EP1760179A2 - Sealing device - Google Patents

Abstract

The head has a frame (1) fixed to a pressurized chamber through a conveyor belt. A set of horizontal rollers (2, 3) includes a set of actuators (6-8) e.g. pneumatic actuators, and seals (4, 5) between the rollers and the frame are in the form of pneumatic actuators without the pistons. The rollers are placed on the top of each other and pressed against opposite faces of the belt, where the actuators are completely sealed and operated at a low pressure. The rollers and a set of seals (4, 5) are connected to the actuators. An independent claim is also included for a control process for a heat treatment machine with sealing heads provided with actuators.

Description

The present relates to the field of the textile industry, in particular the treatment of son by means of heat treatment machines commonly called heat-setting machines, and relates to a sealing head for such machines.

These heat treatment machines essentially consist of a pressurized heat treatment chamber for textile threads deposited on a conveyor belt passing through said chamber, which is closed at its two ends by sealing heads each comprising a frame attached to the pressurized enclosure. a pair of superposed horizontal rollers which are pressed against the opposite faces of the conveyor belt and sealing means to form a seal between the rollers and the frame.

At present, the horizontal rollers are actuated by clamping means allowing at least one of the rollers to move towards one another and the sealing means are in the form, on the one hand, of an upper element and an elongate lower member and supported against generatrices of the two rollers and, secondly, lateral sealing plates slidably pressed against the corresponding ends of the rollers.

The application of the sealing means, both horizontal and vertical is effected by means of actuators, in the form of hydraulic cylinders with high pressure, rods or drilled-block cylinders for horizontal elements and hydraulic cylinders at high pressure with angle lever, for side sealing plates. The bored block cylinders are, in fact, cylinders having a plurality of pistons and piston rods which are aligned parallel in a single block of cylinders and has a single hydraulic supply, their operation being, moreover, identical to that of the usual hydraulic cylinders .

These known actuators, in the form of jacks, make it possible to respond adequately to the problems posed, on the one hand, by the pressurized application of the horizontal rollers against the conveyor belt and, on the other hand, by sealing means against said rolls.

However, because of their constitution in the form of high pressure hydraulic cylinders, namely operating at a pressure of the order of 80 bar, there is a risk of leakage of hydraulic fluid may cause a flow of the latter on the rollers and / or on the textile material and, as a corollary, pollution of the latter. It is therefore necessary to carry out a recycling of the oil. It follows that the hydraulic pressurizing device is subjected to a significant heating that can cause a stoppage of the machine and corresponding maintenance work.

Furthermore, because of the application of the pressures by means of a hydraulic fluid, which is incompressible, the entire sealing head has a totally rigid pressurizing system allowing no fluctuation or pressure variation on any of the actuators.

Finally, by the very fact of the constitution of the current sealing heads with actuators in the form of hydraulic cylinders, the maintenance work is relatively complex and long and lead to corresponding long stops of the machines, which reduces the performance of the latter.

The present invention aims to overcome these disadvantages by providing a sealing head for son heat treatment machines for easy access to the wear elements and to avoid the disadvantages of hydraulic actuators at high pressure.

For this purpose, the sealing head for wire heat treatment machines, which essentially consists of a frame attached to a pressurized chamber traversed by a conveyor belt, by a pair of superposed horizontal rollers which are pressed against the opposite faces of the conveyor belt and by sealing means to form a sealing between the rollers and the frame, at least one of the horizontal rollers and the sealing means being connected to corresponding displacement actuators, is characterized in that the actuators of the horizontal roller (s) and the sealing means between the rollers and the frame are constituted in the form of low-pressure actuators without piston, namely of the balloon or bellows type.

• la figure 1 est un schéma de fonctionnement d'une tête d'étanchéité conforme à l'invention ;
• la figure 2 est une vue en élévation frontale d'un mode de réalisation préféré de l'invention ;
• la figure 3 est une vue en coupe suivant A-A de la figure 2 ;
• la figure 4 est une vue en coupe suivant B-B de la figure 3, et
• la figure 5 est une vue partielle en coupe, à plus grande échelle suivant C-C de la figure 2.

