JPH084856B2 - Piston rod manufacturing method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hollow piston rod, and more particularly to a method of manufacturing a piston rod from a pipe material.

[0002]

2. Description of the Related Art As the oldest method of manufacturing this piston rod, it has been manufactured by casting.
It is also well known. However, casting has been rarely used in recent years because it is expensive in terms of cost due to pollution and machining after casting.

Instead, piston rods are manufactured by the method of machining steel. The mechanical processing is completed by processing work such as welding / cutting or punching. The machined product and the cast piston rod were machined in solid form. However, although the solid body has sufficient strength and rigidity in terms of strength, since it is a solid body, energy loss is large for use as a piston rod, and improvement is required.

As a result, piston rods using pipe material have been developed. For example, JP-A-57-314
As disclosed in Japanese Patent No. 25, the fixing pins are press-fitted on both ends of the tubular piston rod, and cold kneading is performed. A tubular piston rod, that is, round rods are fitted at both ends of the pipe material, and step portions are formed on the round rods, so the pipe material is compressed and joined to the round rod fitted by the cold hammer. The method of doing is adopted.

Further, in order to reduce the weight of the rod (hereinafter, piston rod is simply referred to as a rod), a raw material is a pipe material, and a closing member (a pin or a sphere) is inserted at an axial end of the material to form a pipe material together with the pipe material. A technique of shaving and integrating is disclosed in Japanese Patent Application Laid-Open No. 57-103948.

As described above, the rod is made of pipe material,
It is known to fix pins to both ends or one end of the pipe material. However, fixing by pinning a pin that is considerably thinner than the inner diameter of the pipe material also causes wrinkles on the inner diameter side. Also, if the pins are firmly fixed to both ends of the pipe, the hollow rod will be sealed on the inner diameter side with the rust-preventive oil that had adhered from the time of the pipe material, the oil and fat used in the above processing, and the water remaining. It will be heated and vaporized when it is heat treated,
May cause an explosion.

Further, Japanese Patent Laid-Open No. 63-119938 discloses a pipe forming method and apparatus. According to this forming method, the inner periphery is squeezed by the ironing punch while the outer periphery is unconstrained in response to the pipe coming off the die after drawing, so that the dimension of the inner periphery becomes constant. . Therefore, it is deformed so as to expand the outer peripheral side of the pipe formed by drawing, which is suitable for forming a product whose outer peripheral dimension can be ignored.

[0008]

DISCLOSURE OF INVENTION Problems to be Solved by the Invention Since pins are inserted into both ends or one end of a pipe and the diameter of the pipe is reduced and squeezed by cold kneading, the wall thickness of the pipe material becomes smaller than that of the pipe material as a base material. It is not preferable in terms of strength.

Further, when the pin is inserted while the shaving process is performed and the pin is firmly fixed together with the diameter reduction of the pipe material,
Wrinkles due to the shaving process are concentrated on the inner diameter side, and the pin is held in a wrinkled state, which may result in promoting material destruction from this end.

Therefore, the present invention uses a pipe material, and does not cause wrinkles on the inner diameter side which is reduced in diameter by swaging, and the edges and corners are thickened by the processing. An object of the present invention is to provide a manufacturing method of a rod that is processed and has a plug inserted into the shaft end.

[0011]

DISCLOSURE OF THE INVENTION The present invention made in view of the above-mentioned circumstances is a method in which a long pipe material is cut into a predetermined length .
One material and ₍₁ a), the slightly thinner mandrel than the hole inner diameter of the first material said first element <br/> material from one end of ₍₁ a) (10)
Is obtained by the second step of inserting the
Mandrel slightly thinner than the hole inner diameter of the second material ( _1b )
The third step of inserting (11) and performing the second drawing, and
The inner diameter of the hole of the third material (1 _c ) obtained in the third step .
Insert a slightly thinner mandrel (12) and perform the third squeeze.
It consists of the fourth step, and is the same as the first diaphragm and the second diaphragm.
In addition, the shaft end is made into the small diameter part (3) by the three steps of the third drawing.
Swage to reduce the diameter and fix the plug to the shaft end
In the method for manufacturing that the piston rod, the third stop end
After that, the shaft end formed into the small diameter portion (3) is subjected to induction heat treatment.
Rutotomoni, in the manufacturing method of a piston rod, characterized in that the plug shaft end fixed shrink fit.

