JPH0745183B2 - Friction welding orientation system - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates generally to friction welding systems or rotary welding systems, and more particularly to a friction welding orienting system for accurately orienting and mounting thermoplastic fasteners in substantially the same position relative to a substrate each time. Regarding

[0002]

BACKGROUND OF THE INVENTION Various types of fastener friction welding systems are well known in the art, as evidenced by the following U.S. patents. That is US Pat. No. 2, 470,96
No. 3, No. 3,438,825, No. 3,580,793
No. 4,250,596, 4,477,307
No. 4,551,189, 4,636,124
No. 4,824,304. Friction or rotation welding techniques typically fuse a thermoplastic fastener to a substrate by frictionally heating the interface between the fastener and the substrate by applying rotational and axial forces between the substrate and the fastener. Including doing. As a result, rotation is stopped when a molten state is achieved at the interface of the thermoplastic fastener and the substrate,
On the other hand, the axial force is still maintained for a sufficient time to form an adhesive bond between them.
The thermoplastic fastener may be a stud, post or any other design element that it is desired to be fused to the substrate.

US Pat. No. 4,477,307 (Japanese Patent Publication No. 4-8217) discloses a friction welding fixing system in which a thermoplastic fastener is fused to a work. The system includes a tool that rotates to apply pressure to the fastener and a device that automatically stops the rotation of the fastener and maintains contact pressure between the fastener and the workpiece. A device for automatically stopping rotation has at least one heat sensitive thermoplastic ear located adjacent to the primary fuser surface and at least one protrusion formed on the tool,
Therefore, when the ears are weakened to a predetermined strength by frictional heat, the protrusions cut the ears and stop the rotation of the fastener.

US Pat. No. 4,551,189 discloses a friction welding fastener system that fuses thermoplastic material fasteners to a substrate with frictional heat generated by the application of rotational and axial forces applied to the fasteners. . A cavity is formed inside the bottom surface of the thermoplastic base of this fastener. A heat activated adhesive having an adhesive affinity for both the base and the substrate is inserted into the cavity to form a layer having a thickness equal to or greater than the thickness of the base. The base is rotated with sufficient rotational and axial forces to attach the heat activated adhesive layer to the substrate.

In US Pat. No. 4,824,304 (Japanese Patent Publication No. 3-43052), a rotary welding member made of plastic having a post and a disk-shaped flange integrally attached to one end of the post. Is listed. The flange has a plurality of radially extending ribs formed on one side thereof for flowing cooling air therethrough to dissipate excess heat generated. Therefore, deterioration of the substrate to be friction welded to the flange is prevented.

[0006]

Common major drawback to all of the prior art rotary welding system, regardless of whether or not to use the INVENTION Problems to be Solved] In connection with the thermoplastic fastener heat activated adhesives, every time <br The point is that neither of these systems has a method of providing the correct orientation of the thermoplastic element to the substrate to be welded. For example, as shown in FIGS. 1 and 2, the thermoplastic component has a hook which must be matched at the end of the spin welding operation as facing down direction. This is essential for later use, such as when the hooks are inserted into mating holes, such as when it is useful to attach a molding strip to the exterior of an automobile body.

Accordingly, to provide a friction welding system improved the relative Every time the substrate mounting directing accurately the thermoplastic fastener into place, desirable. It is also advantageous to have the friction welding system increase the frictional characteristics between the fastener and the holding tool to facilitate driving of the fastener.

Accordingly, it is a general object of the present invention to provide an improved friction welding system that overcomes the problems of prior art rotary welding systems.

One object of the present invention is to provide an improved friction welding system and method for accurately orienting and mounting thermoplastic fasteners in position relative to a substrate each time.

[0010]

[MEANS FOR SOLVING THE PROBLEMS] Each time, after a preset number of rotations for accurately orienting and mounting a thermoplastic fastener at a predetermined position with respect to a substrate, it is stopped at the same reference position as the starting position . A friction welding orientation system with a programmable direct current servomotor that is controllable.