The invention will be better understood, thanks to the following description, which relates to a preferred embodiment, given as a non-limiting example, and explained with reference to the attached schematic drawings, in which:

• Figure 1 is an operating diagram of a sealing head according to the invention;
• Figure 2 is a front elevational view of a preferred embodiment of the invention;
• Figure 3 is a sectional view along AA of Figure 2;
• FIG. 4 is a sectional view along line BB of FIG. 3, and
• FIG. 5 is a partial view in section, on a larger scale along CC of FIG. 2.

FIGS. 1 to 4 of the appended drawings represent, by way of example, a sealing head for wire heat treatment machines, which essentially consists of a frame 1 fixed to a pressurized enclosure (not shown) traversed by a band conveyor 100, by a pair of superposed horizontal rollers 2 and 3 which are pressed against the opposite faces of the conveyor belt 100 and by sealing means 4 and 5 to form a sealing between the rollers 2 and 3 and the frame 1 at least one, 2, horizontal rollers and the sealing means 4 and 5 being connected to corresponding displacement actuators 6 to 8.

According to the invention, and as shown more particularly, in schematic representation, Figure 1 of the accompanying drawings, the actuators 6 to 8 of the horizontal roller or rollers 2 and / or 3 and sealing means 4 and 5 between the rollers 2 and 3 and the frame 1 are constituted in the form of low-pressure actuators without piston, namely of the balloon or bellows type. Preferably, these actuators 6 to 8 are actuators operating at a maximum operating pressure of the order of 8 bars.

It should be pointed out that the representation according to FIG. 1 is schematic and the arrangement of the actuators 8 for the sealing means 5 is only symbolic, in order to perfectly highlight the action of said actuators 8, the positioning of such an actuator being shown in Figure 5.

The actuators 6, which are intended to apply at least one of the two horizontal rollers on the conveyor belt 100 against the other horizontal roller 3, are advantageously double-acting diaphragm cylinders and are arranged on the frame 1, from and other said rollers horizontal and 2 and 3 and act on the drive shaft or guide of said horizontal rollers 2 and 3, at their ends, by means of sliding bearings 9 guided in the corresponding ends of the frame 1 and cooperating with push rods 10, connected at one end to said sliding bearing 9 and connected at their other end to the corresponding membrane of the actuator 6 (Figure 4).

It is also possible to produce each actuator 6 in the form of two actuators of the balloon or single-acting bellows type, these two actuators each acting on either side, or of the support bearing of the shaft of the corresponding roller, or on a moving means connected to said bearing.

Thus, it is possible to move at least one of the horizontal rollers 2 and / or 3 of the sealing head to allow, for example, the replacement of the conveyor belt 100 and thus a loosening of this conveyor belt 100, this possibly with a complete disengagement of the drive pinions 11 of said horizontal rollers 2 and 3, then to perform the clamping of the latter according to a predetermined pressure and a contact of the pinions 11 ensuring their perfect functionality, even under maximum application pressure.

The sealing means 4 between the rollers 2 and 3 and the frame 1, which are constituted, for each roller 2 and 3 by a sealing strip 12 mounted on a pivoting support 13 bearing on the frame 1 by the intermediate of a longitudinal pivoting abutment 14, each cooperate with the corresponding actuator (s) 7, in the form of balloons or bellows, via a load transfer rod 15, mounted on the frame 1 between the corresponding actuator 7 and the pivoting support 13 and loaded by a return spring 15 '(Figure 3). Thus, it is possible to perform the application of the sealing strip 12 on the roller 2 or 3 corresponding under a predetermined load by the supply pressure of the actuators 7, the power failure of said actuators 7 having the effect release the pressure on the pivoting support 13 which can thus either release the sealing strip 12 of the lower horizontal roller 3 under the effect of the own weight, or be raised for disengagement of the upper horizontal roller 2 by means of an operating lever 13 'of said upper pivoting support 13.

The actuators 8 are advantageously bellows or balloon actuators and act on the sealing means 5 between the horizontal rollers 2 and 3 and the frame 1, which are constituted in the form of sealing plates, by means of a force transfer device in the form of a bent lever 16 pivotally mounted by an axis 16 'on the frame 1 and pivotally actuated by means of a transmission rod 17 having a return spring 17 '. Thus, the pressurization of the bellows or balloon forming each actuator 8 has the effect of moving the transmission rod 17 in the direction of a tilting actuation of the bent lever 16 about its axis 16 ', resulting in a corresponding transmission the force in the direction of the corresponding plate forming the sealing means 5 and the application under a predetermined pressure of said plate against the ends of the rollers 2 and 3. By the provision of a bent lever 16, it is possible to performing an overdrive of the application force of the sealing means 5 by matching a transmission torque ratio corresponding to the ratio of the lever arms of the bent lever.

