JP7486994B2 - Method for fixing components using ultrasonic swaging horn - Google Patents

Description

The present invention relates to a horn for ultrasonic swaging and a method for fixing components using the horn.

The ultrasonic swaging horn described above is used, for example, to melt a member to be fixed, which is made of a thermoplastic resin material, and to fix a member to be fixed, such as a metal member, to the member to be fixed (see, for example, Patent Document 1).

The horn described in Patent Document 1 has a horn tip that is formed in an uneven shape with a central recess that recesses toward the base end and a protrusion that protrudes toward the tip end around the central portion. The protrusion around the central portion of the horn tip is provided with a curved portion that recesses toward the base end.

The fixed target position, which fixes the target member to the fixed member, is configured as a concave groove into which the target member is recessed, and the concave groove, which is the fixed target position, is surrounded by an upright wall portion (inner wall portion) that extends upward above the target member placed at the fixed target position.

When fixing a target member to a member to be fixed, the target member is placed in the target position, which is a concave groove, and the horn tip is pressed against the target member to melt the target member with ultrasonic vibrations and pressure. At this time, the convex portion around the center of the horn tip is pressed against the upright wall of the target member, melting the upright wall with ultrasonic vibrations and pressure, and deforming the upright wall so that it protrudes toward the target member. This deformation of the upright wall forms a covering that covers the top of the target member, and the target member is fixed in a state where it is embedded in the target member.

JP-A-6-349235 (see [0035] to [0039], Figs. 7 and 8)

In the horn described in Patent Document 1, when the horn is pressed against the member to be fixed and melted, the convex portion around the center of the tip of the horn is pressed against the upright wall of the member to be fixed, and the upright wall of the member to be pressed is melted. As a result, there is nothing to resist the pressing force of the tip of the horn, making it difficult to apply an appropriate pressing force and to adjust the strength of the pressing force. As a result, it is difficult to make the covering portion that covers the top of the member to be fixed a sufficient size (thickness) or to adjust it to the desired size (thickness), making it difficult to make the fixing strength of the member to be fixed to the member to be fixed an appropriate strength and difficult to adjust the fixing strength of the member to the member to be fixed to the desired strength.

In view of this situation, the main object of the present invention is to provide an ultrasonic swaging horn that can easily apply an appropriate pressing force to a member to be fixed and that can also easily adjust the pressing force. Another object of the present invention is to provide a member fixing method that, when fixing a member to a member to be fixed using the ultrasonic swaging horn, can provide an appropriate fixing strength of the member to the member to be fixed and can easily adjust the fixing strength of the member to the member to be fixed to the desired strength.

A first characteristic configuration of the present invention is a horn for ultrasonic swaging, which includes a horn body that can be pressed against a member to be fixed, which is made of a thermoplastic resin material, and which melts the member to be fixed by pressing the horn body against the member to fix the member to which the object is to be fixed, and which includes:
The horn tip of the horn body is provided with a protrusion that protrudes toward the tip side beyond the horn tip surface,
The protrusion is provided so as to be movable in the longitudinal direction of the horn body,
The horn body is configured so that the horn tip portion can be pressed against the fixed member with the protruding portion abutting against the fixed target member.

According to this configuration, when pressing the horn tip of the horn body against the member to be fixed, the horn tip can be pressed against the member to be fixed with the protruding portion abutting against the member to be fixed. This allows the member to resist the pressing force by abutting the protruding portion against the member to be fixed, making it easy to apply an appropriate pressing force and to easily adjust the strength of the pressing force. Furthermore, since the protruding portion is movable in the length direction of the horn body, as the horn tip is pressed against the member to be fixed, the protruding portion retracts toward the base end of the horn body, allowing the horn tip to be pressed against the member to be fixed appropriately without being hindered by the protruding portion.

The second characteristic feature of the present invention is that the protrusion is provided on the base end side of the horn body so that it can be freely retracted depending on the amount of pressure movement of the horn tip against the fixed member.

