JP5229980B2 - Metal member fixing method and flanged shaft member - Google Patents

Description

  The present invention relates to a method for fixing a metal member simply and firmly and a shaft member with a flange obtained by the method. In the present application, “metal” is used in a broad sense including all types such as iron and non-ferrous.

  There are various methods for joining metals together. For example, a member made of a metal rod that has a surface (flange) surrounding the outer surface of the rod and not parallel to the length direction of the rod The following methods have been proposed to firmly fix the bar and the plate when they are made from the material and the plate.

  “High-speed shearing” is a method of punching a plate with a hammer against a plate on a die. “Shaving joining” in which a bar having a taper formed with a screw is pushed into a plate having holes (bottomed) or holes (penetrated) in advance. For example, a “high-strength plastic bond” in which a bar with high hardness is driven into a plate with low hardness.

  In addition, a hole (bottomed) or hole (penetration) in which the bar is fitted to the plate material is formed, and the plate material is heated to a temperature at which it can expand to fit the bar material at room temperature, and the contraction action when the plate material returns to room temperature. The so-called “shrink fit”, in which the bar is tightened and fixed. The opposite of shrink fitting, the bar is cooled to a temperature at which it can shrink, and is fitted into a hole or hole in the room temperature plate, and fixed by relative tightening with the plate by the expansion action when the bar returns to room temperature. "Cold fit".

Furthermore, Patent Document 1 below is a patent in which both members are heated to a temperature higher than the minimum temperature required for superplastic deformation, and the boundary surface between the members is fused and integrated while plastically deforming.
Patent Registration No. 2980661

  However, the conventional method has the following problems. First, “high-speed shear bonding” requires a dedicated device for driving the hammer at high speed, and cannot be performed with an existing press device, for example.

  In “shaving joining”, the plate material may be heated, so the holes and holes provided in the plate material are accurately set so that the threaded portion of the bar material is properly screwed in anticipation of dimensional changes after thermal expansion and contraction. It is necessary to design to.

  “High-strength plastic bonding” requires a difference in hardness, so that there is a problem that the combination of the material of the plate and the bar is limited. In addition, there is a problem that it is necessary to separately quench when high strength bonding is desired.

  Furthermore, “shrink fit”, “cold fit”, and the above-mentioned Patent Document 1 need to design fit dimensions that have been calculated in advance for expansion or contraction according to the type and size of the material, and are required for thermal expansion or contraction. There is a problem that it is necessary to accurately control the temperature of the material, which is inefficient, inexpensive and cannot be produced in large quantities.

  Moreover, since patent document 1 fuses and integrates members, both members must be heated more than the minimum temperature required for superplastic deformation. Therefore, metallurgical knowledge and facilities are required, and it is not so easy as to be mechanically fixed. Therefore, it is inefficient and inexpensive and cannot be produced in large quantities.

  The problem to be solved by the present invention is that the "high-speed shear bonding" cannot be performed by an existing press device, and the "high-strength plastic bonding" is limited in the combination of the plate material and the bar material, In addition, it is necessary to perform quenching separately, and in “shaving joining” and “shrink fitting” or “cold fitting”, it is necessary to accurately calculate and design the dimensions of the holes and holes formed in the plate material. The document 1 is to solve the problem that simple and strong fixing cannot be performed.

In order to solve the above-described problems, the present invention is such that the plate-like one member which is a metal member is smaller by 10 to 50% than the cross-sectional dimension of the other shaft-like member which is also a metal member. After forming a hole or hole having a shape similar to the cross-sectional shape of the other shaft-shaped member having a size , the shaft-shaped other member has a strength of 1/2 to 1 to the extent that thermal expansion can occur. / 3 is heated to a temperature that softens, and the other one of the plate-like members is heated to a temperature that softens the one member that pushes in the other member of the shaft that has been brought to room temperature. The member was pushed in.

  In the metal member fixing method according to the present invention, it is necessary to form a strict and highly accurate hole or hole, such as “shaving joining”, “shrink fitting” and “cold fitting”, on one plate-like metal material. Moreover, unlike the “high-speed shear bonding”, it is not necessary to down the hammer at a high speed by a special device, and it can be performed by an existing press device.

