JP6384873B2 - Ultrasonic welding apparatus and ultrasonic welding method - Google Patents

Description

  The present invention relates to an ultrasonic welding apparatus and an ultrasonic welding method for forming an annular welded portion connected to an object to be welded.

  As an ultrasonic welding apparatus that forms a welded portion connected in a ring shape to a welded body, for example, Patent Document 1 discloses an ultrasonic wave that forms a welded portion connected in a rectangular shape by a single ultrasonic welding (clamping step). A welding apparatus is disclosed.

JP 11-138644 A

In forming a welded portion connected in a ring shape on the welded body, it is necessary to perform ultrasonic welding (clamping step) in a plurality of times depending on the size of the welded portion.
For example, this corresponds to the case where the size of the horn that performs ultrasonic vibration is smaller than the desired size of the welded portion. In such a case, multiple ultrasonic weldings are performed on the welded object. By carrying out, the welding part connected in an annular shape can be formed.

However, even if such ultrasonic welding is performed a plurality of times, an annular welded portion that is not necessarily disconnected is not necessarily formed, and the welded portion becomes discontinuous and a non-welded portion is formed between the welded portions. May be.
When such a non-welded part is formed, it will be treated as a defective product. For example, when the welded body is a cloth-like body such as a nonwoven fabric, a woven fabric, a knitted fabric, or a mesh-like body, the non-welded part is formed. If it is done, the thread may come off from this part.

  Therefore, an object of the present invention is to provide an ultrasonic welding apparatus and an ultrasonic welding method capable of forming an annular welded portion that is connected without interruption even when ultrasonic welding is performed a plurality of times.

  In order to achieve the above object, the ultrasonic welding apparatus of the present invention is an ultrasonic welding apparatus that forms a welded portion connected in a ring shape to the welded body by performing ultrasonic welding a plurality of times on the welded body. A rotating body that is formed to be rotatable about a predetermined axis and that performs intermittent rotation that repeats rotation and stop, and a rotation angle regulating means that regulates the rotation angle of the rotating body during intermittent rotation, A receiving mold provided on the rotating body and formed with a continuous convex portion connected in a ring shape, and operates so as to be able to advance and retreat with respect to the receiving mold, and between the continuous convex portion at the time of advancement and when the rotating body is stopped A horn that clamps the welded body and transmits ultrasonic vibrations to the welded body, and the rotation angle restricting means sets the rotation angle during the intermittent rotation to the rotation of the horn around the axis. A facing surface facing the welded body; Serial in the range of the continuous convex portion is overlapped configured so as to regulate the angle smaller than the angle corresponding.

  Further, the ultrasonic welding method of the present invention is an ultrasonic welding method for forming a welded portion connected in a ring shape to the welded body by performing ultrasonic welding a plurality of times on the welded body. An intermittent rotation step for causing the rotating body formed to be rotatable about an axis to perform intermittent rotation that repeats rotation and stop, a rotation angle regulating step for regulating the rotation angle of the rotating body during the intermittent rotation, and an ultrasonic wave A horn that vibrates is made to move forward and backward with respect to a receiving mold provided on the rotating body and formed with a continuous convex portion connected to the ring, and when the horn is advanced and when the rotating body is stopped, A welding step of sandwiching the welded body between the continuous convex portions and transmitting ultrasonic vibration to the welded body, and in the rotation angle regulating step, the rotation angle at the intermittent rotation is Centered on the axis There a method for regulating the angle smaller than the angle corresponding to the range of the continuous convex portion and the facing surface overlap facing the object to be welded of the horn.

  According to the present invention, the rotation angle of the rotating body during intermittent rotation is restricted to an angle smaller than the angle corresponding to the range where the opposing surface of the horn and the continuous convex portion overlap, so that each ultrasonic welding performed multiple times That is, since an overlap welded portion that is overlapped and welded to the welded body is formed for each clamping step, it is possible to form an annular welded portion that is continuous without being discontinuous. it can.

It is a perspective view of the ultrasonic welding apparatus which concerns on 1st embodiment which used the rotary body as the rotary table. It is a schematic diagram of the intermittent welding process which shows the relationship between the arrangement | positioning of a horn, and a rotation angle when forming four overlap welding parts in a to-be-welded body. It is a front view of the to-be-welded body in which the annular welding part and four overlap welding parts were formed. It is a schematic diagram of the intermittent welding process which shows the relationship between arrangement | positioning of a horn, and a rotation angle when forming eight overlap welding parts in a to-be-welded body. It is a perspective view of the ultrasonic welding apparatus which concerns on 2nd embodiment which used the rotating body as the rotating drum and provided the receiving type | mold with which the continuous convex part was formed in the drum surrounding surface. It is a flowchart which shows the procedure of an intermittent welding process.