According to this configuration, the protrusion retracts toward the base end of the horn body according to the amount of pressing movement of the tip of the horn body against the fixed member, so the distance between the horn tip and the fixed member also changes according to the amount of pressing movement. The thermoplastic resin material melted by pressing the horn tip flows between the horn tip and the fixed member and deforms to cover the fixed member, so increasing the distance between the horn tip and the fixed member increases the thickness of the covering that covers the fixed member. Therefore, in order to adjust the thickness of the covering, it is only necessary to manage the amount of pressing movement of the horn tip against the fixed member, and the thickness of the covering can be easily adjusted.

The third characteristic feature of the present invention is that the horn tip surface of the horn body is formed flat.

According to this configuration, since the horn tip surface of the horn body is formed flat, if the portion of the fixing target member facing the horn tip portion is also formed flat, the distance between the horn tip surface of the horn tip portion and the fixing target member can be made constant or approximately constant. This allows the thickness of the covering portion that covers the fixing target member to be constant or approximately constant, and there are no localized portions of weak strength in the covering portion, making it possible to strengthen the fixing strength of the fixing target member to the fixing target member.

The fourth characteristic feature of the present invention is that the tip of the protrusion is provided with an engagement portion that can be freely engaged with the fixed target member.

With this configuration, when the protrusion is brought into contact with the target member, the engagement portion can be engaged with the target member, so the horn body can be aligned with the target member.

A fifth characteristic configuration of the present invention is a method for fixing a target member to a member to be fixed by using the ultrasonic swaging horn according to any one of the first to fourth characteristic configurations, comprising:
a contact step of contacting the protrusion with the target member disposed at a target position of the target member;
The method includes a pressing process in which, with the protrusion abutted against the member to be fixed, the protrusion is retracted toward the base end side of the horn body while pressing the horn tip against the member to be fixed.

According to this configuration, by performing the abutment process before the pressing process, the protrusion can be appropriately abutted against the fixed member installed at the fixed position of the fixed member. Therefore, in the pressing process, the horn tip can be pressed against the fixed member with an appropriate pressing force while the protrusion is in contact with the fixed member, and the strength of the pressing force can be easily adjusted, so that the fixing strength of the fixed member to the fixed member can be made appropriate and the fixing strength of the fixed member to the fixed member can be easily adjusted to the desired strength. Moreover, since the horn tip is pressed against the fixed member while the protrusion is retracted toward the base end of the horn body, the horn tip can be pressed against the fixed member appropriately and smoothly without being hindered by the protrusion.

1 is a cross-sectional view of a horn body, and an exploded perspective view of the horn body with each member removed. A plan view of the fixed member with the target member placed on the fixed member. Side view of the installation process Side view of the contact process Side view of the pressing process A side view showing a state in which a fixing target member is fixed to a fixed member.

An embodiment of a horn for ultrasonic swaging according to the present invention will be described with reference to the drawings.
As shown in Figures 1 and 6, this ultrasonic swaging horn 1 is pressed against a member 11 to be fixed, which is made of a thermoplastic resin material, to melt the member 11 to be fixed by ultrasonic vibration and pressure, thereby fixing a member 12 to the member 11. Figure 1(A) shows a cross-sectional view of the horn tip 3 with the protrusion 4 and the like attached, and Figure 1(B) shows an exploded perspective view of the horn tip 3 with the protrusion 4 and the like removed. Also, Figure 6 shows the state in which the member 12 to be fixed has been fixed to the member 11 to be fixed using the ultrasonic swaging horn 1.

The ultrasonic swaging horn 1 is provided with a horn body 2 that melts a fixed member 11 by pressing it against the fixed member 11. As shown in FIG. 1, the horn body 2 is provided with a horn tip portion 3 that protrudes toward the tip side (the lower side in FIG. 1), and the horn tip surface 31 of the horn tip portion 3 is formed flat. The horn tip portion 3 is provided with a protrusion 4 that protrudes toward the tip side beyond the horn tip surface 31 of the horn tip portion 3, and the protrusion 4 is provided to be freely movable in the length direction of the horn body 2.

