JPH02251330A - Forging method - Google Patents

Abstract

PURPOSE:To reduce the frictional resistance between a die and a material, to raise the effective flowability of the material, to reduce the deformation resistance and to improve a charging rate to the die by giving an ultrasonic vibration to the die at pressing the material. CONSTITUTION:At a rotary forging machine, the main shaft 32, the 1st, 2nd and 3rd driving gear 38, 52, 56 and the crank shaft 14 are driven respectively by servomotors and are controlled with a numerical control device. The ram 12 is lifted while revolving the tool holder 60 at a prescribed tilt angle and the material W is pressed by narrowing the distance between a upper die 26 and a lower die 26 and a rotary forging is performed. At that time, the ultrasonic vibration is given to the rotating upper die 26. The face friction of die between the upper die 26 and the material W is reduced by the ultrasonic vibration. Therefore, the direction of the force which is loaded on the material W is stabilized and the forging is performed smoothly. Then, the effective flowability of the material is raised and the deformation resistance is reduced and the charging rate to the die is improved.

Description

[Detailed description of the invention] "Industrial application field" The present invention relates to a forging method.

"Prior Art" In general, in forging, mold surface friction between a die and a material impedes the flow of the material and adversely affects processing limits, product quality, or material yield. In order to reduce mold surface friction, conventional forging methods use lubricants.

Furthermore, in the conventional rotary forging method, processing conditions such as the number of rotations of a mold and the amount of indentation are set in advance according to the characteristics of the material.

"Problem to be Solved by the Invention" However, it would be more convenient if the lubricant could be dispensed with. Furthermore, even if a lubricant is used, if mold surface friction can be further reduced, the machining limit will be improved.

Furthermore, the conventional rotary forging method, in which processing conditions are set in advance, may not be able to adequately accommodate the characteristics of the material. For this reason, for materials with high hardness or materials with poor elongation, the fluidity of the material is hindered and the filling rate into the mold becomes poor. Therefore,
Previous pretreatment steps were required, such as softening the material through heat treatment and processing the material into a shape that matches the mold shape.

The present invention has been made in view of the above problems, and its purpose is to provide a forging method that can reduce die surface friction.

Another object of the present invention is to provide a forging method that can increase the effective fluidity of the material within the mold and increase the filling rate of the mold.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a forging method characterized by applying ultrasonic vibration to a die while pressing a material.

In addition, as a second invention, ultrasonic vibrations are applied to the mold that is pressing the material, and processing conditions such as the amount of depression of the mold are controlled in response to changes in the frequency of the ultrasonic vibrations or the ultrasonic excitation output. Provided is a forging method characterized by successive processing.

"Operation" According to the above method, the frictional force between the mold and the material is reduced by ultrasonic vibration. Therefore, the deformation resistance of the material within the mold is reduced.

Further, in the second invention, when the mold to which ultrasonic vibrations are applied presses the material, the frequency of the ultrasonic vibrations or the oscillation output for ultrasonic excitation changes depending on the processing force applied to the material. It is based on this knowledge. Therefore, by controlling the indentation amount of the mold in response to changes in frequency or excitation output, stable processing force is maintained and sequential processing is performed, effectively improving the fluidity of the material and the ability to fill the mold. to improve.

"Example" Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view showing the oval configuration of a rotary forging machine 111 to which the present invention is applied. The main body frame 1o has a bottom plate 101
．． bed102. Side plate 103. ．． 104 and ceiling board 10
5 is integrally constructed.

A ram 12 is slidably guided in the bed 102 in the vertical direction, and a crank mechanism 13 is disposed below the bed 102.
is connected to. The crank mechanism 13 is a crankshaft 14
The ram 12 is made up of four connecting arms 15□16, 17, and 18 connected to each other, and the ram 12 is raised and lowered in accordance with the rotation of the crankshaft 14. On the side of the ram 12 is a linear scale detection section 2o.
is fixed. The bottom plate 1 faces the detection section 20.
A linear scale 21 is fixed to a bracket 22 that is provided upright at 01. Linear scale 20, 21
is a detector for detecting the vertical position of the ram 12.