[0012]

As described above, the drawing process by swaging is performed in three steps by inserting the mandrel (10, 11, 12), which is slightly thinner than the inner diameter of the hole of the material (1) , in the drawing process. , The mandrel (10, 11, 1
2) uses a material that is gradually thinned according to the sequence of processing steps, so the small diameter part (3) is formed from the material (1).
Against squeezing-diameter to the inside diameter direction, to prevent the occurrence of wrinkles. Then, the mandrels (10, 11, 12) work to maintain the circularity of the inner diameter and the outer diameter, and prevent the inner diameter from being extremely reduced. Furthermore, as the most notably, since alters as the wall thickness increases with increasing the smooth end of the pipe material (1), in the axial projecting like a rod, which or extruded always Although the load receives a buckling load, the reduced-diameter corner portion that bears the load is formed to have a large wall thickness, so that the load is distributed. Therefore, the load is an axial load as viewed from the usage state of the rod, and acts more effectively on vibration damping due to the load.

[0013] The following is a description I along an example to the accompanying drawings.

First, referring to FIGS. 1 to 3, the case of Embodiment 1 in which the small diameter portions 2 and 3 are formed in two steps at the end of the rod is shown in the order of the drawing process. The first blank _1a is obtained by cutting the pipe blank 1 into a certain length. In this example, the outer diameter D ₀ of the material 1 is 25,2 _mm and the thickness T _{0 is}
Uses 3.5 _mm pipe material.

[0015] from one end of the first material 1 _a, the grinding bars or round bar to insert the processed mandrel 10, although not shown, the diaphragm and squeezing the first material 1 _a in the central direction in the swaging machine processing To do. Thickness M ₁ of this mandrel 10
Used was 9 _mm . The reduced diameter portion 2 _{b has} an outer diameter D ₁ of 18 _mm and a wall thickness T ₁ of 4,5 _mm . And the small diameter portion 2 _b and the connecting portion 4 with the original material 1
_b (tapered portion in FIG. 1) has a thickness of 3,6 _mm near the point E and 3 near the point F.
The thickness has changed to 7 _mm , and is slightly thicker than the original thickness T ₀ . This not only first material 1 _a by drawing the longitudinally extending, in the connecting portion 4 _b formed by narrowing, it is considered that there is meat moves due to plastic deformation. The mandrel 10 is withdrawn when the first stop is completed, the second material 1 _b, and the sent to the next step.

[0016] The second material 1 _b, the mandrel 11 is inserted, in a manner similar to that formed by drawing the first material 1 _a, by squeezing the second small-diameter portion 3 _c toward the center in the swaging machine It is drawn. At this time, the mandrel having a thickness M ₂ of 6 _mm was used. The outer diameter D ₂ of the small diameter portion 3 _c is 13
_{mm 2} , and the wall thickness T ₂ is 3.5 _mm . This wall thickness T ₂
Is determined by the thickness M _{2 of the} mandrel 11 to be inserted and the inner diameter D _{2 of the} die to be swaged. Similarly, in the first drawing or the third drawing described later, it is determined by the mandrel 10 or 12 to be combined and the die for swaging.

In this second diaphragm, the thickness of the connecting portion _4c near the point E is 3,6 _mm , and the thickness near the point F is 3,7.
_mm , the thickness of the connecting portion 5 _c near the point K and the point L is about 4,6 _mm , respectively, and the thickness T ₁ at the substantially central portion of the small-diameter portion 2 _c does not change and changes on average. . This small diameter part 3
The thickness T _{2 of c} is set to be 3.5 _mm because the original thickness T ₀ is set when the mandrel 11 is inserted and the diameter is reduced.
This is because it is not thinner than that, and because it is considered that the inner diameter side is wrinkled so as not to wrinkle. Then, the small diameter portion 2 _c does not become thick, the swaging die to press the small-diameter portion 3 _c, 1 part of the material, the connecting portion 4 _c and the small-diameter portion 2 _c
The outer contour of the connecting portion 5 _c and the small-diameter portion 3 _c formed respectively, because the flow of compressed-diameter to the material was set to the outer end direction, the second material 1 _b is small-diameter portion 3 It extends toward the outer end of _c . After this second drawing, the mandrel 11 is extracted, and the third material _1c is obtained.

