FR2890891A1 - Blow-moulding machine preform heater has rapid actuator for heating chamber barrier to halt process in event of moulding machine failure - Google Patents

Abstract

The preform heater, comprising a transfer conveyor (24, 26) with holders for the preforms (28) inside one or more heating chambers (34), incorporates a system that provides for rapid movement of a heating chamber barrier to halt preform heating in the event of a blow-moulding machine failure. The system consists of a column (42) that is moved relative to a fixed component (44) by a drive that is activated by a control unit for maintenance purposes or in an emergency stop mode.

Description

2890891 1

  The present invention relates to a device for preform heating for a container blowing machine. It also relates to a machine for blowing containers using such a heating device.

  In the state of the art, it is known to blow-mold a container such as a bottle of thermoplastic material from a preform. The preform has the shape of a substantially cylindrical tube called a body whose one end is closed and will serve as a bottom to the container of final shape and the other end is open and serve as a neck or opening to the container of final shape.

  Initially, the preforms are at room temperature before being introduced into the blow mold. The body of the preforms must be uniformly heated throughout the mass at a temperature ensuring its softening, except where appropriate its neck portion which must be protected from heating.

  To do this, the preforms are introduced one after the other while rotating them in a heating device, and this, while protecting the neck of a possible heater.

  In the state of the art, and reference can be made to the documents published in the name of the applicant, it is described how to ensure the heating of a preform as uniformly as possible throughout the mass of its material. It has also been described how to ensure the protection of the neck portion without it undergoes a detrimental softening, for example when the neck has a thread for the closure of the container of final shape. Finally, it has been described how to provide the two functions mentioned above in a preform heating device when they run at a very high rate because the blowing machine in which the heating device is installed has to work at a rate of 30%. very high production.

  However, when operating such a blowing machine, it appeared a particular problem that the invention aims to solve. Indeed, for various reasons, there are situations in which the blowing machine must be stopped as quickly as possible. This is the case when an incident occurs on part of the blowing machine. In particular, it should be understood that such container blowing machines are machines having a very high number of fixed or moving mechanical components and that failure circumstances, even when they are reduced by construction as much as possible , can occur dramatically. In particular, it has appeared that, during the operation of such a machine, a sudden stop of the blowing machine leads to a situation in which the preforms being heated in the heating device associated with the machine at a standstill come in extreme deformation sticking and then cool on the active components of the heater. As a result, the heater must be disassembled and cleaned completely, and sometimes even some active components need to be changed.

  Moreover, because in particular because the collar regions of the preforms may not have the same geometric configuration when a new blowing campaign of a different container model is initialized, it is particularly necessary to modify the configuration of the heating device, in order to adapt it to the particular neck shape and sometimes even to different dimensions or shapes of the preform compared to the preforms used during the blow molding campaign of the previous model. In this case, it is then necessary to disassemble the heating device 2890891 3 more or less completely until you can access the components that must be changed to change its configuration according to the new campaign.

  In either of these two problems, the maintenance operations are long. As a result, the blowing machine is immobilized for a period during which it does not produce. The invention aims to considerably reduce these disadvantages of the state of the art. In

  The present invention relates to a preform device for a blow molding machine of the type comprising a transfer chain provided with preform gripping means which runs in at least one heating chamber. According to the invention, the heating device comprises means for rapidly moving at least one limiting element of the heating chamber.

  According to one aspect of the invention, the means for rapidly moving at least one limiting element of the heating chamber comprises at least one column movable relative to a fixed part.

  According to one aspect of the invention, the means for rapidly moving at least one limiting element of the heating chamber comprises a motor means which cooperates with a control means to activate the mobilization of at least one moving part of the minus a heating chamber during a maintenance mode or an emergency stop mode.

  According to one aspect of the invention, said motor means cooperates with a locking means.

  According to one aspect of the invention, at least one heating enclosure element has a movable portion relative to a fixed portion.

  According to one aspect of the invention, the mobile part of the enclosure element is mounted on a hinge-type hinge relative to said fixed part.

  According to one aspect of the invention, at least one movable part 5 of at least one heating chamber cooperates with a braking means.

  The invention also relates to a machine for blowing containers from preforms which comprises at least one heating machine as defined above.

  Other features of the present invention will be better understood with the aid of the description and the appended figures in which: FIG. 1 is a diagrammatic front view of a heating device of the state of the art; - Figure 2 is a schematic top view of the heater of Figure 1; FIG. 3 is a schematic view of part of a heating device according to a first embodiment of the invention; FIG. 4 is a schematic view of the heating device of FIG. 3 in a second state; FIG. 5 is a schematic view of part of a heating device according to a second embodiment of the invention and FIG. 6 is a schematic view from above of an application of the invention to a zigzag architecture of the preform transfer chain.

  In FIG. 1, a heating device of the state of the art has been represented by a partial face study, with part of a transfer device, 5, the heating device being composed of a plurality of heating enclosures 9 - 1 to 9 - n. The transfer device 28 comprises a transfer chain which is built around two drive wheels 3 and 7 of vertical axis. The transfer chain comprises a plurality of gripping means each of which carries at least one preform which has not been shown to lighten the drawing.