A lower mold 25 is fixed onto the ram 12 via a lower mold stand 24. A material W, which is a workpiece, is placed inside the lower die 25 . The upper mold 26 that forms a pair with the lower mold 25 to form a mold is,
It is attached to the rotating swing section 30 fixed to the ceiling plate 105.

The rotating and swinging section 30 will be explained. A rotating swing unit case body 31 having a substantially hollow cylindrical shape is fixed to a ceiling plate 105 of the main body frame 10. The main shaft 32 is rotatably supported on the ceiling plate 105 by bearings 33 and 34, and its shaft end protrudes into the hollow part of the rotary swing unit case body 31. A circular hole 3 eccentric from the rotation center axis CL is located on the shaft end surface of the main shaft.
28 is formed. The main shaft 32 is rotationally driven by a main shaft motor (not shown).A first ring body 35 is rotatably supported by a bearing 36 on the rotary swing unit case body 31, facing the shaft end surface of the main shaft 32. An upper ring-shaped gear 37 is fitted onto the first ring body 35 and rotates integrally therewith. The ascending gear 37 is an annular gear with internal teeth 37B and external teeth 37A formed on the inner and outer peripheries,
The external teeth 37A are meshed with the first drive gear 38, and are rotationally driven by the first drive gear 38 integrated with the shaft 39.

On the other hand, an upper rotating gear 41 is rotatably fitted into the eccentric circular hole 32A on the end surface of the main shaft 32, and the gear 4 of the upper rotating gear 41
A portion of the gear 1A meshes with the internal teeth 37B of the upper ring gear 37. A spherical seat 4 is provided at an eccentric position on the end face of the upper rotating gear 41.
1.8 is formed, and a tool holder 60 is mounted on the spherical seat 41B.
The upper line surface shape portion 60A is in sliding contact. The upper line-shaped portion 60A of the tool holder 60 is held by the bushing 42 so as not to fall off.

Here, the eccentric circular hole 32A in the end face of the main shaft 32 and the eccentric spherical seat 41B of the upper rotating gear 41 constitute a 21ii center mechanism. By controlling the rotational position of the upper ring gear 37 in accordance with the rotational position of the main shaft 32, the center position of the spherical seat 41B with respect to the rotational center axis CL of the main shaft 32, that is, the center of the upper line surface shaped portion 60A of the tool holder 60. Position is controlled.

A double eccentric machine ellipse is also incorporated below the rotating swing unit case body 31. That is, the lower drive large gear 51 is connected to the main shaft 32.
It is rotatably supported by the rotating swing part case body 31 about the same rotational center axis CL. The lower drive large gear 51 has teeth 51A formed on its outer periphery, meshes with the second drive gear 52 that is integrated with the shaft 53, and is rotationally driven. Lower drive large gear 51
An eccentric inner diameter surface 51113 is formed therein, and the lower rotating gear 54 is rotatably fitted into the eccentric inner diameter surface 51B. The lower rotating gear 54 also has an eccentric inner diameter surface 54B.
have. A lower ring-shaped gear 55 is rotatably supported on the upper surface of the lower drive large gear 51. The lower ring-shaped gear 55 is an annular gear having internal teeth 55B and external teeth 55A on its inner and outer peripheries, and the external teeth 55A mesh with the third drive gear 56 that is integrated with the shaft 57 to be rotationally driven. Further, a portion of the internal teeth 55B of the lower ring-shaped gear 55 meshes with the teeth 54A of the lower rotating gear 54. Eccentric inner diameter surface 5 of lower rotating gear 54
4B, a child spherical shaped portion 60B of the tool holder 60 is made to come into sliding contact.

Here, the inner diameter surface 51B of the lower driving large gear 51 and the inner diameter surface 54B of the lower rotating gear 54 constitute the side of the double eccentric machine.

By controlling the rotational positions of the lower drive large gear 51 and the lower rotation gear 54 by the second and third drive gears 52 and 56, the center position of the child spherical portion 60B of the tool holder 60 is controlled.

