JP2011148212A - Press-fitting method and press-fitting apparatus to synthetic resin molding of nut - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that a variation occurs in a press-fitting state in press-fitting work of a nut into an insert hole of a synthetic resin molding. <P>SOLUTION: In a press-fitting method to the synthetic resin molding, an energization is carried out between pinching members through the nut or an energization is carried out per each pinching member not through the nut while holding the nut aligned on the insert hole formed on the synthetic resin molding by a pinching member which is a pinching and heating means with a first pressure, by which a temperature of the nut is increased to a first temperature and further, after holding of the temperature for first hour, a second pressure is added by a pushing means to press-fit the nut into the insert hole. Thereby, the synthetic resin of the inner wall in the insert hole is buried while melting. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a technique for embedding a nut for fastening or attachment to a synthetic resin molded case part or other synthetic resin member.

  Various methods have been conventionally employed in which a nut is embedded in an insert hole formed in a synthetic resin molded body and a device part is configured using a screw, or a lid, a cover, or the like is fixed. A conventionally employed method for embedding this nut is to heat and soften the insert hole through the nut, and push the nut into a predetermined depth by pressing in that state (for example, Patent Document 1, Patent Document 2).

Patent Document 1 (Japanese Patent Laid-Open No. 62-142632) discloses the following technique.
Using a heating plate (electric heating plate) for placing and heating the nut as an insert, the nut is heated to a predetermined temperature on this heating plate, and a jig (tool) is attached to the heated nut. The holding part fixed to the tip of the rotating shaft is screwed and taken out. Next, the heating nut is pressed into the insert hole of the synthetic resin molding (work) while being rotated by the rotating shaft of the jig, and the surrounding synthetic resin is buried while being softened by the amount of heat retained.

On the other hand, Patent Document 2 (Japanese Patent Laid-Open No. 11-325029) describes the following technique.
It has hitherto been performed to press-fit a knurled metal screw, which is a fastening metal member using ultrasonic vibration and has a grid-like groove formed on its outer periphery, into a resin component. The frictional heat is generated between the resin component and the metal screw by the ultrasonic vibration, the resin component is melted, and the metal screw is press-fitted into the resin component while the molten resin is filled in the groove of the metal screw.

Japanese Patent Laid-Open No. 62-142632 JP 11-325029 A (Prior Art)

However, each of these technologies has a problem that the press-fit state of the nut varies from the following points.
According to the technique disclosed in Patent Document 1, a heating plate (electric heating plate) must be prepared. Although it takes time to take out from the heated plate and press-fit, it is impossible to press-fit at a constant temperature because there is a variation in this time.

  According to the technique described in Patent Document 2, since it is frictional heat generated by ultrasonic vibration, accurate temperature reproducibility cannot be obtained, so press-fitting at a constant temperature cannot be performed. Furthermore, the contact state on the contact surface to which the ultrasonic vibration is applied is not constant every time of press-fitting.

  The present invention has been made to solve the above-mentioned problems, and has as its first object to provide a method for press-fitting a nut into an insert hole of a synthetic resin molded body with good temperature reproducibility and uniform pressure. It is a second object of the present invention to provide a press-fitting device that can realize this press-fitting method.

  The method of press-fitting a nut into the synthetic resin molded body according to the invention of claim 1 is the first pressure by the clamping member of the heating means for clamping the nut positioned on the insert hole formed in the synthetic resin molded body. The nut is heated to the first temperature by energizing each of the clamping members without passing through the nut, while energizing between the clamping members while holding the After holding the temperature for a first time, a second pressure is applied by a pushing means, and the nut is pressed into the insert hole to embed the synthetic resin on the inner wall of the insert hole while melting. It is.

  A method for press-fitting a nut into a synthetic resin molded body according to a second aspect of the invention is characterized in that the clamping member according to the first aspect is heated and held at a second temperature before the nut is clamped. is there.

  The method of press-fitting a nut into a synthetic resin molded body according to a third aspect of the present invention is the method of pressing the nut into the insert hole by the pushing means by the holding force of the nut by the holding member according to claim 1 or 2. When it is, it is set as the 3rd pressure.

