JP3884333B2 - Injection press for forming elastomer parts - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an injection press for forming elastomer parts.
[0002]
In particular, the present invention
The first and second platens are movable in parallel between each other by a slide along a central axis between a closed position that is relatively close to each other and an open position that is spaced from each other. A first and a second platen disposed on
It has at least one mold, the mold itself has two mold parts, and the two mold parts are in close contact with each other so that at least one elastomer part can be molded, and the elastomer part is a mold. A molding device disposed between the first platen and the second platen that is movable relative to each other along a central axis between an open position that allows release from
An injection device adapted to inject the elastomer into the mold,
At least one heating device adapted to heat the elastomer to vulcanize the elastomer present in the mold;
The invention relates to an injection press for molding an elastomer part, comprising a control device having at least one hydraulic jack adapted to move a first and a second platen between an open position and a closed position.
[0003]
[Prior art]
In this type of known injection press, once all the molded elastomer parts have been injected into the cavities of the molding equipment and vulcanized, the elastomer parts must be removed from all the cavities when released from the cavities. Make it possible. Therefore, such an injection press has a rather long operating cycle if vulcanization lasts several minutes. In order to make up for this drawback and to achieve fairly high production rates, the molding apparatus generally has a large number of cavities (eg 16).
[0004]
These known injection presses are satisfactory with respect to the effectiveness of closing the molding apparatus and the small size of the injection press itself.
[0005]
[Problems to be solved by the invention]
Nevertheless, such an injection press has the following drawbacks.
[0006]
The elastomer injection device of an injection press is particularly expensive because it must be able to fill a large number of cavities simultaneously.
[0007]
The elastomer injection device of the injection press is used for only a short time and is therefore not very productive, which is particularly problematic for expensive equipment as described above.
[0008]
Since the molding device has a large number of cavities, the cavities are connected to the injection device via a relatively long supply flow path, and thus significantly lose material during molding. The elastomer present in such a flow path itself is vulcanized while the molded part is being vulcanized, so that the elastomer such as vulcanized rubber present in the flow path at the end of molding is regenerated. It cannot be used.
[0009]
Due to the long supply flow path, it is necessary to inject the elastomer at a relatively low temperature to ensure that the elastomer does not begin to vulcanize in the flow path before filling the cavity. As a result, vulcanization is slow because relatively long heating is required in the cavity.
[0010]
A particular object of the present invention is to eliminate these drawbacks.
[0011]
[Means for Solving the Problems]
For this reason, according to the present invention, this type of injection press is:
The molding apparatus includes a turret that is rotated by an axis disposed on a central axis and holds n (two or more) independent molds. The mold includes p turrets (p ≧ p n) can be moved by rotating between fixed stations, these stations include at least one injection station and a mold release station;
When the first and second platens are in the closed position, the two mold parts belonging to each mold in a station other than the mold release station are secured together in the closed position, while the mold release station It is characterized by being able to open the mold inside.
[0012]
With this configuration, each mold can be continuously passed through various stations of the injection press. During each of these movements, the elastomer parts present in the mold at the mold release station are released from the mold.
[0013]
This makes it possible to achieve considerably higher productivity without having to use a mold with a large number of cavities. Therefore, it is possible to use a low cost elastomer injection device. Furthermore, it is also possible to shorten the length of the cavity supply channel in the mold, so that firstly material loss is suppressed and secondly the elastomer can be injected at a higher temperature, thereby Vulcanization takes place at a higher speed.
[0014]
Finally, the injection device of the injection press of the present invention is used for most of the time and is therefore highly productive.
[0015]
In preferred embodiments of the invention, one or more of the following configurations may optionally be used.
[0016]
The controller pulls the first and second platens apart, rotates the turret to move the mold from one station to another, and then each mold present at a station other than the mold release station. On the other hand, the operation of bringing the first platen and the second platen closer is periodically repeated so that the two mold parts are fixed to each other in the closed position.
[0017]
The first and second platens are stationary without rotating about the central axis, and at least one of the first and second platens has a first and second platen in the closed position. A notch corresponding to the mold release station is provided to allow the mold in the mold release station to be opened.
