WO2021059465A1

WO2021059465A1 - Extrusion press device, and platen for extrusion press device

Info

Publication number: WO2021059465A1
Application number: PCT/JP2019/038082
Authority: WO
Inventors: 武治山本
Original assignee: 宇部興産機械株式会社
Priority date: 2019-09-27
Filing date: 2019-09-27
Publication date: 2021-04-01
Also published as: JP7107446B2; US20220152678A1; JPWO2021059465A1

Abstract

This extrusion press device is provided with a die 60 for extrusion molding a workpiece, a cylinder 83 for imparting a pressing force pressing the workpiece against the die, and a platen 20 for accepting the pressing force from the die 60, wherein the platen 20 is provided with an outside element 30, and an inside element 40 disposed coaxially with the outside element 30, inside the outside element 30. The inside element 40 is provided sandwiching the outside element 30 from both the front and rear sides of the outside element 30.

Description

Extrusion press and platen of extrusion press

The present invention relates to an extrusion press device used for extrusion molding of a metal, for example, an aluminum alloy, and particularly to a platen.

To extrude a metal material with an extrusion press, the billet is pressed against the die placed on the platen via a pressure ring with extrusion force. This extrusion force is applied by the main cylinder provided in the extrusion press device. During the extrusion process, when the reaction force of the extrusion force acts on the platen and the main cylinder housing, the platen is bent. As the platen bends, the pressure ring and die bend. This platen is sometimes referred to as the end platen.

FIG. 9 shows the deflection generated in the platen 220.
As shown in the upper figure of FIG. 9, the reaction force f of the extrusion acting force F acts on the substantially central portion of the platen 220 in the extrusion direction via the die 260 and the pressure ring 250. The extrusion direction is shown in the same direction as the white arrow indicating the extrusion force F. On the other hand, with respect to this reaction force f, a drag force f'in the opposite direction to the reaction force f is generated in the tie rod 287. The tie rod 287 resists this reaction force f by deforming (stretching) in the elastic region parallel to the extrusion direction. As a result, the platen 220 generates a bending moment M that tends to bend the substantially central portion of the platen 220 so as to project in the extrusion direction. However, the platen 220 in which the discharge path 242 penetrating in the thickness direction is formed in order to continuously extrude (discharge) the product behind the platen 220 resists the bending moment M in the vicinity of the discharge path 242. It is physically difficult to secure sufficient rigidity. Therefore, in the extrusion process, bending and bending deformation as shown in the lower figure of FIG. 9 occur.

Although FIG. 9 is a schematic plan view, since the tie rods 287 are arranged at the four corners of the platen 220, the platen 220 is bent as in the plan view even when viewed from the side. That is, three-dimensionally, the bending is such that the substantially central portion of the platen 220 protrudes in the extrusion direction.

Further, when the platen 220 is bent by the extrusion force F in the extrusion process, the pressure ring 250 and the die 260 fixed to the platen 220 are also deformed in response to this bending.

The extrusion force acting on the platen during the extrusion process fluctuates from the start of extrusion to the completion of extrusion, and specifically decreases as shown in FIG. 10, so that the deflection of the platen 220 decreases during the extrusion process. With this reduction in deflection, the deformation of the pressure ring and dice can also be reduced. Therefore, the dimensions of the product extruded from the die fluctuate from the start to the completion of the extrusion process, and it becomes difficult to obtain the desired dimensional accuracy for the product depending on the degree of fluctuation in the deformation of the die. The horizontal axis of the graph shown in FIG. 10 indicates the length L of the billet during the extrusion process, and the vertical axis indicates the extrusion force F required for extrusion molding the billet. The extrusion force F is represented by the sum of the required push force Fa acting on the die via the billet and the frictional force fb on the outer peripheral surface of the billet and the inner peripheral surface of the container in which the billet is housed, that is, F = Fa + fb. .. The decrease in the extrusion force during the extrusion step described above is due to the decrease in the frictional force fb. Further, the required push output Fa is constant and does not fluctuate during the extrusion process if the heat effect is ignored.

Patent Document 1 discloses a pressure ring capable of suppressing bending during an extrusion process and an extrusion breath device using this pressure ring. The pressure ring of Patent Document 1 has a double structure including an outer member and an inner member, and the outer member is shrink-fitted on the inner member. According to the pressure ring of Patent Document 1, since the outer member is shrink-fitted to the inner member, stress is applied to the inner member from the outer side to the inner side in the radial direction. Therefore, even if a load is applied in the axial direction of the pressure ring, the stress from the outside to the inside opposes the load, so that the deflection is suppressed.

Japanese Unexamined Patent Publication No. 10-258309

According to Patent Document 1, bending of the pressure ring can be suppressed. However, the deflection of the pressure ring is based on the deflection of the platen, and even if a stress is generated from the outside to the inside of the double-structured pressure ring, the deflection of the platen is not eliminated. Therefore, it is difficult to suppress fluctuations in pressure ring and die deformation during the extrusion process to a sufficient extent to obtain high dimensional accuracy for the product.

Therefore, an object of the present invention is to provide an extrusion press device provided with a platen capable of suppressing the occurrence of bending.

The extrusion press device according to the present invention includes a die for extruding a work material, a cylinder for applying a pressing force for pressing the work material to the die, and a platen for receiving the pressing force from the die.
The platen according to the present invention includes an outer element and an inner element coaxially arranged with the outer element inside the outer element.
The inner element according to the present invention is provided by sandwiching the outer element from both the front and back sides of the outer element.

