JPS5921772B2 - Ultrasonic welding method for two parts - Google Patents

Description

Detailed Description of the Invention 5 The present invention relates to a method for ultrasonic welding of two members, and in particular, the inner circumferential surface of one member made of resin is fitted into the outer circumferential surface of the other member made of resin, and both members are welded by ultrasonic welding. This invention relates to a method of sonic welding.

Conventionally, when ultrasonically welding two resin parts,
Due to vibrations applied to the members during welding, the assembly welding position of both members deviates from the normal position, making welding errors inevitable.

In particular, if a movable valve member or the like is provided in the internal space of the two members to be welded and is biased by a spring, the two parts 15 will be pushed up by the biasing force of the spring and inserted into the interior space during welding. There were cases where valve members etc. that were attached would fly out. Therefore, it is necessary to use a special jig to hold and weld both members against the biasing force of the spring, resulting in a decrease in assembly work efficiency. 20 Therefore, an object of the present invention is to reliably assemble two members by temporary fixing without requiring a special jig during ultrasonic welding.

The basic configuration of the present invention for achieving the above object is to place a plurality of large diameter protrusions 25 formed on the outer peripheral end of one member into a step portion formed on the other member and having a smaller diameter than the large diameter protrusions. arranging the large-diameter protrusion of the one member as a guide, and temporarily fixing both members by inserting the large-diameter protrusion of the one member into the stepped portion of the other member so as to generate a frictional force therebetween; and temporarily fixing the two members. and then ultrasonically welding both members by a welding portion that is located following the large-diameter protrusion of the one member in the axial direction and protrudes in the radial direction.

With the above configuration, the one member and the other member are temporarily fixed by the frictional force generated between the large-diameter protrusion of the one member and the stepped portion of the other member 35.

Therefore, even if a valve member biased by a spring is disposed between the two members, both members are sufficiently held in their normal positions against the biasing force of the spring. Therefore, when performing the well-known ultrasonic welding of the welded part of one member to the other member, when high vibration is applied to one member and the frictional force accompanying the vibration welds the two, both members are in the normal position. No problems such as misalignment will occur. An embodiment embodying the present invention will be described below with reference to the accompanying drawings. Figure 1 shows a retainer 1 made of polyacetal resin, etc.
9, and the other member shown in FIG. 3 is a plate 20 made of polyacetal resin or the like. The retainer 19 of one member is the plate 20 of the other member.
In order to be ultrasonically welded to the retainer 19 , a step 21 formed on the outer peripheral surface of the retainer 19 is fitted into a step 22 formed on the inner peripheral surface of the plate 20 . Step portion 21 of retainer 19
A plurality of large diameter protrusions 23 are appropriately formed on the outer peripheral end of the plate 2 at equal intervals on the circumference.
The diameter of the stepped portion 22 is larger than that of the retainer 19. Therefore, when the retainer 19 is fitted into the step 22 of the plate 20, the large-diameter protrusion 23 acting as a guide is forcibly urged inwardly, that is, radially inward, by the step 22 of the plate 20. Therefore, a frictional force is generated between both members 19 and 20, and the retainer 19 and plate 20 are sufficiently temporarily secured so that they do not come out of their normal positions. Both members 19,
20 is temporarily fixed, the large diameter protrusion 23 of the retainer 19
Both members 19 and 20 are ultrasonically welded by a welding portion that is located following the axial direction of the welding portion 23 and protrudes in the radial direction and has a larger diameter than the large diameter protrusion 23 . In this way, the retainer 19 and plate 20 are temporarily fixed by the frictional force generated between the large-diameter protrusion 23 of the retainer 19 and the stepped portion 22 of the plate 20, so both members 19 and 20 are specially Can be assembled securely without the need for jigs.

Furthermore, a mechanism is provided in which a valve member (not shown) is disposed in the internal space of the plate 20, and the valve member is maintained in a normal position by a spring (not shown) that is engaged with the retainer 19. Even if the retainer 19 and the plate 20 are disposed, the retainer 19 and the plate 20 are sufficiently held in the normal position against the biasing force of the spring. Therefore, when performing ultrasonic welding to the plate 20 via the welded portion of the retainer 19, high vibration is applied to the retainer 19, and when both members are welded by the frictional force accompanying the vibration, the retainer 19 and the plate are welded together. This prevents problems such as 20 shifting from its normal position. As is clear from the above description of the embodiments, according to the present invention, two members to be ultrasonically welded are arranged at a normal welding position, and a means is provided for temporarily fixing the two members at the normal position. Even if high vibrations are applied to one or both of the above members during ultrasonic welding, there is no disadvantage such as the two members being welded at a position deviated from their normal position.

Further, the temporary fixing means has an extremely simple structure, and the two members can be simply inserted and assembled together with a small force, and there is no need to use a special jig, which has the effect of improving workability and productivity. This effect is particularly noticeable when, for example, an elastic means such as a spring is provided inside two parts to be ultrasonically welded, and has a biasing force to separate the two parts, and is effective in minimizing welding errors. be. Furthermore, since the large-diameter protrusions of the one member are formed as a plurality of protrusions formed on the outer peripheral edge of the stepped portion, there is no need for force cutting when the one member is molded with resin, and the material of the one member can be reduced. may be made of any thermoplastic resin, and also has the effect that molding of one member is easy.

In addition, the temporary fixing force of both members is determined by the difference in diameter between the large-diameter protrusion of one member and the stepped part of the other member, that is, the height of the protrusion of the large-diameter protrusion. By setting it appropriately, it becomes possible to apply it to welding of cylindrical members having a relatively large diameter and also to welding of resinous cylindrical members having high rigidity. That is, the present invention is not limited by the diameter of the cylindrical member serving as one member or by the rigidity of the resin material, and the range of cylindrical members to which it can be applied is extremely wide.

[Brief explanation of the drawing]

1 to 3 show an embodiment according to the present invention, in which FIG. 1 is a sectional view of one member to be welded, FIG. 2 is an enlarged sectional view of section D in FIG. 1, and FIG. It is a sectional view of the other member to be welded. 19... One member, 20... Other member, 21... Step portion, 22... Step portion, 23
・・・・・・Large diameter protrusion.

Claims (1)

[Claims] 1. The step formed on the outer peripheral surface of one resin member is
In a method of ultrasonically welding both members by fitting into a stepped portion formed on the inner circumferential surface of the other resin member, maintaining equal intervals on the circumference on the outer circumferential edge of the stepped portion of the one member. arranging a plurality of large-diameter protrusions formed in the stepped portion of the other member, the diameter of which is smaller than the large-diameter protrusions and larger than the stepped portion of the one member; By fitting the one member into the stepped portion of the other member using the large diameter protrusion of the one member as a guide, the large diameter protrusion is forcibly biased radially inward by the stepped portion of the other member. a step of generating a frictional force therebetween so as to temporarily fasten the two members; A method for ultrasonic welding two members, the method comprising the step of ultrasonically welding the two members together using a welding portion that is formed to protrude in the radial direction and has a diameter dimension of.