JPH1099934A - Forging press type forming equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a work by a punch with small punch force with less burrs by providing a moving equipment in witch an oscillator provided with the punch is vertically oscillated at high speed, a clamp to hold the work is gradually moved nearer to the oscillator and the work is punched. SOLUTION: A rack shaft stock 11 in which a core is inserted is clamped by a clamp 25, a base 22 is located to the working position, a lock member 71 is interposed between a lower frame 21A and the base 22, and the rack shaft stock 11 is placed at the work starting position. An oscillator 26 is vertically oscillated at high speed by an oscillation device 27, the rack shaft stock 11 is moved upward by a bellows cylinder 61 of a stock moving equipment 28 while a punch 20 is pressed against the rack shaft stock 11 to gradually deepen the rack tooth, and punch-forming is completed when an upper end of a lower frame 23 is abutted on a lower end of an upper frame. The lock member is withdrawn, and the base is lowered to take out the rack. Since the work is punch-formed though repetition of the plastic deformation, the work can be formed by the punch with small force with less burrs.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forging press forming apparatus for forming rack teeth on the side surface of a hollow pipe-shaped rack shaft material.

[0002]

2. Description of the Related Art In general, a rack shaft used in a steering mechanism of an automobile is formed by flattening a part of a peripheral surface of a round bar and forming rack teeth there. At this time,
The use of a hollow pipe as the rack shaft material has been implemented because of a demand for weight reduction.

As a method of forming rack teeth by plastic working on a rack shaft material, Japanese Patent Publication No. 58-31257 discloses a method of forming a rack tooth portion of a material by using an upper mold having a rack tooth shape, and perpendicular to an axis of the material. The method of pressing in the direction is shown.

[0004] Japanese Patent Publication No. 3-5892 discloses a molding die in which an uneven surface corresponding to a rack tooth is formed on a flat portion of a rack shaft material formed of a hollow pipe having a tooth row forming portion as a flat portion. A method is shown in which a tooth is formed by pressing a punch into the hollow pipe to apply the flesh of the flat portion to the uneven surface of the mold.

[0005]

However, the prior art has the following problems. It is necessary to perform a step of forming a flat portion in advance on the rack tooth forming portion on the side surface of the hollow pipe which is the workpiece, and the productivity is poor.

[0006] A large working force (pressing force) is required to plastically deform the rack tooth forming portion of the workpiece using a mold, a punch, or the like, so that burrs are easily formed around the formed rack teeth.

SUMMARY OF THE INVENTION An object of the present invention is to reduce the processing force, reduce the occurrence of burrs, and improve productivity when forming a workpiece with a punch.

[0008]

According to a first aspect of the present invention, there is provided a forging press forming apparatus for forming a workpiece by repeatedly pressing a processing surface of a punch against the workpiece. A vibrator having a punch, a clamp for holding the workpiece, and a workpiece moving device for gradually bringing the clamp closer to the vibrator and performing predetermined processing on the workpiece by the punch. It is made to be.

According to a second aspect of the present invention, in the first aspect of the present invention, the clamp is provided on a lower frame capable of moving up and down with respect to the base, and the workpiece moving device is provided with a base. And a bellows cylinder interposed between the lower frame and the lower frame.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the processing surface of the punch is formed with rack teeth, and the workpiece forms rack teeth. It is made to be done.

According to the present invention, the following operations are provided. A punch is provided on the vibrator, and the clamp of the workpiece is gradually approached to the vibrator side by the workpiece moving device, so that the processing surface of the punch is repeatedly pressed against the workpiece. Accordingly, the punch vibrates at a high speed to apply plastic deformation little by little to the workpiece, and a desired formed shape can be given to the workpiece by stacking the plastic deformation.

When a workpiece is a hollow pipe, and rack teeth are formed on a part of a flat surface of a peripheral surface of the hollow pipe,
There is no need to provide a plane portion in advance on a part of the peripheral surface of the hollow pipe. That is, the punch can form a flat portion having a rack tooth on a part of the peripheral surface of the hollow pipe only by the punch by stacking plastic deformation applied to the peripheral surface of the hollow pipe as described above, thereby improving productivity. it can.