  A preferred embodiment of an ultrasonic welding apparatus according to the present invention will be described with reference to FIGS.

  As shown in FIGS. 1, 2 and 4, the ultrasonic welding apparatus 1 according to the first embodiment of the present invention includes a rotary table 2, a receiving mold 3, and a horn 4.

  The turntable 2 is an example of a rotating body, is formed so as to be rotatable in a horizontal direction around a predetermined axis O, and rotates by receiving power from driving means such as a motor. Further, the driving means is controlled to be turned on / off by a computer including a CPU, whereby intermittent rotation that repeats rotation and stop can be performed.

The receiving mold 3 is configured to be attachable to the rotary table 2 through screwing means such as screws and bolts, and includes a continuous convex portion 31 connected in an annular shape on the upper surface thereof. The continuous convex part 31 of this embodiment is formed as a continuous convex part connected in circular shape, for example.
The continuous convex part 31 is provided with a flat surface having a width of, for example, 5 to 10 mm on the upper surface over the entire circumference, and the welded body 5 is sandwiched between the flat surface and the horn 4. At the same time, by receiving ultrasonic vibration, a weld 50 having the same shape as the flat surface is formed as shown in FIG.
Further, the height of the continuous convex portion 31 (the distance from the upper surface of the receiving mold 3 to the flat surface of the continuous convex portion 31) can be arbitrarily set according to the thickness of the welded body 5.

In addition, the receiving die 3 includes a plurality of needle-like bodies 32 as holding means for holding the adherend.
The needle-like body 32 protrudes in the vertical direction on the upper surface of the receiving mold 3, and when the welded body 5 is a cloth-like body made of synthetic fibers (thermoplastic) having a predetermined texture, the welded body is formed. By pressing 5 against the receiving mold 3, the needle-like body 32 penetrates the welded body 5 and is held. Further, the welded body 5 in the holding state is lifted upward so as to be separated from the receiving mold 3, whereby the welded body 5 is removed from the needle-like body 32.

The horn 4 is a device that transmits ultrasonic vibrations to the adherend 5.
The horn 4 is joined to a vibrator (not shown) that generates longitudinal vibration by being connected to a predetermined oscillator, and ultrasonic vibrations are welded using a facing surface 41 facing the welded body 5 as a radiation surface. Transmit to the body 5.
As shown in FIG. 2, the facing surface 41 has a size that does not overlap with all of the continuous convex portions 31 but overlaps with a part thereof. In the present embodiment, in order to improve versatility of the horn 4, ).
The horn 4 is connected to a predetermined pressing device and is configured to advance and retract with respect to the continuous convex portion 31 (receiving die 3). The direction in which the horn 4 is advanced and retracted is a direction parallel to the axis O (a direction along the axis).

  A range in which the opposing surface 41 and the continuous convex portion 31 overlap, that is, a welding range S, has an arc shape. The welding range S is a region defined by the inner line 31a of the continuous convex portion 31, the outer line 31b of the continuous convex portion 31, and the outer shape line 41a of the facing surface 41. This welding range is obtained by a single ultrasonic welding. A weld portion corresponding to S is formed on the welded body 5.

Thus, since the welding range S has an arc shape, it is necessary to perform ultrasonic welding a plurality of times in order to form a continuous annular welding portion 50 as shown in FIG. Further, when performing such multiple times of ultrasonic welding, in order to prevent the welded portions from becoming discontinuous and forming no non-welded portions between the welded portions, the overlapping range of the welded portions, that is, the overlap welded portion 51 must be provided.
Therefore, in order to provide such an overlap welded portion 51, the rotary table 2 is caused to perform intermittent rotation at a rotation angle smaller than an angle corresponding to the welding range S centered on the axis O.