[0018]
The first platen is slidably mounted on a surrounding cylinder, which is parallel to the axis and arranged around the turret.
[0019]
The first platen is slidably mounted on a stationary structure fixed to the second platen, the central axis is substantially vertical, and the first platen is located below the second platen. The turret is mounted so that it slides freely on the shaft with idle movement, the shaft is provided with an abutting member that restricts the downward sliding of the turret, So that the forming device is sufficiently in contact with the first and second platens when supported by the contact member and when the first and second platens are in the open position; The first platen is lowered.
[0020]
The number p of stations is equal to the number n of molds.
[0021]
The number n of dies is 4 or more.
[0022]
The station contains p-2 vulcanization stations.
[0023]
At least some of the stations are equipped with a heating device (the heating device is thus stationary, avoiding the need to use a rotating electrical connection).
[0024]
At least some of the station heating devices each have a heater surface secured to one of the first and second platens.
[0025]
Each mold is capable of simultaneously molding several elastomer parts ranging from one to four.
[0026]
Each mold part has an outer case fixed to the turret and a block which is supported by the case and has an inner shape complementary to the elastomer part to be molded.
[0027]
The control device has at least first and second hydraulic jacks, the first hydraulic jack is arranged at a position corresponding to the injection station, and the second hydraulic jack is arranged around a central axis. It is diametrically opposed to the first hydraulic jack.
[0028]
Each mold part of each mold is an upper mold and a lower mold, and the mold release station has a mold opening device adapted to lift and separate the upper mold from the lower mold.
[0029]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings. In the various figures, the same reference numerals indicate identical or similar elements.
[0030]
FIG. 1 shows an injection press 1 for rubber or similar elastomeric material that constitutes an embodiment of the present invention.
[0031]
The injection press 1 has a fixed structure, and the fixed structure itself is fixed to the base 2 fixed to the ground, four vertical cylinders 3 fixed to the base 2, and the vertical cylinder 3. And a horizontal upper fixed platen 4.
[0032]
Furthermore, the injection press 1 is located between the base 2 and the stationary platen 4 and also has a horizontal lower movable platen 5 attached so as to slide vertically on the vertical cylinder 3. The movable platen 5 can be moved downwardly to the “open” position and upwardly to the “closed” position by two hydraulic jacks 6 disposed between the movable platen 5 and the base 2.
[0033]
Further, a molding device 7 extending substantially horizontally is disposed between the movable platen 5 and the fixed platen 4. This molding device 7 is mounted so as to rotate between vertical cylinders 3 about a vertical axis Z by a vertical control shaft 8 clearly shown in FIG.
[0034]
This shaft 8 is constrained to rotate together with the shaft 8 by an axial longitudinal groove 10 on the shaft 8 engaged with the other groove of the turret 9, and supports the turret 9 holding the mold. Yes.
[0035]
Furthermore, the turret 9 can slide vertically over a distance with respect to the axis 8. This slip is limited by a contact member such as a collar 11 fixed to the shaft 8 and positioned below the turret 9.
[0036]
As shown in FIG. 3, the turret 9 has a plurality of incisions 12 that open radially outward, each adapted to receive a mold 13. In the example shown, the turret 9 has four notches 12 disposed at intervals of 90 ⁰ to each other, therefore, it is adapted to hold four molds 13, the present invention is The same applies to an injection press having a turret adapted to hold at least two molds 13, optionally six, and in some cases eight.
[0037]
Each mold 13 has an upper mold 13a and a lower mold 13b, which can be separated from each other when the mold is opened and the elastomer parts formed in the mold are released from the mold. it can.
[0038]
Furthermore, as shown in FIG.
An injection head 14 for injecting rubber having an injection nozzle 15 at the tip which can move vertically (alone or with the head assembly);
A molding apparatus so that the respective molds can be successively and sequentially positioned at an injection station 17 located below the injection head 14, two vulcanization stations 18 and 19, and a mold release station 20 (see FIG. 5). A motor 16 that drives the shaft 8 to rotate the shaft 7 about the axis Z;
A mold opening device 21 located in the mold releasing station 20;
For example, a control panel 22 including a programmable controller is provided to control the entire injection press.