As described above, the punch applies plastic deformation little by little to the workpiece, and completes the desired forming by stacking the plastic deformation. Therefore, a large working force is not required, and the generation of burrs is small. Things.

The workpiece moving device is constituted by a bellows cylinder. Therefore, by gradually increasing the internal pressure of the bellows cylinder, the clamp of the workpiece can be gradually moved so as to approach the vibrator side. Further, since the bellows cylinder is interposed between the lower frame on the clamp side and the base on the gantry side, transmission of the vibration processing sound of the punch to the gantry side can be buffered.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a front view showing an example of a forging press forming apparatus, FIG. 2 is a schematic view showing the periphery of a punch of the forging press forming apparatus, and FIG. FIG. 4 is a schematic diagram showing a resistance generating portion of the vibration chamber, FIG. 5 is a schematic diagram showing an oil seal of the vibration chamber, FIG. 6 is a schematic diagram showing a rack shaft, and FIG. 7 is a rack shaft material. It is a schematic diagram which shows the rack tooth machining state.

As shown in FIG. 6, the rack shaft 10 has a large number of axially intersecting flat side surfaces which are a part of the peripheral surface of a hollow round shaft material 11 (workpiece). It has rack teeth 12.

The forging press forming apparatus 100 presses a rack toothed surface 20 A provided on the tip end surface of the punch 20 against the side surface of the rack shaft blank 11 with the mandrel 13 inserted into the hollow portion of the rack shaft blank 11. The punch 20 is repeatedly vibrated, and the rack shaft material 11 is gradually
Then, the rack shaft material 11 is stopped at a position where the rack shaft material 11 finally obtains a predetermined shape of the rack teeth 12, and the machining is completed.

As shown in FIGS. 1 and 2, the forging press forming apparatus 100 includes a gantry 21, a base 22, a lower frame 23,
It has an upper frame 24, a clamp 25, a vibrator 26, a vibration device 27, a material moving device 28, and a base moving cylinder 29.

Hereinafter, the configuration of each part of the forging press forming apparatus 100 will be described. (A) The gantry 21, the base 22, the lower frame 23, and the upper frame 24 (FIG. 1,
FIG. 2) The gantry 21 is a lower gantry 2 which is connected by columns 31 on both sides.
1A and an upper base 21B. The base 22 is supported on the lower base 21A via a base moving cylinder 29.
Supports a first lower frame 23A and a second lower frame 23B via a material moving device 28. The upper frame 21B supports a first upper frame 24A and a second upper frame 24B.

(B) Clamp 25 (FIGS. 1 and 2) Left and right clamps 25A and 25B are placed on the second lower frame 23B.
Are held, and the clamps 25A and 25B are opened and closed by a clamp opening / closing device (not shown) so that the rack shaft material 11 into which the mandrel 13 is inserted can be clamped from the left and right. One end of the mandrel 13 is embedded in the clamps 25A and 25B. The clamps 25A and 25B are provided with a U-shaped recess 31 that holds one end of the mandrel 13 and that opens upward, whereby the mandrel 13 is inserted into the clamps 25A and 25B from above, and is turned around. Be stopped.

Incidentally, a material support 32 is built in the second lower frame 23B. The material support base 32 is formed in a thick plate shape having a flange 32A, and its upper end is clamped to the left and right clamps 25A.
Positioned between A and 25B, the rack shaft material 11 can be supported by its upper material support surface. The material clamping surfaces of the left and right clamps 25A and 25B and the material supporting surface of the support base 32 are continuous with the outer peripheral surface of the rack shaft material 11 with the same curvature.

An ejector cylinder 33 is built in the first lower frame 23A. The ejector pin 33A of the ejector cylinder 33 abuts against the flange 32A of the support table 32 in the second lower frame 23B, and after the processing is completed, the rack shaft material 11 can be protruded from the left and right clamps 25A and 25B to be taken out. .

