JPS58221017A - Blank for wounded bush bearing and cutting die for obtaining thereof - Google Patents

Abstract

PURPOSE:To make it possible to easily cut a wound bush forming plate having inclined end faces, by using cutting dies comprising a lower cutting blade of a square cross-sectioned shape, an inclined block beginning from a position horizontally retracted from the share point of the lower cutting blade and an upper cutting blade of a square cross-sectioned shape. CONSTITUTION:A plate member 1 is cut by using cutting dies comprising a lower cutting blade 14 of a square cross-sectioned shape, an inclined block 15 having an inclined surface beginning from a position horizontally retracted from the share point of the lower cutting blade 14 and an upper cutting blade 13 of a square cross-sectioned shape. At first, when the plate member 1 is fed to the cutting dies, a gap 20 is formed between the inclined surface 16 and the plate member 11. Meanwhile, the shearing and plastic deformation of the plate member 1 is initiated when the upper cutting blade 13 is lowered, and the cutting is completed when the upper cutting blade 13 is fully lowered. The cut plate member 1 is made into a wound bush blank having inclined surfaces 7b', 8b' at the axial end faces thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cutting die for obtaining a blank for a wound bushing bearing. ~More specifically, it relates to a blank having an inclined side surface so that a chamfer is automatically formed on the annular end surface when used as a wound bush bearing, and a cutting die for obtaining such a blank. It is something.

In general, chamfers provided on the annular end face of cylindrical bearings, including wound bush bearings, (1) avoid local contact with the mating material;

■Prevents damage to the mating shaft material.

0 bearing damage prevention.

Prevents θ galling.

■Ensure normal force ``contact'' against the bearing sliding surface of the mating shaft material.

■Easy to insert the mating shaft material into the bearing.

■Easy to press-fit the bearing into the housing.

■Avoid other inconveniences in general handling due to the presence of corner parts.

It is carried out for such purposes.

The size of the chamfer is determined by taking into account the wall thickness and diameter of the bearing, and it is common to chamfer a large chamfer for large and thick bearings, and a small chamfer for small and thin bearings. Usually, the edges are cut at a 45 degree angle, and when the length of each cut edge is 1 mm, it is called 1C chamfering, and when it is 2 mm, it is called 2C chamfering.

When chamfering is applied, unless the chamfer is intended to have a special function for purposes other than those mentioned above, very strict consideration is not given to the chamfer in design or manufacturing. The chamfering applied to the inner diameter end face and the outer diameter end face of the bearing is usually done to the extent that the edges are lightly scraped (scraped off), leaving the flat part at the end of the bearing. Avoid chamfering so large that no flat portion remains.

Simply put, there is no need to do so, and if a chamfer is made that large, a new corner will be created there, which will serve one of the purposes of the chamfer mentioned above. be.

Furthermore, in some cases, the effective area of the bearing sliding surface may be reduced, leading to problems such as the design surface pressure exceeding the design surface pressure or the permissible surface pressure. Furthermore, we can add to this the reason that it looks so strong that it is hard to get used to it.

Chamfering on bearings is usually done by cutting with a knife.

If the bearing material is plastic or a sintered alloy, cutting can be carried out in a mold during molding, but in the case of bearings made of castings or thin metal plates as in the present invention, cutting is usually carried out.

However, in extremely small diameter cylindrical bearings, for example, diameters of several millimeters or less, there are problems in various aspects, even if only a small amount is removed by cutting.

In other words, ■The effort required for chamfering work is almost the same as that required for small-sized bearings.
Chamfering costs account for a higher proportion of manufacturing costs.

■Removal of cutting chips that have entered the inner diameter of the bearing is more difficult than in the case of small and medium-sized bearings.

■If done manually, handling is extremely complicated.

There are other issues that need to be resolved.

However, in such extremely small-diameter cylindrical bearings, problems that occur in large-diameter bearings, medium-sized, and small-sized bearings do not pose much of a problem.

In other words, even if a large chamfer as mentioned above creates a new corner, it may hurt your hand or damage the parts, partly because bearings with extremely small diameters are lightweight. It can be said that there will be no problems in general handling such as contact and damage, and even if the chamfer is large compared to the wall thickness and diameter, the absolute amount is 1" 1C. Since it is an order, it is actually a very small blue chamfer, so if you carefully observe it or force it, you won't be able to tell its condition. Such problems are unlikely to occur.

The inventors of the present invention have carried out extensive experiments to solve the problem in view of the above-mentioned circumstances, and have come up with the present invention.

In other words, instead of the conventional method of making a bush and then chamfering, the blank itself was improved so that a chamfer was automatically formed on the annular end surface of the bearing when it was made into a rolled bush bearing. is added.

Specifically, when a wound bush bearing is used, both side edges of the blank on the side that form the conch end face protrude from the front and back surfaces of the blank with sloped surfaces, respectively, and the side slopes meet to form a cut surface that forms a ridgeline. The present invention provides a blank for a rolled bush bearing that is constructed with a long life, and a cutting die for obtaining such a blank.

