JPS624213B2 - - Google Patents

Description

[Detailed description of the invention]

This discovery is based on the inlet in the air cleaner that cleans the air sent to the engine intake system.
That is, regarding a method of manufacturing an inlet, which is an introduction cylinder member for introducing air to be purified, into the case of an air cleaner, in particular, a pair of resin members to be joined, each having a shape in which a cylinder body is divided into two along the axial direction, is manufactured. , relates to a manufacturing method for integrating the above inlet by friction welding, which is a type of fusion joining. For example, as shown in FIG. 1, an inlet 4 of an air cleaner 2 of a vehicle or the like extends outward from the side of an air cleaner case 6 that houses a filter element, etc., in order to function as an air introduction part of the air cleaner 2. Usually, it is fixed to the case 6 so as to extend. Nowadays, due to the demand for weight reduction, there is a tendency for such air cleaner inlets to be made of synthetic resin, and it is now possible to create the desired inlet by abutting a pair of members to be joined together and joining them together as described above. is being carried out. In that case, various joining methods can be considered for integration, but in particular friction welding, in which the joint surfaces of both parts are pressed against each other and friction is generated, heat is generated and melted to join them, the equipment is simple and the joining cost is low. It is said to be one of the most advantageous joining methods because it is also excellent in productivity and physical properties of the joint. Normally, when this friction welding is employed, a joint is formed on the portions of the pair of welded members that form the inlet that butt against each other, protruding a certain dimension outward from each side and extending along the welding direction. Each flange is provided, and a specified welding jig is used to apply an appropriate pressing force between the joint surfaces of the flanges, allowing them to slide relative to each other in a reciprocating manner, resulting in heat generation and melting of both joint surfaces. , and subsequent solidification forms an integrated cylindrical inlet. By the way, during this welding process, if molten resin is pushed out from the joint of the joint flange to the inside and outside of the inlet due to the extrusion force of the jig, etc., and burrs are formed, the appearance of the product may be impaired or the function may be impaired. In addition, the process of removing burrs is complicated, leading to an increase in manufacturing costs. Therefore, in the joint portion of each of the joint flange portions, burr reservoirs (relief corresponding to the volume of burr) are located on both sides in the width direction facing each other and extend along the longitudinal direction of the flange portions. The molten resin flowing outside and inside the inlet as the friction welding operation progresses is introduced into each of the burr reservoirs, and at the end of the welding operation, the burr reservoirs facing each other are combined. When forming the closed space, a measure is taken to prevent burrs from forming inside or outside the inlet by storing the molten resin in a confined state within the closed space. From the perspective of preventing burrs, this is certainly a sound method. However, when a burr reservoir is provided as described above during the inlet manufacturing process and friction welding is performed, the welded part 8, which includes the joining flange part and its vicinity, is formed on the inside of the inlet 4, as shown in FIG. There is a strong tendency for the phenomenon of protruding inward, in other words, inward curvature (inward curvature), and this has been pointed out as a major problem. This internal warpage is a phenomenon that occurs even if there is no deviation in the width direction of each joint flange, and the reason for this is probably that the welding jig is applied from behind the joint flange as shown by the arrow in Figure 2. Due to the pressure applied, the distribution of surface pressure at the joint is higher on the outside than on the inside of the inlet, creating a gradient in the amount of heat generated and, ultimately, the amount of melting.Furthermore, due to the presence of the burr reservoir (void), It is presumed that this is due to the fact that the vicinity of the joint is easily deformed, which causes a protruding force directed inward of the inlet. In any case, the inward protrusion of the welded part causes various problems in manufacturing the inlet, and the
