according to a second embodiment.

[0071] Referring to FIG. 5, the anvil unit includes an anvil 310 having a shape obtained as the result of a sphere being cut and a support portion 320 having formed therein an inner space having a size corresponding to the external surface of the sphere.

[0072] An upper flat surface 311 of the anvil 310 is formed so as to protrude further than the upper end of the support portion 320.

[0073] The anvil 310 and the support portion 320 have corresponding sizes without a space therebetween, and a lubricant is added between the anvil 310 and the support portion 320, whereby the anvil 310 is rotatable in the support portion 320. It is preferable for the upper flat surface 311 of the anvil to have a size protruding farther than the upper end 330 of the support portion even though the anvil is rotated.

[0074] FIG. 6 is a front view of an anvil according to a third embodiment.

[0075] Referring to FIG. 6, the anvil 410 is configured to have a flat section formed by cutting a cylinder perpendicularly to the lower surface thereof such that less than 50% of the cylinder remains, wherein the section becomes an upper flat surface of the anvil. A central axis 401 of the anvil 410, which has a cut cylindrical shape, about which the anvil is rotated, coincides with a central axis of the horn 110.

[0076] In this structure, the rotation angle of the anvil 410 may be maintained within an overall range of 0 to 360 degrees such that parallelism between the anvil and the welding surface of the horn is achieved.

[0077] FIG. 7 is a perspective view of an ultrasonic welding apparatus according to a fourth embodiment.

[0078] Referring to FIG. 7, an anvil 510 has a three-dimensional structure in which a section provided at the upper part of the anvil becomes an upper flat surface 511 of the anvil, and a support portion 520 is configured to have a structure in which a fixing shaft of the support portion extends through the anvil 510 in order to fix the anvil 510 to the welding main body 300.

[0079] Since the anvil 510 is securely fixed to the welding main body 300 by the fixing shaft of the support portion 520, the fixed state of the anvil may be maintained even when the horn 110 is vibrated.

[0080] FIG. 8 is a front view of an anvil according to a fifth embodiment.

[0081] Referring to FIG. 8, the anvil 610 is configured to have a semicircular column formed by cutting a cylinder perpendicularly to a circular side surface thereof, and a support portion 620 of the anvil 610 is configured to have a structure in which a fixing shaft extends through the anvil 610 in a thickness direction (T of FIG. 9) to fix the anvil 610 to the welding main body, wherein the fixing shaft is parallel to a portion of a curved surface of the semicircular column, i.e. a rotating surface 618, of the anvil 610.

[0082] (b) of FIG. 8 shows the state in which the anvil 610 shown in (a) of FIG. 8 is rotated about the support portion 620 as the fixing shaft in a counterclockwise direction, and (c) of FIG. 8 shows the state in which the anvil 610 is rotated about the support portion 620 as the fixing shaft in a clockwise direction. FIG. 9 is a perspective view showing various shapes of the anvil.

[0083] Referring to FIG. 9, (a) to (d) of FIG. 9 show three-dimensional shapes having sections, wherein the sections become upper flat surfaces 711a, 711b, 711c, and 711d, on each of which a target to be welded is disposed.

[0084] Specifically, (a) of FIG. 9 shows a quadrangular pyramid shape, (b) of FIG. 9 shows a shape formed by cutting an oval column along a line parallel to the major diameter of one oval surface thereof, and (c) of FIG. 9 shows a shape formed by cutting an oval column along a line parallel to the minor diameter of one oval surface thereof. The external shape of (d) of FIG. 9 is identical to the external shape of (b) of FIG. 9 except that through-holes 250 are formed through the anvil in a thickness direction T. In another embodiment of (d) of FIG. 9, the interior of the anvil is filled, as shown in (a) to (c) of FIG. 9 and recesses are formed on the outer surface of the anvil, which is included in the category of the present invention.

[0085] The anvil shown in (a) of FIG. 9 is applicable to the case in which the support portion is configured to have a structure in which the fixing shaft of the support portion is parallel to the upper flat surface of the anvil, and each of the anvils shown in (b) to (d) of FIG. 9 is applicable to the case in which the support portion is configured to have a structure in which the fixing shaft of the support portion is parallel to the upper flat surface of the anvil, the case in which the support portion is parallel to a portion of the rotating surface of the anvil, or the case in which the support portion has an inner space formed therein.

[0086] A welding method according to the present invention includes (S1) a step of disposing a target to be welded on an upper flat surface of an anvil, (S2) a step of disposing a welding surface of a horn on the upper surface of the target to be welded, (S3) a step of rotating the anvil to align the anvil such that the upper flat surface of the anvil is parallel to the welding surface of the horn, and (S4) a step of applying ultrasonic waves to perform welding.

[0087] Specifically, the target to be welded is disposed on the upper flat surface of the anvil, the welding surface of the horn is disposed on the target to be welded, and the horn is pushed in a direction toward the upper flat surface of the anvil. As a result, the anvil is rotated such that the entirety of the upper flat surface of the anvil and the entirety of the welding surface of the horn come into tight contact with each other. When parallelism between the upper flat surface of the anvil and the welding surface of the horn is achieved based on the target to be welded as the result of the rotation of the anvil, the rotation of the anvil is stopped. In this state, ultrasonic waves are applied to perform welding.

[0088] Those skilled in the art to which the present invention pertains will appreciate that various applications and modifications are possible within the category of the present invention based on the above description.

DESCRIPTION OF REFERENCE SYMBOLS

[0089] 100: Horn unit

[0090] 10, 110: Horns

[0091] 111: Welding surface

[0092] 120: Vibrator

[0093] 130: Horn holder

[0094] 30: Target to be welded

[0095] 20, 200: Anvil units

[0096] 210, 310, 410, 510, 610: Anvils

[0097] 211, 311, 511, 711a, 711b, 711c, 711d: Upper flat surfaces

[0098] 220, 320, 520, 620: Support portions

[0099] 222: Inner space

[0100] 230, 330: Upper end of support portion

[0101] 250: Through-hole

[0102] 300: Welding main body

[0103] 401: Central axis

[0104] 618: Rotating surface

[0105] T: Thickness direction

INDUSTRIAL APPLICABILITY

[0106] The present invention relates to an ultrasonic welding apparatus including an anvil rotatable to achieve parallelism between a welding surface of a horn for ultrasonic welding and an upper surface of the anvil in order to prevent deviation in parallelism therebetween and a welding method using the same, and therefore the present invention has industrial applicability.