[0039]
As shown in detail in FIGS. 1 and 4, the upper fixed platen 4 is advantageously complementary to the mold 13 so that the upper mold 13a of the mold slides vertically through the cut. A cut 4a having a shape is provided.
[0040]
Furthermore, the mold opening device 21 is, for example,
A fixed upper plate 23 mounted a certain distance above the upper platen 4;
A movable platen 24 that is mounted by three guide posts 25 to slide vertically relative to the stationary plate 23 and is controlled by an actuator 26;
Two locking actuators 27 held by the movable platen 24 and configured to fix the upper mold 13a of the mold below the movable platen can be further provided. The locking actuator 27 may be constituted by a “right turn (quarter turn)” type actuator, for example, an actuator sold under the trademark “CYTRAC” by CITEC, France.
[0041]
Further, in the mold release station 20, the movable platen 5 includes a support plate 28 positioned above the lower movable plate 29 that holds the operating rod 30 protruding upward.
[0042]
The movable plate 29 can be moved vertically by the actuator 31 so that the operating rod 30 penetrates a recess (not shown) of the support plate 28 and the lower mold 13b of the mold located in the mold release station 20. it can. Accordingly, the actuating rod 30 is provided on the lower mold 13b of the mold and ejects an elastomer part (not shown but basically known in the art) formed in the mold 13 located at the mold release station 20. Can work as).
[0043]
As can be seen in particular in FIGS. 1 and 2, the heating plate 37 is located below the upper fixed platen 5, below the upper movable platen 24, and below the lower movable platen at the four fixed stations 17 to 20 described above. It is fixed to the upper side of the platen 5 and the upper side of the support plate 28, respectively. These heating plates 37 transmit heat to the mold 13 when the lower platen 5 is lifted to the closed position by the hydraulic jack 6, and vulcanize raw rubber previously injected into the mold. It is heated electrically continuously so that it can.
[0044]
Finally, as shown in FIG. 6, each of the upper mold 13a and the lower mold 13b of each mold 13 has two parts:
Each outer case 32a, 32b of standard shape adapted to be held by the turret 9 (for this purpose, the lower case 32b is a support rim 32c adapted to be supported by the turret 9 And may have
Having one or more inner cavities 33a, 33b shaped to mold the elastomer part in one or more mold cavities 34 (actually one to four mold cavities) Is preferred.
[0045]
Therefore, the cases 32a and 32b can be reused regardless of the parts molded by the injection press. When changing the type of parts manufactured by the injection press, the internal blocks 33a and 32b of the cases 32a and 32b It is only necessary to replace 33b.
[0046]
As can be seen from FIG. 6, the upper case 32a and the upper block 33a form a vertical flow path 35 adapted to receive the injection nozzle 15 of the injection head 14, and the vertical flow path 35 is horizontal. Via the flow path 36, it communicates with the mold cavity 34 of the mold 13.
[0047]
The above-described injection press operates as follows. For example, the lower movable platen 5 is lowered by the jack 6 at a constant time interval ranging from several seconds to several tens of seconds. As a result, the turret 9 holding the mold 13 hits the collar 11 provided on the shaft 8. Stop. Once the platen 5 is lowered sufficiently, the molding device 7 is no longer in contact with the fixed part of the injection press.
[0048]
The programmable controller provided in the control panel 22 then rotates the motor 16 to cause the shaft 8 and the turret 9 to make a quarter turn in the direction of the arrow 38 shown in FIG. It can be seen that the rotation of the turret 9 by the drive of the shaft 8 allows the motor 16 to be disposed above the upper platen 4 and thus reduces the area on the ground occupied by the injection press.
[0049]
Thus, the empty mold 13 that was previously in the mold release station 20 is moved to a predetermined position in the injection station 17 while the block is filled with rubber and the stations 17 to 19 have previously been filled. The molds 13 that were inside are now in stations 18 to 20, respectively.
[0050]
It can be seen that this rotation is facilitated because the mold 13 does not rub against any fixed part.
[0051]
While the molding apparatus 7 is rotating, the respective molds 13 may be slightly opened, but it is understood that there is no obstacle, and in some cases, the mold 13 may function to release gas. When it is desirable to keep the mold 13 airtightly closed even when the movable platen 5 is in the open position, a lock device (not shown) is provided between the upper mold 13a and the lower mold 13b of each mold. It would be possible to provide it.