  In FIG. 2, the heating device is seen from above and each heating chamber is constituted by a pair of elements such as elements 9-1a and 9-1b around the forward part of the transfer chain. 5 and the elements 9 - 1c and 9 - 1 d around the return portion of the transfer chain 5. Each pair of element which is described makes it possible to constitute a relatively closed enclosure inside which the preform is set in motion so as to standardize the heating over most of the mass of material of the preform, by using a rotation of the preform fixed to the transfer means (not shown) on the transfer chain 5.

  A preform 17 is fed by a loading device not shown, according to the arrow 11 so as to be loaded in an available transfer means which passes on the input wheel 3 and the preform 17 then follows the path indicated by the arrow 12 on the forward part of the transfer chain 5. Each preform such as the preform 17 travels and at a relatively constant speed the entire path indicated by the arrow 12, publishes the preform follows a turn of turn by turning on the wheel 7 return to enter the heating chambers constituted by the plurality of heating elements that surround the return path. Then the heated preform follows the path indicated by the arrow 15 under the action of a particular transfer device not shown to join a loading means (not shown) in a blow mold (not shown) and will then undergo the treatment of blow molding which is not directly concerned by the present invention.

  When a failure occurs, and an emergency stop is triggered, the preforms are suddenly immobilized in the heating chambers and their deformations reach such degrees that they can stick against the heating elements or the walls of the speakers. heater. It is then necessary to intervene on the heating device so as to clean it and if necessary to repair the elements that have been damaged.

  To reach the cleaning parts of the heater, the transfer chain 5 must be removed and the elements of the heating enclosures removed, which has been described above as a costly, time-consuming and complicated operation.

  In Figure 3, there is shown a heater according to a first embodiment of the invention. The view of FIG. 3 is a transverse view of a machine substantially equivalent to the machine represented in FIGS. 1 and 2, in which a camber 20 is shown schematically, inside which is visible a wheel 22 of the transfer chain. with the forward portion 24 and the return portion 26, which bear visible, respectively a preform 28 and a preform 30. The wheel 22 is integral with an axis and is rotated by a fixed portion 32, fixed to the ground. Each enclosure of a heater according to the invention is composed of a first portion 34 and a second portion 36 which completely surround a forward portion of the transfer chain. Similarly, the return portion of the transfer chain is surrounded by an enclosure having a first portion 38 and a second portion 40.

  Each heating chamber portion has a plurality of heating elements such as elements 34 - a, 34 - b, 34 - c, for example consisting of infrared lamps. These heating elements are integral with a reflector element 34 - d which is, for example, integral with the walls limiting the enclosure 34.

  According to one aspect of the invention, each heating chamber portion is mounted on at least one column 42 which is mobilized in a fixed portion 44 by a motor means not shown.

  In normal operation, the motor means, associated with the fixed part 44, cooperates with a brake and / or locking means (not shown), so that the relative position of the transfer chain 24, 26 and each element enclosure 34, 36 remains fixed throughout the normal operating period. The motor means associated with the fixed part 44 is controlled by a control means, itself activated by means for detecting an emergency situation, or by a configuration means in the maintenance mode of the heating device. 'invention.

  In a particular embodiment, each speaker part is associated with at least one column associated with a single fixed part.

  In a particular embodiment, several enclosure parts are associated with at least one column associated with at least one stand.

  In FIG. 4, the device of FIG. 3 is shown in an operating mode in which the removal of the enclosure elements 34 and 36 has simply been requested. In this configuration, the control means concerned have deactivated a locking means of the enclosure 34,36, then activated the motor means which lowers the enclosure elements 34 and 36, so as to make them easily accessible part 24 of the transfer chain has remained in the high position.

  In other applications, all the heating elements are all simultaneously down to the maintenance position. Note that in this arrangement, the entire transfer chain 24,26 is accessible and can be repaired easily. Similarly, the heaters are all clear of the transfer chain and can be accessed by maintenance personnel.

  In Figure 5, there is shown another embodiment of a heating device according to the invention. While in the case of Figure 3 or 4, the heating device is mobilized in translation, and at least for one element, entirely, the heating device of the embodiment of Figure 5 is mobilized simply in part, and in rotation. For this purpose, each element of enclosure as the element 50, includes an outer wall 52 which is movable about an axis or hinge 56. A fixed part 58 of the enclosure 50 is mounted on a stand 54. The elements 65, mounted on the reflector 62, are integral with the rocking wall 52.

  In the normal position, the speaker element 50 (FIG. 5) is not distinguished from the speaker element 34 (FIG. 3) When initiating a maintenance configuration of the heating device by an action of FIG. an operator on the machine for controlling the operation of the blowing machine, or during an emergency stop of the entire blowing machine on detecting a failure state of a part of the machine; blowing machine by a suitable emergency state sensor, or by the manipulation by an operator of an emergency stop button, the means for controlling the motor means associated with the enclosure element 50, deactivated a locking means (not shown) which makes it possible to join the movable wall 52 to the fixed part 58 of the enclosure element 50 in normal operation. In a particular embodiment of the motor means are simply constituted by the gravity and by a suitable configuration of elé inertial elements of the movable part 2890891 9 52, 62, 60 allowing automatic lowering of the moving parts 52 of the enclosure elements, according to the rotation indicated by the arrow 60.