In the platen according to the present invention, preferably, the outer element and the inner element are fitted together, a tensile stress is generated in the inner element in the axial direction (C), and a compressive stress corresponding to the tensile stress is generated in the outer element. It has occurred.

The inner element according to the present invention is preferably provided by sandwiching the outer element by fastening.

In the platen according to the present invention, preferably, the outer element and the inner element to be fitted to each other have a gap in a portion not related to the fitting.

The inner element according to the present invention preferably includes a large-diameter portion provided on the front side, a small-diameter portion connected to the large-diameter portion, and a fastening member fastened to the small-diameter portion.
Tensile stress is generated by pressing the outer element of the fastening member by being tightened to the small diameter portion in advance and applying a preliminary load equal to or larger than the load acting during the extrusion process.

In the outer element according to the present invention, compressive stress is preferably generated in the region sandwiched by the inner element.

The outer element according to the present invention is preferably fitted to the outside of the first outer element adjacent to the inner element and to the outside of the first outer element adjacent to the inner element. The second outer element is provided. The inner element is provided by sandwiching the first outer element from both the front and back sides of the first outer element.

The inner element preferably has a tensile stress in the axial direction (C), and the first outer element has a compressive stress corresponding to the tensile stress.

In the outer element according to the present invention, preferably, the first outer element and the second outer element are fitted by a shrink fit.

The inner element according to the present invention preferably has a fluid supply structure 160 that supplies a cooling medium to the extruded product.

The inner element according to the present invention is preferably made of a metal material having substantially the same Young's modulus as the outer element, or a metal material having a Young's modulus larger than that of the outer element.

According to the present invention, the inner element sandwiches the outer element from the front and back of the outer element. By this pinching, tensile stress can be generated in the inner element and compressive stress can be generated in the outer element. Therefore, even if a load is applied in the extrusion direction during the extrusion process, the tensile stress generated in the inner element and the compressive stress generated in the outer element are reduced but maintained. Therefore, even if the outer element is bent, the portion where the tensile stress and the compressive stress are generated is unlikely to be bent.

It is a partial cross-sectional plan view which shows the schematic structure of the extrusion press apparatus which comprises the platen which concerns on 1st Embodiment. It is a partial sectional plan view which shows the structure of the platen of FIG. 1, and is an enlarged view of a part thereof. It is a figure which shows the platen of FIG. 2 decomposed in the axial direction. It is a figure which shows the other form of the platen of FIG. It is a front view which shows the platen which concerns on 2nd Embodiment. It is a partial cross-sectional plan view which shows the structure of the platen of FIG. It is a figure which shows the platen of FIG. 6 decomposed in the axial direction. It is sectional drawing which shows the structure of the fluid supply structure 160 provided in the platen of FIG. It is a figure explaining the bending which occurs in a platen. It is a graph which shows the fluctuation of the extrusion force F during the extrusion process.

Hereinafter, the extrusion press device according to the present invention will be described based on the embodiment. The extrusion press device according to the present embodiment has a platen composed of a plurality of elements divided in the radial direction. The pressure ring is fixed to the element arranged inside in the plurality of divisions, and the element is sandwiched from the front and back through the element arranged outside the element. By providing this structure, the platen according to the present embodiment can suppress bending during the extrusion process.
The present embodiment includes a first embodiment having a structure divided into two in the radial direction and a second embodiment having a structure divided into three in the radial direction. Hereinafter, the first embodiment and the second embodiment will be described in this order.

[First Embodiment]
The platen 20 according to the present embodiment will be described based on the extrusion press device 1 according to the first embodiment.
As shown in FIG. 1, the extrusion press device 1 has an extrusion portion 10 from which billet B, which is a work material, is extruded, a holding portion 70 that accommodates and holds the billet B, and a billet B accommodated in the holding portion 70. It includes a pressure generating unit 80 that generates a load that presses against the extrusion unit 10. The platen 20 is a main element constituting the extruded portion 10.

[Extruded section 10]
As shown in FIGS. 1, 2 and 3, the extruded portion 10 includes a platen 20, a pressure ring 50 supported by the platen 20, and a die 60 supported by the pressure ring 50.
The platen 20 includes an outer element 30 and an inner element 40 coaxially supported inside the outer element 30 by fitting, and has a two-layer structure divided in the radial direction.

[Outer element 30]
As shown in FIGS. 2 and 3, the outer element 30 is a rectangular parallelepiped-shaped member including a thick-walled portion 31 provided on the rear side and a thin-walled portion 33 connected to the thick-walled portion 31 and provided on the front side. .. The "thickness" of the thick portion 31 and the thin portion 33 indicates the distance from the inner peripheral surface of the holding hole 35, which will be described later, to the outer peripheral surface of the outer element 30. The outer element 30 is provided inside the thick portion 31 and the thin portion 33, and is provided with a holding hole 35 for penetrating in the front-rear direction and for aligning the inner element 40. The holding hole 35 includes a small inner diameter portion 36 corresponding to the thick wall portion 31 and a large inner diameter portion 37 corresponding to the thin wall portion 33, and is formed in a stepped shape in the front-rear direction. The outer element 30 is usually made of cast iron. The same applies to the inner element 40.
In the extrusion press device 1, the side (F) shown in FIG. 1 is defined as the front side, and the side (B) is defined as the rear side. Further, the radial dimension is determined with reference to the central axis C shown in FIGS. 1 and 2.

