JP5973323B2 - Insert mold joint structure - Google Patents

Description

  The present invention relates to a joint joint structure of an insert mold which is a structure of a joint portion between a metal part and a resin material in an insert mold (metal resin composite) in which the metal part and the resin material are integrated.

  Regarding the method of joining the metal part and the resin, as proposed in Patent Document 1, a chemical etching process is performed on the metal surface to provide fine irregularities, and the resin melted at the time of insert molding is applied to the fine irregularities. A method of physically bonding the resin and the metal by the effect of anchors (crews) formed in the resin after the resin is cooled and hardened, or as proposed in Patent Document 2, There is a method of providing a film-forming layer and chemically bonding a metal and a resin by a chemical change generated by heat and pressure during molding.

  In the method using the anchor effect of Patent Document 1, the resin molecule and the metal molecule are not molecularly bonded. When viewed microscopically, for example, an environmental change such as a temperature change is repeated in the product. When loaded, it is presumed that a force due to the difference in the expansion coefficient of the material is applied between the resin and the metal, and in the long term, a minute gap is generated at the interface between the resin and the metal. Therefore, in principle, it is difficult to ensure airtightness or the like for a long time against an external force due to temperature fluctuation or the like applied to the insert mold product.

  Further, even in the method using the chemical change in Patent Document 2, since the external force that can be withstood by the joint portion between the resin and the metal is finite, the molecule of the metal part and the molecule of the resin are initially bonded. Even if a close contact state is established, no measures are taken to reduce the force applied to the external force due to the temperature fluctuation or the like, and it is difficult to maintain airtightness in the long term.

International Publication No. 2008/047811 JP 2007-221099

  The present invention is configured such that when an environmental change such as a temperature change is applied to a joint between a resin and a metal of a product, a force generated there due to a difference in expansion coefficient between the metal material and the resin material can be reduced. An object of the present invention is to provide a joint joint structure of an insert mold made of a resin material and a metal material having excellent durability.

1 of the present invention is an insert mold joint structure in which a metal part subjected to a surface treatment for improving the bonding property with a resin is joined or internally molded to the surface or inside of a resin molded article. The thickness of the metal part of the insert mold part is expanded from the inner end between the inner end and the outer end of the joint part or interior part due to the cross section in the direction perpendicular to the direction from the inner end to the outer end. A part having a different first cross-sectional area, a part having a different second cross-sectional area having the smallest thickness, a part having a different third cross-sectional area exceeding the thickness of the part having a different second cross-sectional area at the outer end, It is the joint joint structure of the insert mold which formed.

2 of the present invention is a joint joint structure of the insert mold according to 1 of the present invention, wherein the metal part has a different first cross-sectional area, a second cross-sectional area is different, and a third cross-sectional area is different. Is formed continuously over the entire circumference of the joint part of the metal part to the resin molded product or the interior part.

3 of the present invention is the joint joint structure of the insert mold of 1 or 2 of the present invention,
Each of the cross-sectional shapes of the metal part having a different first cross-sectional area, a part having a different second cross-sectional area, and a part having a different third cross-sectional area are substantially parallel surface portions or circular curved surfaces constituting both surfaces of the metal part. It is constituted by a combination of the shape parts.

4 of the present invention is a joint joint structure of the insert mold of 3 of the present invention, wherein the metal part has a different first cross-sectional area, a second cross-sectional area is different, and a third cross-sectional area is different. The shape of the shape transition part between the adjacent parts of each is an arc curved surface.

  According to the joint joint structure of the insert mold of 1 of the present invention, when an environmental change such as a temperature change is applied thereto, the force generated by the difference in expansion coefficient between the metal material and the resin material is reduced. As a result, excellent durability can be obtained.