  The automatic descent movement may be, in a particular embodiment, braked by a braking means, comprising for example a gas spring.

  As shown in FIG. 5, it can be seen that one of the effects of the invention is to allow rapid deconfinement of the enclosures composing the heating device of the invention.

  In this way, in case of an emergency stop of the blowing machine, the thermal inertia of the heating device has no negative effects, thanks to the deconfining measure provided by the mobilization of the moving parts of the enclosure elements.

  FIG. 6 is a schematic illustration of another embodiment of a transfer chain and a heating device embodying the invention. The heating device of the invention used in the machine of FIG. two rows 93A and 93B of active heating elements are provided, in particular, with vertical rows of infrared lamps (not shown) which cooperate with suitable reflectors as described in FIGS. aforementioned embodiments.

  Each row 93A or 93B produces heating radiation on each side to an Al or A2 containment element for the row of active heating elements 93A or to a confinement element B1 or B2 for the row of active heating elements 93B .

  The preforms or blanks then perform four successive passes of the heating device - and therefore four successive heating interspersed with periods of thermal stabilization. The blanks arriving at E are delivered by loading means 910 (such as a cladding wheel) to the transport means 92 in the form of a chain 92, in a closed loop, of support devices. The chain 92 then enters the portion A1, 93A of the heating device 91 by its branch 94A where the blanks undergo a first heating, then, after passing over the section 98A loop, a second heating on the branch 95A, in the part 93A, A2 of the heater 91.

  The blanks then pass over a connection section 911, which also defines a thermal stabilization zone, leading them to the second part B1, 93B and 93B, B2 of the heating device in which they follow a similar path: branch 94B with heating in part B2, 93B of the heating device 91, section 98B in loop with thermal stabilization, branch 95B with heating in the part 93B, B2 of the heating device 91.

  At the outlet of the branch 95B, a section 912 brings the blanks to unloading means 913 (such as a "stripping" wheel) where they are detached from the support devices of the chain 92 (which returns to the means of loading 910) and are evacuated in S towards, for example, a blow-molding or stretch-blow unit.

  Because the unloading means 913 are not contiguous immediately at the exit of the furnace, the section 912 is also a thermal stabilization zone completing the diffusion of heat within the thermoplastic material.

  The four branches of the preform transfer chain 94A, 95A, 94B, 95B can be mutually parallel, so that it is possible to provide a simple and compact arrangement device with less heat loss.

  In order to apply the displacement of a limiting element of the heating enclosures of the embodiment of the invention, it is provided according to the variants to mobilize all or only part of the confinement elements A1 or A2 and B1 or B2 and / or or their respective rows 93A and 93B of active heating elements, so that the confinement and / or the application of heat are immediately avoided or during an emergency stop or during a maintenance operation or when changing the configuration of the heater.

  The heating elements 93A and 93B can simply be arranged between two pairs of reflectors such as the two reflectors labeled A1 and A2 on either side of the heating element line 93A and as the two reflectors labeled B1 and B2 on the left and right sides. other of the heating element line 93B. In this case, the deconfinement can be ensured by a deconfining movement of only the outer reflectors, respectively at the top of the drawing and at the bottom of the drawing of FIG. 6. Such a deconfinement movement can be executed as described above. high, or by a rotational movement around a common hinge reflectors, horizontal axis parallel to the reflectors, or by a vertical translation movement in a direction perpendicular to the plane of the drawing of Figure 6.

2890891 12

Claims (4)

  1 - Apparatus for heating preforms (28, 30) for a container blowing machine, of the type comprising a transfer chain (24, 26) provided with means for gripping preforms which run in at least one heating chamber (34). , 36), characterized in that it comprises means (42, 44; 52, 58) for rapidly moving at least one limiting element (52) of the heating chamber.   2 heating device according to claim 1, characterized in that the means for rapidly moving at least one limiting element of the heating chamber comprises at least one movable column (42) relative to a fixed portion (44).   3 Device according to any one of claims 1 or 2, characterized in that the means for rapidly moving at least one limiting element of the heating chamber comprises a motor means which cooperates with a control means to activate the mobilization of at least one moving part of at least one heating chamber during a maintenance mode or an emergency stop mode.   4 Device according to claim 3, characterized in that said motor means cooperates with a locking means for securing said movable part to the rest of the heating chamber during a normal operating mode of the heating device.     Device according to any one of the preceding claims, characterized in that at least one heating enclosure element comprises a part movable relative to a fixed part, so that a deconfinement measurement of the heating chamber is applied during displacement of at least one limiting element.   6 Device according to claim 5, characterized in that the movable portion of the enclosure member is mounted on a hinge type hinge relative to said fixed part.   7 Device according to any one of the preceding claims, characterized in that at least one movable portion of at least one heating chamber cooperates with a braking means, activated during the deconfinement movement.   8 Machine for blowing containers from preforms, characterized in that it comprises at least one heating machine according to any one of the preceding claims.