As shown in the figure, first, it is unavoidable that the dimensional accuracy of the inlet 4, especially the dimensional accuracy in the direction facing the welded part, deteriorates (insufficient dimension). In particular, in the case of a type of air cleaner that allows intake of warm air as well as outside air through a duct provided separately in the inlet, actuating members such as the damper 10 are installed in the inlet 4 in order to switch the air or adjust the mixture ratio. Normally, it is installed internally, but since it is difficult to properly ensure the above-mentioned dimensional accuracy, interference with the inlet 2 may impede the smooth operation of the damper 10, etc., or make the operation itself difficult. Defects are likely to occur. In addition, due to the protrusion of the welded part 8, as shown in Fig. 3, the burr reservoirs located inside the joint parts may not be completely closed even at the end of welding, or they may open once closed. This often occurs, and as a result, the molten resin contained in the burr reservoir may flow inward and form burrs, further aggravating the problem when installing the above-mentioned actuating member or impairing the burr removal process. Sometimes additions were necessary. Furthermore, due to the above-mentioned internal scabbing, normal welding cannot be performed, leading to the problem that the inlet joint strength is insufficient.According to one experiment, even though the maximum load was planned to be 100 kg in the design, 60 kg ~70
It has been reported that the joints of inlet products are separated (broken) under a load of Kg. This is thought to be caused by the generation of burrs, that is, by leakage of the molten resin, which prevents the burr reservoir from being completely filled, and by the fact that the thickness of the fused layer is not uniform. The present invention has been made against the background of the above-mentioned circumstances, and its object is to provide a pair of joined members having a shape in which a cylindrical body is divided into two in the axial direction, as described above. When a resin inlet for an air cleaner is manufactured by integrating the burr reservoir at the joint part of joint flange parts that are butted against each other by friction welding, the welded part protrudes inside the inlet. An object of the present invention is to provide a manufacturing method that can effectively prevent this. In order to achieve this object, the present invention provides a concavo-convex fitting mechanism extending in the joining direction between the joining flange portion and a welding jig that presses the joining flange portion from behind. The friction welding operation can be performed while preventing the welded portion from protruding inwardly into the inlet by the uneven fitting mechanism. By doing the above, even if a protruding force acts on the welded part inward of the inlet, it will be blocked by the above mechanism, so that the welded part will not be forced to protrude inward. It can be prevented. Therefore, the dimensional accuracy of the inlet product in the direction in which the welded parts face each other is ensured, and the molten resin is prevented from flowing out from the burr reservoir located inside the inlet during welding, and a damper etc. is installed inside the inlet. Even when an operating member is provided, its smooth operation is ensured. Furthermore, it has been confirmed that the joint strength of the inlet joints is greatly increased, and although this point has not been theoretically elucidated, the clamping force from the welding jig acts more evenly on the joints. This seems to be because this prevents unevenness in the thickness of the molten resin layer and also prevents the formation of voids in the burr reservoir. Embodiments will be described in more detail below based on drawings showing examples. First, FIGS. 4 to 6 show an example of a resin inlet to which the method of the present invention is applied. The illustrated inlet 20 is a pair of joined members, in this case, an upper member 22, which has a shape in which a predetermined cylindrical body is bisected along a plane parallel to the axial direction.
and the lower member 24 are integrated by friction welding, and are fixed to the air cleaner case 26 in which the over-element etc. are housed at the proximal opening, and directly from the distal opening or from the opening. The air to be purified is indirectly taken in through an introduction hose or the like connected to the section and guided to the case 26. Furthermore, in this example, as is clear from Fig. 5,
A duct 28 is fixed to the middle part of the lower member 24 of the inlet 20, and air heated in the vicinity of the engine is guided to the inlet 20, and a damper 30 that adjusts the amount of introduced heated air is connected to the inlet. 20 so as to be rotatable around an axis perpendicular to the axial direction thereof. Then, the air taken in from the opening at the tip of the inlet 20 and the heated air (warm air) taken in through the damper 30 mix;
Alternatively, by using only one of them, the temperature of the air supplied to the case 26 is adjusted, and the air purified by the case 26 is sent to the intake system of the engine. Combining warm air intake in this way is said to be effective in increasing the combustion efficiency of the engine. Now, the upper member 22 and the lower member 24
are made of a suitable synthetic resin, such as polypropylene, polyamide (nylon), or a combination of them with glass fiber, and are integrally molded by injection molding or the like. Both members 22 and 24, except for their tip portions,
Each of the joint flange parts 32 and 34 having a predetermined width are provided outwardly along both side edges, and are butted against each other at the joint flange parts 32 and 34, and are integrally formed by friction welding as described later. bonded. As is clear from FIG. 7, the parts (joint parts) of the respective joining flange parts 32 and 34 to be joined.