[Inner element 40]
As shown in FIGS. 2 and 3, the inner element 40 is connected to the large diameter portion 41 on which the mounting surface 48 of the pressure ring 50 is provided and the large diameter portion 41, and is provided so as to penetrate the thick portion 31 in the front-rear direction. It is a cylindrical member including a small diameter portion 43 to be formed. The inner element 40 is similar in appearance to a bolt, with the large diameter portion 41 corresponding to the head and the small diameter portion 43 corresponding to the body portion.
The outer diameter of the inner element 40 is smaller than the length of the outer surface (upper and lower surfaces and both side surfaces) of the outer element 30, and is considered to replace a part of the inner diameter side of the outer element 30. When a preliminary load is applied, the following surface pressure ΔP corresponding to the preliminary load is generated on the pressure receiving surface 32 of the outer element 30 (thick wall portion 31) in FIG. The large diameter portion of the inner element 40 that determines the area of the ring-shaped pressure receiving surface 32 so that the surface pressure ΔP is lower than the yield point of the material strength of the outer element 30 and the surface pressure allows for a safety factor. The diameter of each of the 41 and the small diameter portion 43 is determined in consideration of the diameter of the die 60 used and the diameter of the pressure ring 50.
ΔP = A / F
A = π ・ (D ^2- d ² ) / 4
ΔP: Surface pressure of pressure receiving surface 32 F: Extrusion force (preliminary load MF)
A: Area of pressure receiving surface 32 ΦD: Outer diameter of large diameter portion 41 Φd: Outer diameter of small diameter portion 43

The inner element 40 is provided with a discharge path 42 penetrating in the front-rear direction from the large diameter portion 41 to the small diameter portion 43. The extruded product extruded through the die 60 is discharged rearward from the extrusion press device 1 through the discharge path 42. Further, the inner element 40 has a screw 44 cut at the outer peripheral end portion on the rear side of the small diameter portion 43. The screw 44 of the small diameter portion 43 is tightened with the female screw 47 of the fastening member 46 described later. Further, the inner element 40 includes a pressure receiving surface 45 connecting the large diameter portion 41 and the small diameter portion 43. The pressure receiving surface 45 is a surface that receives pressure in a direction parallel to the central axis C from the outer element 30, that is, in the axial direction. The pressure receiving surface 45 and the pressure receiving surface 32 of the outer element 30 are exemplified by a plane orthogonal to the central axis C, but may have other shapes as long as they can receive pressure from each other. For example, a tapered surface inclined in the extrusion direction Ed (FIG. 1), a stepped surface, or the like can be applied.

The inner element 40 includes a fastening member 46 for fixing the large diameter portion 41 and the small diameter portion 43 to the outer element 30. The fastening member 46 has the same shape as a nut, and a male screw 44 formed on the small diameter portion 43 and a female screw 47 to be tightened are cut on the inner peripheral surface. In the first embodiment, when the extrusion press device 1 is assembled, the fastening member 46 is previously tightened from the rear side of the platen 20 to the small diameter portion 43 in a state where a preliminary load MF is generated, so that the central axis C is attached to the inner element 40. It is characterized in that a tensile stress PF parallel to is constantly generated.
The preload MF is set to a value equal to or higher than the rated load acting on the inner element 40 during the extrusion process via the pressure ring 50 and the die 60. An example of the procedure for generating the preload MF will be described later.

In the first embodiment, at least the male screw 44 of the small diameter portion 43 is projected to the rear of the outer element 30, and the female screw 47 of the fastening member 46 is tightened to the male screw 44. As a result, the thick portion 31 of the outer element 30 is sandwiched by the inner element 40 and the fastening member 46.

The fastening member 46 can be screwed into the screw 44 of the inner element 40 from the rear side of the platen 20, and a discharge path 42 for discharging the product extruded from the die 60 from the platen 20 can be formed. It is a necessary requirement. If this requirement is satisfied, as shown in FIG. 4, a portion protruding from the screw 44'and the fastening member 46'to the inner peripheral surface of the small diameter portion 43 because the inner peripheral surface of the small diameter portion 43 of the inner element 40 is machined. It may be in a form in which the male screw 47'processed on the outer peripheral surface of the above is tightened.

[Pressure ring 50]
As shown in FIGS. 1 to 3, the pressure ring 50 is attached to the mounting surface 48 of the inner element 40 with a bolt or the like (not shown), receives a pressing force from the die 60, and applies a pressing force to the inner element 40. introduce. The pressure ring 50 includes a passage 51 leading to the discharge passage 42 of the inner element 40. The pressure ring 50 is made of a higher strength material than the outer element 30 and the inner element 40, such as tool steel.

[Holding unit 70]
As shown in FIG. 1, the holding unit 70 holds a container 71 for holding the billet B, a container holder 73 for holding the container 71, and a container cylinder 75 for pressing the container 71 against the die 60 via the container holder 73. I have.
The container 71 includes a holding chamber 72 that penetrates in the front-rear direction while being supported by the container holder 73. The billet B is held in the container 71 in a state of being housed in the holding chamber 72.
The container holder 73 holds the container 71. The container 71 held by the container holder 73 can reciprocate in the front-rear direction integrally with the container holder 73.
The container cylinder 75 includes a cylinder 76 fixed to the platen 20 and a piston rod 77 provided so as to be able to advance and retreat with respect to the cylinder 76. The tip of the piston rod 77 is fixed to the container holder 73, and the container 71 can be pressed against the die 60 via the container holder 73 by operating the container cylinder 75.