Further, the third material _1c has a thickness M ₃ of 4
_The mandrel 12 of _mm is inserted. Then, the inner diameter _{D 3} of the small-diameter portion 3 of the swaging die as 11,1 _mm, processed stop squeezed swaging machine. The wall thicknesses at this time were almost the same as the measured values obtained by the second diaphragm at the points E and F in the connecting portion 4 and the substantially central point J in the small diameter portion 2. K points in the connecting portion 5 is _{4, 0 mm,} and _{4, 0 mm} in L point, had slightly thinner as compared to the second aperture. Then, it is confirmed that the small-diameter portion 3 extends toward the outer end thereof, and that the thickness T ₃ is the difference between the inner diameter D ₃ based on the swaging die and the mandrel 12, that is, about 3,55 _mm. It was

As a result, in the third drawing step, the formed rod has its inner diameter determined by the inserted mandrel 12, conforms to the mandrel 12, and its outer diameter conforms to the swaging die, in other words, It is compressed by the mandrel 12 and the swaging die, and is clamped and reduced in diameter in the outer end direction so as not to generate wrinkles. Then, since the meat of the connecting portion 5 squeezes the small diameter portion 3 toward the center,
The mandrel 11 of the second drawing step to the difference (M 2 _{-M 3)} the inner diameter direction of the mandrel 12 in the third drawing process, is moved together with the meat of the connecting portion 5 _c. Therefore, the thickness T ₃ of the small diameter portion 3 is formed thick in the third throttle, and the inner diameter D ₃ of the mold in the small diameter portion 3 is set to be large in order to facilitate the outward flow of the material. 11 and the inner diameter of the mold D ₂
It is a little bigger than the difference.

When the third squeezing is completed, the mandrel 12 is pulled out and the product is discharged. In this product, the material extends in the direction of the outer end of the small-diameter portion 3, and the length may be made uniform, and in order to correct the irregularity of the outer peripheral edge, the product may be made by cutting or pressing. Furthermore, the convenience of use, the small-diameter portion 3 Jikushu may also be engraved machining a male screw.

Next, a second embodiment will be described in which the small-diameter portion 3 is connected to the raw material 1 by the taper-shaped connecting portion 5 as shown in FIGS. 4 to 6.

The second embodiment is the same as the first embodiment.
Using material _{1 a,} mandrel at drawing step 10,1
Since the thicknesses of 1 and 12 are the same, and the inner diameter dimension for squeezing the small diameter portion 3 in the swaging die is also the same, the same portions will be described using the same reference numerals and the same names.

[0023] In the first step, with respect to the first material 1 _a which is obtained by cutting a pipe member of the long, the thickness M ₁ mandrel 1
1 Insert the squeezing drawn a small diameter portion 3 _b. The inner diameter side swaging dies at this time, are to form part the outer contour of the connecting part 5 _b and the small diameter portion 3 _b of the material 1. By squeezing molding of the mold, near the point E in the connecting portion _{5 b} is _{3, 8 mm,} in the vicinity of point F has been molded a _{4, 5 mm.} The thickness _{T 1} of the small-diameter portion _{3 b} is in the _{4, 5 mm.}

[0024] In the second drawing step, by inserting the mandrel 11 of the thickness M ₂ to the second material 1 _b obtained in the first drawing step, swaging again. At this time, pulling the material by an amount that is thinner mandrel 11, the small-diameter portion 3 _c
With the material transition to, the E point of the connecting portion _{5 c} 3, 8
_It became slightly thin at 4.2 _{mm at the} point _mm and L.
As a matter of course, the thickness T _{2 at the} point G near the center of the small-diameter portion 3 _c
Was 3.5 _mm .

Also, the third material 1 obtained in the second drawing step
A mandrel 12 having a thickness of M ₃ is inserted into _c and further swaged. In this case as well, the same as the above-mentioned second diaphragm, but since the mandrel 12 is made thin, the connecting portion 5 _c is formed thinner than the connecting portion 5 _b . That is, at the point E in the connecting portion 5, 3,
8 _mm is the same, but at point L it is 4,0 _mm , and the small diameter part 3
The thickness T ₃ at the approximate center of is about 3.5 _mm . This indicates that when the small-diameter portion 3 is compressed and compressed, the meat of the connecting portion 5 is pulled to some extent and transferred to the small-diameter portion 3, and the small-diameter portion 3 extends in the longitudinal direction. And thin part 3
The diameter M ₃ of the mandrel 12 and the inner diameter D _{3 of the} swaging die are made to facilitate the material transfer at the same time as the diameter reduction at
Is slightly larger than the difference between the mandrel 11 of the second diaphragm and the inner diameter D ₂ of the swaging die to allow a margin.

As described above, since there is no great difference between Example 1 having the connecting portions 4 and 5 and Example 2 in which the connecting portion 5 is formed, there is no great difference in the drawing process and the process after the drawing process, and therefore detailed description will be given together. To do.