A pair of groove-shaped burr reservoirs 36 and 38 are provided on both sides of the flange portions 36 and 38 in the width direction, respectively, so as to face each other and extend in the longitudinal direction of each flange portion 32 and 34, that is, in the joining direction. ing. In this example, the burr reservoirs 36 and 38 are connected to the rear surface 4 from each joint surface of the joint flange parts 32 and 34.
It is formed toward 0,42, and the burr reservoir 3
The edges of the outer end walls and inner end walls (hereinafter collectively referred to as burr stops) of 6 and 38 come into contact with each other at the end of the welding process, thereby closing the burr reservoirs 36 and 38 that face each other. It happens. Back surfaces 40, 4 of the joining flange portions 32, 34
Rib-shaped protrusions 44 and 46 (also referred to as protrusions) having a rectangular cross-sectional shape are provided on the 2 side, respectively. The protrusions 44 and 46 protrude from the flange back surfaces 40 and 42 at right angles, respectively, and are joined along the tip (outer end) edges of both the flange portions 32 and 34, as shown in FIGS. 4 and 5. It is formed to extend in the direction. In addition, with respect to the burr reservoirs 36 and 38 located on the tip end side of the flange parts 32 and 34, a protrusion 4 is provided almost behind them.
4,46 will be located. Further, in FIG. 7 and the like, only the joint portion on one side of the upper and lower members 22, 24 is shown, but the same applies to the joint portion on the opposite side. On the other hand, as shown in FIG. 8, in the friction welding operation of both the upper and lower members 22, 24,
A set of welding jigs 48 and 50 will be used. The welding jigs 48 and 50 are connected to the joining flange portion 3.
2 and 34 from behind them, in other words, the back 4
0 and 42 from the direction perpendicular to each other,
This creates an appropriate frictional force at the joint.
The welding jigs 48 and 50 have both flange portions 32 and 3 on each of their opposing tip surfaces (squeezing surfaces).
Fitting grooves 52 and 54 are respectively provided to fit into the protrusions 44 and 46 provided on the grooves 4, and a concave-convex fitting mechanism is formed by these grooves 52 and 54 and the protrusions 44 and 46. In the fitted state, the clamping surfaces of the inner parts of the jigs 48 and 50 are brought into close contact with the back surfaces 40 and 42 of the flange parts, and both side surfaces of the grooves 52 and 54 are precisely engaged with the protrusions 44 and 46 to form the protrusions. Forces acting in the width direction of 44 and 46 can be received. Also, groove 5
A slight gap is ensured between the bottom surfaces of the protrusions 44, 46 and the tips of the protrusions 44, 46, so that no clamping force is applied in the height direction of the protrusions 44, 46, and the protrusions 44, 46 are located inside them. Compressive deformation of the outer flash reservoirs 36, 38 is also avoided. This is effective in alleviating the occurrence of unbalanced loads at the joints. If you look at the above-mentioned concave-convex fitting mechanism differently, the portions located between the side walls of the upper and lower members 22, 24 and the protrusions 44, 46, respectively, are regarded as concave portions, and the welds that fit into these concave portions are considered to be concave portions. Jig 4
It is also possible to consider a portion of 8 and 50 to be a convex portion, and to understand that the above mechanism is formed by these concave and convex portions. In any case, the upper member 22 and the lower member 2
When friction welding and integrating the 8th
As shown in the figure, both members 22, 24 are held by welding jigs 48, 50, respectively, and with the protrusions 44, 46 and grooves 52, 54 fitted, the joining flanges 32, 34 are are pressed from behind, and the joint surfaces of the two are relatively slid back and forth over minute dimensions (for example, several millimeters). Usually, using a welding jig 48 or 50,
One of the members to be joined is fixed, and the other member is made to move linearly (vibrate) in the joining direction, and a molten resin layer is created at the joint part due to the frictional heat generation and shear heat generation that occurs between the two joining surfaces. A portion of the molten resin flowing therefrom is introduced into burr reservoirs 36 and 38 located on both sides of the joint. In the first half of this welding operation, the burr reservoir 3
The distal edges of the burr stops 6 and 38 are kept slightly apart from each other in order to prevent burrs from forming due to sliding contact between these edges. As shown in FIG. 9, at the end of the welding operation, as the welding progresses, the burr stops facing each other come into contact with each other, causing the burr reservoirs 36, 38
are closed and filled with molten resin. After the set time of the welding operation has elapsed and a sufficient molten layer has been formed at the joint, the vibration of the welding jig 48 or 50 etc. is stopped, and the molten layer and burr are cooled and maintained for a predetermined short period of time. The resin in the reservoirs 36 and 38 is re-solidified, and then both the upper and lower members 2 are integrated.