  Furthermore, the method for fixing the metal member according to the present invention is not limited to any combination of the material of the plate material and the bar material, as in “high-strength plastic bonding”, and it is not necessary to separately quench, Further, unlike Patent Document 1, it is not necessary to heat both the plate-like one member and the shaft-like other member to the minimum temperature required for superplastic deformation.

  That is, the diameters of the holes and holes in the metal member fixing method according to the present invention will be described in detail later. When the other shaft-shaped member is pushed into the one plate-shaped member, the other shaft-shaped member is a plate. Since the inner surface of the hole or hole of the one-piece member is sheared, in other words, the inner surface of the hole or hole of the plate-like one member is scraped off and the adhesion force on the new surface is generated, it may not be an accurate dimension. is there.

  In addition, as described above, the accuracy of the hole and the hole diameter is not required, and it is only necessary to generate an adhesion force on the new surface between the plate-like one member and the shaft-like other member. However, it can be carried out by an existing press apparatus, is not limited by the hardness of the metal species, and further, it is not necessary to heat the other shaft-shaped member.

  Furthermore, as described above, the present invention has an adhesive force generated between the outer surface of the other shaft-shaped member and the new surface (shaved) on the inner surface of the hole or hole of the plate-shaped one member, and Since the outer surface of the other shaft-like member is firmly tightened by heat shrinkage during cooling of the one plate-like member, no separate quenching is required.

  In addition, since the present invention is preliminarily formed with holes and holes in the plate-like one member and heated to a degree of softening, when the shaft-like other member is pushed into the plate-like one member, The load can be reduced.

  Therefore, the metal member fixing method according to the present invention can easily and firmly fix a plurality of different metal members with a small number of man-hours as required, and can be mass-produced with high efficiency and can be completed. Cost reduction.

  The flanged shaft member, which is created by the metal member fixing method according to the present invention and the other shaft-shaped member penetrates or reaches halfway with respect to the thickness of the plate-shaped one member, is obtained by the above method. Since it is created, it can be produced in large quantities with high efficiency, and the other metal material in the shape of a shaft is difficult to come off from one metal material in the shape of a plate, and it is difficult to rotate the shaft, resulting in excellent mechanical strength. .

  The present invention, for example, from a metal plate-like member (the other member: hereinafter referred to as a shaft member) and a metal plate-like member (one member: hereinafter referred to as a plate member) to a shaft member having a flange made of a plate material ( Hereinafter, when creating a flanged shaft member, the following first and second modes are implemented.

  In the present example, the shaft material is a cylindrical material that is long in the axial direction, but the cross-sectional shape is not limited to this (meaning that it is an elongated material). In this example, the plate material is a circular flat plate for the sake of explanation, but the outer shape and the thickness distribution are not limited thereto.

  In the first embodiment, basic explanation will be given. In the second embodiment, points different from the first embodiment will be explained, and duplicate explanations will be omitted.

(First form)
First, a hole (small diameter) that is similar in shape to the cross-sectional shape of the shaft material to be pushed into the plate material and that is 10-50% smaller than the cross-sectional shape of the shaft material (in this case, the outer diameter). Or a hole is formed. In this example, a hole (through) is formed.

  Here, the reason why the hole is similar to the cross-sectional shape of the shaft member and the reason why the hole size is 10-50% smaller than the cross-sectional size of the shaft member will be described. In the metal member fixing method of the present invention, the shaft material is pushed into the plate material to cause shear deformation of the plate material, and the adhesive force on the new surface at that time and the strong fixing force by heat shrinkage when the plate material is cooled. To be expressed.

  The shaft member needs to be pushed so as to scrape off the inner surface of the hole formed in the plate member. However, if there is no hole, a large force is required to push the shaft member. However, if the emphasis is on reducing the force at the time of pushing, the adhesion force on the new surface that expresses the fixing force cannot be generated satisfactorily.