  Between the inner end (boundary inside and outside of the resin part) or the outer end (the innermost part of the resin part) joined to or embedded in the resin part of the metal part of the insert mold, the inner end Since three or more parts having different cross-sectional areas due to the cross section in the direction orthogonal to the outer end are formed, the part having the largest cross-sectional area among the parts having different cross-sectional areas is When receiving a force in a direction toward the outer end, an anchor effect is exhibited between the resin portion and the macroscopic displacement between the resin portion and the metal part can be prevented. As described above, since this action is macroscopic, it is not possible to expect to maintain airtightness due to molecular bonding between the resin part and the metal part due to the action at the part. Absent.

  Of course, the smallest area of the cross-sectional area of the metal part is smaller than the largest cross-sectional area. For example, when an intermediate cross-sectional area portion is arranged on the outer end side, it is generated by the temperature change with respect to the outer end (tip portion) of the intermediate cross-sectional area portion. The buffering effect of the force to be exerted.

  Of the cross-sectional area of the metal part, the part of the middle area, particularly when it is positioned at the outer end, receives the effect of the part of the minimum area, and the outer end part and the resin part that covers it The molecular bond between them can be maintained and high airtightness can be maintained.

  According to the joint joint structure of the insert mold of 2 of the present invention, at least three portions of the metal part having different cross-sectional areas are joined over the entire circumference of the joint part of the metal part to the resin molded product or the interior part. Because it is continuously formed, even if an environmental change such as a temperature change is applied to this, the force generated by the difference in expansion coefficient between the metal part and the surrounding resin material is applied to any outer end of the entire circumference. This part (tip part) can be appropriately relaxed, and reliable airtightness can always be ensured at any outer part part (tip part) of the entire circumference.

  According to the joint joint structure of the insert mold of 3 of the present invention, each cross-sectional shape of the portion having a different cross-sectional area of three or more portions of the metal part is substantially parallel or circular curved surface part constituting both surfaces of the metal part. Therefore, even if an environmental change such as a temperature change is applied, the difference in expansion coefficient between the metal part and the surrounding resin material can be achieved. The generated force can be moderated appropriately, and reliable airtightness can be secured particularly at the outer end of the joint.

  According to the joint joint structure of the insert mold 4 of the present invention, it is possible to avoid stress concentration from occurring in the shape transition portion between the adjacent portions in the three or more portions having different cross-sectional areas of the metal part.

The schematic perspective view for description which shows the external appearance of an example of simple insert mold components. The expanded sectional view which shows the AA line cross section of FIG. Cross-sectional explanatory drawing modeled in order to analyze the structure of the one side of the coupling part 1 of FIG. Sectional drawing which shows the BB line cross section of FIG. The graph which shows the result of having calculated the force which generate | occur | produces in this insert metal part when the temperature change is given to the insert metal part which consists of a resin part and insert metal part using Formula 8, and changes the thickness of this metal part 2 . FIG. 3 is a partial cross-sectional view showing the joint joint structure of the insert mold according to the first embodiment. The figure which shows the example of the stress distribution result calculated by simulation using strength analysis software about the joint joint structure of the insert mold of Embodiment 1. FIG. The graph which shows the result of having calculated the stress which generate | occur | produces in this insert metal part with respect to the thickness of the insert metal part of Embodiment 1 when temperature change is given using Formula 7. Cross-sectional explanatory drawing which shows the detail of the site | part from which the 2nd cross-sectional area differs in Embodiment 1, and a front-end | tip part (outer end part). Sectional drawing which shows the joint part of the insert metal component in the joint joint structure of insert mold of Embodiment 2. FIG. Sectional drawing which shows the joint part of the insert metal component in the joint joint structure of insert mold of Embodiment 3. FIG.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the invention will be described in detail with reference to the drawings through explanation of the structure of resin material and metal material insert molds according to the embodiments and the operation of each portion.

