JPH0638015Y2 - Thermal expansion absorption structure of guide rail for hot transfer - Google Patents

Description

[Detailed Description of the Invention] [Industrial application] The present invention relates to a thermal expansion absorbing structure of a guide rail for hot transfer, and in particular, reflow soldering applied as a surface mounting method of parts to a preton wiring board. The present invention relates to a thermal expansion absorption structure of a guide rail for hot transfer, which can be suitably used for an endless transfer mechanism for transferring an object to be transferred under a heated atmosphere, such as an adhesive method and an adhesive curing method.

[Prior Art] In recent years, the demand for miniaturization of electronic devices has become more prominent, and in response to such a trend, electronic parts have been replaced by chip parts instead of those with lead wires. Since it has come to be used, and further, in order to increase the mounting density, a planar mounting method as a chip mounting method has been introduced, etc. , The need for efficient bonding has arisen.

In this case, since the electronic component is very small, it is very difficult to mount the electronic component accurately, and a high technique is required. Therefore, a fixing method using viscosity is often used.

As a fixing method using such viscosity, in addition to a method using cream solder, there is a method using a thermosetting adhesive or an ultraviolet curing agent, and when fixing an electronic component to a printed wiring board by such a method, By supplying cream solder, thermosetting adhesive, and ultraviolet curing agent material to the necessary places on the printed wiring circuit conductor in advance, fixing the electronic parts through this, and applying fixing treatment such as heating. Done.

The fixing process at this time is carried in by carrying out the printed wiring board having the electronic components fixed by the above method in a heating atmosphere such as a reflow furnace or an adhesive curing furnace, and fusing under heating by a heat source provided in the furnace, or It is carried out by irradiating with ultraviolet rays and then carrying it out of the furnace.

FIG. 2 shows an example of the thermal expansion absorption structure of the guide rail for hot transfer which has been already proposed by the applicant as Japanese Patent Application No. 63-138449, and FIG. 3 shows this thermal expansion absorption structure. It is a top view which shows the outline of the whole structure when a structure is applied to the reflow apparatus for printed wiring boards.

That is, according to FIG. 3, the apparatus main body F has an operation panel P on the front surface of which various switches S for operation are arranged, and is placed on a pair of endless conveying means 42, 42 including, for example, a chain conveyor. The carried object 41, for example, the printed wiring board, is carried into the heating space defined by the lid 43 and is formed so that the carrying out can be carried out after the predetermined soldering process is completed. Has been done. The endless conveying means 42 is supported by a pair of guide rails 1 and 1 arranged in the length direction of the apparatus main body F, and the guide rail 1 on one side is operated by a handle 44. The distance between the fixed guide rail 1 on the other side and the distance between the fixed guide rails 1 can be changed and attached.

As shown in FIG. 2, each of the pair of guide rails 1, 1 arranged to support the endless conveying means 42 has a gap t between the abutting end faces via a connecting piece 10.
It is composed of a main guide portion 2 and an auxiliary guide portion 3 which are connected with each other, and the main guide portion 2 is fixed by a screw 14 through an elongated hole 10 provided in the connecting piece 10 in advance. Is supported by the connecting piece 10 so that it can move freely, and is connected to the auxiliary guide portion 3.

[Problems to be Solved by the Invention] By the way, according to the guide rail 1 having the above structure,
The main guide portion 2 and the auxiliary guide portion 3 are limited to the gap t.
However, even when it is exposed to heat and stretched in its length direction, this expansion can be well absorbed, and a pair of guide rails 1 arranged in parallel are arranged. , 1 can be prevented from being distorted such that they become wavy in the left-right direction or the vertical direction, respectively, and the conveyed object 41 such as a printed wiring board is dropped from the endless conveying means 42 or caught in the middle. It is possible to eliminate inconveniences such as breakage due to damage and smooth transport.

However, when the transported object 41 is a printed wiring board, since cream solder, a thermosetting adhesive, or the like is used to fix the electronic component, with the passage of time,
In addition to rosin and resin used for cream solder,
It is unavoidable that a fixed component such as a thermosetting adhesive or an ultraviolet curing agent is attached and accumulated on the guide rail 1.

As a matter of course, such a fixed component also adheres to the long hole 12 portion of the connecting piece 10, clogging the long hole 12 and hindering smooth movement of the main guide portion 2. This may cause a fear that a separate manual work is required to remove it, which is one of the causes of lowering work efficiency.

The present invention has been made in view of the above-mentioned inconvenience in the proposal relating to Japanese Patent Application No. 63-138449 by the present applicant,
It is an object of the present invention to provide a thermal expansion absorbing structure for a guide rail for hot transfer, which can improve work efficiency by forcibly excluding adherence of fixed components to a floating portion of the guide rail. .