[Pressure generator 80]
As shown in FIG. 1, the pressure generating unit 80 includes a main cylinder housing 81 arranged so as to face the platen 20, and a main cylinder 83 supported substantially in the center of the main cylinder housing 81. Further, the pressure generating unit 80 includes a side cylinder 85 supported by the main cylinder housing 81 around the main cylinder 83, and a tie rod 87 supported by the main cylinder housing 81 around the main cylinder 83.
The main cylinder 83 includes a main ram 84, a main crosshead 86 fixed to the tip of the main ram 84, and an extrusion stem 88 attached to the main crosshead 86. When the main cylinder 83 operates the main ram 84 toward the platen 20, the extrusion stem 88 presses the billet B toward the die 60.

The tie rod 87 connects the main cylinder housing 81 and the platen 20 together with the tie rod nut 89. The tie rod 87 and the tie rod nut 89 connect the four corners of the platen 20 and the corresponding four corners of the main cylinder housing 81. During the extrusion process, the platen 20 is extruded through the die 60 and the pressure ring 50, and the main cylinder housing 81 is extruded in a direction in which the platen 20 and the main cylinder housing 81 are separated from each other. The reaction force of the force acts. The tie rod nut 89, which constitutes the large diameter portion of the tie rod 87, resists this reaction force and restrains the movement of the platen 20 and the main cylinder housing 81. The tie rod 87 is configured to have a strength to resist the reaction force of the pressing force while allowing the tie rod 87 to stretch in the elastic region.

[Operation of extrusion press device 1]
The operation of the extrusion press device 1 having the above configuration will be described.
When the billet B, which is a work material, is extruded by the extrusion press device 1, the container 71 is pressed by the container cylinder 75 against the die 60 arranged on the platen 20 via the pressure ring 50 by a holding means (not shown). Then, the extrusion stem 88 is moved to the side of the platen 20, and the billet B stored in the container 71 is pressed against the die 60. This process is called the upset process. By further moving the main ram 84 toward the platen 20, the billet B is pressed against the die 60 by the extrusion stem 88, and a predetermined product is continuously extruded from the die hole 61 of the die 60 to the rear. This process is called an extrusion process. The cylinder rod of the side cylinder 85 is also fixed to the main crosshead 86, and the side cylinder 85 is driven during the extrusion process, that is, when the main crosshead 86 is advanced and when the main crosshead 86 is retracted.

[Procedure for generating tensile stress PF]
Next, an example of a procedure for generating a tensile stress PF on the inner element 40 in parallel with the central axis C in advance by the preliminary load MF will be briefly described. Please refer to FIGS. 1 to 3 as appropriate.

[Temporary fixing of outer element 30 and inner element 40]
First, the pressure ring 50 is fixed to the mounting surface 48 of the inner element 40 of the platen 20 with a bolt or the like (not shown). At this point, the fastening member 46 has been removed.
Subsequently, the inner element 40 to which the pressure ring 50 is fixed is inserted into the holding hole 35 of the outer element 30 of the platen 20 by a crane, a dedicated insertion jig, or the like. The outer diameter of the small diameter portion 43 of the inner element 40 and the inner diameter of the small inner diameter portion 36 of the holding hole 35 have a clearance that satisfies the positioning reference of the inner element 40 with respect to the outer element 30. Therefore, positioning of the inner element 40 with respect to the outer element 30 is not particularly necessary. On the other hand, the opening diameter of the storage chamber 39 in which the large diameter portion 41 is housed is larger than the outer diameter of the large diameter portion 41 of the inner element 40 (FIG. 2), and a predetermined clearance S is secured. The opening diameter of the accommodation chamber 39 is the inner diameter of the large inner diameter portion 37 of the holding hole 35. This clearance S will be described later. In this state, a part of the screw 44 of the small diameter portion 43 of the inner element 40 is exposed behind the outer element 30. By screwing the female screw 47 of the fastening member 46 into the male screw 44 using a crane, a dedicated insertion jig, or the like, the fastening member 46 is temporarily tightened to the small diameter portion 43.

[Action of reserve load MF]
Next, a preliminary load MF equal to or larger than the load acting on the extrusion direction Ed during the extrusion process is applied between the platen 20 and the main cylinder housing 81. Specifically, instead of the die 60, a dummy die having no opening that imitates the product shape or the like is arranged on the pressure ring 50 by a holding means (not shown), and the billet B is provided on the dummy die by the container cylinder 75. Press the uncontained container 71.

Then, the main cylinder 83 and the side cylinder 85 are driven, and the extrusion stem 88 to which an extrusion jig or the like (not shown) is attached to the tip is moved to the platen 20 side in the holding chamber 72 of the container 71 and extruded. The extrusion force is directly applied to the dummy die by the jig. At this time, the extrusion force acting between the platen 20 and the main cylinder housing 81 via the dummy die (preliminary load MF) is equal to or greater than the load acting on the extrusion direction Ed during the extrusion process (rated load). , Controls the hydraulic oil pressure supplied to the main cylinder 83 and the side cylinder 85. The reserve load MF is preferably 105 to 110% of the rated load.

By applying this preload MF, which is larger than the rated load, the platen 20 is compressed more than during the extrusion process at the rated load through the pressure receiving surface 45 of the inner element 40.