  FIG. 1 is a schematic perspective view showing an appearance of an example of a very simple insert mold component, and FIG. 2 is an enlarged view showing a cross section taken along line AA of FIG. As shown in FIGS. 1 and 2, the insert mold component includes a quadrilateral frame-shaped resin portion 1 and a quadrilateral plate-shaped insert metal component 2 in which a four-side joint portion 2 a is embedded in the resin portion 1. . As described above, generally, an insert mold component in which a metal component is inserted into a resin member is connected, and the joint portion 2a of the insert metal component 2 is embedded in the resin portion 1, as shown in FIG. The joint portion 2 a is configured to be fixed inside the resin portion 1. Alternatively, the joint portion of the insert metal part is joined to the surface of the resin portion 1, and the joint portion is fixed to the surface of the resin portion. Here, the former example will be described below.

  In such a configuration, the distance between the end portions 2b of the joint portions 2a on both sides parallel to each other is L, and the linear expansion coefficients of the resin material of the resin portion 1 and the metal material of the insert metal part 2 are α1, α2, respectively. When the temperature change of the entire insert mold part is Δt, the linear expansion difference generated during the distance L is linear expansion difference = L × Δt × (α1−α2).

  The force generated here is obtained by multiplying the linear expansion difference by a rigidity value obtained by synthesizing the physical properties of the resin material of the resin portion 1 and the metal material of the metal component 2, and the tip portion (outer end) Part) 2b is the maximum. It can be easily imagined that the force generated in this way can be very large if, for example, an example of a phenomenon in which water enters a crack in a rock and the water freezes and expands and breaks the rock. .

  Next, the relationship of the force generated in the joint portion 2a is analyzed, and the force generated in the tip portion 2b is due to the bond between the molecule of the metal material of the metal part 2 and the molecule of the resin material of the resin portion 1. We will consider a structure that suppresses the bond strength to be smaller.

  FIG. 3 is an explanatory diagram that models one of the two parallel sides of the metal part 2 in order to analyze the configuration of the joint portion 1. In this model, the relationship between the applied force and the reaction force is the same at the tip portions 2b and 2b of the joint portions 2a and 2a on both sides of the metal part 2 in parallel. In FIG. 3, only the resin part 1 and the insert metal part 2 are illustrated as being fixed to a common wall 3. Further, since the maximum force is generated at the tip portion 2b where the difference in linear expansion is maximized, the resin portion 1 and the insert metal part 2 are joined only by the tip portion 2b and act on the portion. The model analyzes force. In addition, the code | symbol and symbol in the figure which are the same as that of FIG.1 and FIG.2 have shown the component or site | part same as FIG.1 and FIG.2.

  4 shows a cross section taken along the line B-B of FIG. 3. The same reference numerals and symbols in FIG. 3 as those in FIG. 3 are the same as those in FIG. 1 and FIG. Or the site | part is shown.

  The resin part 1 has a depth D and a thickness t1, and the insert metal part 2 has a depth D and a thickness t2, and their cross-sectional areas are given by D × t1 and D × t2, respectively.

In the calculation, each specification and its symbol are defined.
Calculation parameters Temperature change: Δt
Young's modulus Metal member: Ea, Resin member: Ep
Linear expansion coefficient Metal member: αa, Resin member: αp
Length element Calculation distance: L
Material depth: D
Metal member thickness: t2
Resin material thickness: t1
Cross-sectional area (metal member: Sa, resin member: Sp)
t1 ・ D ： Sp
t2 ・ D ： Sa

The relational calculation of the stress of each material generated by the difference in linear expansion based on the specifications is performed below.
Elongation (deformation amount) of metal member λa

  Here, the first term on the right side of Equation 1 represents the elongation of the metal member itself due to the temperature change Δt, and the second term represents the deformation of the metal member due to the load generated by the mating resin member.

  The strain ε and the deformation amount λ have the following relationship: ε = λ / L. When λ = Lε is obtained from this equation and Equation 1 is arranged, the strain εa of the metal member can be expressed by the following Equation 2. .

  The elongation (deformation amount) λp of the resin member can also be expressed by the following equation (3) in the same manner as equation (1) representing the elongation (deformation amount) λa of the metal member.

  The strain εp of the resin member can be expressed by the following formula 4.