In the present invention, the term ridgeline does not necessarily mean only a geometric "line" with no width, but from a microscopic perspective, it may include a small or medium-sized flat or curved surface. It also includes those who are present. In other words, the flat and curved surfaces are negligibly small compared to the length of the inclined surface provided on the blank, which is easily understood from the blank manufacturing process of the present invention detailed below. There will be.

Here, the plate materials used for forming the blank of the present invention are cold-rolled steel plates, aluminum alloy plates, copper alloy plates, etc., and the plate material surface that forms the bearing sliding surface has self-lubricating and wear-resistant properties. Includes board materials that have been previously surface-treated to impart properties.

The plate material has a predetermined width so as to obtain a wound bushing bearing with a predetermined diameter, and the plate material is cut during a certain cutting process and in such a way that the force cut surface is obtained as described above. Assume that the blank is the height of the bush.

It is known that when a plate material is cut using a normal cutting die, the cut surface does not necessarily form a straight line but has a complicated shape, as shown in FIG.

(1) is the plate material, (2) is the top surface, (6) is the back surface,
(4) is the sag that occurred on the upper surface side, (5) is the fracture surface that occurred on the back side, and (6) is the sheared surface that is formed almost at right angles to the surface of the plate material between them. As a result of various experiments, the present inventors supported the plate at a certain angle of inclination to the cutter, and effectively utilized the compressive stress of the cutter applied to the plate to be cut. A blank with a cut surface having a desired ridgeline was obtained by mainly producing shear on the surface and plastic deformation of the material on the opposite surface.

Figure 2 is a vertical cross-sectional view of a conventional cylindrical bearing, (7a) (
7a) is an inner diameter chamfered portion, (&l) is an outer diameter chamfered portion, and (9) (9) is a flat surface portion formed on both end faces.

Figure fa3 is an enlarged vertical cross-sectional view for explaining the chamfered shape of the bearing of the present invention, (Th) (a-j, respectively, the inner diameter chamfered part, (Elx) (8c) the outer diameter chamfered part, and (10) and (1)) are the ridgeline portions formed by these curved portions.

FIG. 4 is a perspective view of a blank for obtaining the chamfered bearing shown in FIG. )(1ω
is the ridgeline.

FIG. 5 is an enlarged longitudinal cross-sectional view of the blank shown in FIG.
The slope (%) <yc>, (+) (ag) is not necessarily constant, and the slope angle does not indicate 45 degrees. This point will be discussed later, but when it is used as a wound bush bearing, there is no particular problem in its role as a chamfer.

FIG. 6 is a vertical sectional view of a cutting die for obtaining the blank shown in FIGS. 4 and 5.

(11) is an upper mold, and (t2) is a lower mold, each of which is fixed to a press (not shown).

(15) is fixed to the upper die (11) via the holding block (C) with the upper cutting blade, and fixed to the lower die (V) via the holding block (i) with the lower cutting blade to (14). has been done.

The upper cutting blade (15) has a cutting edge whose profile in longitudinal section is approximately at a right angle, and the lower cutting blade (M) similarly has a cutting edge which is at a right angle.

(5) is approximately 7ON of the thickness of the plate material (1) to be cut.
A holding block (an inclined block fixed on camphor tree) is set back in parallel from the cutting edge of the lower cutting blade (14) with a limit of
(The slope is the inclined surface. The inclined surface (16) is formed at an angle in the range of 60 to 45 degrees with respect to the upper surface of the lower cutting blade (14).

(17) is a flat surface formed between the cutting edge of the lower cutting blade (14) and the tip of the inclined surface of the inclined block (15>), which corresponds to the amount of movement retreated from the cutting edge by a certain limit as described above. However, the flat surface portion (j7) forms a part of the upper surface portion of the lower cutting blade (14).

(18) has a vertical wall surface that supports the lateral stress that the upper cutting blade (13) receives when cutting the plate material (1) from its back side and guides its vertical movement. This is a backup guide that keeps the blade clearance constant and is fixed to the lower die (12).

(υ) is a guide post whose one end is fixed to either the upper mold (11) or the lower mold (kiri), and guides the mold so that its movement is maintained normally.

Mold members such as backup guides and guide posts whose role is to guide and support the cutter or guide the mold itself may have a configuration other than that shown in the drawings, and in some cases, one of them may be omitted. It is possible.

Attached to these main mold members, the inclined surfaces of the inclined blocks (
A section is provided on the top for guiding and supporting the board to be cut, but is not shown here.

7A□□□, 7B, and 7C are vertical sectional views schematically showing step by step the state in which a plate material is cut by the cutting die of the present invention. However, 17 boards are drawn with their thickness enlarged.

Figure 7A shows the state in which the plate material (1) is supplied to the cutting die, and the plate material (1) is attached to the cutting edge of the lower cutting blade (g) and a part of the inclined surface (16) of the inclined block (15). It is temporarily fixed on the inclined surface (16) while maintaining this state.

(2]) is the inclined surface 1 (16) and the flat surface of the lower cutting blade (
7) and the gap formed by the back surface (3) of the plate material.

