JPH0241900A - Method and device for shearing round bar stock - Google Patents

Abstract

PURPOSE:To prevent a shearing power being reduced and the round bar stock side face being deformed at shearing time by setting the notch groove of a round bar stock between a receiver and push down fitting and concentrating stress into this notch groove. CONSTITUTION:The both end parts of a round bar stock 1 are held by the chuck of a notch grooving machine 7, the round bar stock 1 is revolved with pressure-fitting notch grooving blades 731, 732, 733... with the necessary press force to the outer peripheral face of this round bar stock, and the notch groove 2 in V shaped section is formed a lot on the outer peripheral face of the round bar stock 1 at specified pitch by the grooving blades 731, 732, 733.... This round bar stock 1 is then set on a shearing machine, after supporting the lower part thereof by a receiver 3 and supporter 6, a down pusher 5 is descended, stress is concentrated to the V shaped notch groove 2 located between this down pusher 5 and receiver 3 and the round bar stock 1 is sheared at the groove 2 position with a small shearing force.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention can be used in the mechanical industry, cold forging, precision forging, etc. to produce a forged material to the required length with high precision, minimize changes in external shape, and use less energy. The present invention relates to a shearing method and an apparatus therefor.

[Conventional technology]

In cold forging, a forging material is cut into a required length by shearing or cutting from a round bar having a predetermined diameter that is set in accordance with the size and shape of the product to be forged. Due to the nature of the forging process, this forging material is required to be sheared or cut at right angles to the center axis of the forging material, and it is inappropriate to have deformed or burred sides or cut surfaces. . For this reason, in the past, a round bar of a required diameter was cut by sawing or milling, and even cutting and chamfering were performed to obtain the precision of the cut surface.

[Problem to be solved by the invention]

However, when a saw is used to cut a round bar into a fixed size, the cutting time becomes longer and material is lost due to the width of the saw blade. In addition, when shearing, as shown in Figure 7, a dimensional method stopper is placed in front of the shearing position where the shear receiving blade and cutting blade are vertically opposed, and a round bar material is brought into contact with this dimensional method stopper. However, since the dimensional method is used, the round bar material is rubbed during shearing, causing damage to the sheared surface, and frictional heat is generated at the end surface, which becomes high heat and causes cracks to occur on the material cross section. do. On the other hand, since an overload is generated on the stopper of the cutting machine, the life of the stopper is extremely short, and dimensional measurements cannot be carried out with high accuracy.

Furthermore, in order to support the round bar material to be sheared using round blades for the receiving and cutting blades, supports are provided to provide parallelism to the round bar material, but distortion and deformation at the shearing surface are avoided. arise. This state is shown in FIG.

Although the distortion of the sheared surface portion varies depending on the diameter and material of the round bar, it generally reaches 5 to 10 degrees, and the sheared end surface also has a shape in which the central portion is largely gouged out. For this reason, when the forged material IA that has been sheared to a fixed size is set in a forging die, the axis of the material is inclined as shown in FIG. 9(B), making it impossible to obtain a highly accurate forged product.

In order to solve this problem, after shearing, both sheared end faces are machined or polished to improve the accuracy of the sheared surface, so the processing after shearing is time-consuming.

The purpose of the zero development is to eliminate the above-mentioned drawbacks by forming notch grooves in advance at the shearing position before shearing the round bar.

[Means to solve the problem]

A notch groove having a ■-shaped cross section is formed in advance on a round bar material for forging having a required diameter at the shearing position, and the said notch groove is set so as to be located between the receiver and the push-down tool. Shear so that stress is concentrated.

A double-sided chuck that supports both ends of a round bar and makes it possible to transport a grooving block in which a large number of notched grooving blades are adjustable at a predetermined pitch on the outer circumferential surface of the round bar. a notch grooving machine, which is disposed in It consists of a shearing machine equipped with push-down tools and receivers on the top and bottom to concentrate stress on the grooves and shear the material.

〔Example〕

The present invention will be explained below based on the illustrated embodiments.