A retaining tool operably coupled to the motor for engaging an upper surface of the base of the fastener to increase frictional characteristics between the fastener and the retaining tool, the upper surface of the fastener and the retaining tool of the retaining tool. A friction welding orientation system is provided that is roughened to engage a bottom surface.

Based on these intentions and purposes, the present invention provides
Providing a friction welding orienting system for accurately orienting and mounting thermoplastic fasteners at approximately the same location relative to a substrate each time. The orientation system includes a thermoplastic fastener configured to be fused to the substrate. The fastener is formed of a base and a main fastener integrally molded with the base. The base has a bottom surface configured to be fused to the substrate by frictional heat generated by the application of rotational and axial forces applied to the fastener. A pressure device is provided to apply an axial force to the fastener. A programmable DC servomotor rotates the fastener relative to the board so that the fastener's main fastener is accurately aligned to the same reference position relative to the board each time after a preset number of rotations of the fastener. It is provided to automatically stop the rotation of the.

These and other objects and advantages of the invention will become more fully apparent from the following detailed description when read with reference to the accompanying drawings, wherein like reference numerals designate corresponding parts throughout.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIGS. 5 and 6 show a friction welding orientation system 10 constructed in accordance with the principles of the present invention. The friction welding system includes the use of thermoplastic fasteners 12, which may have a structure as shown in FIGS. The friction welding system 10 is used to attach and orient the thermoplastic fasteners 12 in substantially the same position relative to the substrate each time.

The thermoplastic fastener 12 is a disk-shaped base 1
4 and a main fastener defined by a hook 16 formed integrally with the base. The base 14 has a top surface or front surface 18 and a bottom surface or rear surface 20. The base 14 is arranged adjacent to its peripheral edge,
It has a plurality of holes 22 extending from the top surface 18 to the bottom surface 20.

[0016] At the center portion of the bottom surface 20, the ring-shaped projection fastener first contacts the surface of the substrate to be welded 24
Preferably the Ru provided. To separate the bottom the projection 2 4 are initially brought into contact with the surface of the substrate from the substrate, helps to maintain low starting torque. Therefore, it is heat accumulation in the center of the projection 24 initially welding, gradually dissolving the thermoplastic material so as to weld between the bottom surface 20 and the surface of the substrate of the fastener
In that to form. Then, the thermal melting gradually progresses toward the peripheral edge of the fastener.

[0017] The ho Isuzu central portion of the base 1 4 of the upper surface 18, the hook 16 and ending with the protruding end 26 downwardly has a stem 17 are integrally formed. In order for the protruding end 26 to perform its intended function, it is generally necessary to orient and attach the fastener 12 to the substrate each time in a predetermined position. As pointed out earlier, the fastener hooks 16 are preferably aligned at the end of the rotary welding operation so that the protruding ends 26 face downwards. For example, the protruding end 26 may then need to be insertable into a cooperating hole in the molding strip piece to retain the molding strip.

The thermoplastic fastener 12 is preferably integrally molded of a thermoplastic material. Further, the fastener may be manufactured by any conventional method, such as by insert injection molding. The described fasteners may occupy a variety of shapes and sizes for convenience of illustration only. Further, the fastener may be a stud, post or any other concept element that is desired to be fused to the substrate by friction welding.

Referring to FIG. 4, four thermoplastic fasteners 12a-12d are all accurately oriented and mounted to the substrate 28 in the same manner each time by using the friction welding orientation system of the present invention. An example is shown. It is particularly noted that each of the protruding ends 26 of the respective fasteners 12a-12d face downwards in the same manner. next,
This like projecting end 26 of the can may be accommodated in an opening of the workpiece to be aligned to correspond so as to perform the intended action, such as is it.