As described above, the rod which has been finished by drawing is subjected to high-frequency heat treatment and tempering for the small diameter portions 2 and 3,
A plug (not shown) is fitted / shrink-fitted on the shaft end of the small-diameter portion 3. Can also be heat treated in a furnace, because unless devised container when a heat treatment refining a furnace, thereby to generate a bending or warping of the rod was molded into much trouble straightness, the need to remove the strain Occurs. In addition, inserting this plug increases the strength at the shaft end of the small diameter portion 3,
Also, the plug is driven in for the purpose of increasing the contact area of the end portion, and the plug is shrink-fitted and fixed simultaneously with the high frequency heat treatment. Induction heat treatment can prevent partial bending compared to heat treatment in a furnace and can perform partial heat treatment, and at the same time as heat-treating the small-diameter portion 3 in which the plug is work-hardened, it can be fixed.
A tighter bond can be made than a press bond or a mating bond .

In the first embodiment, the small diameter portions 2 and 3 are provided at both ends of the material 1, and in the second embodiment, the small diameter portions 3 are provided at both ends of the material 1 to form a rod. The small diameter portions 2 and 3 according to the example 1 and the small diameter portion 3 according to the embodiment 2 at the other end may be formed in one rod. In addition, although a small diameter portion may be formed only at one end, in any of such cases, the wall thickness can be smoothly changed from the small diameter portion 3 at the shaft end to the raw material 1. Since the thickness becomes thick at the corner portion from the portion 3 to the connecting portion 5, the load is quickly transmitted to the raw material 1 portion in the central portion when viewed from the use. The diameter of the central portion is larger than that of the small-diameter portion 3 and the thickness of the corner portion is thicker, which serves to damp vibrations.

Further, using the above manufacturing method,
It is needless to say that the small diameter portion 3 is formed at both ends of the material 1 and can be applied to a shaft used in a general machine or a shaft in a vehicle.

[0030]

Process according to the present invention described above, according to the present invention is a material and the pipe material, but were subjected to drawing by swaging the ends of said workpiece, in that drawing, the mandrel also less Since the small diameter part is pressed three times by exchanging it, the compactness of the processed surface peculiar to plastic working can be obtained, and the work hardened small diameter part can be tempered at the same time as a plug and shrink-fitted, and fixed. If you want to repeat a violent linear motion like a piston rod,
Coupled with the thickness at the corner portion between the small diameter portion and the connecting portion is thicker, then dispersed and transmitted to the material of the quickly thick diameter load transmitted to the small diameter portion, the load in the middle is propagated As a result, it has the same strength as a solid shaft, though it is a hollow pipe. Furthermore, since the plug is shrink-fitted to the small diameter portion at the shaft end, without reducing the thickness of the small diameter portion into which the plug is fitted, and without changing the outer peripheral dimension of the small diameter portion, It can be firmly fixed.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view copying a second step in a first embodiment according to the present invention.

FIG. 2 is a partial cross-sectional view copying a third step in the first embodiment of the present invention.

FIG. 3 is a partial cross-sectional view similarly showing a fourth step in the first embodiment.

FIG. 4 is a partial cross-sectional view copying a second step in the second embodiment of the present invention.

FIG. 5 is a partial cross-sectional view similarly showing a third step in the second embodiment.

FIG. 6 is a partial cross-sectional view of a fourth process similarly embodied in the second embodiment.

[Explanation of symbols]

1 Material 1 _a 1st material 1 _b 2nd material 1 _c 3rd material 2 Small diameter part 3 Small diameter part 10 Mandrel 11 Mandrel 12 Mandrel

Claims (1)

[Claims] 1. A long pipe material is cut into a certain length.
The first material, the line of the first aperture by inserting a slightly thinner mandrel than the hole inner diameter of said first material from one end of said first material
The second step and the inner diameter of the hole of the second material obtained in the second step
Insert a slightly thinner mandrel and perform the second diaphragm.
Process, and further inside the hole of the third material obtained in the third process
Insert a mandrel slightly thinner than the diameter to perform the third stop.
Consisting of a fourth step, the first throttle and the second throttle and
A thread for reducing the shaft end to a small diameter portion by the three steps of the third drawing.
Aging process, in the production method of the piston rod to secure the plug to the shaft end, the after the third diaphragm ends
The shaft end, which has been made into a small diameter part, is subjected to high frequency heat treatment
A method of manufacturing a piston rod, characterized in that the plug is shrink-fitted and fixed to the end .