(C) Vibrator 26 and Vibration Device 27 (FIGS. 1 to 5) A vibration device 27 is provided on the upper pedestal 21A. The vibration device 27 includes a disk 42 that rotates in conjunction with a pulley 41 that is rotationally driven by a motor (not shown).
2, a vibrator 26 that comes into contact with the punch 20 via the vibrating portion 27A is provided. The vibrator 26 includes a first upper frame 24A.
And the large diameter portion 2 located on the upper side of the first upper frame 24A.
6A, medium diameter part 26B, medium diameter part 26 continuing to large diameter part 26A
B, and projecting to the lower side of the first upper frame 24A, the punch 2
It is composed of a small diameter portion 26C that comes into contact with zero. And the vibrator 2
6 is provided by a spring 43 provided in the first upper frame 24A.
It is repelled so that it is always pressed against the disk 42 side.

As shown in FIG. 3, the vibrating section 27A includes a disk 4
(A) of the disk 42 and the vibrator 26 so that the vibrator 26 is periodically vibrated in the vertical direction at a high speed by the rotational movement of the disk 42. A plurality of tapered rollers 44 are provided radially and apart from each other in a state of being housed in, for example, a cage or the like between the facing surfaces, and (b) one of the facing surfaces of the disk 42 and the vibrator 26 (in this embodiment, The large-diameter portion 26A) of the vibrator 26 is provided with a plurality of projecting projections 45 radially and spaced apart.

If the vibrating portion 27A converts the rotational motion of the disk 42 into the vibration of the vibrator 26, a cam surface is provided on one of the disk 42 and the vibrator 26, and the other protrusion is provided. Any structure may be used.

The disk 42 receives an upward force each time the vibrator 26 vibrates during its own rotational movement. A thrust bearing 46 is provided on the back surface of the disk 42 so that this force does not become a resistance to the rotation of the disk 42.

In the vibration device 27, the periphery of the vibration portion 27A is partitioned by a vibration chamber 47, and the vibration chamber 47 is filled with oil. An oil seal 51 as shown in FIG. 5 is provided between the upper frame 21B serving as the bottom of the vibration chamber 47 and the large diameter portion 26A of the vibrator 26. Thereby, the collision sound between the disk 42 rotating at high speed and the vibrator 26 vibrating up and down is reduced by the oil damping action, and the disk 42 and the vibrator 26 are vibrated.
This is to reduce the mechanical resistance generated between the two by the lubricating action of the oil.

The vibration device 27 is provided with the vibration chamber 47 described above.
As a method of filling oil into the disk, the rear side of the disk 42 with respect to the vibration chamber 47 is defined as a rear chamber 48, and the oil pumped by the oil pump PM is circulated so as to flow from the rear chamber 48 to the vibration chamber 47. . Deer, a resistance generating portion 50 to the oil passage 49 between the rear chamber 48 and the oscillating chamber 47 provided, so that a large pressure P ₀ of the rear chamber 48 side than the pressure P ₁ of the oscillating chamber 47 side I made it. This differential pressure (P ₀ −P ₁ ) counteracts a part of the working reaction force (thrust force) acting on the disk 42 and reduces the load on the thrust bearing 46 of the disk 42. Therefore, if this differential pressure is set to be larger than a predetermined value, the thrust bearing 4
6 can be abolished. Specifically, as shown in FIG. 4, the resistance generating unit 50 alternately arranges outer blades 50A fixed to the upper pedestal 21B side and inner blades 50B fixed to the disk 42 side in the oil flow path 49. The oil passage 49 can be configured to increase the flow passage resistance.

(D) Material moving device 28 (FIGS. 1 and 2) The material moving device 28 is provided between the base 22 and the first lower frame 23A.
Is interposed. By increasing the internal pressure of the bellows cylinder 61, the first lower frame 23A, the second lower frame 23B, and the clamp 25 are gradually moved upward, and the rack shaft blank 1 held by the clamp 25 is moved.
1 is gradually approached to the punch 20 of the vibrator 26, and the rack shaft blank 11 is subjected to predetermined processing by the punch 20. The upper end 23C of the lower frame 23B moved upward by the bellows cylinder 61 finally abuts against the lower end 24C of the upper frame 24, and the abutting position causes the rack shaft 1 to move.
0 final finish shape is determined. In addition, by supporting the lower frame 23 with the bellows cylinder 61, transmission of the vibration processing sound of the punch 20 to the gantry 21 side can be buffered.