As shown in FIGS. 5 and 6, the friction welding orienting system 10 is precisely designed to automatically stop at the same position as its starting point or at the reference position immediately after it has rotated all the preset number of rotations. Precise position, such as a stepping motor or programmable DC servo motor, which can be controlled in parallel
It has determined Me motor 30. In other words, the motor may be positioned with respect to a limited zero reference position after traveling a predetermined distance (ie 10,000 motor steps equal to one revolution). Positioning motor 30 is preferably part number CPL57-120, CPL83-1.
50, CPH83-150 and CPH106-210, sold by Parker Hannifin, Inc.
Hannifin Corp. ) Compumotor (C
This is the type that is commercially available from the office.

FIG. 10 shows an operation diagram of the positioning motor 30 having a trapezoidal shape so as to stop the fastener in an accurate predetermined direction. As can be seen, the positioning motor has a very rapid acceleration time ta where the speed is increased from zero to maximum speed, ie 3600 rpm. The rate is then maintained at a constant rate for a time tc sufficient to melt the thermoplastic material.

The positioning motor is programmed to have a deceleration time td which occurs after the time tc is complete. In this way, the motor is decelerated for a short period of time prior to stopping, at which time the speed is reduced very quickly from maximum speed to zero. Deceleration time t
By controlling d, the fastener can be stopped in the correct direction after melting of the thermoplastic material at the interface with the substrate.

To this end, a thumbwheel switch 31 (FIG. 5) used to preset the total number of desired revolutions that the motor 30 should make .
Is provided. Of course, the total number of revolutions is selected to frictionally heat the bottom surface 20 of the fastener 12 to sufficiently form a pool of molten thermoplastic material between the fastener 12 and the substrate 28. The number of rotations to obtain this melting interface must be determined by experimentation, and the material of the fastener,
It depends on various factors such as the material of the substrate, the size and shape of the interface, the amount of contact pressure, the rotational speed of the motor and many other indeterminate factors.

Positioning motor 30 includes a shaft 32 (FIG. 6) having a free end that is coupled to one end of a chuck (not shown ).
Is equipped with. The other end of the chuck, the first end portion 33 of the holding tool 34 is configured as you binding (Figure 7). The second end portion 35 of the holding tool 34 is engageable with the upper surface of the fastener parts or elements 12a to Ru is welded to the substrate (FIG. 4). The holding tool is used to initially install the fastener in the starting reference position for the substrate. The substrate 28 is
Below the holding tool, it is supported on a locator 36, which is above the bottom frame 38 (FIGS. 5 and 6) .

The pneumatic or hydraulic cylinder 40 is attached to the substrate 2
8 presses the projection 24 of the fastener 12a toward the upper surface of the fastener 8 (shown in the direction of arrow 42 in FIG. 6).
And a holding tool 34 for holding the fastener portion 12a attached to the substrate are provided for reciprocating movement. The typical pressure applied depends on a variety of factors such as fastener size and shape, about 6.80 to 68.04 kg (15
~ 150 lb) load range. When the pressure reaches a predetermined amount, the motor turns on the push button switch 43 (Fig. 5).
It is activated by pressing. The motor is driven at high speed (ie about 3600) to reach a total number of preset speeds such as those set by thumbwheel switch 31.
After being rapidly rotated at (rpm), it is automatically stopped at exactly the same position with respect to the starting reference position (that is, the zero reference position). In actual experience, the time required to fuse the fastener and the substrate together was about 2-3 seconds.

In this way, the protruding end 26 of the hook 16 is
Are always accurately aligned with the desired position relative to the substrate 28 to provide the structure shown in FIG.
This desired orientation of fasteners causes the molten plastic to cool and harden, thereby fusing the fasteners to the substrate. Finally, the cylinder 40 is
The holding tool is retracted, leaving the fastener 12a welded to No. 8. Next, these operations are performed by the fasteners 12b to 12b.
It can be repeated continuously for d (FIG. 4) so that all protruding ends 26 of the fasteners show aligned rows in the same direction relative to the substrate 28.

