JP4293100B2 - Solder coating apparatus and solder coating method - Google Patents

Description

  The present invention relates to a solder coating apparatus and a solder coating method for joining metal members together by soldering or brazing. More specifically, the present invention relates to a solder application apparatus and a solder application method for applying solder to a joint surface of an aluminum alloy member.

  In a metal member made of an aluminum alloy, since a strong passive film of aluminum oxide is formed on the surface thereof, general soldering is difficult as it is. In contrast, a solder coating method using ultrasonic vibration has been devised. In this technology, the diaphragm is immersed in the molten solder shallowly, or the molten solder is scooped with the diaphragm so that the molten solder is thinly placed on the diaphragm. Then, the joining surface of the aluminum alloy member is placed thereon, and the diaphragm is vibrated by an ultrasonic horn or the like. By doing so, it is possible to cause cavitation in the solder liquid by the vibration of the vibration plate, break the oxide film, and apply the solder material to the joint surface. In the present specification, unless otherwise required, solder and solder are not distinguished from each other and are collectively referred to as solder.

In such an aluminum alloy member joining method, various devices have been devised for forming a more appropriate solder layer on the joining surface (see, for example, Patent Document 1). In the method described in this document, a protrusion is formed at a position of the diaphragm that abuts against the central portion of the joint surface. As a result, the central part of the joint surface is eroded from other parts, so that solder can be accumulated in that part and the joint strength is improved.
Japanese Patent Laid-Open No. 2001-225163 (page 3-4, FIG. 4)

  However, in the above-described conventional solder application method, a recess due to erosion is formed at the center of the joint surface of the members to be joined. Therefore, while the solder material can be collected reliably, a gap is formed between the joint surfaces. For this reason, there was a risk that high contact pressure could not be obtained even if a joint load was applied. In that case, there is a problem that sufficient bonding strength cannot be obtained.

  The present invention has been made to solve the above-described problems of the prior art. That is, an object of the present invention is to provide a solder coating apparatus and a solder coating method that can appropriately apply a solder material to the entire bonding surface and obtain high bonding strength.

A solder coating apparatus according to the present invention, which has been made for the purpose of solving this problem, is a solder coating apparatus that forms a solder layer on a target surface of an object, and heats a bathtub containing molten solder and solder in the bathtub. A heating device, a vibrating member that is partially immersed in the molten solder in the bathtub, and the portion immersed in the molten solder faces the target surface of the object, a vibration device that vibrates the vibrating member, the vibrating member, and the target object The moving device repetitively moves the moving direction in at least two directions within a plane parallel to the plate surface of the portion of the vibrating member immersed in the molten solder. By changing to the above, the vibrating member and the object are relatively moved so as to draw a path of a triangular wave shape or a square wave shape.

According to the solder coating apparatus of the present invention, the molten solder is accommodated in the bathtub, and the vibrating member has the portion immersed in the molten solder facing the target surface of the object. In this way, since the vibration member is vibrated by the vibration device, cavitation is caused in the molten solder between the vibration member and the target surface of the target object, and the oxide film on the target surface is destroyed. Therefore, even if the object is an aluminum alloy member, it is possible to apply solder to the object surface. Furthermore, since the moving device is provided, the vibrating member and the object can be moved relatively. In this way, even if the vibration of the vibration member is a standing wave, the mutually facing parts move, so that the solder can be applied almost uniformly over the entire target surface. Further, for example, if the portion of the vibrating member that faces the object is plate-shaped, and the plate surface of the vibrating member and the target surface of the object are both arranged parallel to the liquid level of the molten solder, What is necessary is just to move a vibration member in the plane parallel to a plate surface in the state which fixed the thing. In particular, it is preferable to move the vibration member and the object relatively in a triangular wave shape or a square wave shape by repeatedly changing the direction of the movement in at least two directions within the plane. In this way, the relatively facing parts can be moved without changing the distance between the object and the vibration member. Further, it is possible to eliminate the part where only the knot portion of the standing wave faces. Therefore, the solder material is appropriately applied to the entire joining surface, and the solder coating device can obtain high joining strength.

The solder coating method of the present invention is a solder coating method in which a solder layer is formed on the target surface of an object, and the target surface of the object and the vibration member are faced in the molten solder to vibrate the vibration member. On the other hand, the vibration member and the object are relatively moved within a plane parallel to the plate surface of the portion of the vibration member immersed in the molten solder, and the direction of movement is repetitively changed in at least two directions to form a triangular wave shape. Alternatively, it is moved so as to draw a square-wave path .