[Tightening the fastening member 46]
Then, in this state, the temporarily tightened fastening member 46 is screwed into the screw 44 of the small diameter portion 43 of the inner element 40 from the rear side of the platen 20 with a dedicated screwing jig or the like to further tighten. Since the preload MF acts on the inner element 40 in the extrusion direction Ed, there is no need for a detenting means for restraining the relative rotational movement of the inner element 40 with respect to the outer element 30. Further, the outer element 30 included in the projected area of the pressure receiving surface 45 in the extrusion direction Ed is further compressed as compared with the extrusion process under the rated load. Therefore, when the preload MF is released after screwing the fastening member 46 into the small diameter portion 43 of the inner element 40 without applying a large screwing force, the preload MF conforms to the preload MF parallel to the central axis C on the inner element 40. Tensile stress PF can be generated at all times.

[Effect of the first embodiment]
Next, the effect of the platen 20 according to the first embodiment will be described. This effect includes a first effect by generating the stress state described above between the outer element 30 and the inner element 40, and a second effect by providing the clearance S. Hereinafter, they will be described in order.

[First effect due to stress state of outer element 30 and inner element 40]
In the first embodiment, the inner element 40 sandwiches the outer element 30 from the front and back of the outer element 30. As a result, a tensile stress PF is generated in the inner element 40 in parallel with the central axis C, and a compressive stress CF is generated in the portion of the outer element 30 sandwiched between the pressure receiving surface 45 of the inner element 40 and the fastening member 46. To do. These tensile stress PF and compressive stress CF are stresses according to the preliminary load MF, which is larger than the rated load. Therefore, even if the load acting on the extrusion direction Ed during the extrusion process is substantially the same as the maximum and rated load, the tensile stress PF generated in the inner element 40 and the compressive stress CF generated in the outer element 30 are present. It is maintained while decreasing. Therefore, even if the tie rod 87 is extended and the outer element 30 of the platen 20 is bent, the fastening state of the inner element 40 and the fastening member 46 at the substantially central portion of the platen 20 is maintained, and the bending is less likely to occur. ..

As described above, according to the present embodiment, during the extrusion process, the fastening state of the substantially central portion of the platen 20 by the inner element 40 and the fastening member 46 and the compressive stress CF due to this fastening state are maintained. Therefore, even if the inner element 40 is formed with a discharge path 42 for pushing out and discharging the product on the rear side of the platen 20, a bending moment M (FIG. 10 (a)) that causes bending of the outer element 30 of the platen 20 in particular. Sufficient rigidity to counteract the above can be ensured at the portion of the thick portion 31 of the outer element 30 held by the inner element 40 (large diameter portion 41) and the fastening member 46 in the vicinity of the discharge path 42. it can. In this way, according to the first embodiment, the first effect of suppressing the bending of the platen 20 can be achieved.

[Second effect of providing clearance S]
In the first embodiment, by providing the clearance S, even if the platen 20 is bent, the influence of the bending on the pressure ring 50 can be suppressed. Hereinafter, description will be made with reference to the partially enlarged view of FIG.
In this partially enlarged view, the outer element 30 is shown by a two-dot chain line before the bending occurs, and the solid line is shown after the bending occurs. A clearance S is provided between the outer element 30 and the inner element 40. The clearance S is a gap provided in a portion not related to the fitting of the outer element 30 and the inner element 40.
This clearance S is set so that the inner peripheral surface 38 for partitioning the accommodation chamber 39 does not come into contact with the large diameter portion 41 of the inner element 40 even if the platen 20, particularly the outer element 30 is bent as shown in the drawing. Clearance.

According to this configuration, the deflection of the outer element 30 does not directly affect the deformation of the pressure ring 50. Therefore, even if the outer element 30 is bent and the bending (deflection amount) fluctuates due to the fluctuation (decrease) of the extrusion force F, the die 60 arranged by the holding means (not shown) on the pressure ring 50 is deformed. The second effect of not causing it to occur can be achieved. Further, as described above, the positioning reference of the inner element 40 with respect to the outer element 30 is between the outer diameter of the small diameter portion 43 of the inner element 40 and the opening diameter of the holding hole 35 into which the small diameter portion 43 is inserted. It only has a clearance that meets the requirements. However, in a state where the outer element 30 is bent, most of the inner peripheral surface of the opening of the outer element 30 into which the small diameter portion 43 is inserted (the inner peripheral surface of the small inner diameter portion 36) is the small diameter portion 43 of the inner element 40. Deforms in the direction away from the outer peripheral surface of. Therefore, when the outer element 30 bends, there is no possibility that the small clearance will affect the deformation of the pressure ring 50. The predetermined clearance S and the deflection of the outer element 30 in FIG. 2 are exaggerated for the sake of easy understanding of the explanation.

On the other hand, during the extrusion process, the outer side is ensured by maintaining the fastening state of the substantially central portion of the outer element 30 by the inner element 40 and the fastening member 46 and maintaining the compressive stress CF by this fastening state. The rigidity for countering the bending moment M that causes the element 30 to bend can be structurally ensured even if the inner element 40 is made of a metal material having substantially the same Young's modulus as the platen 20. Therefore, by manufacturing the inner element 40 with a metal material having a Young's modulus larger than that of the platen 20, the strength itself of the central portion is improved in addition to the compressive stress CF generated in the substantially central portion of the platen 20. It is also possible to further increase this rigidity.

In this way, the inner element 40 and the fastening member 46 generate tensile stress PF in the inner element 40 and compressive stress CF in the outer element 30, thereby improving the rigidity of the substantially central portion of the outer element 30 and extruding. It is possible to suppress the deflection (deflection amount) of the outer element 30 during the process.