  Therefore, the hole has a similar shape so that the entire inner surface of the hole of the plate material is surely scraped by the entire outer surface of the shaft member. Further, if the size of the hole is smaller than 50% with respect to the outer diameter of the shaft member, the same amount of force as that in which no hole is formed is required for pushing the shaft member. If the diameter is large, no adhesive force is generated on the new surface, so the hole has a size smaller by 10 to 50% than the size of the cross-sectional shape of the shaft.

  In other words, the hole has a range of 10 to 50% smaller than the cross-sectional dimension of the shaft member, and it is not necessary to consider any thermal expansion, thermal contraction, fit dimensions, etc. Can be designed easily.

As described above, the hole has a size that is smaller by 10 to 50% than the cross-sectional shape of the shaft member. As a result, the outer surface of the shaft member always cuts the inner surface of the hole. Therefore, the adhesion force on the new surface is uniformly generated on the inner surface of the hole , and the fixing force can be uniform. Further, as described above, the hole may be a bottomed hole.

  Subsequently, after forming holes in the plate material, the plate material is heated to a temperature at which the plate material is softened. In addition, about the board | plate material, when producing by hot forging, for example, you may use the board | plate material in a high temperature state after forging, without heating again after forging.

  Here, the softening temperature means a temperature at which the plate material itself is more easily deformed than normal temperature, and the shaft material is harder to the shaft material, and when the shaft material is pushed in. It means a temperature at which the plate material softens to such an extent that a hardness difference that allows the shaft material to be inserted or penetrated is produced. Specifically, it is sufficient that the strength at the time of heating the plate material is softened to 1/2 to 1/3 of the strength of the shaft material at room temperature.

  Further, the softening temperature means a temperature at which sufficient thermal expansion can occur, although thermal expansion occurs naturally when heated to a softening temperature. However, the meaning of the softening temperature does not include the temperature at which the plate material flows in a liquid phase.

  The reason for this is that the metal material fixing method according to the present invention mechanically fixes metal members already in a solid phase to each other, for example, using an existing press device or the like, but extremely firmly and firmly. Because it specializes in.

  Here, one member (plate material) is necessarily heated, and the other member (shaft member) is at room temperature. Further, the heating temperature varies depending on the metal species of the plate material and cannot be uniformly determined. However, if the above-described conditions are satisfied, it is not necessary to heat to a higher temperature.

  As described above, the present invention does not need to heat both the plate member and the shaft member because the metal members are not “integrated fusion-bonded” with each other. Rather, it is preferable not to heat the shaft member. Later).

  Subsequently, the plate material is placed in the lower mold of the press device. When the shaft is pushed into the hole in the plate material or into the hole in the plate material, in any case, the shaft is placed on the surface opposite to the surface on the side where the shaft material is pushed in the plate material. It is desirable to form a hole (which may be a hole) for receiving the plate material extruded.

  This is because if the hole is not formed in the lower mold, the plate material is depressed (distorted) around the pushing portion of the shaft material. That is, the pushing portion of the shaft material in the plate material moves in the surface direction of the plate material, and the flatness is impaired.

  Then, a normal temperature shaft material is arranged in the upper die of the press device. At this time, the shaft material is positioned at a pressing position with respect to the plate material. In particular, the shaft member may be buckled and deformed when the shaft is gripped by the upper die at a position away from the portion pushed into the plate member in the axial direction on the opposite side. Therefore, the upper die only needs to grip the portion directly above the pushing portion in the shaft member.

  And in the case of this example, a shaft material is pushed in with respect to a board | plate material with a press apparatus. Of course, the plate material may be pushed into the shaft material, or both may be pushed together. At this time, pushing in the present invention means that the following conditions are satisfied.

  First, when the shaft member is pushed into the plate member over time with respect to the heated plate member, the shaft member is heated and softened by heat transfer from the plate member, and may not be pushed in due to deformation caused by the heating. Further, even if heat from the plate material is not transmitted to the shaft material, the shaft material must be pushed so as to scrape the inner surface of the hole of the plate material softened by heating.