Here, since λa = λp, from Equation 1 and Equation 3,
αa ・ Δt ・ L + (σa ・ L) / Ea = αp ・ Δt ・ L- (σp ・ L) / Ep
When both sides of this formula are divided by L and arranged,
αa ・ Δt + σa / Ea = αp ・ Δt-σp / Ep
The following formula 5 is obtained.

  From the balance of forces, W1 = W2, and since the force is the relationship between the product of stress and cross-sectional area, that is, W = σS, it is said that σa · Sa = σp · Sp. To establish.

Therefore, substituting Equation 6 into Equation 5 gives
Δt (αa-αp) + σa / Ea + (σa ・ Sa / Sp) / Ep = 0
this is,
Δt (αa-αp) + σa / Ea + (σa ・ Sa) / (Sp ・ Ep) = 0
Δt (αa-αp) + σa (1 / Ea + Sa / (Sp ・ Ep)) = 0
σa ((Sp ・ Ep + Ea ・ Sa) / (Sp ・ Ea ・ Ep)) =-Δt (αa-αp)
Can be rewritten to the following equation (7).

The stress σa acting on the metal part 2 was found from the above equation (7). Next, the force Wa generated in the metal part 2 is obtained from the obtained stress σa. Since there is a relationship of W = σS as described above, it is the force Wa generated by multiplying σa in Equation 7 by the cross-sectional area S.
That is,
Wa = Sa (-Δt (αa-αp) ((Sp ・ Ea ・ Ep) / (Sp ・ Ep + Ea ・ Sa)))
= (-Δt (αa-αp) (Sp ・ Ea ・ Ep)) / ((Sp ・ Ep + Ea ・ Sa) / Sa)
When further rewritten, the following formula 8 is obtained.

The meaning indicated by Equation 8 will be described.
Ea and Ep, which are Young's moduli of the metal member and the resin member, are values determined by their respective materials, and αa and αp, which are their respective linear expansion coefficients, are also values determined by their materials. When the cross-sectional area Sp of the resin part 1 is set to a constant value and the cross-sectional area Sa of the metal part 2 is regarded as a variable, the denominator of Formula 8 increases as the cross-sectional area Sa decreases. It can be seen that there is a relationship in which the value of the force Wa decreases.

  Further, if the value of the depth D is a constant value, the thickness t2 of the metal member may be reduced in order to reduce the value of the cross-sectional area Sa. That is, by reducing the thickness of the insert metal part 2, the force W generated at the distal end part 2 b when a linear expansion difference occurs between the resin part 1 and the insert metal part 2 due to a temperature change. It can be seen that can be reduced.

  FIG. 5 shows the force W generated in the insert metal part 2 when the temperature change is applied to the insert part composed of the resin part 1 and the insert metal part 2 by changing the thickness t2 of the metal part 2. It is a graph which shows the result calculated using Formula 8. The horizontal axis of the graph is the thickness t2 of the insert metal part 2, and the vertical axis is the force W generated. It can be seen that the generated force W decreases rapidly as the thickness t2 of the insert metal part 2 approaches zero.

  The effects that can be understood by the above calculation are also available around us, for example, when an aluminum plate having a certain thickness (about 10 mm) is bonded and fixed to a resin material using the same type of adhesive, and the same resin is made of very thin aluminum. It is also empirically understood that when the foils are bonded and fixed and the same temperature change is given to them, the aluminum foil is clearly more difficult to peel off. This is considered to be due to the phenomenon analyzed by the calculation.

<Embodiment 1>
Next, Embodiment 1 which is the best embodiment of the joint joint structure of the insert mold derived from the result obtained by this analysis will be described with reference to FIG. In addition, the code | symbol or symbol in a figure and the thing same as that of FIG.1 and FIG.2 has shown the component or site | part same as that of FIG.1 and FIG.2.

  A joint portion 2a of the insert metal part 2 is embedded in the resin portion 1. The resin part 1 is a quadrilateral frame-shaped member, and the metal part 2 is composed of a plate-like part located in the frame of the resin part 1 and joints 2a, 2a. As described above, 2a, 2a,... Are inserted into the resin portion 1 from the inside to the outside and are embedded.