Figure 7B shows the state in which the upper cutting blade (the blade) has descended and started cutting the plate material (1). Shearing and plastic deformation of the plate material (1) by the upper and lower cutting blades has begun, and the gap (2]) is almost Disappear.

FIG. 7C shows a state in which the upper cutting blade (15) has further descended to reach the blade surface of the lower cutting blade (14), and cutting has been completed. Although the cut blank is not in contact with the upper and lower cutting blades as shown, it is shown for convenience in order to show the mutual relationship between the cutting surface, that is, the inclined surface formed on the blank, and the upper and lower cutting blades. It was shown like this.

The cutting operation described above is repeated in sequence to obtain a blank. FIG. 5 shows an enlarged view of the blank thus obtained.

Inclined surface part) is the plastic deformation surface caused by being pressed by the upper surface of the lower cutting blade, (ml) is the sheared surface by the upper cutting blade,
(7d) is the sheared surface by the lower cutting blade, and (i) is the plastic deformation surface caused by being pressed by the lower surface of the upper cutting blade. Although these sloped surfaces are not of equal length, they are forced to face each other. The lengths of the slopes are approximately equal.

Here, the length of the inclined surface (C) is the length of the flat surface (7) of the cut mold.
approximately corresponds to the length of

When designing the cutting die, the material strength of the plate to be used, especially the shear strength, plastic deformability, and thickness of the plate are taken into consideration, and the inclined block (15) for forming the flat surface (i7) described above is ), the backward movement amount (the holding block of the lower cutting blade (fixed in position) at the moved position, and the inclination angle are determined).

According to the experiments conducted by the inventors, when the plate material to be cut is a cold-rolled steel plate and the plate thickness is in the range of 0.5 to 25 mm, the above backward movement amount is calculated as the plate thickness. 5
When the inclination angle was set within the range of 65 to 40 degrees with 0% as the limit, good results were obtained without any noticeable irregularities in the inclined surfaces of the obtained blank.

As explained above, in the wound bush bearing blank of the present invention, an inclined surface that will become a chamfer when the bush is made into a bush can be formed on the side surface of the blank in the second cutting process.

Although these inclined surfaces have some irregularities, they do not have any adverse effect on the bearing performance and do not significantly impair the appearance. In fact, it eliminates the need for a separate chamfering process, and eliminates the inconvenience of chips sticking to the sliding surface, sticking to the sliding surface and remaining there, and damaging the mating material during use. The benefits are far greater.

Another feature is that when cutting using a normal cutting die, the fractured surfaces and sagging portions that sometimes occur are almost invisible.

[Brief explanation of drawings]

FIG. 1 is a side view showing the state of a cut surface when a board is cut using an ordinary cutting die that is not based on the wood invention, and FIG. 2 is a longitudinal sectional view of a conventional cylindrical bearing. 3 is an enlarged vertical cross-sectional view for explaining the chamfered shape of the wound bush bearing of the wooden invention, FIG. 4 is a perspective view of a blank for obtaining the bearing shown in FIG. 3, and FIG. FIG. 5 is an enlarged vertical cross-sectional view of the plan shown in FIG. 4; FIG. 6 is a vertical section of the cutting die of the present invention, FIG. 7A, and FIG. 7B.
FIG. 7C is a longitudinal cross-sectional view schematically showing step by step the state in which the plate side is cut by the cutting die of the present invention. (7b) (7c) (8b) (I3C): Chamfered part, (1]) (1o): Ridge line part, (Sai (7go) (Moe)
(ml): tilting surface part, (11): upper die, (cutting: lower die, (β): upper cutting blade, (14): lower cutting blade,
(?5): Slanted block. Patent applicant Oiles Industries Co., Ltd.

Claims (4)

[Claims] (1) Both side edges of the blank on the side that form the annular end surface of a wound bush bearing protrude from the blank front M1 and the back surface with inclined surfaces, respectively, and both inclined surfaces come together to form a ridgeline and have an eroded cut surface. A blank for a rolled bush bearing, characterized by the following structure: (2) A lower cutting blade that is fixed to the lower mold and has a profile with a vertical cross section that is approximately at right angles, and the thickness of the plate material to be cut, which is 7096 mm.
is fixed there at an angle of 30 to 45 degrees with respect to the upper surface of the cutting blade at a position parallel to and set back from the cutting edge of the lower cutting blade with a limit of Consisting of an inclined block, an upper cutting blade that is fixed to the upper die and has a profile with a longitudinal section that is approximately at right angles, and a die member that guides and supports the movement of the blade without causing misalignment between the upper and lower cutting blades. Features a cutting mold for obtaining blanks for bearings with 17 turns of bushings. (3) The mold member that guides and supports the movement of the blade is a backup guide having a vertical wall surface that guides and supports the back surface of the upper cutting blade, and the backup guide is fixed to the lower mold. A cutting die for obtaining a blank for a wound bushing bearing according to claim 2. (4) The mold member that guides and supports the movement of the blade is a backup guide fixed to the lower mold and/or a guide post whose one end is fixed to either the upper mold or the lower mold. Claim 2: A cutting die for obtaining a blank for a soft 7 wound bushing bearing. −