  That is, the plate material undergoes shear deformation so that the inner surface of the hole is scraped off by the shaft member being pushed in, and the portion scraped into the hole provided in the lower mold is pushed out. Adhesive force is generated at the interface between the new surface of the inner surface of the hole of the plate material generated by shearing and the outer surface of the pressed shaft member. This is because this phenomenon is one of the principles for firmly fixing the shaft member and the plate member.

  Therefore, pressing in the present invention satisfies the conditions that heat from the plate material is not transmitted to the shaft material, and that an adhesive force is generated on the new surface with the plate material when the heat from the plate material is pressed. Means.

  After the shaft material is pushed into the plate material, it is naturally cooled. Since the plate material is expanded by the previous heating, it contracts as the cooling to room temperature proceeds. At this time, the shaft member and the plate member are already fixed by the adhesive force, and the shaft member is further firmly fixed by the tightening due to the contraction of the plate member by cooling the plate member. This phenomenon is another principle of firmly fixing the shaft member and the plate member.

  By doing in this way, the shaft member with a flange which fixed these both simply and firmly can be obtained from a board | plate material and a shaft material. Further, a plurality of shaft members may be pushed into the plate member, the plate member and the shaft member may be made of different metals, and the difference in hardness between the plate member and the shaft member is not strictly required. In other words, the present invention can be easily and firmly fixed even with dissimilar metals.

  As described above, the flanged shaft member created in this way is easy to create, but as a product, both the pull-out load of the shaft material to the plate material and the load of shaft rotation have increased. Therefore, a strong fixed state can be realized even under severe use conditions.

(Second form)
In the second embodiment, a recess is formed on the peripheral surface of the shaft member. The timing of forming the recess in the shaft member may be before or after forming the hole or hole in the plate material, but is preferably before heating the plate material. This is because the heated plate is naturally cooled while the recess is formed in the shaft.

  Moreover, a recessed part is formed in the perimeter of the area | region pushed into a board | plate material in a shaft material, or a part of surrounding surface. Further, the shape of the concave portion is not limited, but when a plurality of shafts that are long in the axial direction are formed in parallel with the circumferential direction, the rolling load of the shaft member can be particularly increased. When formed, the pull-out load can be particularly increased.

  The shaft member with a flange according to the second embodiment created in this way has an adhesive force at the interface between the new surface of the inner surface of the hole generated by the shearing of the pressing of the shaft member into the hole of the plate member and the outer surface of the pressed shaft member. In the same manner as the first embodiment, the plate material and the shaft material are firmly fixed later by thermal contraction due to natural cooling of the plate material.

  Here, in the second embodiment, in particular, when the plate material is contracted by heat, a part of the contracted and deformed plate material is fitted into the concave portion of the shaft material, so that the shaft material not formed with the concave portion is used. The mechanical strength corresponding to the shape of the recess, for example, the load for pulling out and rotating the shaft can be greatly increased.

  As an effect of the second embodiment, for example, if a recess is formed in the shaft member in consideration of a load in a direction to be strengthened (specialized), the working surface can be improved. That is, for example, by forming a recess whose diameter gradually decreases in the pushing direction over the entire peripheral surface, it is possible to increase the extraction (pushing) load specialized in the pushing direction. An effect that the pressure required for pushing can be reduced can also be obtained.

  Hereinafter, the experiment performed in order to confirm the effect is demonstrated about the fixing method of the metal member which concerns on this invention.

(Experiment 1)
Experiment 1 is a comparison between 1) the force when the shaft is pushed into the plate, and 2) the pull-out load when creating a shaft member with a flange through which the shaft penetrates the plate from the disk-shaped plate and shaft. did.

In the metal member fixing method (Example 1) according to the first aspect of the present invention and the metal member fixing method (Comparative Example 1) not adopting the present invention, the plate material and the shaft material have common specifications.
Plate material: The diameter is 48 mm, the thickness is 8 mm, and the metal type is JIS S45C.
Shaft material: The diameter is 8 mm, the length is 60 mm, and the metal type is JIS SCM435.
In the shaft member with flange, the thickness center of the plate material is located at the center in the axial direction of the shaft material.