(E) Base Moving Cylinder 29 (FIG. 1) The base moving cylinder 29 is interposed between the lower frame 21A and the base 22, and positions the base 22 at a predetermined working position. When the base 22 is positioned at a predetermined machining operation position by the base moving cylinder 29, a left and right lock is provided between the lower base 21A and the base 22 to release the support load of the base moving cylinder 29. The members 71, 71 are interposed. Thereby, the base moving cylinder 2
9 is not subjected to vibration during machining and a large load, and the life of the cylinder 29 can be extended as much as possible.

Therefore, the forging press molding apparatus 100
It works as follows. (1) The rack shaft blank 11 into which the mandrel 13 is inserted is clamped to the left and right clamps 25A and 25B.

(2) The base 22 is moved by the base moving cylinder 29.
Is positioned at a predetermined machining operation position, and a lock member 71 is interposed between the lower frame 21A and the base 22. Thereby, the rack shaft blank 11 is positioned at the processing start position.

(3) The vibrator 26 is vibrated up and down at a high speed by the vibrating device 27, and the rack tooth processing surface 20A of the punch 20 is pressed against the side surface of the rack shaft material 11, so that the punch 21 is repeatedly vibrated. At the same time, the material moving device 28
The rack shaft material 11 is gradually moved upward to the punch 20 side by the bellows cylinder 61, and the depth of the rack teeth 12 formed on the side surface of the rack shaft material 11 is gradually increased.

(4) Bellows cylinder 6 of material moving device 28
1 at a position where the upper end 23C of the lower frame 23 moved by the first abutment with the lower end 24C of the upper frame 24.
1 is stopped, and the machining is finished when the rack teeth 12 of the rack shaft blank 11 have obtained the final finished shape.

(5) By removing the lock member 71 described in (1) above and contracting the base moving cylinder 29, the base 22 is returned to the pre-machining standby position. Then, the left and right clamps 25A and 25B are opened, and the rack shaft material 11 is taken out by the ejector pins 33A of the ejector cylinder 33.

The specific specifications of the forging press forming apparatus 100 are, for example, as follows. (1) Material of rack shaft material 11 SEA1541 (A pipe), outer diameter 28mm, wall thickness 5mm

(2) Vibration device 27 Amplitude of vibrator 26 0.5 mm Frequency of vibrator 26 3600 rpm Hydraulic pressure P _{0 in} rear chamber 48 kgf

(3) Material moving device 28 (bellow cylinder 6
1) Forming load 700 ton Forming stroke 12mm (Maximum stroke of bellow cylinder 61 20mm)

(4) Base moving cylinder 29 Approach, setup stroke 250 to 300 mm

In the forging press molding apparatus 100, as shown in FIG. 7, the core metal 13 has a cross-sectional shape with respect to a portion where the rack shaft blank 11 is to be formed with a rack tooth through a gap. It is provided with a processing support surface 13A which is separated, and the processing support surface 13A has a middle height. At this time, it is preferable that the processing support surface 13A is formed in a middle and high shape by the central flat surface 13B and the tapered surfaces 13C, 13C on both sides.

That is, the cross-sectional shape of the mandrel 13 inserted into the rack shaft material 11 is such that the processing support surface 1 is separated from the portion where the rack teeth of the rack shaft material 11 is to be formed with a gap.
3A, and since the processing support surface 13A has a middle height (FIG. 7A), the arc length (upper side) of the inner circumference of the material between both ends of the processing support surface of the mandrel 13 is long. Become. On the other hand, the gap between the clamp surface outside the material and both ends of the processing support surface also increases. This makes it easier for the force applied from the tip side of the rack tooth processing surface 20A of the punch 20 to shift the material side surface to the mandrel side, and the flat processing support surface 13B of the mandrel prevents deformation of the material. You can regulate faster. Therefore, racking of the rack of the material becomes faster, and the processing efficiency can be increased. In addition, the processing support surface 1 of the core
Since 3A has a middle height, the moment by which the force of the tooth tip of the rack tooth processing surface 20A of the punch 20 acts on the end of the processing support surface can be increased. Therefore,
The gap 13D formed between the material and the mandrel in the early stage of the rolling process can be efficiently filled, and in the processing in the final stage of the rolling process, there is little unevenness in the outer peripheral side of the material, and accordingly, the material yield is good. Since there is little force against the clamping force on the outer periphery of the material when there is less uneven thickness on the outer peripheral side of the material, a rack shaft having high roundness can be formed.

