JP6143142B1 - High-precision extruder capable of constant feeding - Google Patents

Abstract

[PROBLEMS] To thoroughly wipe away fluctuations in the driving force of a stem in a direct extruder so that the dimension of a molded product can be finished with high accuracy, and that a high-temperature molded product jumps out of a die. To be able to completely eliminate any dangers. SOLUTION: A die holder 3, an extruding portion 4 for feeding billet B toward a die 2 held by the die holder 3, and a molded product receiving portion provided at a position for receiving a molded product formed through the die 2. 5, and the extrusion unit 4 includes a feed screw mechanism 16 disposed with its axis parallel to the billet feed direction, a drive unit 17 that applies a rotational driving force to the feed screw mechanism 16, and a drive unit 17. And a stem moving portion 15 for propelling the extrusion stem 20 that pushes the billet B toward the die 2 with the linear power extracted from the feed screw mechanism 16 during the rotational drive. [Selection] Figure 1

Description

  The present invention relates to a high-precision extruder capable of quantitative feeding, which can be suitably used when a metal billet is extruded.

Of the extruders that extrude metal billets such as aluminum, many of the so-called "direct extruders" press the heated billet against the die by an extrusion stem driven by hydraulic pressure, and the billet is Are deformed plastically into a cross-sectional shape corresponding to the die hole (including a circular shape having a diameter smaller than that of the billet, various polygons, L-type, H-type, C-type, etc.).
However, this type of hydraulically driven extruder has problems such as noise, oil leakage, and running costs, and recently, as shown in Patent Document 1, the driving of the extrusion stem has been promoted. It has been proposed to use an electric type instead of a hydraulic type.

  The extruder of Patent Document 1 has a shape in which the extrusion stem is extended backward, and then, one end portion of the wire is connected to the rear end of the extrusion stem, and the wire is wound in the drawing direction by the electric drum installed in the front. By doing so, the extrusion stem was propelled and driven toward the die.

Japanese Patent No. 5382137

  Originally, in the case of an extruder that drives an extrusion stem hydraulically, the hydraulic oil charge pressure fluctuates due to load fluctuations during molding and changes in oil temperature, etc. The speed at which the material is fed into the die is also adversely affected (speed fluctuation), and as a result, the finished dimensions of the molded product exiting the die are adversely affected. In particular, when the charge pressure is instantaneously increased, there is a risk that a high-temperature molded product may jump out of the die.

  In contrast, in the extruder described in Patent Document 1, as described above, the wire is drawn by the rotation of the electric drum, and the propulsion amount of the stem is controlled by this pulling amount. There arises a problem that the rotational speed of the electric drum fluctuates due to disturbance such as elongation. That is, in the extruder of Patent Document 1, the variation is derived from the speed at which the billet is fed into the die, and therefore, the problem of adversely affecting the finished dimensions of the molded product has not been solved at all. I can say that. In addition, since the problem that the pushing amount of the extrusion stem increases instantaneously when the load at the time of molding is released, etc. can naturally occur, the risk of the hot molded product jumping out of the die is eliminated. It can be said that it has not reached.

  The present invention has been made in view of the above circumstances, and thoroughly wipes out fluctuations in the driving force of the extrusion stem so that the dimensions of the molded product can be finished with high accuracy. It is an object of the present invention to provide a high-precision extruder capable of quantitative feeding that can completely eliminate the danger that a high-temperature molded product jumps out of a die.

In order to achieve the above object, the present invention has taken the following measures.
That is, the high-precision extruder capable of quantitative feeding according to the present invention includes a die holder for holding a metal billet forming die, an extrusion unit for feeding the billet toward the die held by the die holder, and the die. A molded product receiving portion provided at a position for receiving a molded product molded through, and the push-out portion is arranged with a feed screw mechanism arranged in parallel with the billet feeding direction, and the feed screw A driving part for applying a rotational driving force to the mechanism, a stem moving part for propelling an extruding stem for pushing out a billet with linear power extracted from the feed screw mechanism at the time of rotational driving by the driving part toward the die, and the stem moving A tie rod constructed to be supported at both ends by a pair of platens opposed to each other over a stroke in which the portion moves in the billet feed direction; And a linear motion guide comprising a guide rail provided parallel to the guide and a slider slidably held with respect to the guide rail, and the tie rod is a path of the die. The linear movement guide is provided so as to penetrate the stem moving part at a position distant from the line in the radial direction, and the slider is coupled to the stem moving part .