Further, even if the outer element 30 is bent (amount of bending) and fluctuates during the extrusion process due to the fluctuation (decrease) of the extrusion force F, the outer peripheral surface of the large diameter portion 41 of the inner element 40 and the large diameter Due to the configuration in which the inner peripheral surface of the holding hole 35 of the outer element 30 on which the portion 41 is arranged does not come into contact with each other, a predetermined clearance S is secured while being reduced, so that the deflection of the outer element 30 is a deformation of the pressure ring 50. Does not directly affect.

As a result, with respect to the extrusion press apparatus disclosed in Patent Document 1, the deformation (deformation amount) of the pressure ring 50 and the die 60 and its fluctuation during the extrusion process can be significantly suppressed, and the extrusion process can be started. From to completion, the product extruded from the die 60 can be obtained with the desired dimensional accuracy.

[Second Embodiment]
Next, the platen 120 according to the second embodiment of the present invention will be described with reference to FIGS. 5 to 8.
As shown in FIGS. 5 and 6, the platen 120 according to the second embodiment has a three-layer structure including a second outer element 130, a first outer element 140, and an inner element 150. The second outer element 130 is a rectangular parallelepiped member. Further, the first outer element 140 and the inner element 150 are cylindrical members and are arranged coaxially on the central axis C. The first outer element 140 is fitted inside the second outer element 130, and the inner element 150 is fitted inside the first outer element 140. The inner element 150 is provided by sandwiching the first outer element 150 from both the front and back sides of the first outer element 150.

[Second outer element 130]
As shown in FIGS. 5, 6 and 7, the second outer element 130 includes a thick-walled portion 131 provided on the rear side and a thin-walled portion 133 connected to the thick-walled portion 131 and provided on the front side. The second outer element 130 is provided inside the thick portion 131 and the thin portion 133, and is provided with a holding hole 135 for penetrating in the front-rear direction and for aligning the first outer element 140. The holding hole 135 includes a small inner diameter portion 136 corresponding to the thick wall portion 131 and a large inner diameter portion 137 corresponding to the thin wall portion 133, and is formed in a stepped shape in the front-rear direction.

[First outer element 140]
As shown in FIGS. 5, 6 and 7, the first outer element 140 includes a small diameter portion 141 provided on the rear side and a large diameter portion 143 connected to the small diameter portion 141 and provided on the front side. The first outer element 140 is provided with a holding hole 145 for penetrating the small diameter portion 141 and the large diameter portion 143 and for aligning the adjacent inner elements 150. The holding hole 145 includes a small inner diameter portion 146 and a large inner diameter portion 147, and is formed in a stepped shape in the front-rear direction.

Here, it is preferable that the second outer element 130 and the first outer element 140 are fitted by a shrinkage fit. By being fitted by the shrink fit, a compressive stress is generated in the radial direction between the second outer element 130 and the first outer element 140. Therefore, the portions of the second outer element 130 and the first outer element 140 have higher rigidity than the portions having an integral structure. Further, if the Young's modulus of the material constituting the first outer element 140 is larger than that of the material constituting the second outer element 130, the rigidity of the second outer element 130 can be further improved.
As described above, if sufficient rigidity can be secured for the second outer element 130, the clearance S provided in the first embodiment can be minimized or omitted.
Shrink-fitting and cold-fitting are known as shrink-fitting. When applying shrink-fitting, the second outer element 130 and the first outer element 140 are fitted together in a state where the second outer element 130 is heated to a predetermined temperature and expanded in the radial direction. When the cooling fit is applied, the second outer element 130 and the first outer element 140 are fitted in a state where the first outer element 140 is cooled to a predetermined temperature and contracted in the radial direction.

[Inner element 150]
As shown in FIGS. 5, 6 and 7, the inner element 150 is connected to the large diameter portion 151 provided with the mounting recess of the pressure ring 50 and the large diameter portion 151, and penetrates the accommodating chamber 39 in the front-rear direction. It is provided with a small diameter portion 153 provided.

The inner element 150 is provided with a discharge path 152 that penetrates in the front-rear direction from the large diameter portion 151 to the small diameter portion 153. The extruded product extruded through the die 60 is discharged rearward from the extrusion press device 1 through the discharge path 152. Further, the inner element 150 has a screw 154 cut at the outer peripheral end portion on the rear side of the small diameter portion 153. The screw 154 of the small diameter portion 153 is tightened with the female screw 157 of the fastening member 156. Further, the inner element 150 includes a pressure receiving surface 155 that connects the large diameter portion 151 and the small diameter portion 153. The pressure receiving surface 155 is a surface that receives pressure parallel to the central axis C from the second outer element 130 and the first outer element 140.

The inner element 150 includes a fastening member 156 for fixing the large diameter portion 151 and the small diameter portion 153 to the first outer element 140. The fastening member 156 has a shape similar to that of a nut, and a male screw 154 formed on the small diameter portion 153 and a female screw 157 to be tightened are cut on the inner peripheral surface. In the second embodiment as well, the central axis C is attached to the inner element 140 by previously tightening the fastening member 156 from the rear side of the platen 20 to the small diameter portion 153 in a state where the preliminary load MF is generated at the time of assembling the extrusion press device 1. The inner element 140 is arranged substantially inside the center of the platen 120 in a state where the tensile stress PF parallel to the platen 120 is constantly generated.

The inner element 150 is fixed to the first outer element 140 in a state where a tensile stress PF is generated in advance in the extrusion direction by a preliminary load MF equal to or larger than the load acting in the extrusion direction during the extrusion process. This relationship is the same as the stress relationship between the outer element 30 and the inner element 40 of the first embodiment.