  A press-fitting device into an insert hole formed in a synthetic resin molded body of a nut according to a fourth aspect of the present invention clamps the nut from the direction orthogonal to the press-fitting direction with first and third pressures; Holding and heating to the first temperature while holding the nut through or without the nut; holding and heating means to raise and hold the second temperature before holding the nut; And a pushing means for pushing into the insert hole with a second pressure from the upper part in the press-fitting direction.

  An apparatus for press-fitting a nut into a synthetic resin molded body according to a fifth aspect of the invention is characterized in that the heating means according to the fourth aspect is a pulse heat power source.

  An apparatus for press-fitting a nut into a synthetic resin molded body according to a sixth aspect of the invention is characterized in that the heating means according to the fourth aspect is a resistance welding power source.

  According to the first to third aspects of the present invention, the nuts are reproducible because the energization is performed while clamping the nut on the insert hole by the clamping / heating means, and the heating is controlled to reach a predetermined temperature. Therefore, it is possible to provide a method for press-fitting a nut into a synthetic resin molded body with little variation.

  In particular, according to the invention according to claim 3, since the nut is heated to a predetermined temperature in advance before clamping the nut, the temperature rise of the nut quickly reaches the predetermined temperature. Can be provided.

  According to the invention which concerns on Claims 4-6, the press injection apparatus to the synthetic resin molding of a nut suitable for the press injection method of said nut can be provided.

It is a schematic block diagram of the press injection apparatus to the synthetic resin molding of the nut which becomes this invention. It is a schematic flowchart figure of the press injection method to the synthetic resin molding of the nut which becomes this invention. It is a general | schematic timing chart figure of the press injection method to the synthetic resin molding of the nut which becomes this invention.

Next, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic configuration diagram of an apparatus for press-fitting a nut into a synthetic resin molded body according to the present invention, FIG. 2 is a schematic flowchart diagram of a method for press-fitting a nut into a synthetic resin molded body according to the present invention, and FIG. It is a general | schematic timing chart figure of the press injection method to the synthetic resin molding of the nut which becomes.

  The present embodiment described below does not unduly limit the contents of the present invention described in the claims, and all the configurations described in the present embodiment are indispensable as means for solving the present invention. Not always.

(Example: Example using a pulse heat power source)
In FIG. 1, reference numeral 1 denotes a nut in which grooves are formed on the outer periphery to be press-fitted into an insert hole 2 a to be described later, 2 is a synthetic resin molded body having an insert hole 2 a, and 3 is a synthetic resin molded body 2. The belt conveyor 4 conveys the synthetic resin molded body 2 in the process of press-fitting the nut 1 into the insert hole 2a of the synthetic resin molded body 2. The belt conveyor 4 controls the operation of the belt conveyor 3 according to the press-fitting process of the nut 1 into the insert hole 2a. It is a conveyance control part.

  Reference numeral 5 denotes a suction nozzle that sucks one nut at a time from a nut collecting portion (not shown) and conveys the nut 1 to the position immediately above the insert hole 2a. Reference numeral 6 denotes a suction nozzle that controls the suction and conveyance of the nut 1 by the suction nozzle 5. It is a conveyance control part.

  7 and 9 hold the nut 1 from a surface (for example, left and right as shown in FIG. 1) facing each other with a predetermined pressure, and generate current by passing an electric current. The nut 1 held by the heat is predetermined. Heater tool for heating to a temperature of 8, 8 and 10 are pressurizing / heating control units for controlling the temperature by the clamping force and heat generation of heater tools 7 and 9, respectively, and 11 is a push-feed for pushing the nut 1 into the insert hole 2a. The head 12 is a feed control unit that controls the feed of the push head 11, and 13 is a nut controller that controls the transport control unit 4, the suction transport control unit 6, the pressurization / heating control units 8, 10, and the feed control unit 12. It is the whole control part which controls all the processes of the press injection to a synthetic resin molding.

The heater tools 7 and 9 and the pressurization / heating control units 8 and 10 constitute a sandwiching / heating means, and the heater tools 7 and 9 correspond to sandwiching members. Further, the push control unit 12 and the push head 11 constitute push means.
It should be noted that each of the nuts 1 required for adsorption / conveyance, conveyance of the synthetic resin molded body 2 by the belt conveyor 3, clamping / pressing / heating of the nuts 1 of the heater tools 7, 9 and pushing of the nuts 1 into the insert holes 2a. Since the mechanism and the equipment are not directly related to the gist of the present invention, illustration and explanation are omitted.