It is preferable that the driving part of the pushing part has a servo motor.
It is assumed that the feed screw mechanism of the pushing portion is provided with a gear mechanism that transmits the rotational force from the worm to the worm wheel in a transmission system that converts the rotational force as the input by the driving portion into the linear power as the output. Is good.
The die holder is provided with a second slider that is slidably held while meshing with a guide rail included in the linear guide of the pushing portion, and the billet holds the die held by the die holder. It is preferable that a fluid pressure damper is provided on the platen that is disposed at the end of the platen so that the die holder pushes back the movement away from the pushing portion.

  The fluid pressure damper may be provided with a counterbalance that controls the discharge of the fluid in the damper in synchronization with the extrusion pressure when the billet passes through the die held by the die holder.

  The high-precision extruder capable of quantitative feeding according to the present invention is capable of thoroughly wiping out fluctuations in the driving force of the extrusion stem and finishing the dimensions of the molded product with high accuracy. The danger of the molded product jumping out of the die can be completely eliminated.

It is front sectional drawing which showed 1st Embodiment of the high precision extruder which concerns on this invention. It is the front view which showed 1st Embodiment of the high precision extruder which concerns on this invention. 1 is a plan view showing a first embodiment of a high-precision extruder according to the present invention. It is the left view which showed 1st Embodiment of the high precision extruder which concerns on this invention. It is the hydraulic circuit which showed a mode that the counter balance was provided with respect to the fluid pressure damper. It is the sectional view on the AA line of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a front sectional view showing a first embodiment of a high-precision extruder 1 capable of quantitative feeding according to the present invention, FIG. 2 is a front view, FIG. 3 is a plan view, and FIG. It is a left side view. 6 is a cross-sectional view taken along line AA in FIG.
As is apparent from FIGS. 1 to 3, this high-precision extruder 1 has a die holder 3 that holds a die 2 for molding in the center, and the pass line direction of the die 2 (see FIGS. 1 to 3). Extruded portions 4 are arranged on the primary side of the die holder 3 (each right side in FIGS. 1 to 3) in each of the left and right directions, and the secondary side of the die holder 3 (each of FIGS. 1 to 3) The molded product receiving portion 5 is arranged on the left side).

  In the high-precision extruder 1 of the first embodiment, the entire apparatus including the die holder 3, the extrusion unit 4, and the molded product receiving unit 5 has a short side of about 1100 mm and a long side of about 1100 mm in plan view (FIG. 3). It is assumed that it is installed on a base 6 having a rectangular shape of 2100 mm (about one size larger than Tatami 1 tatami). This size of extruder is classified as a small device when compared to a hydraulically driven general direct extruder.

On the base 6, a pair of platens 10, 11 are disposed opposite to each other in the long side direction, and a plurality of tie rods 13 (a pair of platens 10, 11 holding a parallel relationship with each other) ( In the example shown in FIG. These tie rods 13 are parallel to the pass line of the die 2.
Both end portions of each tie rod 13 are fixed by penetrating the platens 10 and 11 in a skewered manner, whereby the pair of platens 10 and 11 are firmly connected and fixed to each other, including the base 6 as a whole. Rigidity is ensured.

In the following, for convenience of explanation, the platen 10 shown on each right side of FIGS. 1 to 3 is referred to as a “primary side platen 10”, and the platen 11 shown on each left side of FIGS. 11 ”.
The extruding unit 4 includes a stem moving unit 15 that is movably held along the tie rod 13, and a feed screw mechanism 16 and a driving unit 17 provided for the primary side platen 10.

The stem moving unit 15 is for feeding and pressurizing the metal billet B (see FIG. 2) toward the die 2 held by the die holder 3, and on the surface facing the die holder 3, The extrusion stem 20 is held in a state in which the tip portion protrudes in an arrangement that matches the two pass lines.
The movement of the stem moving portion 15 is guided by using a part of the tie rods 13 (two arranged on the upper side in the first embodiment) as a guide bar, and the other tie rods 13 (lower side). It is also guided by a linear motion guide 21 configured with two cores arranged in the center. That is, the stem moving unit 15 is configured to move by receiving a double guide.