[Means for Solving the Problems] The present invention has been made to solve the above problems, and its structural feature is that each of the pair of guide rails arranged to support the endless conveying means is , A main guide portion and an auxiliary guide portion that are connected to each other through the connecting piece and with a gap between the abutting end surfaces, and the main guide portion passes through a long hole provided in advance in the connecting piece. By that,
A thermal expansion absorbing structure for a guide rail for hot transfer, which is movably supported by the connecting piece, wherein the main guide portion is movably connected to the elongated hole of the connecting piece. Is to dispose an air injection mechanism having nozzles whose ejection ports are opposed to each other so that air can be blown from the exposed surface side.

[Operation] Therefore, by adhering air to the elongated hole of the connecting piece from the injection port of the nozzle, the adhered component can be blown off, and the main guide portion can always move freely through the elongated hole. It can be secured stably.

Embodiment An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is an enlarged perspective view of an essential part showing an embodiment of a thermal expansion absorbing structure of a guide rail for hot transfer according to the present invention.

That is, each of the pair of guide rails 1, 1 having a predetermined width and arranged in parallel at equal intervals has a required length,
A main guide portion 2 formed of a metal material such as an aluminum material, and an auxiliary member having a length shorter than the main guide portion 2 and formed of a metal material such as a stainless material. The guide unit 3 is divided into two parts, and inside the main guide part 2 and the auxiliary guide part 3, there is substantially U to guide the endless conveying means 42 such as a chain conveyor shown in FIG. A groove portion 4 having a letter shape is arranged.

Further, the main guide portion 2 and the auxiliary guide portion 3 which form the pair of guide rails 1 and 1 are separated from each other by the length of a predetermined gap t between the butt end surfaces 5 and 6. The holding part with the connecting piece 10 located on the upper side under
They are screwed together via 11 and connected to each other.

In this case, the attachment structure of the connecting piece 10 to the main guide portion 2 is such that a collar or the like is inserted through one or more long holes 12 formed in the holding portion 11 of the connecting piece 10 in the length direction. This is performed by tightening a screw 14 having a mounting material 15 interposed in a screw hole 7 provided on the main guide portion 2 side so as to allow the main guide portion 2 to move freely.

Further, the attachment structure of the connecting piece 10 to the auxiliary guide portion 3 is not only by welding means, but also a through hole is formed in the holding portion 11 of the connecting piece 10, and the auxiliary guide portion 3 is inserted through this through hole.
Alternatively, it can be carried out by tightening a screw into the screw hole on the side of.

On the other hand, with respect to the elongated hole 12 of the connecting piece 10 to which the main guide portion 2 is movably connected, the ejection port 18 is arranged face-to-face so that air can be blown from the side of the exposed surface thereof. An air spraying mechanism 16 having a nozzle 17 is provided.

That is, the air blowing mechanism 16 is used in the guide rail 1
And a cover body 19 attached via the side wall portion 20 of the cover body 19, and a branch for branching and supplying the air sent from the compressor (not shown) through the air supply pipe 21. Connector 22 and this branch connector 22
Nozzle connected to the pipe end of the branch pipe 23 branched via
It has 17 and.

Of these, the cover body 19 is a long hole 12 in the connecting piece 10.
The cover main body 24 formed to have a volume sufficient to sufficiently cover the portion, the mounting portion 25 mounted on the upper surface of the guide rail 1, and the side of the auxiliary guide portion 3 in the guide rail 1. Are integrally formed with fixing portions 26 and 27 for separately fixing the upper surface and the outer surface of the cover body to the outer edge portions of the fixing portions 26 and 27, respectively. A U-shaped cutout 28 is provided along the length direction of the guide rail 1 so that the attachment / detachment 19 can be fixed easily.

On the other hand, positioning pieces 30 and 31 are fixedly provided in advance on the respective portions of the auxiliary guide portion 3 that face the fixing portions 26 and 27 of the cover portion 19. The screw 32 is tightened and screwed through the cutout portion 28 of the fixing portion 26, 27 into the screw hole formed through each of the facing portions of the portion 3, so that a correct positional relationship can be obtained. The cover portion 19 can be fixed to the guide rail 1.

Further, from the branch connector 22 fixed to the cover body portion 24, branch pipes 23 having a variable number corresponding to the number of the long holes 12 provided in the connecting piece 10 are arranged, and each pipe end has a branch pipe 23. ,
A nozzle 17 having one or more ejection ports 18 and arranged so as to allow the ejection ports 18 to face the elongated hole 12 is connected. Moreover, these nozzles 17 are
The fixed state is secured by the supporting and fixing portions 29 provided on the inner wall surface of 24 at appropriate positions, so that they are supported.