Moreover, the center part of the tool holder 60 has two ring bodies 71.
It is engaged with a rotation prevention mechanism consisting of 72, and is prevented from rotating. That is, the bottles 73 and 74 protruding from the first ring body 71 are inserted into the horizontal small holes 31A and 31B provided in the rotary tank moving part case body 31, and the first
The ring body 71 is swingable and axially (horizontal direction in the drawing)
It is movably supported. The first ring body 71
A second ring body 72 is supported by a bottle (not shown) so as to be swingable and movable in a direction perpendicular to the plane of the paper.

The tool holder 60 is inserted through the second ring body 72, and the bins 75.7 are provided to protrude left and right from the tool holder 60.
6 is engaged to restrict rotation of the tool holder 60. The tool holder 60 can be freely oscillated by the oscillation and horizontal movement of the two ring bodies 71 and 72.

The tool holder 60 is formed into a hollow shape that opens downward, and an ultrasonic horn 80 is installed in the hollow portion.

The substantially axially shaped ultrasonic horn 80 has two upper and lower support flange portions 81 and 82, and an ultrasonic vibrator 83 made of an electrostrictive element is fixed to the upper end. Further, an upper mold 26 is attached to the lower end and is removable. Ultrasonic horn 8
The diameter near the lower end of 0 is reduced in order to amplify ultrasonic vibrations. The support flange portions 81 and 82 are attached to the ultrasonic horn 80 at a node where the vibration amplitude in the axial direction is the smallest when excited by the ultrasonic vibrator 83.
They are formed in two positions, upper and lower.

In the ultrasonic horn 80 to which the ultrasonic vibrator 83 is coupled, the cylindrical surface of the upper support flange portion 81 is in sliding contact with the inner diameter surface of the tool holder 60, and the cylindrical surface of the lower support flange portion 82 is in sliding contact with the stepped hole surface 60C. It is incorporated into the inner diameter portion of the tool holder 60 so as to be a sliding fit.

Then, the end surface of the lower support flange portion 82 is pushed upward by a cylindrical flange pressing member 84 and fixed.

The ultrasonic transducer 83 is connected to an external ultrasonic oscillator (not shown) via an electric wire 85. The ultrasonic vibrator 83 vibrates ultrasonically by applying a high frequency voltage from the ultrasonic oscillator. This ultrasonic vibration is transmitted to the ultrasonic horn 80, the amplitude is increased, and the -L mold 26 is excited. The ultrasonic oscillator is equipped with a circuit that constantly monitors its oscillation frequency and oscillation output.

The operation of the mechanical configuration will be explained. By changing the rotational position of the upper rotating gear 41 relative to the rotational position of the main shaft 32, the amount of eccentricity of the center point of the upper area surface shape portion 60A of the tool holder 60 with respect to the central axis CL of the main shaft 32 can be changed. Therefore, after determining the amount of eccentricity by rotating the upper rotating gear 41, by rotating the main shaft 32 and the upper rotating gear 41 together, the upper floor surface shape portion 60A of the tool holder 60 can maintain its eccentricity. Driven to rotate. By gradually changing the rotational phase of the upper rotating gear 41 while the main shaft 32 is rotating, it is also possible to gradually change the amount of eccentricity and change the inclination angle of the tool holder 60 while turning.

The horizontal operation of the lower double eccentric machine is basically the same. By changing the rotational positions of the lower drive large gear 51 and the lower rotating gear 54, the position of the center point of the child spherical portion 60B of the tool holder 60 in the horizontal plane can be changed arbitrarily.

Therefore, the center of the child spherical shaped part 60B is aligned with the central axis CL of the main shaft 32, and the upper floor shaped part 60 of the tool holder 60 is
It is also possible to make a rotational movement of A, and the child spherical shape part 60
It is also possible to rotate the tool holder 60 while holding the center of B at a position eccentric from the center axis CL. Further, by rotating the lower driving large gear 51 and the lower rotating gear 54, the child spherical portion 60B can also be caused to rotate. Furthermore, in synchronization with the rotation of the main shaft 32, the upper rotating gear 41. By rotating the three gears of the lower rotating gear 54 and the lower large driving gear 51, it is also possible to cause the tool holder 60 to swing in one direction instead of rotating.

