JP2001030038A - Method for forming flange in upsetter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a flange at the end part of a large-sized shaft without lowering productivity by using a device low in equipment cost. SOLUTION: In an upsetter 1 for forming a flange 3 by clamping the shaft with a die while making the one end part of a shaft 2 having both end parts into a free state and making another end part into a projecting state, and performing the hot upsetting of the end part of the projecting shaft, when upsetting the end part of the projecting shaft, an upsetting condition is set so that an elongation in the axial direction of the free end of the shaft 2 is allowed by a prescribed quantity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming a flange at an end of a shaft by an upsetter (upsetting forging machine).

[0002]

2. Description of the Related Art As a technique for forming a flange at an end of a large shaft such as a marine propulsion shaft or an intermediate shaft, for example, Japanese Patent Publication No.
The one described in -12333 is known. In this conventional technique, a root with a flange at one end of a shaft is guided by a guide mold without clamping, and a forming axial force applied to one end of the shaft is supported at the other end of the shaft. A flange was formed at one end of the shaft. The guide mold,
It is provided to prevent the guiding shaft portion from being compressed or buckled in the axial direction, and does not have a function for clamping the shaft portion from the radial direction. Was.

[0003] In the above-mentioned publication, as a "production method using an upsetter", "this is a method of gripping a shaft diameter and performing upsetting forging (hot) on a protruding portion to form a flange. Because it is very large, the current upsetters currently use only small diameter ones. " In other words, the conventional flange forming technique using an upsetter is to completely grip the shaft diameter so that the shaft does not slip (elongation of the free end of the shaft).

[0004]

In order to support the conventional non-molding shaft end, a moving device, a position detecting device, a fixing device, and the like for the supporting portion are required. Was expensive. In such a facility, when the flange is formed, it is necessary to position and fix the bearing in accordance with the length of the shaft to be machined. In each case, a setup change is required, and the productivity is reduced. There was a problem that it was not suitable for the production of varieties.

On the other hand, in the conventional upsetter, which does not support the shaft end on the opposite side of the forming side and completely clamps the root with the flange without slipping, when forming the flange at the end of the large shaft, a very large clamping force is required. Therefore, there is a problem that a large clamping die is required and the equipment cost is high. Therefore, the present invention is to solve the above problems, using a device with low equipment cost, without lowering the productivity,
An object of the present invention is to provide a method of forming a flange in an upsetter, which enables the formation of a flange of a large shaft end.

[0006]

Means for Solving the Problems In order to achieve the above object, the present invention takes the following measures. That is, the feature of the flange forming method of the present invention is that one end of a shaft having both ends is set in a free state, the other end is set in a protruding state and clamped by a mold, and the end of the protruding shaft is hot-upset. In an upsetter for forming a flange by (upsetting forging), when upsetting the protruding shaft end, an upsetting condition is set so as to allow a predetermined amount of axial elongation of the free end of the shaft.

[0007] By using the diameter of the shaft as a parameter,
It is preferable that the axial elongation of the free end of the shaft is determined in advance under predetermined upset conditions, and the upset conditions for the actual operation are set based on the obtained data. The upset condition is such that the heating temperature distribution of the protruding shaft end and the clamp portion clamped by the mold is substantially constant, and the clamp portion is clamped with a force equal to or less than the clamping force that makes the free end portion of the shaft have no elongation. And the upset speed is kept constant.

It is preferable that two-thirds of the clamp portion from the end of the protruding shaft be heated to 800 ° C. or higher, which is the same as the end of the protruding shaft, and that the upset speed be 10 mm / sec or less.

[0009]

Embodiments of the present invention will be described below. FIGS. 1 and 2 show an upsetter 1 used in the method of the present invention, which forms a flange 3 at an end of a shaft 2 by hot upsetting (upset). The upsetter 1 includes a cylinder frame 4 opposed to the cylinder frame 4 at a predetermined interval in the horizontal direction.
And a base frame 5. Both frames 4 and 5 are connected by a tie rod 6. The cylinder frame 4
Is provided with a main cylinder 7 that extends in the horizontal direction due to hydraulic pressure or the like, and a push plate 8 is provided on the main cylinder 7. A clamp die 9 is provided on the base frame 5 so as to face the push plate 8.