The inner element 150 comprises a fluid supply structure 160. As shown in FIG. 5, the fluid supply structures 160 are provided at four locations, for example, at equal intervals in the circumferential direction.
As shown in FIGS. 6 to 8, the fluid supply structure 160 supplies a first structure 161 that supplies a fluid consisting of a liquid or a gas that cools the extruded product, and air for forming an air curtain. The second structure 165 and the like are provided.
The first structure 161 includes a first flow path 162 for flowing a cooling medium from a supply source (not shown), and

first nozzles

163 and 163 for discharging the cooling medium flowing through the first flow path 162. The first flow path 162 extends from the rear to the front inside the small diameter portion 153 of the inner element 150. The

first nozzles

163 and 163 are connected to the tip of the first flow path 162, and the discharge port thereof is directed inward in the radial direction of the small diameter portion 153.
The second structure 165 includes a second flow path 166 through which air supplied from a supply source (not shown) flows, and a second nozzle 167 provided at the tip of the second flow path 166. The second flow path 166 extends from the rear to the front inside the small diameter portion 153 of the inner element 150. The second nozzle 167 is connected to the tip of the second flow path 166, and its discharge port is directed inward in the radial direction of the small diameter portion 153.

The first structure 161 is hardened into the extruded product by supplying a cooling medium to the extruded product that has just passed through the discharge path 152, that is, immediately after extrusion, and cooling the extruded product so as to follow a desired temperature history, and by other heat treatment. It is provided to obtain effects such as strength improvement. The cooling medium to be supplied is selected from air, a gas such as an inert gas, and a liquid such as water, but from the viewpoint of cooling capacity, it is preferable to spray a liquid, particularly water.

When the cooling medium is made liquid, there is a concern that the sprayed liquid will corrode the part to which it adheres. For example, the sprayed liquid adheres to the die 60 via the discharge path 152 of the inner element 150 and the passage 51 of the pressure ring 50, causing the die 60 to rust, or the generated rust to be mixed into the extruded product. I want to avoid problems. Therefore, in the present embodiment, a second structure 165 is provided as a preferred embodiment. That is, by providing the second structure 165 on the front side closer to the die 60 than the first structure 161 and supplying air from the second structure 165, the liquid sprayed from the first structure 161 reaches the die 60. Form an air curtain to prevent.

Here, as a preferred embodiment, the liquid is sprayed from the first structure 161 onto the extruded product, but the gas can be sprayed from the first structure 161 onto the extruded product. In this case, since there is no risk of corrosion of the die 60 or the like, the second structure 165 can be omitted.
Further, as shown in the upper diagram of FIG. 8, the fluid supply structure 160 may be provided with the first nozzle 163 and the second nozzle 167 exposed to the inside of the inner element 150 via a short pipe. As shown in the lower figure of 8, the first nozzle 163 and the second nozzle 167 can be provided in the recess formed on the inner peripheral surface of the inner element 150. In the former case, it is preferable to provide a protective body 164 that covers the first nozzle 163 and the second nozzle 167.

[Effects of the second embodiment]
Next, the effect of the second embodiment will be described.
The platen 120 according to the second embodiment is composed of a second outer element 130, a first outer element 140, and an inner element 150, and has a three-layer structure in the radial direction, but is between the first outer element 140 and the inner element 150. , A stress structure by pinching is provided as in the first embodiment. Therefore, as in the first embodiment, the deformation of the platen 120 during the extrusion process is suppressed.
Further, if the second outer element 130 and the first outer element 140 are fitted by shrinkage fitting, a compressive stress is generated in the radial direction between the second outer element 130 and the first outer element 140. Therefore, it is expected that the portions of the second outer element 130 and the first outer element 140 have higher rigidity than the portions having an integral structure, and the deformation of the platen 120 during the extrusion process is further suppressed. it can. As described above, if sufficient rigidity can be secured for the second outer element 130, the clearance S provided in the first embodiment can be minimized or omitted.

Next, in the second embodiment, since the fluid supply structure 160 is provided on the inner element 150, the rigidity of the second outer element 130 and the first outer element 140 of the platen 120 can be ensured as described below.
For example, it is assumed that drilling is performed in order to provide the first flow path 162 and the second flow path 166 of the fluid supply structure 160 around the discharge path 242 of the platen 220, which is integrally formed as shown in FIG. .. Then, when the platen 220 bends, stress is concentrated on the cut hole machined portion, which may cause damage to the platen 220.
Instead of drilling holes, the pipes constituting the first flow path 162 and the second flow path 166 can be arranged on the peripheral edge of the discharge path 242. However, in order to adopt this alternative means, it is necessary to increase the opening diameter of the discharge path 242, including the rising height of the cooling nozzles corresponding to the first nozzle 163 and the second nozzle 167. Therefore, if this alternative means is adopted, the rigidity of the platen 220 is reduced.