  The joint portion 2a described above includes a portion 4 having a different first cross-sectional area, a portion 5 having a different second cross-sectional area, and a portion 5 having a different second cross-sectional area. It is comprised with the part 6 from which an area differs. The cross-sectional area referred to here refers to a cross-sectional area in a case where a cross section is taken in a direction orthogonal to the direction from the portion not covered with the internal resin portion 1 toward the portion 6 having a different third cross-sectional area at the outer end.

  About the joint part 2a, the structure and effect | action of each part are demonstrated in order of the outer part from the inner part sequentially.

  The portion 4 having a different first cross-sectional area has a larger cross-sectional area than the portion not covered with the resin portion 1 inside the resin portion 1. That is, as shown in FIG. 6, the portion 4 having the different first cross-sectional area is along the direction from the portion not covered by the inner resin portion 1 to the portion 6 having the third outer cross-sectional area different. Thus, the upper and lower surfaces are formed in a circular curved shape. More specifically, the upper surface side is formed in a partially circular curved surface shape that bulges upward, and the lower surface side is formed in a partially circular curved surface shape that bulges downward. When the three cross-sectional areas are crossed along the direction toward the portion 6, a partial circular cross section is formed as shown in FIG.

  Thus, as described above, the portion 4 having a different first cross-sectional area has a direction orthogonal to the direction from the portion not covered by the inner resin portion 1 to the portion 6 having a different third cross-sectional area at the outer end. Although the cross section is a problem, the area of the cross section is configured to be larger than the area of the cross section of the portion not covered with the resin portion 1 inside the resin portion 1. Accordingly, when the insert metal part 2 receives a force in the + X direction or the −X direction shown in FIG. Due to the anchor effect of the parts 4) having different areas, the macro shift in the direction between the resin part 1 and the insert metal part 2 is prevented. The term “macro” as used herein refers to a range of about 10 μm to several hundreds of μm in terms of approximate numerical values. Moreover, in this Embodiment 1, since the said macro shift | offset | difference is assumed, maintaining airtightness by the molecular coupling | bonding between the said resin part 1 and the said insert metal component 2 of this part is maintained. Not what you expect.

Next, the configuration and operation of the portion 5 having a different second cross-sectional area will be described.
The portion is a portion having the smallest cross-sectional area in the joint portion 2a. As shown in FIG. 6, a portion 6 having a third cross-sectional area different from the portion not covered by the inner resin portion 1 is different from that of the inner end. It is the plate-shaped part which comprised the upper and lower both surfaces extended along the direction which goes to the parallel surface mutually parallel. The dimension between the upper and lower surfaces, that is, the thickness is the smallest part in the joint portion 2a. FIG. 6 naturally shows the thinnest plate-like cross section.

  Accordingly, the action of the portion corresponds to the smallest portion of the cross-sectional area Sa obtained by analyzing the force relationship using the FIGS. 3 and 4, and the thickness t2 of the insert metal part 2 is reduced. By setting, by reducing the sectional area Sa, the force W generated at the tip 2b is reduced. Since the portion 5 having a different second cross-sectional area is formed in the joint portion 2a as described above, the buffering action of the force generated in the tip portion 2b due to the temperature change is exhibited as described above. To do.

Finally, the portion 6 having a different third cross-sectional area will be described.
The upper and lower surfaces are formed in a circular curved surface, and the upper and lower surfaces are connected on the outer end side. As a result, as shown in FIG. 6, when the section is cut along a direction from the portion not covered with the inner resin portion 1 toward the portion 6 having a different third cross-sectional area at the outer end, It has a configuration that appears in a form in which a circular cross section having a diameter exceeding the thickness is added to the outer end (tip) of the portion 5 having a different second cross sectional area.