Indeed, as shown in Figure 5 of the accompanying drawings, the provision of a lever arm of greater length between the pivot axis 16 'and the axis of the transmission rod 17 of one of the wings of the elbow lever 16 and another shorter length between said pivot axis 16 'and the point of application of the force on the sealing means 5 allows a mechanical increase in the force applied to the sealing means 5.

According to a characteristic of the invention, the actuators 6 to 8 are advantageously pneumatic actuators. The use of such pneumatic actuators makes it possible, due to the compressibility of the air or a gas, to obtain damping of the vibrations and / or deformations. It is, however, also possible to make these actuators in the form of hydraulic actuators, oil or aqueous fluids, such as water or glycol, in particular.

In any case, these actuators, because of their constitution without sliding element outside their pressure chamber, are perfectly sealed, so that the risk of leakage of fluids are eliminated. Moreover, their operation at low pressure prevents any risk of overheating, which could be harmful for their operation.

These actuators 6 to 8 are advantageously commercial bellows flexible cylinders known by the name pneuride, of dimension 6 "x 1", and available in particular under the references PM31061 from NORGREN, 9109004 from PARKER or SP1536 from WEFORMA, and flexible bellows guns on the market known under the name pneuride, of size 4 "1/2 x 1", available in particular under the references PM31041 from NORGREN, 9109400 from PARKER or SP2334 from WEFORMA, and double-acting diaphragm cylinders, available in particular under the trade references KHGS from CEF and COD600-50 from REXROTH PARKER- BOSCH.

dans laquelle:

• I =taux d'isolation
• Fe = fréquence d'excitation en Hertz
• Fn = fréquence naturelle du soufflet en Hertz.

With such flexible cylinders, for a given cylinder height, the developed force is proportional to the pressure of the fluid and, when the sealing head is clamped in the closed position, said cylinders behave like pneumatic springs and the insulation to vibrations follows the law: $$\mathrm{I}\mathrm{=}\mathrm{1}\mathrm{-}\left[\mathrm{1}\mathrm{/}{\left(\mathrm{Fe}\mathrm{/}\mathrm{Fn}\right)}^{\mathrm{2}}\mathrm{-}\mathrm{1}\right]$$

in which:

• I = insulation rate
• Fe = excitation frequency in Hertz
• Fn = natural frequency of the bellows in Hertz.

The balloons constituting the actuators 6 to 8 can be made, depending on the conditions of use, of natural or synthetic rubber of the butyl, epichloro or nitrile type, these materials being optionally combined with a textile reinforcement.

If the fluid used is incompressible, the damping effect will be limited to the deformability of the balloon, which is generally defined for a maximum operating pressure of 8 bar and an operating temperature of between -40 ° C. and + 130 ° C. depending on the material of the balloon. It is also possible to add to this material anti-UV agents for improving the resistance to ozone or to provide special protection on the surface of the bellows.

Thus, the actuators 6 to 8 simultaneously act as actuators and air springs and allow, while being compact construction, obtaining a high power in a small footprint, and a high reliability and flexibility important operation. In addition, these actuators are maintenance-free, resistant to aggressive environments and their service life is very important.

In addition, as the flanges of these actuators are guided by an axis, the bellows is protected from harmful side vibrations, even in case of asymmetrical wear of a blade or a sealing plate.

The membranes being, moreover, in a known manner, protected against the projections of chemical agents by a stainless steel shield ensuring a perfect control of the stroke of the bellows, this protection is also effective against tears, scratches, nicks, the projections of particles and against shocks, as well as against the accidental overpressure of the fluid, the shielding preventing loosening.

According to another characteristic of the invention, the various actuators 6 to 8 are each provided with a drain valve 6 'to 8' and are advantageously controlled automatically, either by means of a programmable controller 200, or by via a pneumatic automaton implementing elements of pneumatic logic, standard logic or electropneumatic logic acting on control valves 6 "to 8" arranged in the supply circuit of these actuators 6 to 8 (FIG. 1).