The linear guide 21 is equivalent to a sliding stable product generally called by a trade name such as an LM guide, a linear guide, or a linear way. The linear guide 21 slides in contact with the guide rail 22 while meshing with the guide rail 22. It has a slider 23 that can be freely combined, and exhibits high vibration damping properties and rolling properties (low friction properties) during linear movement.
Specifically, the tie rods 13 are arranged with two upper sides and two lower sides so that the pass line of the die 2 is spaced at an equal distance upward and downward (in the radial direction) from the pass line at the height center. It is set. The upper two parallel interval centers and the lower two parallel interval centers are set to coincide with the vertical position of the pass line.

  As shown in FIG. 6, the guide rails 22 of the linear guide 21 are attached to the two lower tie rods 13 so as to embrace them from above and below. The guide rail 22 is formed with a pair of vertical surfaces (two parallel surfaces facing each other back) separated by a uniform distance in the horizontal direction (radial direction) with the axis of the tie rod 13 as a boundary. I can say that.

  For such a total of four tie rods 13, the stem moving portion 15 is provided with a cylindrical bush 25 (see FIG. 1) that is slidable on the tie rod 13 at a position through which the upper two tie rods 13 penetrate. It is. Further, the lower end portion of the stem moving portion 15 is in a state (a sandwiched state) in which the guide rails 22 attached to the two lower tie rods 13 are simultaneously in contact with each other while facing two vertical surfaces. A pair of arranged sliders 23 are combined.

  From these things, the stem moving part 15 has a double guide structure composed of two tie rods 13 on the upper side and two linear guides 21 assembled on the basis of the two tie rods 13 on the lower side. Stable linear movement without vibration is realized. In particular, since the linear motion guide 21 is provided, there is no possibility of being adversely affected by a sliding failure of the stem moving portion 15 or a lateral slide due to the bending of the tie rod 13 or the like, as compared with the case of only the tie rod 13. The advantage of being kept in a state is obtained.

The driving part 17 of the pushing part 4 is a driving source for moving the stem moving part 15. In the first embodiment, an electric servo motor 26 (see FIGS. 3, 4, and 6) is used for the prime mover 17.
The feed screw mechanism 16 of the extruding unit 4 is a mechanism for converting the rotational drive input from the driving unit 17 into linear power directed to the stem moving unit 15 and outputting it to the stem moving unit 15.

  Specifically, as shown in FIG. 1, the feed screw mechanism 16 includes a screw shaft 28, a nut member 29 screwed to the screw shaft 28, and a transmission portion 30 that transmits rotational power to the nut member 29. doing. In short, one of the screw shaft 28 and the nut member 29 is held so as not to be axially movable, and the other is held so as to be axially movable so that relative rotation occurs between the screw shaft 28 and the nut member 29. By rotating one (rotating one and holding the other non-rotatable or rotating both in the opposite direction), either one is relatively screwed (takes out linear power along the axial direction) It is a thing.

In the first embodiment, the nut member 29 is allowed to be rotated while being held so as not to move the shaft, and the screw shaft 28 is basically held so as to be non-rotatable and freely movable (in a screwable state). Adopted. The details are described below.
The screw shaft 28 is arranged with its axis parallel to the direction in which the billet B is fed (pass line of the die 2). In the first embodiment, the axis of the screw shaft 28 is arranged so as to coincide with the pass line of the die 2.

The screw shaft 28 is held by a slide bearing 32 fixed to the primary side platen 10 so as to be movable in the axial direction. Further, a key structure, for example, is provided between the outer surface of the screw shaft 28 and the inner surface of the slide bearing 32 so that the screw shaft 28 is held in a non-rotatable state in principle.
It should be noted that the primary side platen 10 is visually shielded from the outside so that when the screw shaft 28 moves in the primary direction (each right side in FIGS. 1 to 3), the end of the shaft protrudes. A shaft cover 33 for securing is provided.