According to the solder coating method of the present invention, even if the vibration state of the vibration member is steady, the facing position between the target surface of the object and the vibration member relatively moves, so that it is suitable for the entire joint surface. Solder material is applied to the surface, and high bonding strength can be obtained. Furthermore, if the movement direction is repetitively changed in at least two directions and moved to a triangular wave shape or a square wave shape , the solder material is applied almost uniformly to the entire joint surface.

  According to the solder coating apparatus and the solder coating method of the present invention, a solder material is appropriately applied to the entire bonding surface, and high bonding strength can be obtained.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the best mode for embodying the present invention will be described in detail with reference to the accompanying drawings. In the present embodiment, the joining method of the present invention is applied to a solder coating apparatus that coats solder on the joining surfaces in order to join metal members such as aluminum alloys.

  As shown in FIG. 1, the solder coating apparatus 1 according to the present embodiment includes a solder melting tank 11 and a heater 12 for keeping the inside of the solder melting tank 11 at a high temperature. Solder 13 is accommodated in the solder melting tank 11. The vibration plate 14 is a metal plate such as SUS bent in a staircase shape, and its lower step is immersed in a very shallow position of the solder 13. An ultrasonic horn 16 connected to an ultrasonic oscillator 15 is attached to the upper stage of the diaphragm 14.

  Further, as shown in FIGS. 1 and 2, the upper end portion of the ultrasonic horn 16 is held by a robot hand 17. A buffer material 18 is sandwiched between the robot hand 17 and the ultrasonic horn 16 so that the natural frequency of the diaphragm is constant. The robot hand 17 is attached to a general industrial robot 30 and can be moved three-dimensionally.

  The workpiece 21 to which the solder is applied by the solder applying apparatus 1 is a metal member such as an aluminum alloy member. As shown in FIG. 1, the workpiece 21 is held horizontally with the joining surface to which the solder is applied immersed in the solder 13 very shallowly. More specifically, the joining surface of the workpiece 21 is disposed on the upper side of the lower step portion of the vibration plate 14 and at a depth position very close to the upper surface of the lower step portion of the vibration plate 14. FIG. 1 shows an example in which two workpieces 21 are penetrated together by two workpiece fixing rods 22 and their joint surfaces are held horizontally. When the workpiece 21 is an aluminum alloy member, it is preferable to use zinc aluminum or zinc aluminum copper solder as the solder 13.

  In this solder coating apparatus 1, the entire vibration plate 14 can be vibrated by driving the ultrasonic oscillator 15 to vibrate the ultrasonic horn 16. As a result of analyzing the state of vibration at each part of the diaphragm 14, it was found that the vibration was a standing wave vibration in which peaks and valleys (black circles in the figure) having a large amplitude were arranged in a lattice shape as shown in FIG. Furthermore, a knot portion (white circle in the figure) having a very small amplitude is arranged between them. For example, in the AA cross section of FIG. 3, as shown in FIG. 4, five mountain valleys (P1 to P5) and four nodes (Q1 to Q4) are formed. Note that FIG. 3 shows an example of the vibration mode of the diaphragm 14. The actual vibration mode differs depending on various factors such as the shape of the diaphragm 14. For example, it may be a hexagonal arrangement.

  Next, a solder coating method using the solder coating apparatus 1 will be described. In this solder coating apparatus 1, first, solder 13 is placed in a solder melting tank 11 and heated by a heater 12. The inside of the solder melting tank 11 is kept at the melting point of the solder 13 + 20 ° C. In general, the solder 13 having a high melting point is sometimes referred to as brazing and the solder having a low melting point is referred to as soldering. However, the solder coating apparatus 1 can be applied to any of them.

  Next, the work 21 is held at a predetermined position by the work fixing rod 22. At this time, one workpiece 21 may be held, or a plurality of workpieces 21 may be simultaneously used as long as they can be immersed in the solder melting tank 11. Then, the ultrasonic oscillator 15 is driven, and the diaphragm 14 is vibrated by the ultrasonic horn 16. At the same time, the industrial robot 30 is driven to move the robot hand 17. As shown in FIG. 1, this moving path is in a horizontal plane where the lower step portion of the vibration plate 14 is immersed in a very shallow position of the solder 13, and the joint surface of the workpiece 21 and the lower step portion of the vibration plate 14. The distance from the top surface is kept constant.