A material such as a round bar (hereinafter referred to as round bar material) that is made of a metal that matches the material of the product manufactured by cold forging or precision forging (hereinafter referred to as round bar material) is made to a length that matches the thickness and shape of the product. A shearing position is determined for each dimensional interval, and a large number of notched grooves 2, 2, . . . are formed at the shearing positions for each predetermined dimensional interval. The notched groove 2 is formed on the outer circumferential surface of the round bar 1, if necessary, so as to have a V-shaped cross section and a sufficient depth so as to have a chamfered shape on the sheared end surface.

In this way, the notch grooves 2 are formed on the outer circumference of the round bar 1 at a fixed pitch, and the grooves are sheared. In order to suppress the reaction, this receiver is provided with a presser 4 that presses the round bar above the tool 3 from above, and the receiver holds the round bar 1 from above and below between the tool 3 and the presser 4. Moreover, the shearing position is the notch groove 2.
The receiving tool 3 is placed on one side of the notched groove 2, and the pushing tool 5 is placed on the opposite side and is movable up and down to a position above the round bar 1.
to be placed. At this time, the receivers are provided with the tool 3 and the pusher 5 so that the stress applied to the round bar 1 is concentrated at the bottom of the ■-shaped notch 12.

In addition, 6 is a support tool, and the push-down tool 5 is a support so that the round bar material on the side to be sheared between the tools 3 (hereinafter referred to as forged material IA) and the round bar material 1 are supported concentrically and parallel to each other. Eggplant.

When carving the notch grooves 2 in the round bar material 1, it is possible to cut the notch grooves 2 at regular pitches using a cutting tool, but in order to do this more efficiently, the notch grooves 2 as shown in Figs. 3 to 6 are used. Input machine 7 can be used. This notch grooving machine 7 has a chuck 7 that holds and rotates both ends of a round bar 1 in a centered manner.
1.72 are arranged opposite to each other, and a plurality of grooved blocks 73a, 73b, 73c are provided between both chucks 71.72.
, 73d are arranged on each slotted block 73.
At positions a, 73b... are alignment support roller devices 74a, 74 that rotatably support the round bar 1 in an alignment manner.
b, 74c, and 74d, and each introduction block has a plurality of notched groove blades 731 and 732 at a fixed pitch.
, 733..., each notched grooved blade 731゜7
32... Adjustment blocks 741, 742, 743 between
..., the adjustment blocks and the notched grooving blades are arranged alternately, and a part of the notched grooving blades is brought into contact with the slope 741S of this adjustment block, and the bottom of this block 741 is brought into contact. By moving the wedge-shaped adjustment tool 751 in contact with the adjustment blocks 741, 742..., the adjustment blocks 741, 742, etc. are adjusted to protrude and retract, that is, to protrude and retract in the radial direction of the round bar 1, and the notched groove blades 731, 732, which are in contact with the adjustment blocks 741, 742... 733 pitch. Further, the pitches of the notch grooving blades of each of the grooving blocks are equal, and by synchronizing the movement of the adjustment tool 751 of each block, the pitch between the notch grooving directions of all the large groove blocks can be varied.

The grooved blocks 73a, 73b, 73c,
73d each has a notched grooved blade 73 located at the front row position.
1 as a base point, and the other notch grooving blades 732, 733, 734 adjacent to this through each adjustment block are all arranged at equal intervals, and the notch grooving blade 7 serving as this base point
By moving 31, all other notched and grooved blades 7
By moving 31, all other notched and grooved blades 7
32, 733... are simultaneously moved by an equal distance to adjust the interval to be sheared. In this way, when it is necessary to adjust the shear length according to the diameter of the round bar,
It will be adjusted. The notch grooving blade 731 at this base point (origin) is moved by rotating the screw rod to move the core force, but it can also be done by moving a wedge-shaped adjusting tool 751 as shown.

In this way, by adjusting the notch grooving blade 731 of the block, the notch grooving blade 731 that is the base point of each block and all other notch grooving blades can be moved simultaneously, and the pitch between the notch grooves can be adjusted. It is.

Using the apparatus configured as described above, the notch grooving machine 7 first cuts the notches I42 at the predetermined pitches L and L on the round bar t1. Then rotate the round bar 1 clamped by the chuck of the notch grooving machine, or fix the round bar 1,
It is assumed that either the grooved block 73 is rotated along the outer circumferential surface of this round bar material or the other is selected. Next, a method for rotating the round bar material will be explained.