  The shaft end on the secondary side (left side in FIGS. 1 to 3) of the screw shaft 28 is connected to the stem moving portion 15 of the pushing portion 4 via the connecting bracket 34 and the rotary joint 35. The rotary joint 35 is for absorbing the deviation (so as not to be transmitted to the stem moving portion 15) even when a slight rotational angle deviation occurs with respect to the screw shaft 28.

  The transmission unit 30 that transmits rotational power to the nut member 29 is formed mainly of a gear mechanism having a worm wheel 37 that is provided integrally with the nut member 29 and a worm 38 that meshes with the worm wheel 37. . Of these, the worm 38 is connected to the driving unit 17 through the winding transmission unit 39 and the spur gear mechanism 40 so as to be capable of transmission. It should be noted that a bevel gear mechanism or the like may be used instead of (or in combination with) the winding transmission unit 39 to cause the axis centers to cross (change direction) during transmission.

  As described above, in the first embodiment, since the movement of the stem moving unit 15 is basically performed by the feed screw mechanism 16, the linear movement amount of the screw shaft 28 with respect to the nut member 29 is the lead of the screw shaft 28. It is physically governed by the correlation between the angle and the number of rotations, and is maintained at a constant amount. In addition, the backlash between the nut member 29 and the screw shaft 28 is minimized, and smooth transmission with little play is possible.

Needless to say, the moving speed of the stem moving unit 15 can be controlled arbitrarily and with high accuracy by controlling the rotation speed of the screw shaft 28 (rotation drive of the servo motor 26 employed in the driving unit 17).
In addition, in the case where a gear mechanism having a worm wheel 37 and a worm 38 is employed in the transmission unit 30, by making the advance angle of the worm groove small enough to obtain a self-lock, Even if a disturbing rotational force is applied to the shaft 28 by an external force (vibration during extrusion, etc.), the rotational force is not transmitted to the nut member 29. In addition, backlash is minimized between the worm wheel 37 and the worm 38, and smooth transmission with little play is possible. Therefore, it is possible to prevent the extrusion pressure from fluctuating unexpectedly during extrusion.

As a result, during extrusion (during molding) of the billet B, the extrusion stem 20 is thoroughly prevented from being pushed back by the extrusion reaction force, and a highly reliable pushing force without vibration or the like can be obtained. is there.
On the other hand, the die holder 3 is provided with a second slider 43 that is slidably held while meshing with the guide rail 22 included in the linear motion guide 21 of the pushing portion 4. The second slider 43 is structurally substantially the same as the slider 23 provided in the stem moving portion 15 of the pushing portion 4. Therefore, stable linear movement without vibration is realized for the die holder 3 as well.

  The die holder 3 holds the die 2 as described above, and incorporates a heater for heating the billet B so as to surround the outer periphery of the die 2. In the first embodiment, in order to enable maintenance of the die 2 and replacement with the die 2 having different die holes, a structure is adopted in which a part of the peripheral wall of the die holder 3 is detachable by bolting (FIG. 2). The maintenance lid 44 is shown in FIG. In addition to the replacement of the die 2, a device such as dividing the heater into an upper heater, a lower heater, a lateral heater, etc. is added so that the heater surrounding the die can also be replaced (detailed illustration is omitted).

Since the die holder 3 is provided with the second slider 43 as described above, the die holder 3 generates a total reflection resting force when the die holder 3 receives a pressure to push the billet B into the die 2. Instead of moving in the secondary direction (each left side in FIGS. 1 to 3).
Therefore, a fluid for receiving the die 2 held at the tip of the billet B passing through the die 2 held by the die holder 3, that is, the secondary side platen 11 disposed on the secondary side while relaxing the pressure received by the die holder 3. A pressure damper 45 is provided. The fluid pressure damper 45 is provided with a counterbalance 46 (see FIGS. 2 and 5).

  In the first embodiment, the fluid pressure damper 45 is a double-acting hydraulic cylinder. Therefore, as shown in FIG. 5, each fluid pressure damper 45 has a tail end side port 45 a (port that supplies oil when pushing the rod 48) and a head side port 45 b (port that supplies oil when the rod 48 is pulled back). And a hydraulic circuit 51 including two electromagnetic valves 49 and 50 is configured.