In this embodiment, since the shape of the opposing surface 41 does not have the same curvature as that of the continuous convex portion 31, the angle corresponding to the welding range S is from the angle B determined by the inner line 31a and the outer line 41a to the outer side. The angle is in a range up to an angle C determined by the line 31b and the outline 41a.
The intermittent rotation of the turntable 2 can be set smaller than the angle C and larger than the angle B, but in this case, a minute non-welded portion is formed between the welded portions, which is not preferable.
Therefore, in order to prevent the non-welded portion from being formed between the welded portions, the smallest angle B among the angles corresponding to the welding range S is set as a reference angle, and the intermittent rotation angle of the turntable 2 is set from this angle B. It is necessary to set a smaller value.
When the angle B corresponding to the welding range S is specified as 110 °, for example, the intermittent rotation angle A of the turntable 2 can be determined to be smaller than the angle B, such as 90 °.

The rotation angle restricting means restricts the intermittent rotation angle of the turntable 2 to the angle A.
The rotation angle regulating means can be, for example, a computer that controls a motor that rotates the turntable 2.
The motor is preferably a servo motor having an encoder or a motor capable of controlling the rotation angle, such as a stepping motor, and the computer controls the motor to perform intermittent rotation and stop of the angle A on the rotary table 2. The operation is repeated alternately.
The computer also controls a press device that causes the horn 4 to advance and retract at the same time.
Specifically, the press device is controlled so that the horn 4 is retracted (separated) from the continuous convex portion 31 during intermittent rotation of the motor, and the horn 4 is advanced (closed) to the continuous convex portion 31 while the motor is stopped. To do.
At the time of advancement, it is preferable to clamp the welded body 5 between the horn 4 and the continuous convex portion 31 with a force of 2200 N (0.45 Pa) for about 0.7 seconds, for example.
The rotation angle restricting means is not limited to the above, and a latch mechanism that latches for each angle A can also be adopted.

In the ultrasonic welding apparatus 1 having the above-described configuration, at least two welded bodies 5 (cloth-like bodies) are overlapped so as to cover the continuous convex portion 31 or received in a state where one is folded and overlapped. Place on mold 3. Then, at the position indicated by the solid line in FIG. 2, the horn 4 is moved back and forth in the direction perpendicular to the paper surface (the horn 4 does not rotate), and the rotary table 2 is intermittently rotated with a rotation angle A of 90 °. The rotary table 2 is rotated once.
Then, a total of four intermittent welds are performed (see the two-dot chain line), and as shown in FIG. 3, the four welded parts 51 are provided, and the welded part 50 formed in a ring shape without being interrupted is formed. The welded body 5 is manufactured.
Such a welded body 5 can be used, for example, in a circular water-absorbing filter built in a humidifier by cutting along the periphery of the welded portion 50.

The overlap welded portion 51 can also expand the range by further reducing the angle A.
Moreover, the number of the overlap welding parts 51 can also be increased as follows.

FIG. 4 is a schematic diagram of an intermittent welding process showing the relationship between the arrangement of the horn 4 and the rotation angle A when the eight overlap welds 51 are formed on the welded body 5.
In this example, in order to increase the number of overlap welds 51, the position of the horn 4 and the rotation angle A are changed from those in FIG.
Specifically, the horn 4 is configured to be movable in a direction orthogonal to the axis O, and the horn 4 is moved in the direction P from FIG.
Thus, by configuring the horn 4 to be movable in a direction orthogonal to the axis O, the welding range S can be expanded and contracted without replacing the horn 4 itself, and welding is performed by bringing the horn 4 closer to the axis O. The range S is widened, and the welding range S is narrowed by moving the horn 4 away from the axis O.

In the example shown in FIG. 4, the horn 4 is moved away from the axis O as compared with the example shown in FIG. 2, so that the welding range S is narrowed.
From this welding range S, the angle B (reference angle) corresponding thereto can be specified as, for example, 50 °, and the intermittent rotation angle A of the turntable 2 is determined to be smaller than the angle B, for example, 45 °. be able to.
As a result, when the turntable 2 is rotated once, a total of 8 intermittent welds are performed (see the two-dot chain line), and the eight weld welds 51 are provided, and the welds 50 connected in an annular shape without interruption are formed. The welded body 5 thus produced is manufactured.
Thus, the welding strength can be increased by increasing the number of the overlap welding parts 51. In addition, it is considered that the increase in the number of the overlap welded portions 51 is less burdened on the welded body 5 (heating, heat curing, etc.) than the expansion of the range of the overlap welded portions 51.