2 and 24, the inlet as a product is taken out. Through the process of the friction welding operation as described above, the welding operation proceeds with the protrusions 44, 46 of the joining flanges 32, 34 fitted into the grooves 52, 54 of the welding jigs 48, 50 as described above. In order to
During vibration, friction, and melting, these joining flange parts 3
Even if a protruding force (unbalanced load) toward the inside of both the upper and lower members 22, 24, that is, toward the inside of the inlet, acts on the welded portion including the welds 2, 34 and their vicinity, the welding jigs 48, 50 will prevent this from occurring. Since it can be received by the weld, inward protrusion (inward curvature) of the welded part is effectively avoided. At the same time, the burr reservoirs 36 and 38 on the inner side will not open and the molten resin will not be forced out into the inlet. As is clear from Fig. 10, inlet 20, which is a product made through the above process,
The dimension in the direction parallel to the joint surface is ensured with high precision, and therefore, even when the damper 30 is provided inside the inlet 20 as shown in FIG. 5, its smooth operation is guaranteed. In fact, the effect of preventing internal sagging by the method according to the present invention is clear from the following experimental results. The experimental conditions and results are briefly shown below. -Experiment example- (1) Materials used...The material of the top member and lower member was NP125-9 (filler included) manufactured by Sumitomo Chemical Co., Ltd. (trade name). (2) Dimensions of the projections: The dimensions of the rib-like projections as shown in FIG. 8 etc. were 2 mm in width and 3 mm in height. (3) Friction welding conditions: The following conditions were set. Amplitude...2.0mm Vertical surface pressure...50Kg Welding time...5.5 seconds Holding time...3.0 seconds Friction welding was performed under the above conditions, and the dimensional accuracy of the obtained inlet A, especially the 1
At the measurement position shown in Figure 0, the width _L1 of the upper member and the width _L2 of the lower member were measured, and the results are shown in Table 1. In addition, the dimensions L ₁ and L ₂ of the inlet B obtained by carrying out the same welding operation without providing the rib-like projections are also shown in Table 1. In addition, the preset L ₁ , L ₂
The regular dimensions of each were 70mm.

[Table] *Unit: mm
As is clear from the results shown in Table 1, the dimensions L ₁ and L ₂ of inlet B are considerably smaller than the standard dimensions, so the inward protrusion (inward curvature) of the welded part is noticeable, and L ₁ , L ₂ , and the overall distortion is large. This seems to be because the lower member was fixed and the upper member was vibrated, which caused a larger internal undulation on the vibrating side. On the other hand, in Inlet A, the dimensional accuracy of L ₁ and L ₂ is high, and it can be seen that there is almost no internal sagging. It has also become clear that the dimensions L ₁ and L ₂ are maintained approximately equal. On the other hand, regarding the strength of the joint, inlet A
Good results were obtained with Inlet B, about 2% compared to Inlet B.