  The action of the portion 6 having the different third cross-sectional area is caused by the action of the portion 5 having the different second cross-sectional area, and particularly the force W generated at the outer end portion, that is, the tip end portion 2b is reduced. It is to maintain the molecular bond between the resin part 1 that is in the exterior state at the part and thereby maintain high airtightness.

FIG. 7 shows an example of the stress distribution result calculated by simulation using the strength analysis software for the joint joint structure of the insert mold of the first embodiment shown in FIG.
According to this, a large stress is generated in the portion 5 having the different second cross-sectional area, and the tip portion 2b of the portion 6 having the different third cross-sectional area is compared with the portion 5 having the different second cross-sectional area. It can be seen that the generation of stress is small.
In general, when a unit cross-sectional area is considered, the stress value can be regarded as a force W. Therefore, from FIG. 7, the force W is relaxed in the portion 5 having the second cross-sectional area different from that shown in FIG. It can be seen that the force generated at the tip 2b is small.

  However, in actual product design, it is not possible to simply set the cross-sectional area Sa to be smaller. The reason is described below.

  FIG. 8 is a graph showing the results of calculating the stress generated in the insert metal part 2 with respect to the thickness t2 of the insert metal part 2 when the temperature change is given to the insert mold product, using Equation 7. FIG. 6 is a calculation result based on the same specifications as the calculation result of the force generated in the metal part 2 shown in FIG. 5.

  As can be seen from the graph of FIG. 8, the stress generated increases as the thickness t2 of the insert metal part 2 decreases. It can be seen that when the insert metal part 2 has a certain thickness, that is, the allowable line Lr or less, the stress exceeds the allowable value specific to the material of the insert metal part 2. If the allowable value indicated by the allowable line Lr is exceeded, the material will be destroyed. Therefore, when the thickness t2 of the insert metal part 2 is set to the minimum thickness, the thickness of the allowable line Lr must be set. I must. Accordingly, the allowable line Lf of the generated stress corresponds to that when the metal part 2 has the minimum thickness, and the generated stress is allowed to be less than that.

Furthermore, the effect | action of the part 6 from which a 3rd cross-sectional area differs exists in the point which maintains the airtightness by the molecular coupling | bonding of the said resin part 1 and the said insert metal component 2. FIG.
The reason why the cross-sectional area of the portion 6 having the different third cross-sectional area is larger as described above than the portion 5 having the different second cross-sectional area is that the molecular bond is exhibited. This is because the projected area of the tip 2b as viewed from the X-axis direction in FIG. 6 is increased.

FIG. 9 shows details of the portion 5 having a different second cross-sectional area and the tip portion 2b.
The portion in the range indicated by the arrow at the tip 2b in FIG. 9 hits the portion where the force W generated between the resin portion 1 and the insert mold metal part 2 is small as described above, and the generated force Since W is smaller than the bonding strength of the portion, it is a portion suitable as a bonding surface range for the purpose of ensuring airtightness.

  Further, in the transition portion of the cross-sectional shape extending from the inside to the outside of the portion 5 having the different second cross-sectional area and the portion 6 having the third cross-sectional area different as shown in FIG. A shape transition portion 6a having a part of a substantially circumferential shape is provided. Such an action of the shape transition portion 6a is that of a stress concentration alleviation shape to a portion where the cross-sectional shape is well known in engineering, and as shown in FIG. It is necessary to set the shape transition portion 4a to the portion where the cross-sectional shape changes between the straight portion extending to the portion not covered with the resin portion 1 and the portion 4 having the different first cross-sectional area, It is necessary to set the shape transition portion 5a to a portion where the cross-sectional shape changes between the portion 4 having a different first cross-sectional area and the portion 5 having a different second cross-sectional area. Each shape of the following other embodiments also needs to be set to the same part, although not described every time.