  At this time, as described above, the vibration of the diaphragm 14 has peaks and valleys and knots, and the positions of the peaks and valleys move together with the diaphragm 14. Here, in the valley portion, the amplitude of the diaphragm 14 is large, and the cavitation energy with respect to the joint surface of the workpiece 21 is large. Therefore, the oxide film is easily broken at the portion of the surface of the work 21 that faces the mountain and valley portions, and the material of the work 21 and the solder 13 are in metal contact. On the other hand, since the amplitude of the vibration plate 14 is small at the joint, the cavitation energy with respect to the joint surface of the work 21 is also small, and the oxide film is hardly broken. For this reason, metal contact does not occur at the knot portion as in the mountain valley portion. That is, the cavitation energy is concentrated in the peaks and valleys by the standing wave vibration of the diaphragm 14, and the oxide film is locally destroyed.

  Here, examples of movement paths of the robot hand 17 are shown in FIGS. In these drawings, the plurality of circles on the diaphragm 14 visually indicate the peaks and valleys of the vibration. As shown in FIG. 3, the mountain and valley portions are regularly arranged in a lattice pattern. Here, FIG. 5 shows a first path M1 for moving the diaphragm 14 in an oblique direction. This path has a triangular wave shape whose amplitude is about the interval between the peaks and valleys and whose wavelength is about twice the interval between the peaks and valleys.

  According to the first route M1, a certain valley portion moves as indicated by a solid line in the figure. The other peaks and valleys move as indicated by broken lines in the figure. For this reason, the mountain valley part will pass through the part which did not correspond to the mountain valley part in the initial arrangement. In particular, the central position of the four mountain valleys corresponds to a knot, and according to this route, the mountain valley passes through that position. That is, there is no portion of the joint surface of the workpiece 21 where only the joint portion faces. Accordingly, the mountain and valley portions pass through many portions of the joint surface of the workpiece 21, and the solder adheres over a wide area.

  FIG. 6 shows a second path M2 that moves the diaphragm 14 in a right angle direction. This path has a square wave shape whose amplitude is equal to or greater than the interval between the peaks and valleys and whose wavelength is about three times the interval between the peaks and valleys. According to the second route M2, a certain valley and valley moves as shown by the solid line in the figure. The other peaks and valleys move as indicated by broken lines in the figure. For this reason, the mountain valley part will pass through the part which did not correspond to the mountain valley part in the initial arrangement. In particular, in the second path M2, the same area of the joint surface of the workpiece 21 passes through a longer distance than the first path M1. As a result, the number of places where the valleys face each other increases, and solder adheres in a wider area. In these paths, the amplitude and wavelength of the path waveform may be changed.

  In order to move the robot hand 17 in this way, the route is stored using the instruction operation panel of the industrial robot 30. Alternatively, it may be stored in the industrial robot 30 directly by teaching. Further, the route may be automatically selected based on the size of the joint surface of the workpiece 21.

  In this solder coating apparatus 1, the vibration plate 14 is moved in a zigzag manner in a horizontal plane, so that each mountain and valley portion of the vibration plate 14 moves relative to the joint surface of the workpiece 21. Here, in the place where the material of the workpiece 21 and the solder 13 once contacted with metal, the metal contact is maintained even if the mountain and valley portions are left. For this reason, metal contact occurs throughout the joint surface of the workpiece 21 due to the movement of the diaphragm 14. As a result, the solder 13 is applied to the entire joint surface of the workpiece 21.

  At this time, the time during which the workpiece 21 and the diaphragm 14 are close to each other varies depending on the moving speed of the diaphragm 14. Therefore, it is preferable that the moving speed of the diaphragm 14 is appropriately set with respect to the width of the diaphragm 14. Further, it is preferable that the moving range of the vibration plate 14 is from a position where the rear end portion of the work 21 and the front end portion of the vibration plate 14 overlap each other until the rear end portion of the vibration plate 14 passes the front end portion of the work 21. . Within that range, the moving direction is changed as described above. In this way, the diaphragm 14 is close to all parts of the joint surface of the workpiece 21 for the same amount of time.