The clamp mold 9 is divided into upper and lower parts,
A hole for clamping the shaft 2 is formed at the center thereof. A clamp device 10 is provided for clamping the shaft 2 in the hole by bringing the upper and lower molds closer to each other. The clamp device 10 is configured by a hydraulic cylinder or the like. One end of the shaft 2 clamped by the clamp mold 9 is in a free state,
The other end protrudes from the mold, and the protruding shaft end is pressed in the axial direction by the pusher 8 to form a flange 3 having a predetermined outer diameter and a predetermined thickness. Axis 2
Before being set in the upsetter 1, the end of the protruding shaft and the clamp portion 11 having a predetermined length to be clamped by the mold 9 are heated to 800 ° C. or higher. In this embodiment, heating is performed at 1200 ° C., and the temperature distribution of the heating section is substantially constant.

In the present invention, when the projecting shaft end is upset, the upsetting condition is set such that a predetermined amount of axial extension of the free end of the shaft is allowed. That is, the upset conditions include a forming force (thrust by the pressing plate 8), a clamping force (gripping force by the clamp die 9),
There are mold length, flange thickness, flange diameter, shaft diameter of clamp part, heating condition, upset speed (moving speed of the press platen), etc. By setting these upset conditions appropriately, the shaft at the free end of the shaft can be used. That is, a predetermined amount of directional elongation is allowed.

The graphs shown in FIGS.
The relationship between the clamping force, the axial resistance of the shaft 2 due to the clamping force, and the thrust of the pusher 8 is shown using the shaft diameter as a parameter. This shows the limit of the slip (elongation of the free end) of the slab. 3, the material having a deformation resistance value of 2.00 kg / mm ² and a frictional resistance of μ = 0.30 is molded from a material having a mold length of 400 mm and a maximum clamping force of 2,111.
When upsetting in a ton device, the shaft diameter is 480
mm, the thrust and the resistance intersect, so 480
The graph shows that no slip occurs when the shaft diameter is equal to or less than mm, and slip occurs when the shaft has a larger diameter.

Table 1 shows the limit of slip suppression depending on the magnitude of the clamping force.

[0014]

[Table 1]

The term "clamping force" in the above table refers to a clamping force that generates the maximum axial resistance at each mold length. However, as a precondition, the maximum value of the shaft diameter of the clamp portion is set to 800 mm. When the mold length is 400 mm, the maximum shaft diameter without elongation is 480 mm. At this time, the necessary clamping force is about 1200 tons as shown in FIG. 3, and the clamping force exceeding that is offset by the upper and lower molds. You. As is clear from Table 1, when the flange forming of the flanged shaft having a shaft diameter of up to 800 mm is performed by the upset method, the equipment is designed without allowing the sliding of the clamp portion as in the related art. And mold length 800m
m, large equipment with a clamping force of more than 3,500 tons is required.

In the present invention, the clamping force is set small,
The elongation that occurs is allowed and predicted, and the flange is formed into an appropriate shape. That is, in the embodiment of the present invention, as shown in FIG. 7 instead of FIG.
And the maximum clamping force is 1,000 tons. still,
“Slip” in FIGS. 3 to 7 and Table 1 means that the shaft 2 relatively moves against the frictional force with the mold 9. It does not mean that the free end of the shaft 2 extends in the axial direction including the flow of the material, not only the relative movement against the frictional force with the mold 9. Therefore, the “slip amount” refers to the “movement amount” of the shaft end. Hereinafter, these are referred to as “elongation”.

According to the present invention, there is provided a method of manufacturing a target shape by allowing elongation without increasing the mold length and clamping force in order to completely suppress elongation.
Therefore, it is necessary to predict the accuracy when elongation is allowed. FIG. 8 shows the relationship between the growth prediction error and the allowance. FIG.
Shows the allowance when the error is 0 mm with respect to the elongation prediction. When the amount of elongation becomes larger than the predicted elongation, the allowance for the flange thickness increases, and the allowance for the inside and diameter decreases (see FIG. 10). In addition, when the amount of elongation is smaller than the predicted elongation, the allowance for outside work is reduced, and the allowance for internal work and diameter are increased (see FIG. 11). FIG. 8 shows this relationship.
It is.