Next, a method for press-fitting a nut into a synthetic resin molded body according to the present invention will be described in the order of steps with reference to FIGS.
FIG. 3 schematically shows timing, temperature, and pressure, but not absolute values. However, as illustrated, the first temperature 1 is higher than the second temperature 2, and the melting temperature of the synthetic resin molding 2 is higher than the second temperature and lower than the first temperature. The temperature of the nut 1 is higher than the melting temperature of the synthetic resin molding 2 while being pressed into the insert hole 2a. The first pressure 1 is higher than the third pressure 3.
Note that all control is performed under the control of the overall control unit 13, but the explanation is complicated and will be omitted.

First, as a parameter from the operation unit separately provided in the overall control unit 13, the second temperature that becomes the idle temperature of the heater tools 7, 9 according to the material, shape, etc. of the nut 1, the nut 1 with the heater tools 7, 9 The pressure applied to the push head 11 when the nut 1 is press-fitted into the insert hole 2a, the first time 1, which is the pressure applied when heating the first, the first temperature 1, and the first time during which the temperature is maintained. A second pressure 2 and a third pressure, which is a pressure applied to the heater tools 7 and 9 at this time, are set in time series (S201 in FIG. 2, FIG. 3).
In addition, it is preferable to experimentally obtain these temperatures, pressures, and respective required times in advance using nuts or synthetic resin moldings that are actually used.

  Next, the synthetic resin molded body 2 is placed on the belt conveyor 3 using a publicly-known conveying means provided separately (S202 in FIG. 2). Then, the belt conveyor 3 is operated under the control of the conveyance control unit 4, and is conveyed so that the insert hole 2 a of the synthetic resin molded body 2 is directly below the feeding head 11.

  During this time, current is supplied from the pressurization / heating control units 8 and 10 to the heater tools 7 and 9, respectively, the heater tools 7 and 9 themselves generate heat, the heat is fed back, and the currents flow to the heater tools 7 and 9 respectively. The heater tools 7 and 9 are heated to the second temperature 2 by controlling (S203 in FIG. 2, (1) in FIG. 3). The reason why the heater tools 7 and 9 are heated in advance is that when the nut 1 is actually heated, the first temperature 1 is reached quickly and surely.

  Next, under the control of the suction / conveyance control unit 6, the upper part of the nut 1 is sucked from the nut accumulation part (not shown) by using the suction nozzle 5 and lowered directly above the insert hole 2a. For example, the nut 1 is transferred to a position where it is embedded in the insert hole 2a (S204 in FIG. 2). This alignment may be realized by setting a movement amount and a movement direction in advance, and controlling the movement of the suction nozzle by the suction / conveyance control unit 6 according to this, or a separate image alignment mechanism may be provided. It may be realized by controlling the movement of the suction nozzle 5 by the suction / conveyance control unit 6 according to this measurement information while capturing the insert hole 2a as an image and performing image measurement. These methods can also use known techniques.

  Next, the nuts 1 are sandwiched by the heater tools 7 and 9 under the control of the pressurization / heating control units 8 and 10 and pressurized to the first pressure 1 (S205 in FIG. 2, (2) in FIG. 3). . Here, the first pressure 1 is necessary and sufficient to ensure good conduction of the heat of the heater tools 7 and 9 to the nut 1 described later, and does not deform the threaded portion inside the nut 1. Is.

  Thus, when the clamping force of the nut 1 reaches the first pressure, current (this current is larger than the current) is supplied from the pressurization / heating control units 8 and 10 to the heater tools 7 and 9, respectively. The heater tools 7 and 9 themselves further generate heat. Then, this heat is fed back, and the heater tools 7 and 9 are heated to the first temperature 1 by controlling the currents flowing through the heater tools 7 and 9 (S206 in FIG. 2, (3) in FIG. 3). ). Since the first temperature 1 is set in time series, no current flows through the heater tools 7 and 9 when the first time elapses, and thereafter the temperature is lowered by natural cooling.

  The first temperature 1 is the temperature of the heater tools 7 and 9, but the nut 1 reaches a temperature determined according to the material of the synthetic resin molded body 2 in which the insert hole 2a is formed by an experiment before setting the parameters. Since the temperature is calculated, the nut 1 is press-fitted into the insert hole 2a while the temperature of the nut 1 melts the inner wall of the insert hole 2a of the synthetic resin molding 2 after the first time has elapsed after reaching the first temperature 1. Ready to do.