  For example, when the width of the moving plate 14 is about 10 cm, the moving speed is set to 5 to 20 cm / second. If it does in this way, the diaphragm 14 will adjoin each part of the joint surface of the workpiece | work 21 for 1 to 2 seconds. If the proximity time is too long, the joint surface of the workpiece 21 may be eroded, which is not preferable. If the proximity time is too short, the oxide film on the bonding surface of the workpiece 21 may pass through before being completely destroyed, which is not preferable.

  If the solder 13 is applied to the workpiece 21 by the solder application apparatus 1, the vibration plate 14 vibrates in proximity to each small area of the joint surface of the workpiece 21 is almost the same. Further, since the diaphragm 14 is moved in a zigzag manner, the portion of the diaphragm 14 that is close to each small region of the joint surface changes with time. Therefore, only a valley or a knot does not come close to a specific part, and the difference in the application state of the solder 13 by each small area of the joint surface becomes very small.

  The solder coating method using the solder coating apparatus 1 can be applied to the following applications. For example, in joining the cylinder head and the cylinder block, the solder 13 is applied to the joint surfaces of the cylinder head and the cylinder block by the solder applying device 1. Thereafter, both joint surfaces are preheated and pressed together. Or when joining a cylinder liner to a cylinder block, the solder 13 is apply | coated with the solder application | coating apparatus 1 to the joining surface of a cylinder liner. The cylinder liner is preheated, set in a die-casting die, and the cylinder block is cast.

  As described above in detail, according to the solder coating apparatus 1 of the present invention, the diaphragm 14 can be moved in a zigzag while vibrating, so that the adjacent valley portions are connected to each part of the joint surface of the workpiece 21. The position of the knot portion changes. Therefore, the solder 13 can be applied almost uniformly to each part of the joint surface of the workpiece 21. Thereby, the solder material can be appropriately applied to the entire joint surface, and high joint strength can be obtained.

In addition, this form is only a mere illustration and does not limit this invention at all. Therefore, the present invention can naturally be improved and modified in various ways without departing from the gist thereof.
For example, in the above embodiment, the workpiece 21 is held by the workpiece fixing rod 22, but the holding method is not limited to this as long as the joining surface can be held at an appropriate position. For example, it can be held by another robot hand or a suction device.
Further, for example, in the above embodiment, the diaphragm 14 is moved by the robot hand 17, but the diaphragm 14 and the work 21 may be moved relatively. The workpiece 21 may be moved instead of the diaphragm 14.
Further, for example, the movement route is not limited to the above two types, and any movement route may be used as long as the movement direction is changed within a predetermined plane. For example, a curved movement path may be used.

It is a schematic block diagram which shows the solder application | coating apparatus of this form. It is a schematic block diagram which shows the robot which moves a diaphragm. It is explanatory drawing which shows the vibration state of a diaphragm. It is explanatory drawing which shows the vibration state of a diaphragm. It is explanatory drawing which shows the movement path | route of a diaphragm. It is explanatory drawing which shows the movement path | route of a diaphragm.

Explanation of symbols

1 Solder coating device 11 Solder melting tank (bathtub)
12 Heater (heating device)
13 Solder 14 Diaphragm (Vibration member)
15 Ultrasonic oscillator (vibration device)
16 Ultrasonic horn (vibration device)
17 Robot hand (moving device)
21 Workpiece (object)
30 Industrial robot (mobile device)

Claims (2)

In a solder coating apparatus that forms a solder layer on the target surface of an object,
A bathtub containing molten solder;
A heating device for heating the solder in the bathtub;
A vibration member that is partially immersed in the molten solder in the bath and in which the portion immersed in the molten solder faces the target surface of the object;
A vibration device for vibrating the vibration member;
A moving device for relatively moving the vibrating member and the object;
The moving device repetitively changes the direction of movement in at least two directions within a plane parallel to a plate surface of a portion of the vibrating member that is immersed in molten solder. Is moved so as to relatively draw a path of a triangular wave shape or a square wave shape. In a solder coating method for forming a solder layer on the target surface of an object,
The target surface of the target object and the vibrating member face each other in the molten solder,
While vibrating the vibrating member, the moving member is repeatedly moved in at least two directions in a plane parallel to the plate surface of the portion of the vibrating member immersed in the molten solder, relative to the vibrating member. A solder coating method, wherein the solder coating method is moved while drawing a path of a triangular wave shape or a square wave shape while changing.

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