7 and 8 show enlarged views of the holding tool 34 used in the friction welding orientation system of the present invention. As shown, the first end 33 of the holding tool is configured to be housed in a chuck (not shown) and the second end 35 of the tool is configured.
Are configured to engage the top surface of the fastener. The holding tool comprises a stem 17 of the fastener to be welded (Fig.
3 ) It has an internal recess 44 having a contour that is generally designed to fit the contour. The lower drive surface of the holding tool is designed to facilitate the drive of the fastener in order to overcome the friction existing between the fastener and the substrate and increase the frictional characteristics between the holding tool and the fastener to be welded. Rough surface 4
There are six. The roughened surface 46 can be made in any suitable manner, such as by sandblasting, crossing parallel lines or knurling. This roughened surface 46 also helps distribute the torque substantially across the entire top surface of the fastener, thus reducing the torque about the stem 17 in the middle of the fastener.

The upper surface 18 of the fastener 12 may be roughened 18a to further increase the necessary mutual frictional relationship between the holding tool and the fastener as shown in FIG. Board 28
If, allowed to flow into the molten plastic during the spin welding process to form a mechanical stud 48 so as to enhance the fusion together with the base 14 of the fastener 12 (shown in part 2 Tsugazu 9) into the hole 22 of the base 14 May be. Figure 9
The mechanical stud 48 is then provided with a hole 22 so that the fastener 12 to be welded to the substrate 28 is easily permanently secured.
Is formed in. In FIG. 5, 49 is an air coil.
The connector 50 is a power cord.

Thus, from the foregoing detailed description, it will be appreciated that the present invention provides an improved friction welding system for accurately orienting and mounting thermoplastic fasteners in substantially the same position relative to the substrate each time. The orientation system rotates the fastener relative to the substrate with thermoplastic fasteners configured to fuse like the substrate so that the fastener is accurately aligned with the substrate in the same reference position each time. And a programmable DC servomotor that automatically stops the rotation of the fastener after a predetermined number of rotations.

While the preferred embodiment of the invention has been illustrated and described, it will be understood that various changes and modifications may be made without departing from the true scope of the invention and equivalents of the elements of the invention may be substituted. Recognized by those skilled in the art. Furthermore,
Many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the scope of the invention. Therefore, the present invention is not limited to the particular embodiments disclosed as the best mode contemplated for carrying out the invention, and the invention covers all embodiments falling within the scope of the appended claims. It is a thing.

[0031]

As described above, according to the present invention, it is possible to accurately orient and install the thermoplastic fastener at a predetermined position with respect to the substrate each time, and at the same time, the friction characteristic between the fastener and the holding tool is improved. , The work efficiency is remarkably improved. Further, since the plastic melted by frictional heat enters the holes of the fastener to form the mechanical stud, the welding strength of the fastener is further improved.

[Brief description of drawings]

1 is a perspective view of a thermoplastic fastener for use in connection with the friction welding orientation system of the present invention. FIG.

2 is a front elevational view of the fastener of FIG. 1. FIG.

3 is a cross-sectional view of the fastener taken along line 3-3 of FIG.

FIG. 4 is a perspective view showing a plurality of thermoplastic fasteners each fused in the same direction to a substrate by using the friction welding system of the present invention.

FIG. 5 is a side view of a friction welding orientation system constructed in accordance with the principles of the present invention.

6 is a left side view of the friction welding orientation system of FIG. 5; FIG.

7 is a front view of a partial cross section of a holding tool used in the friction welding system of FIG.

8 is a bottom view of the holding tool of FIG. 7. FIG.

9 is a cross-sectional view taken along line 9-9 of FIG. 4 showing mechanical studs coupling fasteners to a substrate.

FIG. 10 is an operating diagram of a positioning motor 30 having a trapezoidal shape to produce the correct orientation of the fastener.