The air that is pressure-fed through the air supply pipe 21 can be switched between normal temperature air and hot air depending on the type of the transported object 41 or the type of electronic component and can be supplied. When the printed circuit board on which the thermionic components are mounted is the object to be transported 41, the temperature distribution condition such as soldering of the mounting board is adversely affected by cooling the room temperature air and the guide rail 1 for quality protection. Hot air can be supplied when there is a risk of causing.

Further, in the above-mentioned embodiment of the present invention, the case where the invention is applied to the carrying mechanism having the endless carrying means in the reflow soldering apparatus for the printed wiring board is explained as an example, but the carrying is carried through the endless carrying means. The object to be conveyed is not limited to the printed wiring board described above, and may be applied to any kind as long as it needs to be conveyed while hot.

Since the present invention is configured as described above, the fixing portions 26, 27 of the cover body 19 are not attached to the guide rail 1.
The air blowing mechanism 16 can be immediately screwed and fixed through the notch 28. Moreover, the attachment of the air blowing mechanism 16 at this time can be performed through the positioning pieces 30 and 31 fixed to the guide rail 1 side, so that the nozzle 17 and the long hole 12 of the connecting piece 10 can be attached. The positional relationship between
It can be always performed in the correct positional relationship without any visual confirmation, and the attachment / detachment work can be performed quickly.

Further, since the elongated hole 12 of the connecting piece 10 can be covered by the cover body 24, the adhesion and accumulation of the fixing component such as rosin, resin, thermosetting adhesive, and ultraviolet curing agent should be minimized. Not only can it be removed, but even if it adheres, it can be immediately blown off by the air blown from the nozzle 17 and automatically cleaned, and it can be effectively prevented from accumulating. .

Therefore, smooth movement is ensured in the main guide portion 2 through the long hole 12 of the connecting piece 10 which is always kept in a state in which the fixed component does not adhere, and this is effectively absorbed against thermal expansion. be able to.

Therefore, the operation is stopped and the adhered components are removed from the long holes of the connecting piece 10.
Even if it is not necessary to separately perform the work of removing from 12, it is possible to reliably prevent the damage of the conveyed object from falling inside the furnace.

[Advantage of the Invention] As described above, according to the present invention, it is possible to prevent the adhered components, which tend to hinder the smooth movement of the main guide part, from adhering to and accumulating in the long holes, and to remove them after the adhering Since it is possible to automatically perform the operation, it is possible to reliably absorb the thermal expansion of the guide rail that is generated hot while eliminating the need to stop the operation and remove the adhered components. It is possible to prevent the drop damage from occurring in advance, and further improve the work efficiency.

[Brief description of drawings]

FIG. 1 is an enlarged perspective view of an essential part showing an embodiment of a thermal expansion absorbing structure of a guide rail for hot transfer according to the present invention. FIG. 2 is an overall perspective view showing a guide rail structure which the present applicant has already applied for. FIG. 3 is a plan view showing an example of a reflow apparatus to which the present invention is applied. DESCRIPTION OF SYMBOLS 1 ... Guide rail, 2 ... Main guide part, 3 ... Auxiliary guide part, 4 ... Groove part, 5,6 ... Butt end surface, 7 ... Screw hole, 10 ... Connecting piece, 11 ... Holding part, 12 ... Long hole, 14 ... Screws, 15 ... Interposer material, 16 ... Air blowing mechanism, 17 ... Nozzle, 18 ... Jet port, 19 ... Cover body, 20 ... Side wall part, 21 ... Air supply pipe, 22 ... Branch connector, 23 ... Branch pipe, 24 … Cover main body, 25… Mounting part, 26,27… Fixing part, 28… Notch part, 29… Support fixing part, 30,31… Positioning piece, 32… Screw

Claims (1)

[Scope of utility model registration request] 1. A pair of guide rails arranged to support the endless conveying means, each of which is connected via a connecting piece and with a gap between the abutting end surfaces and an auxiliary guide. The main guide portion is provided with a main guide portion through a long hole which is provided in advance in the connecting piece to absorb the thermal expansion of the guide rail for hot transfer which is supported by the connecting piece so that the guide piece is allowed to move freely. In the structure, a nozzle having ejection ports arranged to face the elongated hole of the connecting piece to which the main guide portion is movably connected so that air can be blown from the side of the exposed surface thereof. A thermal expansion absorbing structure for a guide rail for hot transfer, characterized in that an air blowing mechanism having the above is provided.