[0052]
After the forming device 7 has rotated, the movable platen 5 is again lifted by the hydraulic jack 6 which is advantageously located in a position corresponding to the injection station 17 and the vulcanization station 19 respectively. Accordingly, the mold 13 located at the injection station 17 and the vulcanization stations 18 and 19 is closed between the platen 4 and the platen 5 and is hermetically closed again. These molds 13 are then maintained at a temperature suitable to allow the mold 13 to vulcanize the rubber (due to the thermal inertia of the mold 13 while the press is open) The mold 13 is heated by a heating plate 37 (which can be maintained at a temperature suitable for continued rubber vulcanization).
[0053]
Once the platen 5 is in the closed position, the injection nozzle 15 is lowered so as to pass through the flow path 35 of the mold 13 located at the injection station 17 (see FIG. 6), and as a result, the mold cavity of the mold 13 34 is filled with raw rubber, and then the raw rubber is vulcanized by the action of the temperature of the mold 13.
[0054]
During this time, the mold 13 already filled with rubber and located in the vulcanization stations 18 and 19 continues the vulcanization process.
[0055]
Finally, at the same time, the movable platen 24 of the mold releasing device is pressed against the upper mold 13a of the mold 13 located at the mold releasing station 20, and the locking actuator 27 is operated to move the upper mold 13a of the mold. Connected to the movable platen 24. Thereafter, the movable platen 24 is lifted by the actuator 26 and passes through the notch 4 a of the upper fixed platen 4.
[0056]
Further, the lower movable plate 29 is then lifted by the actuator 31 so that the upper actuating rod 30 fixed to the plate 29 passes through the lower mold 13b of the mold through the support plate 28, thereby The elastomer part initially contained in the mold 13 located at the mold release station 20 is released from the mold.
[0057]
The parts thus released from the mold are then removed manually or automatically (by means not shown), after which the lower movable plate 29 is lowered again and the movable platen 24 itself is lowered. Thus, the upper mold 13a of the mold is positioned on the lower mold 13b. Next, the locking actuator 27 is operated to release the upper mold 13a of the mold, and then the movable platen 24 is lifted again.
[0058]
It can be seen that during these operations, the upper mold 13a and the lower mold 13b of the mold located at the mold release station 20 are continuously maintained at a high temperature by the heating plate 37 located at the mold release station 20.
[0059]
Thereafter, the injection press 1 periodically repeats the above sequence so as to mold other elastomer parts.
[Brief description of the drawings]
FIG. 1 is a perspective view of an injection press constituting an embodiment of the present invention.
FIG. 2 is a longitudinal sectional view of the injection press of FIG.
FIG. 3 is a perspective view of a turret for holding a mold, belonging to the injection press of FIG. 1;
4 is a partial schematic view of the injection press of FIG. 1 shown in perspective view.
5 is a schematic plan view showing various stations in the injection press of FIG. 1. FIG.