The horn tip 3 is formed in a cylindrical shape with a through hole 32 that extends in the length direction of the horn body 2 (vertical direction in FIG. 1). The horn body 2 is provided with a cylindrical mounting part 21 to which the horn tip 3 can be attached, and the horn tip 3 can be attached to the mounting part 21 by screwing a screw formed on the outer periphery of the mounting part 21 into a screw formed on the inner periphery of the horn tip 3.

The protrusion 4 is provided with an engagement portion 41, an intermediate portion 42, and a support portion 43 in this order from the tip side. Each of the engagement portion 41, intermediate portion 42, and support portion 43 is formed in a cylindrical shape extending in the length direction of the horn body 2 (the vertical direction in FIG. 1), and the axis centers of the engagement portion 41, intermediate portion 42, and support portion 43 are coaxial. The diameters of the engagement portion 41, intermediate portion 42, and support portion 43 are formed so that they increase in the order of the engagement portion 41, intermediate portion 42, and support portion 43, and the diameter of the support portion 43 is the same or approximately the same as the diameter of the through hole portion 32 of the horn tip portion 3.

The protrusion 4 is provided with at least the support portion 43 disposed inside the horn tip portion 3, with at least a portion of the intermediate portion 42 and the entire engagement portion 41 protruding from the horn tip portion 3. The protrusion 4 is supported such that the support portion 43 can move freely along the through hole portion 32 of the horn tip portion 3. As the support portion 43 moves along the through hole portion 32, the protrusion 4 is provided to be movable in the length direction of the horn body 2 (the up and down direction in FIG. 1).

Between the mounting portion 21 of the horn body 2 and the protruding portion 4, an elastic body 5 such as a spring is provided, and the protruding portion 4 is urged to move toward the protruding side from the horn tip portion 3 by the urging force of the elastic body 5. The tip end of the through hole portion 32 in the horn tip portion 3 is provided with a movement regulating portion 33 that regulates the movement of the protruding portion 4 toward the protruding side. The movement regulating portion 33 is provided at the tip end of the through hole portion 32 so as to protrude inward, and the diameter of the through hole portion 32 is smaller than the diameter of the support portion 43. As a result, the movement regulating portion 33 abuts against the support portion 43 of the protruding portion 4, regulating the movement of the protruding portion 4 toward the protruding side and preventing the protruding portion 4 from falling off the horn tip portion 3.

When fixing the fixing target member 12 to the fixing target member 11, the steps of installation, abutment, and pressing are performed in sequence as shown in Figures 2 to 6. In this embodiment, the fixing target member 11 is made of a thermoplastic resin material, and the fixing target member 12 is made of a metal hexagonal nut, but the type of material used for the fixing target member 12 can be changed as appropriate.

(Installation process)
In the installation step, as shown in Figures 2 and 3, the fixed target member 12 is installed at the fixing target position 111 on the fixed member 11. The fixing target position 111 is set, for example, at the center of the fixed member 11, which is circular in plan view, and is configured as a concave groove portion into which the fixed member 11 is recessed. As shown in Figure 2, an upright wall portion 112 extending upward is provided around the fixing target position 111. The upright wall portion 112 is formed to extend upward beyond the fixed target member 12 installed at the fixing target position 111.

The fixed target position 111 is formed in a circular shape, while the fixed target member 12 is formed in a hexagonal shape. Therefore, by fitting the fixed target member 12 into the fixed target position 111, which is a concave groove, the outer periphery of the fixed target member 12 abuts against the inner wall of the upright wall portion 112 that exists around the fixed target position 111, and the fixed target member 12 can be positioned relative to the fixed target position 111.