Therefore, according to the present embodiment, the following operations are provided. The vibrator 26 is provided with a punch 20 and the rack shaft material 1
By making the first clamp 25 gradually approach the vibrator 26 side by the material moving device 28, the rack tooth processing surface 20A of the punch 20 is repeatedly pressed against the rack shaft material 11. Therefore, the punch 20 vibrates at a high speed to gradually apply plastic deformation to the rack shaft material 11, and a desired formed shape can be given to the rack shaft material 11 by stacking the plastic deformation.

When the rack shaft material 11 is a hollow pipe and rack teeth are formed on a part of the peripheral surface of the hollow pipe, it is not necessary to provide a planar part on a part of the peripheral surface of the hollow pipe in advance. That is, the punch 20 can form a flat portion having rack teeth on a part of the peripheral surface of the hollow pipe only by the punch 20 by stacking plastic deformation applied to the peripheral surface of the hollow pipe as described above. Can be improved.

As described above, the punch 20 applies plastic deformation little by little to the rack shaft material 11 and completes the desired forming by stacking the plastic deformation, so that a large working force is not required and burrs are generated. Can also be reduced.

The material moving device 28 has a bellows cylinder 61
It was composed of Therefore, by gradually increasing the internal pressure of the bellows cylinder 61, the clamp 25 of the rack shaft material 11 can be gradually moved so as to approach the vibrator 26 side. Further, since the bellows cylinder 61 is interposed between the lower frame 23 on the clamp 25 side and the base 22 on the gantry 21, transmission of the vibration processing sound of the punch to the gantry 21 can be buffered.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the specific configuration of the present invention is not limited to the embodiments, and the design can be changed within a range not departing from the gist of the present invention. The present invention is also included in the present invention. For example, the method of vibrating the vibrator is not limited to the above description.

[0047]

As described above, according to the present invention, when a workpiece is formed by a punch, the processing force is relatively small, the occurrence of burrs is reduced, and the productivity can be improved.

[Brief description of the drawings]

FIG. 1 is a front view showing an example of a forging press forming apparatus.

FIG. 2 is a schematic diagram showing a periphery of a punch of a forging press forming apparatus.

FIG. 3 is a schematic view showing a vibrating section of a forging press forming apparatus.

FIG. 4 is a schematic diagram showing a resistance generating section of a vibration chamber.

FIG. 5 is a schematic view showing an oil seal of a vibration chamber.

FIG. 6 is a schematic diagram showing a rack shaft.

FIG. 7 is a schematic diagram showing a rack tooth processing state of a rack shaft material.

[Explanation of symbols]

 Reference Signs List 11 rack shaft material (workpiece) 100 forging press molding device 20 punch 20A rack tooth processing surface 22 base 23 lower frame 25 clamp 28 material moving device (workpiece moving device) 61 bellow cylinder

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁶ Identification code FI B21K 27/00 B21K 27/00 Z

Claims (3)

[Claims] 1. A forging press forming apparatus for forming a workpiece by repeatedly pressing a processing surface of a punch against the workpiece, and a vibrator provided with a punch, vibrating in a vertical direction at a high speed, and comprising: A forging press forming apparatus, comprising: a clamp to be held; and a workpiece moving device that gradually brings the clamp closer to the vibrator and performs predetermined processing on the workpiece by a punch. 2. The apparatus according to claim 1, wherein the clamp is provided on a lower frame capable of moving up and down with respect to the base, and the workpiece moving device is constituted by a bellows cylinder interposed between the base and the lower frame. Item 4. A forging press-type forming device according to Item 1. 3. The forging press forming apparatus according to claim 1, wherein the processing surface of the punch is formed with rack teeth, and the workpiece is formed with rack teeth.