  In the hydraulic circuit 51 of FIG. 5, auxiliary equipment such as a spare oil tank, a pump, a drain, and a check valve are omitted. In addition, when returning the fluid pressure damper 45 to the initial extended state, a bypass circuit is provided that allows the tail end side port 45a to be refueled without going through the counterbalance 46 so that the rod 48 can be quickly returned. Although provided, the illustration of the bypass circuit and the meter and switching valve provided in the bypass circuit are also omitted.

Further, as is clear from FIGS. 1 to 4, a total of two fluid pressure dampers 45 are arranged in parallel in an arrangement in which the fluid pressure dampers 45 are equally distributed around the pass line of the die 2. Each of the fluid pressure dampers 45 has a structure in which the axis of the rod 48 is parallel to the pass line of the die 2 and the rod end of the rod 48 is locked to the die holder 3.
The locking structure (see FIG. 1) between the rod end of the fluid pressure damper 45 and the die holder 3 (see FIG. 1) is only when the die holder 3 moves away from the pushing portion 4 (when moving in the secondary direction). This is to act to push back the movement of the die holder 3. Therefore, even if the die holder 3 moves in the reverse direction (primary direction), the rod end portion of the fluid pressure damper 45 is not pulled by the die holder 3, causing movement vibration or mechanical damage. There is no fear.

The counter balance 46 is incorporated between the tail end side port 45a of the fluid pressure damper 45 and the electromagnetic valve 49 on the side connected to the tail end side port 45a in the hydraulic circuit 51 (see FIG. 5). Yes.
Since the counter balance 46 is provided in such a circuit arrangement, the die holder 3 is moved away from the pushing portion 4 due to the pushing pressure when the billet B passes through the die 2, thereby causing the rod 48 of the fluid pressure damper 45 to move. Is pushed in, a small amount of fluid (oil) discharged from the tail end side port 45a of the fluid pressure damper 45 is directly (equal and synchronously) to the head side port 45b of the fluid pressure damper 45. It is possible to form a circuit that is returned.

Therefore, the fluid pressure damper 45 is always kept in a state of pressure balance, and the rod 48 is flexible against various pressure fluctuations while always buffering the movement of the die holder 3 with an appropriate back pressure. To be able to move to.
The secondary platen 11 is provided with the molded product receiving portion 5 described above. In the first embodiment, the molded product receiving unit 5 receives a molded product that has been plastically deformed through the die 2, and a product insertion tube 52 for adjusting the shape stability is directed toward the die holder 3. It is assumed to be provided in a protruding shape.

Needless to say, the product insertion tube 52 is arranged so that the center of the shape of the tube coincides with the pass line of the die 2. In addition, a through hole 53 (see FIG. 1) is formed in the secondary side platen 11 so that a molded product passing through the product insertion tube 52 can be discharged to the secondary side as it is.
As is clear from the above detailed description, the high-precision extruder 1 according to the present invention has a configuration in which the stem moving unit 15 including the extrusion stem 20 is guided by the tie rod 13 and the linear guide 21 for linear movement. Therefore, it is thoroughly wiped out that fluctuations in the driving force (vibrations related to fluctuations in the moving direction as well as fluctuations and rattling in the direction crossing the moving direction) occur, and as a result, the extrusion stem 20 can move smoothly. It has become.

  In addition, since the drive driving of the extrusion stem 20 (stem moving portion 15) is performed by the feed screw mechanism 16, the linear movement amount of the screw shaft 28 with respect to the nut member 29 is determined by the lead angle and the rotational speed of the screw shaft 28. Physically governed as a correlation and held at a constant amount. Thereby, a molded article dimension can be finished with high accuracy. Moreover, the danger that a high temperature molded product may jump out of the die 2 can be completely wiped out.

  Further, by providing the fluid pressure damper 45, the die holder 3 that holds the die 2 can always have an appropriate back pressure that is not excessive or insufficient in synchronism with the extrusion pressure even when it is subjected to the extrusion pressure by the billet B. Since the structure continues to be added, it is avoided that the die 2 and the die holder 3 receive an excessively high load from the billet B. As a result, the molded product passing through the die 2 is molded due to the high load. There is an advantage that a defect is prevented as much as possible.