In this rotary forging machine, the main shaft 32. 1st. The second and third drive gears 38, 52, 56 and the crankshaft 14 are each driven by a servo motor and controlled by a numerical controller. The ram 12 is raised while the tool holder 60 is rotated at a predetermined inclination angle, the interval between the upper die 26 and the lower die 25 is narrowed, and the material W is pressed to perform rotary forging. At this time, the rotating upper die 26 is given ultrasonic vibration. The mold surface friction between the upper mold 26 and the material W is reduced by ultrasonic vibration.

Furthermore, there is a characteristic of ultrasonic vibrations in that as the load applied to the upper mold 26 and the ultrasonic horn 80 increases, the frequency increases and the output from the ultrasonic oscillator increases. Utilizing this characteristic, the frequency of the ultrasonic vibration is constantly monitored and the pushing amount of the ram 12 is controlled to keep the load at a constant value. By keeping the load constant, a stable forging force is maintained and sequential rotational forging is performed.

FIG. 2 is a flowchart showing the processing in the numerical control device that implements the above control. When the power is turned on, rotational driving of the main shaft 32 and each drive gear 38, 52° 56 is started, and rotation of the tool holder 60 is started (step Sl
, 82), and simultaneously starts excitation of the ultrasonic transducer 83 (step S3).

Next, the crankshaft 14 is started to be driven, the ram 12 is raised, and the pressing of the material W is started (step S4.85).

Then, while continuing to raise the ram 12 by -E, the ultrasonic vibrator 8 checks whether the raised position of the ram 12 has reached the command position Wt.
Monitor whether the excitation frequency of No. 3 has increased above a predetermined value (Step S6, 57). If the No. 0 frequency has increased, the forging force of the rotary forging has become excessive, so the process proceeds to Step S8, and the excitation frequency of the crankshaft 14 is The rotational speed is reduced to reduce the pressing speed of the ram 12. Then, it is monitored whether the position of the ram 12 has reached the commanded position and whether the frequency has decreased (step 89, 5IO). Then, the pressing speed of the ram 12 is increased and the process returns to step S6.

Eventually, when the raised position of the ram 12 reaches the commanded position,
Since the material W has been plastically processed to the planned thickness and the forging process has been completed, steps s6 or S9 to step 8
20, the ram 12 is lowered, the excitation of the ultrasonic vibrator 83 is stopped, the rotation of the tool holder 60 is stopped, and the process ends (steps S20, S21, 822).

As described above, in this embodiment, the upper die 26 is rotated at a predetermined inclination angle, and the material W is pressed and subjected to ultrasonic vibration to be plastically worked. In addition, stable forging force is maintained by monitoring the ultrasonic frequency.

In the embodiment described above, the ultrasonic horn 80 was installed in the tool holder 6o to apply ultrasonic vibration to the upper die 26.
An ultrasonic horn 8o may be incorporated into the ram 12 to apply ultrasonic vibrations to the lower die 25.

"Effects of the Invention" Since the present invention applies ultrasonic vibration to the mold as described above, it has the effect of reducing the frictional resistance between the mold and the material. This stabilizes the direction of the force applied to the material and makes forging smooth. In addition, the effective fluidity of the material increases, deformation resistance decreases, and the mold filling rate increases.

In the second invention, in addition to the above, since the forging force is stabilized, the load on the machine is reduced and the filling rate of the material into the mold is increased. Therefore, more reliable plastic working becomes possible.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a sectional view showing a rotary forging machine to which the invention is applied, and FIG. 2 is a flow chart showing the process. 12, Ram, 25, Lower mold, 26,
Upper die, 32, main shaft, 60, tool holder,
80. Ultrasonic horn, 83,, Ultrasonic vibrator.

Claims (1)

[Scope of Claims] 1. A forging method characterized by applying ultrasonic vibration to a die while pressing a material. 2 Applying ultrasonic vibrations to the mold that is pressing the material, and sequentially processing the material while controlling the processing conditions such as the amount of depression of the mold in response to changes in the frequency of the ultrasonic vibrations or the ultrasonic excitation output. Characteristic forging method.