<Embodiment 2>
FIG. 10 shows a joint portion 12a of the insert metal part 12 in the joint joint structure of the insert mold of the second embodiment. This joint portion 12a is similar to the joint portion 2a of the first embodiment shown in FIG. 6 in that a portion 14 having a different first cross-sectional area and a portion 15 having a different second cross-sectional area that are continuous from the inside to the outside. And the third cross-sectional area 16 are different from each other, but their shapes are different from those of the first embodiment. However, the joint portion 2a of the first embodiment and the joint portion 12a of the second embodiment, the portions 4 and 14 having different first cross-sectional areas, the portions 5 and 15 having different second cross-sectional areas, and the third cross-sectional area The parts 6 and 16 having different values perform the same operation. In addition, the coupling | bonding aspect of this insert metal component 12 and the resin part 1 which is not shown in figure is completely the same as that of Embodiment 1. FIG.

  In the joint part 12a of the insert metal part 12 of the second embodiment, as shown in FIG. 10, the cross section (cross section along the outside from the inside) of the portion 14 having a different first cross sectional area is a quadrangle. However, even if the cross-sectional shape is an ellipse, a triangle, or other shapes, the portion 14 having a different first cross-sectional area is not covered by the resin portion 1 inside the resin portion 1. On the other hand, it is not inconvenient if the cross-sectional area (cross section orthogonal to the direction from the inside toward the outside) is large. If so, it is obvious that it is effective in view of the action of the cross-sectional shape of the portion 4 having a different first cross-sectional area in the first embodiment.

  That is, as described above, if the cross-sectional area of the portion 14 having a different first cross-sectional area is large, the insert metal part 12 is in the left-right direction (from the inner side) in FIG. When receiving a force in the outward direction), the macro effect of the resin part 1 and the insert metal part 12 in the inner and outer directions is prevented by the anchor effect of the portion 14 having a different first cross-sectional area. Can do.

  The portion 15 having a different second cross-sectional area has the same shape as that of the portion 5 having the second cross-sectional area different from that of the first embodiment, has the same cross-sectional area, and acts in the same manner as described above. .

  Similarly to the fact that the cross-sectional shape of the portion 14 having a different first cross-sectional area is a quadrangle, the portion 16 having a different third cross-sectional area has a trapezoidal cross section as shown in FIG. However, it is obvious that other shapes such as an ellipse, a triangle, and the like can be effectively formed in the same manner. That is, it is the same as that in the description of the portion 6 having a different third cross-sectional area in the first embodiment, and the portion 16 having the different third cross-sectional area is separated from the portion 15 having the different second cross-sectional area. From the viewpoint of exhibiting the molecular bond due to the large area, this is effective if the projected area of the tip 12b as viewed from the inside and outside directions is increased.

<Embodiment 3>
FIG. 11 shows a joint portion 22a of the insert metal part 22 in the joint joint structure of the insert mold according to the third embodiment. An example in which the joint portion 22a includes a portion 24 having a different first cross-sectional area, two portions 25 and 25 having a different second cross-sectional area, and two portions 26 and 26 having a different third cross-sectional area. It is. The second embodiment is different from the first embodiment in that two portions 25 having different second cross-sectional areas and two portions 26 having different third cross-sectional areas are formed. However, the joint part 2a of the first embodiment and the joint part 22a of the third embodiment, the parts 4 and 24 having different first cross-sectional areas, the parts 5 and 25 having different second cross-sectional areas, and the third cross-sectional area are The different parts 6 and 26 have the same effect. Similarly, the airtightness is ensured by the molecular bond between the distal end portion 22b of the joint portion 22a and the resin portion 1. In addition, the connection mode of the insert metal part 22 and the resin part 1 (not shown) is exactly the same as that of the first embodiment.

  In the third embodiment, as described above, two portions 25 having different second cross-sectional areas and two portions 26 having different third cross-sectional areas are provided, but the number of each portion is one. Since the individual actions are not changed as described above, the same effect is obtained as in the joint portion 2a of the insert metal part 2 in the joint joint structure of the insert mold of the first embodiment.