In contrast to the above, in the second embodiment, the first flow path 162, the second flow path 166, the first nozzle 163, and the second nozzle 167 are arranged inside the inner element 150. Here, as described earlier in the first embodiment (paragraph 0048), the inner circumference of the opening of the outer element 30 into which the small diameter portion 43 is inserted in the state where the outer element 30 is bent in the first embodiment. Most of the surface (inner peripheral surface of the small inner diameter portion 36) is deformed in a direction away from the outer peripheral surface of the small diameter portion 43 of the inner element 40. Similarly, even when the second outer element 130 of the second embodiment is bent, the inner peripheral surface of the opening (small inner peripheral surface of the small inner diameter portion 146) of the second outer element 130 into which the small diameter portion 153 is inserted is large. The portion is deformed in a direction away from the outer peripheral surface of the small diameter portion 153 of the inner element 150. Therefore, for the inner element 150, stress concentration due to the deflection of the second outer element 130 cannot occur, and the preload MF larger than the rated load, which is always generated parallel to the central axis C of the inner element 150, is applied. The tensile stress PF cannot cause a decrease in rigidity.
Further, by fastening with the inner element 150 and the fastening member 156, the portion including the small diameter portion 141 of the first outer element 140, which is a part of the platen 120, is gripped, and the compressive stress CF of the portion is maintained. A stress structure by pinching similar to that of the embodiment is provided. Due to this stress structure, sufficient rigidity is secured to counter the bending moment M that causes the platen 120 to bend, and the bending itself during the extrusion process of the platen 120 is suppressed. Therefore, it is possible to avoid stress concentration and a decrease in rigidity on the first outer element 140 and the second outer element 130 provided outside the inner element 150.
Further, it is easier to drill a hole in the inner element 150, which is smaller in size and weight than the integrated platen 220, than to drill a hole in the platen 220.

Although the preferred embodiments of the present invention have been described above, the configurations listed in the above embodiments can be selected or replaced with other configurations as long as the gist of the present invention is not deviated. For example, the fluid supply structure 160 can be provided on the inner element 40 of the first embodiment.

1 Extrusion press device 10 Extrusion part 20 Platen 30 Outer element 31 Thick part 32 Pressure receiving surface 33 Thin part 33A surface 33B surface 35 Holding hole 36 Small inner diameter part 37 Large inner diameter part 38 Inner peripheral surface 39 Storage chamber 40 Inner element 41 Large diameter Part 42 Discharge path 43 Small diameter part 45 Pressure receiving surface 46 Fastening member 46'Fastening member 48 Mounting surface 50 Pressure ring 60 Die 70 Holding part 71 Container 72 Holding chamber 73 Container holder 75 Container cylinder 76 Cylinder 77 Piston rod 80 Pressure generating part 81 Main Cylinder Housing 83 Main Cylinder 84 Main Ram 85 Side Cylinder 86 Main Crosshead 87 Tie Rod 88 Extrusion Stem 89 Tie Rod Nut 120 Platen 130 Second Outer Element 131 Thick Wall 133 Thin Wall 135 Holding Hole 136 Small Inner Diameter 137 Large Inner Diameter 140 1 Outer element 141 Small diameter part 143 Large diameter part 145 Holding hole 146 Small inner diameter part 147 Large inner diameter part 150 Inner element 151 Large diameter part 152 Outlet path 153 Small diameter part 155 Pressure receiving surface 156 Fastening member 160 Fluid supply structure 161 First structure 162 First 1 Flow path 163 1st nozzle 165 2nd structure 166 2nd flow path 167 2nd nozzle 220 Platen 242 Discharge path 250 Pressure ring 260 Die 287 Tie rod B Billet C Center axis S Clearance

Claims

A die for extruding the work material and
A cylinder that applies a pressing force that presses the work material against the die,
A platen that receives the pressing force from the die, and
The platen is
An outer element and an inner element arranged coaxially with the outer element inside the outer element are provided.
The inner element
The outer element is sandwiched and provided from both sides of the front and back of the outer element.
An extrusion press device characterized by the fact that.
The outer element and the inner element are fitted and
Tensile stress is generated in the inner element in the axial direction, and
The extrusion press device according to claim 1, wherein a compressive stress corresponding to the tensile stress is generated in the outer element.
The inner element
Provided by sandwiching the outer element by fastening.
The extrusion press device according to claim 1 or 2.
The outer element and the inner element that are fitted to each other have a gap in a portion that is not involved in the fitting.
The extrusion press device according to any one of claims 1 to 3.
The inner element
A large-diameter portion provided on the front side, a small-diameter portion connected to the large-diameter portion, and a fastening member to be fastened to the small-diameter portion are provided.
The fastening member is
The tensile stress is generated by pressing the outer element by being tightened to the small diameter portion in advance and applying a preliminary load equal to or greater than the load acting during the extrusion process.
The extrusion press device according to claim 2.
In the outer element, the compressive stress is generated in the region sandwiched by the inner element.
The extrusion press device according to claim 5.
The outer element
A first outer element that is adjacent to the inner element and fitted to the outside of the inner element,
A second outer element that is adjacent to the first outer element and fitted to the outside of the first outer element.
The inner element
The first outer element is sandwiched and provided from both the front and back sides of the first outer element.
The extrusion press device according to claim 1.
Tensile stress is generated in the inner element in the axial direction, and
A compressive stress corresponding to the tensile stress is generated in the first outer element.
The extrusion press device according to claim 7.
The extrusion press device according to claim 7, wherein the first outer element and the second outer element are fitted by a shrink fit.
The inner element is arranged with a fluid supply structure that supplies a cooling medium to the extruded product.
The extrusion press device according to any one of claims 1 to 8.
The inner element is made of a metal material having substantially the same Young's modulus as the outer element, or a metal material having a Young's modulus larger than that of the outer element.
The extrusion press device according to any one of claims 1 to 10.
A platen of an extrusion press that receives pressing force from extrusion molding of dies.
The platen is
An outer element and an inner element arranged coaxially with the outer element inside the outer element are provided.
The inner element
It is arranged inside the outer element in a state where tensile stress is generated in the axial direction in advance by a preliminary load equal to or larger than the load acting during the extrusion process.
Platen for extrusion press equipment.