Preferably, the implementation of a heat treatment machine with sealing heads provided with the actuators 6 and 8 is carried out according to a control method which consists, from an open treatment enclosure position, to temporarily closing the horizontal sealing rollers 2 and 3 around the conveyor belt 100, and then aligning the horizontal sealing rollers 2 and 3 by means of the sealing means 5, to definitively put in pressure the horizontal sealing rollers 2 and 3 against the conveyor belt 100, to then apply under pressure the sealing strips 12 of the sealing means 4 on the horizontal sealing rollers 2 and 3, to then apply under pressure the sealing means; 5 against the ends of the horizontal sealing rollers 2 and 3, then put the treatment chamber under pressure, subject to authorization to put en route delivered by contacts or sensors noting the closing of the various drain valves 6 'to 8' and the opening of the regulation valves 6 "to 8" assigned to the actuators 6 to 8, a pressure drop in the enclosure or an opening command of a sealing head causing a control shutdown of the regulation valves 6 "to 8" simultaneously with an opening of the emptying valve of the enclosure and the delivery of a restart prohibition signal, the actuators 8 for controlling the sealing means 5, 7 for controlling the lamellae 12 forming the sealing means 4 and 6 for controlling the displacement of the horizontal roller or rollers sealing 2 and / or 3 then being successively depressurized to return to an open position of the machine before a new treatment cycle.

The temporary closing of the horizontal sealing rollers 2 and 3 around the conveyor belt 100 is effected by simple depressurization of the double-acting actuators 7, so that the upper roll 2 descends under its own weight until contact with the conveyor belt 100 In the case of mounting the lower horizontal roller 3 also on sliding bearings, it will be necessary to pressurize the corresponding actuators until contact of the roller 3 with the conveyor belt 100.

The alignment of the horizontal sealing rollers 2 and 3 by means of the sealing means 5, after temporary closing of the horizontal sealing rollers 2 and 3 around the conveyor belt 100, is preferably carried out by a series of bets. under pressure and depressurization, actuators 8 acting on the sealing means 5. Such a reiteration of pressurized and depressurized actuators 8 makes it possible to perform the slight relative displacements necessary rollers 2 and 3 for alignment perfect of their end face.

The prediction of a detection of a pressure drop in the treatment machine makes it possible, thanks to the method described above, to prevent any unintentional opening of a sealing head following the emergency stop thus caused and ensures a process of access inside the enclosure of the machine perfectly controlled.

Thanks to the invention, it is possible to produce sealing heads for wire heat treatment machines employing actuators that can be used simultaneously for the displacement of different moving elements and for the damping of the vibrations caused during operation, these actuators can be powered by different fluids, under a low pressure.

In addition, by virtue of the fact of making a sealing head with such actuators, it is possible, in a small space, to develop large forces under a low fluid pressure. Furthermore, the actuators according to the invention, not being equipped with means mobile traversing them in the form of guided parts, are not subject to any internal sealing problem and are of low cost.

In addition, these actuators are extremely robust, withstand aggressive and high temperature environments, are maintenance-free and can operate with angular and axial misalignments.

Finally, the actuators 6 to 8, because of their constitution do not require specific guidance, can be easily and quickly mounted and dismounted, reassembly taking place without complex adjustment or special tools.

Of course, the invention is not limited to the embodiment described and shown in the accompanying drawings. Modifications are possible, particularly from the point of view of the constitution of the various elements or by substitution of technical equivalents, without departing from the scope of protection of the invention.

Claims (12)