6 is a longitudinal sectional view showing an embodiment of a mold for an injection press in FIG. 1. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Injection press 2 Base 3 Vertical cylinder 4 Upper fixed platen 4a, 12 Cut 5 Lower movable platen 6 Hydraulic jack 7 Molding device 8 Vertical control shaft 9 Turret 10 Groove 11 Color 13 Mold 13a Upper mold 13b Lower mold 14 Injection head 15 Injection Nozzle 16 Motor 17 Injection station 18, 19 Vulcanization station 20 Mold release station 21 Mold release device 23 Upper plate 24 Movable platen 25 Guide column 26, 31 Actuator 27 Actuator for locking 28 Support plate 29 Movable plate 30 Operating rod 32a Upper case 32b Lower case 32c Rim 33a, 33b Inner block 35 Vertical flow path 36 Horizontal flow path 37 Heating plate

Claims (14)

An injection press for forming elastomer parts,
The first and second platens (5, 4) move between each other by sliding along a central axis (Z) between a closed position relatively close to each other and an open position that is away from each other Possible first and second platens (5, 4) arranged substantially parallel;
Having at least one mold (13), the mold itself comprising two mold parts, so that the two mold parts (13a, 13b) can mold at least one elastomer part; The first platen and the second platen are movable relative to each other along the central axis (Z) between a close position in close contact and an open position that allows the elastomer part to be released from the mold. A molding device (7) disposed between the platen and
An injection device (14) adapted to inject an elastomer into the mold (13);
At least one heating device (37) adapted to heat the elastomer to vulcanize the elastomer in the mold (13);
A control device (22, 6, 16, 26) having at least one hydraulic jack (6) adapted to move the first and second platens (5, 4) between an open position and a closed position. , 27, 31)
The molding device (7) is rotated by a shaft (8) disposed on the central axis (Z), and holds turrets (n) (n is 2 or more) holding independent molds (13). 9), the mold can be moved by rotating the turret between p (p ≧ n) fixed stations (17-20), at least one of these stations Two injection stations (17) and a mold release station (20) are included,
When the first and second platens are in the closed position, two mold parts (13a) attached to each mold in a station (17-19) other than the mold release station (20). 13b) are fixed to each other in the closed position, while allowing the mold in the mold release station (20) to be opened.   The controller pulls the first platen (5) and the second platen (4) apart and rotates the turret (9) to move the mold (13) from one station to another station. Next, two mold parts (13a, 13b) are fixed to each other in the closed position with respect to each mold (13) existing in a station (17-19) other than the mold release station. The injection press according to claim 1, wherein the operation of bringing the first platen (5) and the second platen (4) closer to each other is periodically repeated.   The first and second platens (4, 5) are stationary without rotating around the central axis (Z), and at least one of the first and second platens includes the first platen (4, 5). And a notch (4a) corresponding to the mold release station (20) that allows the mold in the mold release station to be opened while the second platen (5, 4) is in the closed position. The injection press according to claim 1 or 2, wherein:   The first platen (5) is slidably mounted on a surrounding cylinder (3) parallel to the axis (8) and disposed around the turret (9). The injection press according to any one of claims 1 to 3.   The first platen (5) is slidably mounted on a fixed structure (2, 3) fixed to the second platen (4), and the central axis (Z) is substantially vertical. And the first platen (5) is located below the second platen (4), and the turret (9) is free to slide on the shaft (8) by idle movement. And the shaft includes a contact member (11) for limiting downward sliding of the turret (9), and the control device is configured such that the turret (9) is the contact member of the shaft. (11) is supported, and the molding device (7) does not contact the first and second platens (5, 4) when the first and second platens are in the open position. The first platen to a sufficient extent to 5) and is adapted to lower the injection press according to any one of claims 1 to 4.   The injection press according to any one of claims 1 to 5, wherein the number p of the stations (17-20) is equal to the number n of the molds (13).   The injection press according to any one of claims 1 to 6, wherein the number n of the molds is 4 or more.   The injection press according to any one of the preceding claims, wherein the station comprises p-2 vulcanization stations (18, 19).   The injection press according to any one of the preceding claims, wherein at least some of the stations comprise a heating device (37).   10. At least some of the heating devices at the station each have a heater surface (37) secured to one of the first and second platens (5, 4). The injection press described in.   11. An injection press according to any one of the preceding claims, wherein each mold (13) is adapted to simultaneously mold several elastomer parts ranging from one to four.   Each mold part (13a, 13b) has an outer case (32a, 32b) fixed to the turret and an inner shape (34) which is supported by the case and complementary to the elastomer part to be molded. The injection press according to any one of claims 1 to 11, comprising a block (33a, 33b) having The control device includes at least first and second hydraulic jacks (6), and the first hydraulic jack is disposed at a position corresponding to the injection station (17), and the second hydraulic jack (6). hydraulic jack is diametrically opposite to said first hydraulic jack about the central axis (Z), injection press according to any one of claims 1 to 12 in.   Each mold part (13a, 13b) of each mold (13) is an upper mold (13a) and a lower mold (13b), and the mold release station (20) lifts the upper mold and 14. Injection process according to any one of the preceding claims, comprising a mold opening device (21) adapted to be separated from the lower mold.

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