(Contact process)
In the abutment step, as shown in Fig. 4, the horn body 2 is brought close to the fixed member 11 in which the fixed member 12 is installed at the fixed position 111, and the tip of the protrusion 4 (the tip surface of the intermediate portion 42) is brought into abutment with the upper surface 121 of the fixed member 12. At this time, the engagement portion 41 provided at the tip of the protrusion 4 engages with the screw hole portion 122 formed in the fixed member 12, and the position of the horn body 2 can be aligned with respect to the fixed member 12. By this alignment, for example, the center of the fixed member 12 and the center of the protrusion 4 are in the same position in the horizontal direction, and the abutment point of the tip of the protrusion 4 against the fixed member 12 corresponds to the center of the fixed member 12. The intermediate portion 42 of the protrusion 4 is formed with a larger diameter than the screw hole portion 122 of the fixed member 12, and the upper portion of the screw hole portion 122 can be blocked by abutting the tip surface of the intermediate portion 42 of the protrusion 4 against the upper surface portion 121 of the fixed member 12.

(Pressing process)
4, in a state in which the tip end (tip surface of intermediate portion 42) of protrusion 4 is in contact with upper surface 121 of target member 12, protrusion 4 is retracted toward the base end side (upper side in FIG. 5) of horn main body 2 while horn tip portion 3 is pressed against target member 11 as shown in FIG. 5. In this pressing process, horn main body 2 is moved closer to target member 11 while the tip end (tip surface of intermediate portion 42) of protrusion 4 is in contact with upper surface 121 of target member 12, thereby pressing horn tip surface 31 of horn tip portion 3 against upright wall portion 112 of target member 11. At this time, because the tip of protrusion 4 (tip surface of intermediate portion 42) remains in contact with upper surface 121 of target member 12, protrusion 4 retracts toward the base end side of horn body 2 (upward in FIG. 5) by the amount of approach movement that brings horn body 2 closer to fixed member 11, reducing the amount of protrusion 4 protruding from horn tip surface 31 of horn tip portion 3. In this way, protrusion 4 retracts toward the base end side of horn body 2 in accordance with the amount of pressing movement of horn tip portion 3 (horn tip surface 31) against fixed member 11 (distance corresponding to K in FIG. 5).

By pressing the horn tip surface 31 of the horn tip 3 against the standing wall 112 of the member to be fixed 11, as shown in Figs. 5 and 6, a part of the standing wall 112 (flexible resin material) is melted and the standing wall 112 is deformed so that it protrudes toward the upper surface 121 of the member to be fixed 12. This deformation of the standing wall 112 forms a covering 113 that covers the upper surface 121 of the member to be fixed 12, as shown in Fig. 6, and the member to be fixed 12 is fixed in a state where it is embedded in the member to be fixed 11.

In the pressing process, as shown in FIG. 5, the protrusion 4 is in contact with the upper surface 121 of the fixed member 12, so that a part of the molten standing wall 112 (flexible resin material) does not flow into the location of the protrusion 4. In addition, the tip surface of the middle portion 42 of the protrusion 4 is in contact with the upper surface 121 of the fixed member 12, blocking the upper portion of the screw hole 122, thereby preventing a part of the molten standing wall 112 (flexible resin material) from flowing into the screw hole 122.

As a result, as shown in FIG. 6, an opening 6 is formed on the upper side of the target member 12 along the vertical direction (the length direction of the horn body 2), and the screw hole 122 is prevented from being blocked by the flexible resin material. This allows a fastener such as a screw to be appropriately inserted and removed through the opening 6 into the screw hole 122 of the target member 12.