Sealing head for wire heat treating machines, essentially consisting of a frame (1) attached to a pressurized enclosure traversed by a conveyor belt (100), by a pair of superposed horizontal rollers (2 and 3) which are pressed against the opposite faces of the conveyor belt (100) and by sealing means (4 and 5) to form a sealing between the rollers (2 and 3) and the frame (1), at least one (2) horizontal rollers (2 and 3) and the sealing means (4 and 5) being connected to corresponding displacement actuators (6 to 8), characterized in that the actuators (6 to 8) of the horizontal roll or rollers ( 2 and / or 3) and sealing means (4 and 5) between the rollers (2 and 3) and the frame (1) are constituted in the form of low-pressure actuators without piston, namely of the balloon type. or bellows. Sealing head according to claim 1, characterized in that the actuators (6 to 8) are actuators operating at a maximum operating pressure of the order of 8 bar. Sealing head according to one of Claims 1 and 2, characterized in that the actuators (6) for applying at least one of the two horizontal rollers on the conveyor belt (100) against the other horizontal rollers (3), are double acting diaphragm cylinders and are arranged on the frame (1), on either side of said horizontal rollers (2 and 3) and act on the drive shaft (s) and for guiding said horizontal rollers (2 and 3), at their ends, by means of sliding bearings (9) guided in the corresponding ends of the frame (1) and cooperating with push rods (10), connected to one end to said sliding bearing (9) and connected at their other end to the corresponding diaphragm of the actuator (6). Sealing head according to any one of claims 1 to 3, characterized in that each actuator (6) is in the form of two actuators of the balloon type or bellows single effect, these two actuators each acting on the one hand and on the other hand, either of the support bearing of the shaft of the corresponding roller, or of a displacement means connected to said bearing. Sealing head according to one of Claims 1 and 2, characterized in that the sealing means (4) between the rollers (2 and 3) and the frame (1) are constituted for each roller (2 and 3) by a sealing strip (12), mounted on a pivoting support (13) supported on the frame (1) by means of a longitudinal pivoting abutment (14), each cooperate with the corresponding actuator or actuators (7), in the form of balloons or bellows, via a load transfer rod (15), mounted on the frame (1) between the corresponding actuator (7) and the pivoting support (13) and loaded by a return spring (15 '). Sealing head according to one of Claims 1 and 2, characterized in that the actuators (8) are bellows or balloon actuators and act on the sealing means (5) between the horizontal rollers (2). and 3) and the frame (1), which are formed as sealing plates by means of a force transfer device in the form of a bent lever (16) pivotably mounted by an axle ( 16 ') on the frame (1) and pivotally actuated by means of a transmission rod (17) having a return spring (17'). Sealing head according to one of Claims 1 to 6, characterized in that the actuators (6 to 8) are pneumatic actuators. Sealing head according to one of Claims 1 to 6, characterized in that the actuators (6 to 8) are hydraulic, oil or aqueous fluid actuators, such as water or glycol. Sealing head according to any one of claims 1 to 8, characterized in that the different actuators (6 to 8) are each provided with a drain valve (6 'to 8') and are controlled automatically, either by means of a programmable controller (200), or via a pneumatic automaton implementing elements of pneumatic logic, standard logic or electropneumatic logic acting on control valves (6 "to 8"). ") arranged in the supply circuit of these actuators (6 to 8). Process for controlling a heat treatment machine with sealing heads provided with actuators (6 to 8), according to any one of Claims 1 to 8, characterized in that it consists, from a position of open treatment enclosure, to be closed of the horizontal sealing rollers (2 and 3) around the conveyor belt (100) and then aligning the horizontal sealing rollers (2 and 3) via the sealing means (5), definitively pressurizing the horizontal sealing rollers (2 and 3) against the conveyor belt (100), then applying the sealing strips (12) of the sealing means (4) to the sealing rolls under pressure horizontally (2 and 3), to then apply under pressure the sealing means (5) against the ends of the horizontal sealing rollers (2 and 3), to then put the treatment chamber under pressure, subject to a start-up authorization issued by contacts or sensors noting the closing of the different drain valves (6 'to 8') and the opening of the control valves (6 "to 8") assigned to the actuators (6 to 8) ), a pressure drop in the enclosure or an opening command of a sealing head causing a shutdown of the piloting of the control valves (6 "to 8") simultaneously with an opening of the emptying valve of the chamber and the delivery of a signal of prohibition of restarting, the actuators (8) for controlling the sealing means (5), (7) for controlling the lamellae (12) forming the sealing means (4) and (6) for controlling the movement of the or horizontal sealing rollers (2 and / or 3) then being successively depressurized to return to an open position of the machine before a new treatment cycle. Piloting method according to Claim 10, characterized in that the temporary closing of the horizontal sealing rollers (2 and 3) around the conveyor belt (100) takes place by simple depressurization of the double-acting actuators (7), so that the upper roller (2) descends under its own weight until contact with the conveyor belt. Piloting method according to Claim 10, characterized in that the alignment of the horizontal sealing rollers (2 and 3) by means of the sealing means (5) after temporary closing of the horizontal sealing rollers ( 2 and 3) around the conveyor belt (100) is effected by a series of pressurized and depressurized, actuators (8) acting on the sealing means (5).

Images