FIG. 5 is a perspective view showing the ultrasonic welding apparatus 1 according to the second embodiment of the present invention.
The ultrasonic welding apparatus 1 includes a rotating drum 2 as a rotating body in place of the rotating table, and the horn 4 is advanced and retracted in a direction perpendicular to the axis O, according to the first embodiment. Different from ultrasonic welding equipment.
The receiving mold 3 and the continuous convex portion 31 are provided on the peripheral surface of the rotary drum 2, and the surface of the continuous convex portion 31 is formed as a curved surface. Accordingly, the facing surface 41 of the horn 4 is formed as a rectangular curved surface having the same curvature as the curved surface of the continuous convex portion 31. The welded body 5 (cloth-like body) can be attached via the needle-like body 32 so as to be wound around the circumferential surface of the rotating drum 2 in a state where at least two sheets are overlapped or one sheet is folded and overlapped. .

Also in such an ultrasonic welding apparatus 1, the welding range S has such a size that the opposing surface 41 and a part of the continuous convex portion 31 overlap each other. Therefore, in order to form the annular welding portion 50, a plurality of times It is necessary to perform sonic welding.
Therefore, the rotating drum 2 is intermittently rotated at a rotation angle smaller than the angle corresponding to the welding range S centered on the axis O, and the horn 4 is moved back and forth in a direction perpendicular to the axis O in synchronization with this. . Thereby, while providing the overlap welding part 51, the cylindrical to-be-welded body 5 in which the welding part 50 connected cyclically | annularly without a break is formed is manufactured.
Such a to-be-welded object 5 can be utilized for a bag, a net | network, etc., for example.

The intermittent welding process as described above can be realized by a procedure (ultrasonic welding method) as shown in FIG.
First, an angle corresponding to the overlapping range of the facing surface of the horn and the continuous convex portion is specified (S1).
When this angle has a range, the smallest angle is specified as the reference angle.
Next, the rotation angle A of the rotating body is set to an angle smaller than the angle specified above (S2: rotation angle regulating step).
Subsequently, the number of times of ultrasonic welding is set. The number of weldings is determined as a quotient obtained by dividing 360 ° by the rotation angle A (S3). Since this quotient is preferably an integer, the value of the rotation angle A is selected so that this quotient becomes an integer. Further, when the quotient does not become an integer, the advanced value is used as the number of weldings. In this case, although the rotating body rotates more than one rotation, the occurrence of a non-welded portion can be avoided.
Next, the to-be-welded body 5 (cloth-like body) is placed on the receiving die 3 in a state where at least two sheets are overlapped or one sheet is folded and overlapped so as to cover the continuous convex portion 31. And while making the horn 4 advance (approach) with respect to the type | mold 3, an ultrasonic wave is oscillated, pressing the to-be-welded body 5 between the horn 4 and the continuous convex part 31 (S4: welding process). Thereby, the welding part which has the welding range S in the to-be-welded body 5 is formed.
Next, the rotating body is rotated by the rotation angle A while retracting (separating) the horn 4 from the receiving mold 3 (S5: intermittent rotation step and rotation angle regulating step). Thereafter, it is determined whether or not the number of welding times has reached the set number. If it is determined that the number of welding times has not been reached (S6-No), the operations of S4 and S5 are repeated (intermittent rotation process, rotation angle regulation process and welding). Process).
When it is determined that the number of welding times has reached the set number of times (S6-Yes), the welding process is terminated.
By performing such an intermittent welding process (ultrasonic welding method), it is possible to manufacture the welded body 5 in which the welded portion 50 connected in an annular shape is formed without interruption.

  As described above, according to the ultrasonic welding apparatus 1 and the ultrasonic welding method of the present embodiment, the rotation angle of the rotating body during intermittent rotation is an angle corresponding to the range where the opposing surface of the horn and the continuous convex portion overlap. The angle is smaller than the angle, so each welded multiple times, i.e., the overlap welded part that is welded to the welded body is formed at each clamping step, so the welded part is discontinuous. Therefore, it is possible to form an annular welded portion that is connected without interruption.

  As mentioned above, although preferred embodiment of the ultrasonic welding apparatus and ultrasonic welding method of the present invention was described, the ultrasonic welding apparatus and ultrasonic welding method according to the present invention are not limited to the above-described embodiments, As will be described below, it goes without saying that various modifications can be made within the scope of the present invention.

For example, the rotating body and the receiving mold may be integrated or separate.
Moreover, the drive means of a rotary body may be manual, and what is necessary is just to repeat rotation and a stop manually. The rotation angle regulating means for manually rotating the rotating body manually rotates in conjunction with the rotating body and has a gear having a groove for each intermittent rotation angle A, and the tip is biased toward the groove by a spring or the like. A latch mechanism (ratchet mechanism) that includes a claw member and that engages the claw member with the gear groove each time the rotating body rotates at an angle A can also be employed.