It has been confirmed that the bonding strength can be increased even if the bonding strength is relatively high. This is presumed to be because by preventing internal warping, the fused layer becomes uniform and leakage of resin from the burr reservoir is avoided, thereby strengthening the physical properties of the joint. In the embodiment described above, the protrusions 44 and 46 provided on the joint flange portion had a rectangular cross-sectional shape, but as in the protrusions 56 and 58 shown in FIG. By slanting the inner surface of the protrusion (the outer surface or both surfaces may be slanted), a tapered shape is created in which the width becomes smaller toward the tip of the protrusion, and the groove of the welding jig is also shaped accordingly. It becomes easier to fit the two together. Considering the function of the protrusion, the taper angle θ is about 30° to 50°, and most preferably about 45°. In addition, in the previous explanation, a protrusion was provided on the joint flange and a groove was provided on the welding jig to form a concave-convex fitting mechanism, but as illustrated in FIGS. 12 to 14, the joint While grooves of various shapes are provided on the back surfaces of the flange portions 32 and 34, protrusions that fit into the grooves are provided on the welding jig, and even if the welding operation is performed as described above with both sides fitted, it will not be possible to Almost the same actions and effects as in the embodiment can be obtained. Incidentally, in FIG. 12, the joint flange portion 32,
Similarly, FIG. 13 shows an example in which grooves 60, 62 with a rectangular cross section extending in the joining direction are provided in the center of the back surface of the groove 34, and grooves 64, 62 with a trapezoidal cross section tapered so that the width becomes narrower in the depth direction. FIG. 14 shows an example in which grooves 66 are provided, and FIG. 14 shows an example in which grooves 68 and 70 having a U-shaped cross section are provided. In addition, as shown in FIG. 14, one of the burr reservoirs 72 and 74 facing each other has a groove shape and the other has a notch shape, and various other burr reservoir configurations are also available. In addition, it is also possible to adopt a method in which a protrusion corresponding to the cross-sectional shape of the groove shown in FIGS. 12 to 14 is provided protrudingly on the back surface of the flange portion. Furthermore, although it is most desirable to provide the uneven fitting mechanism as described above continuously in the joining direction, it is not necessarily limited to this method, and it may be provided partially or intermittently at appropriate intervals in the joining direction. Even if it is, a considerable effect can be obtained. It goes without saying that the present invention can be implemented in various other forms without departing from the spirit of the invention.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the overall shape of a general air cleaner, FIG. 2 is a sectional view showing an inlet manufactured by a conventional method, and FIG. 3 is an enlarged view of a portion of FIG. 2. FIG. 4 is a plan view showing an example of an inlet manufactured according to the method of the present invention, FIG. 5 is a sectional view thereof, and FIG. 6 is a perspective view of the inlet. Figure 7 shows the 6th
FIG. 3 is a partial cross-sectional view showing a joined portion on one side of the inlet shown in the figures, etc., which is disassembled into upper and lower members to be joined. 8 and 9 are cross-sectional views chronologically showing the manufacturing process according to an embodiment of the present invention, with FIG. 8 showing the initial stage of welding, and FIG. 9 showing the final stage, respectively. FIG. 10 is a cross-sectional view of the inlet made through this process, and corresponds to FIG. 2. FIG. 11 is a cross-sectional view showing a modified example of a protrusion when a protrusion is provided on the joint flange portion, and FIGS. 12 to 14 are sectional views showing various aspects of the groove when a groove is provided on the joint flange portion, respectively. FIG. 20... Inlet, 22... Upper member, 24...
Lower member (member to be joined), 26... Air cleaner case, 28... Duct, 30... Damper, 32, 34
...Joining flange part, 36, 38, 72, 74...Flash reservoir, 40, 42...Back side of flange part, 44, 4
6,56,58...Protrusion (projection), 48,50...Welding jig, 52,54,60,62,64,66,
68, 70...Groove (recess).

Claims (1)

[Claims] 1. When friction welding a pair of joined members in the shape of a cylindrical body divided into two in the axial direction to form an integrated resin inlet for an air cleaner, the joining is performed at the joint of the joining flange portions of the pair of joined members. In this method, flash reservoirs are provided on both sides of the joint, and the molten resin flowing out as the friction welding operation progresses is contained in the flash reservoirs. A concave-convex fitting mechanism extending in the welding direction is provided between the welding jig and the welding jig which is pressed from behind, and the concave-convex fitting mechanism prevents the welded portion from protruding inward of the inlet. A method of manufacturing a resin inlet for an air cleaner.