As can be seen from FIGS. 8 to 11, if the elongation is incorrectly predicted, a negative value is generated with respect to the machined finished shape, resulting in dimensional defects. Therefore, in the present invention, the elongation must be accurately predicted. It turns out we have to. Therefore,
In the present invention, in order to prevent the elongation prediction error from occurring,
The factors that caused the growth prediction error were analyzed. That is, the change in the amount of elongation changes depending on the forming force, flange thickness, flange diameter, shaft diameter, heating condition, upset speed, and the like. By reliably predicting and stabilizing these parameters,
Accurate prediction of elongation becomes possible.

Therefore, in the present invention, first, it was examined how the change in the upset speed affects the elongation amount. FIG. 12 shows a mold length of 400 mm and a clamping force of 1.0.
When the upset speed (moving speed of the press platen) was changed under the condition of a uniform heating state in a range of 00 tons, a shaft diameter of 480 mm, and a 2/3 range of the protruding shaft end and the clamp portion, the elongation (slip amount) of the shaft end 4) is a graph showing the result of the measurement. From this figure, it can be seen that the amount of elongation tends to increase with an increase in the upset speed, and the gradient of the change amount also increases, so that the upset speed needs to be constant in a low-speed range.

It should be noted that the upset speed and the pressing force of the pressing plate 8 have a correlation, and the higher the speed, the greater the pressing force. Next, the relationship between the heating state and the amount of elongation was examined. That is, the shaft diameter of the clamp portion is 540 mm, and the upset speed is 10 mm / s.
With ec constant, the end of the protruding shaft was heated, and the variation in the amount of elongation when the heating range of the clamp portion 11 was changed was measured. FIG. 13 shows the measurement results. It should be noted that 100% of the heating state of the clamp portion means that the heating is performed to the same temperature as the shaft protruding end portion over the entire length of the clamp mold length 9.

The ideal state of heating is that the flange forming section (projecting shaft end) is uniformly heated at a high temperature and the clamp section 11 is at a low temperature, but the flange forming section and the clamp section 11 are continuous. Since it is a part, it is difficult to keep the flange portion 3 sufficiently and the clamp portion 11 at a low temperature. When the temperature of the flange forming part is high, the clamping part also becomes high temperature and the resistance to the forming force decreases, so the amount of elongation increases, and when the temperature of the clamping part is low, the temperature of the flange forming part also becomes low. Resistance increases, molding force increases, and molding becomes impossible. Or, the formed flange shape becomes inappropriate. From these facts, in estimating the amount of elongation, it is necessary to grasp the change in the amount of elongation due to the heating state of the clamp portion.

According to FIG. 13, it can be seen that when up to about 2/3 (60%) of the clamp portion 11 is uniformly heated to the same temperature as the end of the protruding shaft, the amount of elongation is the smallest. From various other experiments, it was found that the amount of elongation varies depending on the shaft diameter of the clamp portion 11. Therefore, in order to perform accurate elongation prediction, the change in the amount of elongation due to the upset speed and the heating state was quantified using the shaft diameter of the clamp portion as a parameter. Then, the upset speed and the heating condition of the clamp portion where the amount of elongation was minimized were always reproduced, and actual operation was performed based on a table showing the relationship between the shaft diameter of the clamp portion and the amount of elongation under the conditions. FIG. 14 shows an example of the table.

That is, using the diameter of the shaft 2 to be processed as a parameter, the axial extension of the free end of the shaft 2 is determined in advance under predetermined upset conditions, and a table as shown in FIG. 14 is created. Based on this table, the upset conditions for the actual operation are set. For example, when a product having a flange 3 at both ends shown in FIG. 15 (shaft diameter: 500 mm, distance between flanges: 8,000 mm) is formed by upset, how much the material shape and size should be designed, and which position It is determined from the table in FIG. 14 whether the clamping should be performed by the mold 9.

That is, according to the table shown in FIG. 14, when the shaft diameter is 500 mm, the predicted elongation is 20 mm. Therefore, the shaft end is extended by 20 mm due to the upset at one end, and if both ends are upset, the shaft end is extended by a total of 40 mm. Therefore, assuming that the length of the flange forming portion (projecting shaft end) 12 is a and b, the overall length of the material is
a + b + (8,000-40) = (a + b + 7,96)
0) mm. Then, as shown in FIG. 16 (A), when the first end is upset, 7,960 m
Clamp at the position of m and upset under the upset conditions shown in FIG. When upsetting the other end, as shown in FIG. 16 (B), by clamping at a position of 7,980 mm, the distance between flanges shown in FIG.
Shafts of both ends flanges of 00 mm can be formed with high precision. In actual operation, thermal expansion due to heating is taken into account in addition to these.