  In addition, the configuration that enables the horn 4 to move in the direction orthogonal to the axis O is not particularly limited, but the configuration in which the mounting position of the horn 4 can be changed (for example, the horn 4 is made different by loosening a screw or the like that fixes the horn 4). For example, a guide rod extending in a direction orthogonal to the axis O may be provided, and the horn 4 may be moved while being guided by the guide rod.

In the first embodiment, the shape of the continuous convex portion is a circle. However, any shape can be adopted as long as it is a shape connected to a ring shape such as an ellipse, a square, a diamond, and a star.
In addition, the annular shape can include not only those that connect the entire circumference without interruption, but also those that are only partially interrupted (a part of the continuous convex portion is also interrupted). By the ultrasonic welding apparatus of the first embodiment, the welded body 5 having a welding portion connected in a U-shape, that is, a bag body can be manufactured.
Moreover, in this embodiment, although the to-be-welded body was made into the cloth-like body, it is not limited to this, A thermoplastic plastic, a plastic sheet, etc. may be sufficient.

  INDUSTRIAL APPLICABILITY The present invention can be widely used for an ultrasonic welding apparatus that forms a welded portion connected in a ring shape to an object to be welded.

1 Ultrasonic welding device 2 Rotary table, rotating drum (rotating body)
DESCRIPTION OF SYMBOLS 3 Receiving type 31 Continuous convex part 32 Needle-like body 4 Horn 5 To-be-welded body 50 Weld part 51 Overlap weld part

Claims (6)

An ultrasonic welding apparatus that forms a welded portion connected to the welded body in a ring shape by performing ultrasonic welding a plurality of times on the welded body,
A rotating body that is formed to be rotatable around a predetermined axis and performs intermittent rotation that repeats rotation and stop,
Rotation angle restricting means for restricting the rotation angle of the rotating body during intermittent rotation;
A receiving mold provided on the rotating body and formed with a continuous convex portion connected in an annular shape;
A horn that operates so as to be able to advance and retreat with respect to the receiving mold, and transmits ultrasonic vibrations to the welded body by sandwiching the welded body with the continuous convex portion at the time of advancement and when the rotating body is stopped, With
The rotation angle regulating means is
The rotation angle at the time of the intermittent rotation is restricted to an angle smaller than an angle corresponding to a range where the facing surface facing the welded body of the horn centered on the axis and the continuous convex portion overlap. Ultrasonic welding equipment. The direction in which the horn can move forward and backward is a direction parallel to the axis,
The horn is configured to be movable in a direction perpendicular to the axis,
The ultrasonic welding apparatus according to claim 1, wherein a range in which the facing surface of the horn and the continuous convex portion overlap each other can be enlarged or reduced. When there is a range in the angle corresponding to the range where the facing surface of the horn centering on the axis and the continuous convex portion overlap, the smallest angle is set as a reference angle,
The ultrasonic welding apparatus according to claim 1 or 2, wherein the rotation angle restricting means restricts the rotation angle during the intermittent rotation to an angle smaller than the reference angle. The welded body is a cloth-like body,
The ultrasonic welding apparatus according to any one of claims 1 to 3, further comprising needle-like holding means that detachably holds the cloth-like body. The ultrasonic welding apparatus according to claim 1, wherein the facing surface of the horn has a rectangular shape. An ultrasonic welding method for forming a welded portion connected in a ring shape to a welded body by performing ultrasonic welding a plurality of times on the welded body,
An intermittent rotation process for causing the rotating body formed to be rotatable around a predetermined axis to perform intermittent rotation that repeats rotation and stop, and
A rotation angle regulating step for regulating the rotation angle of the rotating body during intermittent rotation;
A horn that performs ultrasonic vibration is made to move forward and backward with respect to a receiving mold provided on the rotating body and formed with a continuous convex portion connected to the ring, and when the horn moves forward and when the rotating body stops A welding step of sandwiching the welded body between the horn and the continuous convex portion and transmitting ultrasonic vibration to the welded body,
In the rotation angle regulating step,
The rotation angle at the time of the intermittent rotation is restricted to an angle smaller than an angle corresponding to a range where the facing surface facing the welded body of the horn centered on the axis and the continuous convex portion overlap. Ultrasonic welding method.

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