[Explanation of symbols]

 10 Friction Welding Orientation System 12 Thermoplastic Fastener 14 Disc-shaped Base 16 Hook (Main Fastener) 18 Top Base (Front) 18a Rough Surface 20a Bottom of Base 20 (Bottom) 22 Base 28 Base 30 Positioning Motor 34 Holding tool 40 Cylinder 46 Rough surface of tool 48 Mechanical stud td Deceleration time

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-59-118427 (JP, A) JP-A-62-41021 (JP, A) JP-A-53-59711 (JP, A) JP-A-63- 28631 (JP, A) JP 58-59035 (JP, A) Actual development 58-39835 (JP, U)

Claims (15)

[Claims] 1. Each time a thermoplastic fastener is attached to a substrate.
In orientation system of friction welding for mounting attach rectangular direction to the thermoplastic fastener in the same direction relative to the substrate, the thermoplastic fastener, et al in addition to the thermoplastic fastener
Frictional heat generated by the addition of rotational force and axial force
A base having a bottom surface fused to the substrate, the thermoplastic with, the predetermined is the reference position with respect to the substrate is constituted by a main fastener molded integrally with said base
A tool device for holding a flexible fastener , and the bottom surface of the thermoplastic fastener through the tool device.
A pressure device that applies the axial force that presses against the substrate, and a rotation speed that is predetermined from the predetermined reference position.
To rotate the tooling device with respect to the board.
Gram-capable, with each revolution a predetermined number of motor
And a motor means including a cup, the thermoplastic fastener being first retained in the tooling device.
To the substrate at the predetermined reference position of
The motor is rotated in the predetermined direction.
After rotation of the number of turns, the tooling device and the thermoplastic fastener
A friction welding orientation system that stops the rotation of the machine . 2. A orientation system of friction welding as claimed in claim 1, wherein the motor means that stops at exit <br/> emitted position and the reference position same after the rotational speed of the predetermined with a program capable of DC servo motor orientation system of friction welding. 3. The friction welding orientation system of claim 2 , wherein the DC servomotor melts the thermoplastic fastener.
An orientation system for friction welding, which later has a predetermined deceleration time . 4. The friction welding orienting system of claim 1 , wherein the tooling device engages a top surface of the base.
And a bottom surface that abuts the thermoplastic fastener of the holding tool,
Friction welding orientation system with rough surface . 5. The friction welding orientation system according to claim 4 , wherein an upper surface of the base that abuts the holding tool is a rough surface.
A friction welding orientation system. 6. The friction welding orientation system of claim 1 , wherein the base has a plurality of holes forming a mechanical stud.
Having a friction welding orientation system. 7. A friction welding orientation system according to claim 1.
In the stem, the friction welding orientation system , wherein the base is disk-shaped . 8. An orientation system for friction welding according to claim 1.
In the stem , the friction weld orientation system, wherein the primary fastener has a hooked portion . 9. An orientation system for friction welding according to claim 1.
In the stem , the friction welding orientation system, wherein the base has an annular protrusion on the bottom surface . 10. Orientation of friction welding according to claim 1
In the system, the motor means is a programmable stepping motor.
Friction welding orientation system , including 11. Orientation of friction welding according to claim 1.
In the system, The motor means rapidly accelerates from a stopped state to a constant speed.
Has an acceleration time, Friction welding orientation system. 12. The method according to claim 12, Orientation of friction welding according to claim 1.
In the system, The pressure device is in front of the tool device and the motor device.
Move towards or away from the board
Including a moving device, Friction welding orientation system. 13. Direction of friction welding according to claim 12
In the The pressure device includes an air cylinder, Friction welding orientation system. 14. Direction of friction welding according to claim 12
In the The pressure device includes a liquid cylinder, Friction welding orientation system. 15. Orientation of friction welding according to claim 1.
In the system, Before adding to the thermoplastic fastener by the pressure device
The axial force is within the range of 6.8kg ~ 68.04kg.
is there, Friction welding orientation system.