In the pressing process, as shown in FIG. 5, the protrusion 4 retracts toward the base end of the horn body 2 according to the amount of pressing movement of the horn tip 3 (horn tip surface 31) against the fixed member 11 (the distance corresponding to K in FIG. 5). For example, the greater the amount of pressing movement of the horn tip 3 (horn tip surface 31) against the fixed member 11 (the distance corresponding to K in FIG. 5), the greater the amount of retraction movement of the protrusion 4 toward the base end of the horn body 2. Therefore, the greater the amount of pressing movement of the horn tip 3 (horn tip surface 31) against the fixed member 11 (the distance corresponding to K in FIG. 5), the smaller the distance between the upper surface 121 of the fixed member 12 and the horn tip surface 31 of the horn tip 3 (the distance corresponding to H in FIG. 5). As a result, there is a one-to-one relationship between the amount of pressing movement of the horn tip 3 and the distance between the upper surface 121 of the fixed target member 12 and the horn tip surface 31.

In the pressing process, a portion of the molten upright wall 112 (flexible resin material) flows between the upper surface 121 of the fixed member 12 and the horn tip surface 31 to form the covering portion 113, so that the distance between the upper surface 121 of the fixed member 12 and the horn tip surface 31 (the distance corresponding to H in FIG. 5) becomes the thickness (wall thickness) of the covering portion 113.

Therefore, the thickness (wall thickness) of the covering portion 113 is controlled by controlling the amount of pressing movement of the horn tip portion 3. For example, to reduce the thickness of the covering portion 113, the amount of pressing movement of the horn tip portion 3 can be increased, and conversely, to increase the thickness of the covering portion 113, the amount of pressing movement of the horn tip portion 3 can be decreased. In this way, when adjusting the thickness (wall thickness) of the covering portion 113, it is only necessary to adjust the amount of pressing movement of the horn tip portion 3, and the thickness (wall thickness) of the covering portion 113 can be easily adjusted.

The thickness (wall thickness) of the covering portion 113 can be made uniform or approximately uniform in the radial direction of the fixed member 11 and the target member 12 because the horn tip surface 31 of the horn tip portion 3 is formed flat. Therefore, the covering portion 113 has a sufficient thickness (wall thickness) on both the inner and outer radial sides of the fixed member 11 and the target member 12, and the fixing strength of the target member 12 to the fixed member 11 can be made strong.

[Another embodiment]
Another embodiment of the present invention will now be described.
The configurations of the embodiments described below are not limited to being applied alone, but may also be applied in combination with the configurations of other embodiments.

(1) In the above embodiment, the tip of the protrusion 4 is provided with an engagement portion 41, but it is also possible to implement the invention without providing the engagement portion 41.

(2) In the above embodiment, the shapes of the fixed member 11, the fixed target member 12, and the protrusion 4, etc. can be changed as appropriate.

Reference Signs List 1: Horn for ultrasonic swaging 2: Horn body 3: Horn tip 4: Projection 11: Member to be fixed 12: Member to be fixed 31: Horn tip surface 41: Engagement portion

Claims (1)

A method for fixing a target member to a member to be fixed using an ultrasonic swaging horn, the method comprising the steps of: (a) providing a horn body that can be pressed against a target member made of a thermoplastic resin material; and (b) melting the target member by pressing the horn body against the target member to fix the target member to the target member;
The horn tip of the horn body is provided with a protrusion that protrudes toward the tip side beyond the horn tip surface,
The protrusion is provided so as to be movable in the longitudinal direction of the horn body,
the horn body is configured so that the horn tip portion can be pressed against the fixed member with the protruding portion abutting against the fixed member,
the protrusion is provided on the base end side of the horn body so as to be retractable in response to an amount of pressing movement of the horn tip portion against the fixed member,
a contact step of contacting the protrusion with the target member disposed at a target position of the target member;
a pressing step of pressing the horn tip portion against the fixed member while retracting the protruding portion toward the base end side of the horn body in a state where the protruding portion is in contact with the fixed member,
In the pressing step, a thermoplastic resin material molten by pressing the horn body is caused to flow between the horn tip portion and the object member to form a covering portion covering an upper surface portion of the object member, and the object member is fixed in a state where it is embedded in the object member;
A member fixing method in which the thickness of the covering portion is controlled by controlling the amount of pressing movement of the horn tip portion .

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