Example 1
A plate material in which a hole having a small diameter of 10% with respect to the diameter of the shaft material is heated to 1000 ° C. (a temperature at which the metal species is easily deformed), and the shaft material is about 100 mm / second by a mechanical press device. It was pushed in at a stroke until the center in the axial direction was located at the center of the thickness of the plate. Thereafter, it was allowed to stand at room temperature for 5 minutes to obtain a flanged shaft member.

(Comparative Example 1)
A hole having a small diameter of 70% (exceeding the upper limit of the range of the present invention) with respect to the diameter of the shaft member is formed, and thereafter, in the same manner as in Example 1, it is heated, pushed in, and left to stand. Got.

1) Pressure required for indentation Example 1 was 180 MPa.
The comparative example 1 was 450 Mpa.

2) Pull-out load Example 1 was 2.4 tons.
The comparative example 1 was 2.0 ton.

  From the above, it was found that the pressure required for indentation in Example 1 was 2/5 times and the extraction load was 1.2 times that in Comparative Example 1.

(Experiment 2)
Experiment 2 is the same as Experiment 1 in creating a flanged shaft member in which the shaft penetrates the plate material from the disk-shaped plate material and the shaft material 1) Force when pushing the shaft material into the plate material 2) Pulling out The load was compared.

In the metal member fixing method (Example 2) and the first mode fixing method (Example 3) according to the second aspect of the present invention, the plate material and the shaft material have common specifications.
Plate material: diameter is 78 mm, thickness is 28 mm, and metal type is JIS S45C.
Shaft material: The diameter of the indentation region is 22 mm, the indentation length is 28 mm from the tip (total length 85 mm), and the metal type is JIS SCM420.
In the shaft member with flange, the thickness center of the plate material is located at the center in the axial direction of the shaft material.

  However, with respect to the shaft material of Example 2, before heating the plate material, the axial length was 8.7 mm in the direction opposite to the pushing direction at a position 23 mm from the tip, and the depth was 2 mm in the entire circumferential direction. Formed.

(Examples 2 and 3)
The plate material in which a hole having a small diameter of 5% with respect to the diameter of the shaft material is heated to 950 ° C. (a temperature at which the metal species softens so as to be easily deformed). The shaft member was pushed in at a stroke at a speed of about 100 mm / second until the center in the axial direction was located at the center of the thickness of each plate member. Thereafter, the flanged shaft member of each of Examples 2 and 3 was obtained by standing at room temperature for 5 minutes.

1) Pressure required for indentation Example 2 was 285 MPa.
Example 3 was 304 MPa.

2) Pull-out load Example 2 was 21.0 ton.
Example 3 was 18.9 ton.

  From the above, it was found that the pressure required for indentation in Example 2 was 0.94 times and the pull-out load was 1.1 times that in Example 3.

  In the example of fixing the shaft member and the plate member, in the plural members of the one member and the other member, the other member is not particularly limited as long as it does not cause plastic deformation or buckling when pushed into the one member, On the other hand, the member is not particularly limited as long as the strength at the time of heating becomes 1/2 to 1/3 of the room temperature strength of the other member, and is not limited to the overall shape and metal type, and can be widely applied.

  Further, the relative pressing between the one member and the other member does not transfer the heat of the heated one member to the other member at room temperature, and also causes an adhesion force on the new surface generated between the one member and the other member when the member is pressed. Then, there is no particular limitation.

Claims (3)

A method of fixing the both metal members of a plate-like one member and the shaft-like the other members, for one member of the plate, only 10-50% relative to the size of the cross-sectional shape of the shaft-like other members After forming a hole or hole having a shape similar to the cross-sectional shape of the other shaft-shaped member having a small size , the shaft-shaped other member has a strength at room temperature that is 1/2 to the extent that thermal expansion can occur. A method for fixing a metal member, characterized in that the metal member is heated to a temperature that is softened to 1/3 and the other shaft-like member that is at room temperature is pushed into the one plate-like member.   The metal member fixing method according to claim 1, wherein a concave portion is formed on a part or the entire circumference of a peripheral surface of the shaft-like other member that is pushed into the plate-like one member.   A flanged shaft member produced by fixing a plate-like one member and a shaft-like other member by the method of claim 1 or 2.