  Under the control of the push control unit 12 after the first time has elapsed, a push force of the second pressure 2 is applied to the push head 11 downward in the figure to start pushing (S207 in FIG. 2, (4 in FIG. 3). )). When this pushing force is detected, the pressurizing / heating control units 8 and 10 reduce the clamping pressure to the third pressure 3 (S208 in FIG. 2, (5) in FIG. 3), and the pushing force of the pushing head 11 makes the nut 1 is smoothly pushed downward.

  In this manner, while the clamping force of the nut 1 between the heater tools 7 and 9 is the third pressure 3, the feeding head 11 continues to be pushed down under the control of the pushing control unit 12, The distance nut 1 is moved (S209 in FIG. 2, (6) in FIG. 3).

  In this manner, the nut 1 heated by the heater tools 7 and 9 advances while melting the inner wall of the insert hole 2a, and is finally buried at a predetermined position.

(Another example: Example using resistance welding power source)
At this time, instead of the heater tools 7 and 9, the welding electrodes 7 and 9 are used, the nut 1 is sandwiched from a facing surface (for example, left and right as shown in FIG. 1) with a predetermined pressure, and the nut 1 is interposed. By passing an electric current through the welding electrode, the nut 1 is heated to be heated to a predetermined temperature. The other points are the same as in the example using the pulse heat power supply except that the temperature raising process of the nut 1 is different.

  Although the present embodiment has been described in detail as described above, it should be readily understood by those skilled in the art that many modifications can be made without departing from the novel matters and effects of the present invention. Accordingly, all such modifications are intended to be included in the scope of the present invention.

  For example, heater tools 7 and 9 that perform pressurization and heating are placed close to the synthetic resin molded body 2, and the nut 1 is sandwiched between them and heated to a predetermined temperature. The side face of the nut 1 can be clamped and transferred to the insert hole 2a, and then the nut 1 can be press-fitted into the insert hole 2a by the push head 11.

  Alternatively, the step of heating to the second temperature 2 in advance can be omitted, and the nut 1 can be heated to the 21st temperature 1 at a stroke after the nut 1 is sandwiched by the first pressure 1.

DESCRIPTION OF SYMBOLS 1 Nut 2 Synthetic resin molding 2a Insert hole 3 Belt conveyor 4 Conveyance control part 5 Adsorption nozzle 6 Adsorption / conveyance control parts 7 and 9 Heater tool (welding electrode)
8, 10 Pressurization / heating control unit 11 Pushing head 12 Pushing control unit 13 Overall control unit

Claims (6)

  Energizing between the clamping members while holding the nut positioned on the insert hole formed in the synthetic resin molded body with the first pressure by the clamping member of the clamping and heating means, or By energizing each of the clamping members without passing through the nut, the nut is heated to a first temperature, and after maintaining this temperature for a first time, a second pressure is applied by the pushing means to A method for press-fitting a nut into a synthetic resin molding, wherein the synthetic resin on the inner wall of the insert hole is buried while being melted by press-fitting the nut into the insert hole.   2. The method for press-fitting a nut into a synthetic resin molded body according to claim 1, wherein the clamping member is heated and held at a second temperature before the nut is clamped.   3. The nut according to claim 1, wherein a clamping force of the nut by the clamping member is a third pressure when the nut is pressed into the insert hole by the pressing means. Press-fitting method to synthetic resin molding. A device for press-fitting into an insert hole formed in a synthetic resin molding of a nut,
Holding the nut from the direction orthogonal to the press-fitting direction with the first and third pressures; holding the nut while raising the temperature to the first temperature with or without the nut; Clamping and heating means for raising the temperature to the second temperature and holding it before clamping;
A device for press-fitting a nut into a synthetic resin molding, comprising: a pushing means for pushing the nut into an insert hole with a second pressure from above in a press-fitting direction.   5. The apparatus for press-fitting a nut into a synthetic resin molding according to claim 4, wherein the heating means is a pulse heat power source.   5. The apparatus for press-fitting a nut into a synthetic resin molding according to claim 4, wherein the heating means is a resistance welding power source.

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