  Furthermore, since the feed screw mechanism 16 and the fluid pressure damper 45 (counter balance 46) are combined, a reaction force without loss is obtained from the fluid pressure damper 45 against the extrusion pressure that is reliably generated by the feed screw mechanism 16. Therefore, there is an advantage that the substantial molding pressure that is the differential pressure between the extrusion pressure and the reaction force can be reduced. As a result, the extrusion pressure by the extrusion unit 4 (feed screw mechanism 16) can be reduced by about 30%.

By the way, this invention is not limited to the said embodiment, It can change suitably according to embodiment.
For example, in the feed screw mechanism 16 of the push-out portion 4, a rotational force is applied to the screw shaft 28 to cause the nut member 29 to be screwed (that is, linearly moved), and from the screwing of the nut member 29 to the straight line of the stem moving portion 15. Power can be taken out.

It is possible to employ an electric motor other than the servo motor 26 in the driving unit 17. In some cases, a hydraulic motor or the like may be employed.
The die holder 3 may be guided not only by the linear motion guide 21 but also by the tie rod 13.

DESCRIPTION OF SYMBOLS 1 High precision extruder 2 Die 3 Die holder 4 Extrusion part 5 Molded product receiving part 6 Base 10 Platen (primary side platen)
11 Platen (secondary side platen)
DESCRIPTION OF SYMBOLS 13 Tie rod 15 Stem moving part 16 Feed screw mechanism 17 Driving | moving part 20 Extrusion stem 21 Linear motion guide 22 Guide rail 23 Slider 25 Cylindrical bush 26 Servo motor 28 Screw shaft 29 Nut member 30 Power transmission part 32 Slide bearing 33 Shaft cover 34 Connection bracket 35 Rotary joint 37 Worm wheel 38 Worm 39 Winding transmission part 40 Spur gear mechanism 43 Slider 44 Maintenance lid 45 Fluid pressure damper 45a Tail end side port 45b Head side port 46 Counter balance 48 Rod 49 Solenoid valve 50 Solenoid valve 51 Hydraulic circuit 52 Product insertion tube 53 Through hole B Billet

Claims (5)

A die holder for holding a metal billet forming die;
An extruding part for feeding the billet toward the die held by the die holder;
A molded product receiving portion provided at a position for receiving a molded product molded through the die, and
The extruding part is
A feed screw mechanism arranged with its axis parallel to the billet feed direction;
A driving portion for applying a rotational driving force to the feed screw mechanism;
A stem moving unit for propelling an extrusion stem that pushes out a billet with linear power extracted from the feed screw mechanism at the time of rotational driving by the driving unit toward the die;
A tie rod constructed with both ends supported by a pair of platens disposed opposite to each other over a stroke in which the stem moving part moves in the billet feeding direction;
A linear motion guide configured to include a guide rail provided in parallel to the tie rod and a slider slidably held with respect to the guide rail;
The tie rod is provided in an arrangement penetrating the stem moving portion at a position radially away from the die pass line,
The linear motion guide is a high-precision extruder capable of quantitative feeding, wherein the slider is coupled to the stem moving part .   2. A high-precision extruder capable of quantitative feeding according to claim 1, wherein the driving part of the pushing part has a servo motor.   The feed screw mechanism of the pushing portion is provided with a gear mechanism that transmits the rotational force from the worm to the worm wheel in a transmission system that converts the rotational force as the input by the driving portion into the linear power as the output. A high-precision extruder capable of quantitative feeding according to claim 1 or 2. In the die holder,
A second slider is provided that is slidably held while meshing with a guide rail of the linear guide of the pushing portion;
A fluid pressure damper is provided on the platen that is disposed at the tip where the billet passes through the die held by the die holder so that the die holder pushes back the movement away from the pushing portion. The high-precision extruder capable of quantitative feeding according to any one of claims 1 to 3 . In the fluid pressure damper,
5. A high-precision feed capable of quantitative feeding according to claim 4 , wherein a counterbalance is provided for controlling the discharge of the fluid in the damper in synchronization with the extrusion pressure when the billet passes through the die held by the die holder. Extruder.

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