When the round bar material 1 is rotated while the notched grooved blades 731, 732... are pressed against the outer peripheral surface of the round bar material with the required pressing force, the round bar material is shaped into the grooved cuffs 31, 732, 733... A large number of notch grooves 2 having a V-shaped cross section are simultaneously formed at predetermined intervals on the outer peripheral surface of the material 1. At this time, the material in the V-shaped notch groove moves toward the outer circumference and bulges on the outer circumferential surface of the round bar material as shown in FIG. 6(B). The image is shaped as shown in Figure 6 (C).

Next, the round bar 1 having a large number of notched grooves 2 cut at a fixed pitch is set in a shearing machine. The lower part of the round bar 1 is supported by the support tool 3 and the support tool 6, arranged and fixed in parallel, and when the push-down tool 5 is lowered, the push-down tool 5 and the support tool 3 form a ■-shaped notch groove 2 between them. Stress is concentrated in the groove and sheared accurately in the groove.

At this time, if the diameter of the round bar 1 is Do and the diameter of the notched groove is Ds, then Do area/D s area It is known that the stress concentration coefficient 1 of a V-shaped groove is several times larger, so the notch was added. A round bar can be cut with less shearing force than a round bar of the same size without notches.

The one shown in FIG. 11 is a different embodiment, in which a V
This is a device that simultaneously carves a 1M2 letter-shaped notch and shears it.In this case, the chuck holding one end of the round bar 1 is fed by a fixed pitch, and the notch 71ζ-entering blade 73 is rotated to cut the notch groove 2. to be engraved. At this time, notch grooves are cut one by one by feeding the round material at regular pitches. Shearing is performed at the front position where the notch grooves are carved.

〔Effect of the invention〕

The present invention provides the following effects. V
The shear force decreases due to the cross-sectional reduction and stress concentration caused by the shaped groove. This means that the surface pressure on the receiving surface and the pressing surface is reduced, and the surface pressure on the side surface of the material is sheared within the elastic deformation, which prevents deformation of the side surface of the material and also reduces the horsepower of the shearing machine. .

Since the sheared surface is pre-machined with a V-shaped notch groove, the perpendicularity can be maintained. Furthermore, this notched groove is chamfered on the sheared surface, which prevents damage and allows easy installation at the center position when pressurizing.

There is no need to accurately adjust the spacing between the cutting blade and receiving blade, eliminating maintenance of the cutting blade and improving shear dimensional accuracy. Accurate shearing can be performed without installing a stopper, simplifying the equipment. Material loss can be reduced to substantially zero.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing the shearing method, Fig. 2121 is an enlarged view of the shearing position, Fig. 3 is a plan view of the notch grooving machine, Fig. 4 is an enlarged side view, and Fig. 5 is an enlarged view of the notch grooving blade. An enlarged view, FIG. 6 is an explanatory diagram of a method for forming notched grooves, FIGS. 7 and 8 are a known shearing method, FIG. 8 is an explanatory diagram of sheared residue, and FIG. 9 is an explanatory diagram during pressing. , FIG. 10 is an explanatory diagram of a known shearing blade, and FIG. 11 is a diagram of a different embodiment.

Claims (2)

[Claims] (1) A notch groove having a V-shaped cross section is formed in advance at the shearing position in a round bar material of the required diameter used for forging, and the notch groove is set between the receiver and the pusher, and the stress is applied to the notch groove. A method for shearing round bars, which is characterized by shearing in a concentrated manner. (2) A grooving block, in which a large number of notched grooving blades are adjustable and arranged at a predetermined pitch on the outer circumferential surface of a round bar, supports both ends of the round bar and can be transported. A notch grooving machine is provided with a notch grooving machine, which is provided with a centering roller that is disposed on both chucks and cooperates with the grooving block to hold the round bar material in a centered manner, and a notch grooving machine that is provided with a notch groove. A device for shearing round bars for forging, which consists of a shearing machine equipped with push-down tools and receivers on the top and bottom to concentrate stress in each groove and shear the material that has been formed.