The present invention is not limited to the above embodiment.

[0026]

According to the present invention, a low-cost, high-productivity flanged shaft material can be produced.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an upsetter used in the method of the present invention.

FIG. 2 is a sectional view of the mold of FIG. 1;

FIG. 3 is a graph showing the relationship between the clamping force, thrust, and resistance of the upsetter when the mold length is 400 mm, with the shaft diameter of the clamping unit as a parameter.

FIG. 4 is a graph showing the relationship between the clamping force, the thrust, and the resistance of the upsetter when the mold length is 500 mm, using the shaft diameter of the clamping unit as a parameter.

FIG. 5 is a graph showing the relationship between the clamping force, the thrust, and the resistance of the upsetter when the mold length is 600 mm, using the shaft diameter of the clamping unit as a parameter.

FIG. 6 is a graph showing the relationship between the clamping force, thrust, and resistance of the upsetter when the mold length is 700 mm, with the shaft diameter of the clamping unit as a parameter.

FIG. 7 is a graph showing a relationship between a clamping force, a thrust force, and a resistance force of the upsetter used in the embodiment of the present invention, using a shaft diameter of a clamp portion as a parameter.

FIG. 8 is a graph showing the relationship between the growth prediction error and the allowance.

FIG. 9 is a drawing showing the relationship of allowance when the elongation prediction error is 0.

FIG. 10 is a drawing showing the relationship of allowance when the elongation prediction error is +.

FIG. 11 is a drawing showing the relationship of the allowance when the elongation prediction error is-.

FIG. 12 is a graph showing a relationship between an upset speed and an elongation amount.

FIG. 13 is a graph showing a relationship between a heated state of a clamp portion and an elongation amount.

FIG. 14 is a table of a clamp part shaft diameter and an elongation amount;

FIG. 15 is a front view showing a shaft material of both end flanges formed by the method of the present invention.

FIG. 16 is an explanatory diagram showing the method of the present invention.

[Explanation of symbols]

 1 Upsetter 2 Axis 3 Flange 9 Mold 11 Clamp

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kenji Miyazaki 2-3-1, Shinhama, Arai-machi, Takasago-shi, Hyogo Inside Kobe Steel, Ltd. Takasago Works (72) Inventor Toshiyuki Ochi 2-chome, Araimachi, Takasago-shi, Hyogo Prefecture No. 1 Inside Kobe Steel, Ltd. Takasago Works (72) Inventor Koji Takahara 2-3-1, Shinhama, Araimachi, Takasago City, Hyogo Prefecture Inside Kobe Steel, Ltd. Takasago Works (72) Inventor ▲ Hideki Mori Mori Hyogo Prefecture 2-3-1 Shinhama, Arai-machi, Takasago-shi Kobe Steel, Ltd. Takasago Works F-term (reference) 4E087 AA10 BA17 CA31 CA46 CB01 CC01 DB15 EA32 EA34 EB03 EC22 EC50 EC54 EF03 HA35 HB13

Claims (4)

[Claims] 1. An upsetter, wherein one end of a shaft having both ends is free, and the other end is protruded, clamped by a mold, and the protruding shaft end is hot-set to form a flange. A method of forming a flange in an upsetter, comprising setting upset conditions so as to allow a predetermined amount of axial extension of a free end of the shaft when upsetting the protruding shaft end. 2. An axial elongation of a free end of the shaft is determined in advance under a predetermined upset condition using the diameter of the shaft as a parameter, and based on the obtained data, an upset condition of an actual operation is determined. 2. The method according to claim 1, wherein the flange is set. 3. The upset condition is such that a heating temperature distribution of a protruding shaft end and a clamp portion clamped by a mold is made substantially constant, and a force equal to or less than a clamping force that makes elongation of a free end of the shaft zero. 3. The method for forming a flange in an upsetter according to claim 1, wherein the clamp portion is clamped and the upset speed is kept constant. 4. A two-thirds portion of the clamp portion from the side of the protruding shaft is heated to 800 ° C. or higher, which is the same as the end of the protruding shaft.
4. The flange forming method in an upsetter according to claim 3, wherein the upset speed is 10 mm / sec or less.