  In the first, second, and third embodiments, the metal parts 2, 12, and 22 are subjected to a surface treatment that improves the bonding property with the resin that constitutes the resin part 1 that embeds the joint parts 2a, 12a, and 22a. As described above, this surface treatment can be performed by using various known existing techniques. For example, TRI System (Shitoman, Tamayama-ku, Tamayama-ku, Iwate Prefecture), which forms an adhesive layer as an adhesive comprising a specific triazine compound and an organic compound capable of reacting with the specific triazine compound on the metal surface. For example, surface treatment is performed using a surface treatment technique called “Iwano 20-7”. This surface treatment is a means for forming a chemical film-forming layer as the above-mentioned adhesive layer on the metal surface and chemically bonding the metal and the resin by a chemical change generated by heat and pressure during molding.

  In the above first, second, and third embodiments, only the case where the joint portion is embedded in the resin portion from the inside toward the outside has been described. As described above, the joint portion may be joined to the surface of the resin portion. And when joining such a joint part to the surface, like those of the first, second, and third embodiments, the portions having a plurality of different cross-sectional areas, for example, the first, second, and third cross-sectional areas are different. Part is formed and these are joined to the surface of the resin part.In this case, naturally, the parts with different cross-sectional areas of the joint part are the dimensions in the direction orthogonal to the direction from the inside to the outside. Since this is achieved by changing (thickness), the portion facing the surface of the resin portion to be joined becomes a surface that is uneven toward the surface of the resin portion. Therefore, when the insert mold (metal resin composite) is molded, the surface of the resin part is also formed into a corresponding uneven shape, and the first, second, and third cross-sectional areas of the joint part are different in thickness. This will be embedded in the resin part side. The joint portion acts exactly the same as that of the first, second, and third embodiments.

DESCRIPTION OF SYMBOLS 1 Resin part 2 Insert metal part 2a Joint part 2b The front-end | tip part (outer end part) of a joint part
4 Part with different first cross-sectional area 4a Shape transition part 5 Part with different second cross-sectional area 5a Shape transition part 6 Part with different third cross-sectional area 6a Shape transition part D Depth of resin part t1 Thickness of insert metal part T2 Thickness of insert metal part Sa Cross-sectional area of insert metal part 12 Insert metal part 12a Joint part of insert metal part 12b Tip part (outer end part) of joint part
14 Part with different first cross-sectional area 15 Part with different second cross-sectional area 16 Part with different third cross-sectional area 22 Insert metal part 22a Joint part of insert metal part 22b Tip part (outer end part) of joint part
24 Part with different first cross-sectional area 25 Part with different second cross-sectional area 26 Part with different third cross-sectional area

Claims (4)

In an insert mold joint structure in which a metal part subjected to a surface treatment for improving the bondability with a resin is joined or internally molded to the surface or inside of a resin molded product,
In the metal part of the insert mold part to be joined or housed in the resin molded product, the cross section in the direction orthogonal to the direction from the inner end to the outer end, between the inner end and the outer end of the joint or interior part. A portion having a different first cross-sectional area that is thicker than the inner end, a portion having a different second cross-sectional area having the smallest thickness, and a portion having a thickness different from that of the second cross-sectional area at the outer end. A joint joint structure of an insert mold in which three cross-sectional areas are different . A part of the metal part having a different first cross-sectional area, a part having a different second cross-sectional area, and a part having a different third cross-sectional area are joined to the resin molded product of the metal part or the entire circumference of the interior part. The joint joint structure for an insert mold according to claim 1, wherein the joint joint structure is formed continuously over the entire area. Each of the cross-sectional shapes of the metal part having a different first cross-sectional area, a part having a different second cross-sectional area, and a part having a different third cross-sectional area are substantially parallel surface portions or circular curved surfaces constituting both surfaces of the metal part. The joint joint structure for an insert mold according to claim 1 or 2, wherein the joint joint structure is constituted by a combination of shaped parts. The shape of the shape transition part between each adjacent part of the part where the first cross-sectional area of the metal part is different, the part where the second cross-sectional area is different, and the part where the third cross-sectional area is different is an arc curved surface Item 3. The joint joint structure of the insert mold of item 3.