DE1629383C3 - Device for pressing and heating a belt, in particular a drive belt or conveyor belt - Google Patents

Description

The invention relates to a device according to the preamble of the preceding claim 1.

When producing a belt, such as a drive belt or conveyor belt made of rubber or plastic, this tape is brought into a press for vulcanization or curing, in which it is pressed and is heated or cooled depending on the requirements. Difficulties arise from the fact that the length of the tape is usually larger than that of the press. From FR-PS 13 73 896 it is known, for example, in the production of impregnated tapes, one tape length to cure the impregnating resin insert between two flat heated plates,

ίο which are then pressed against each other hydraulically or in some other way will. After a period of time, the panels are taken apart and the cured part of the tape is forward emotional. This process is repeated until the entire tape is cured.

Using a press with a single pair of plates can only result in an unsatisfactory one Working speed can be achieved. The advance of the tape must always be suspended for so long until the length of tape currently in the press has hardened. In terms of the big This disadvantage is particularly significant when investing capital in the machine system used. As another The disadvantage, however, are the difficulties involved in maintaining an accurate tape feed makes that is necessary to locally double hardening or too weak hardening to avoid.

The FR-PS 13 87 202 describes a device for pressing and heating a tape, the higher Working speeds. This device is used in a system in which a Volume is to be built up from several layers. The facing sides with a stick Coated layers of tape become a uniform between a pair of cylindrical rollers Band merged, which is then between the heatable and pressurizable plate pair a first press unit occurs. After closing the pair of plates, the press unit is around one of them Length corresponding distance moved forward, where it pulls the following tape. Well will placed behind the first press unit, a second press unit in position, the pair of plates around the the tape length immediately following the first press unit closes. Now both press units moved forward together by a distance corresponding to the length of a press unit, so that a third press unit can be attacked on the subsequent belt length. The number of so Pressing units assembled into a train depends on the time it takes for the tape to harden needed between the press plates. After sufficient curing, the pair of plates becomes the foremost Press unit opened, after which this press unit is returned to the beginning of the train.

The press plates of each press unit are pressurized by means of elastic bellows, which are arranged behind the pressure plates and into which pressure medium is pumped from a pressure medium source can be. Since the press units perform a circular cycle, the pressure medium supply prepares Difficulties, especially when the press units cover long distances.

In addition, the device described is complex, since it is used to apply pressure to the pairs of plates each press unit is assigned its own pressure-applying organs.

The invention is based on the object of providing a device of the type described improve that the pressurization of the plate pairs simplified and thus the device less becomes expensive.

According to the invention, this object is achieved with a device according to the preamble of claim 1 solved by the features claimed in the characterizing part of this claim.

The invention is based on the observation that the initial compressive force which has to be applied to the belt in order, for example, to press the rubber into the mesh of a tensile part or to produce a uniform belt surface, does not have to be maintained over the entire curing time. It is sufficient to apply this force at the beginning of each curing process and then decorate for the rest of curing to a value to reduc- _t sufficient to overcome the pressure between the plates as a result of vapor formation in the present in the to be heated band moisture.

It can thus be provided a stationary press, which the plate pairs at the beginning of a Pass through the heating process successively in order to apply the required initial compressive force to become, after which this pressure force, possibly to a reduced extent, by immediately on locking devices acting on the plates are maintained. The fixed press can be stable be constructed and resemble conventional curing presses in their shape.

While in the device according to FR-PS 13 87 202, the heating of the plate pairs over the entire working path is carried out by applying electrical heating elements to the pairs of plates Sliding contacts current is supplied, have according to an advantageous development of the invention Plates have sufficient heat capacity for sufficient heating of the belt over the working distance after initial heating without any additional heat supply.

A device for preheating the strip to be heated is expediently the working section upstream.

The term "heating", which is generally used here, is intended to mean vulcanizing with regard to rubber and with respect to plastics and other materials also include any process which does Applying pressure and controlling temperature requires removing the material from a mold to transfer to another, for example to convert a paste-like or liquid material into a solid, to transform self-sustaining form.

Exemplary embodiments of the invention are described below with reference to drawings described in more detail. It shows

F i g. 1 shows a cross section of a press unit comprising a pair of plates,

F i g. FIG. 2 shows a longitudinal section of adjacent press units of the type shown in FIG. 1 type shown, the end face are tied together,

F i g. 3 another embodiment of a press unit comprising a pair of plates,

F i g. 4 is a schematic end view of a stationary press with devices for heating the Pairs of plates of the press units, with one press unit located in the press,

5 shows a schematic end view of a stationary one Double press, with two press units in the press,

F i g. Figure 6 is a schematic representation of the duty cycle when two are continuously heated Conveyor belts run side by side in the same plane,

F i g. Fig. 7 is a schematic representation of the cycle of continuous heating of an individual Conveyor belt using a stationary double press and

F i g. 8 is a further view of the FIG. 7 devices shown.

As the F i g. 1 and 2 show, a press unit 71 is composed of plates 72 and 73, between which is a section 74 of a conveyor belt. By the width and thickness of a portion 74 that heats is to set and to produce straight edges on this, two edge strips 75 are provided, which have straight edges and can be arranged so that one edge of each bar abuts a side edge of section 74. Each of the edge strips 75 has two openings (not shown) to attack hydraulic or pneumatic (not shown) drives that the edge strips 75 press into contact with section 74. Furthermore, 75 are perpendicular in the edge strips to the conveyor belt feed direction two rows of (not shown) openings provided with tenons 76 attached to top plate 72 cooperate to secure skirting 75 in the required position Position after they are in contact with section 74.

The lower plate 73 is delimited by a pair of angles 77, one of which is leg to a side edge surface the plate 73 is attached and the other leg is an extension of the support surface the plate 73 creates in the transverse direction.

A second pair of rectangular brackets 78 of dimensions smaller than brackets 77 are within Legs of the angle 77 arranged, with one in section between the angles 77 and the angles 78 Rectangular layer of insulating material 79 lies in order to minimize the heat loss of the plate 73 to belittle. The angles 77, 78 and the insulating material 79 are connected to form a unit.

The angles 78 serve as guide and support surfaces for the press unit 71. They act with guide wheels 80 and support wheels 81 together, which can be rotated horizontally and vertically at right-angled Support arms 82 are attached. The support arms 82 extend in the direction of advance of the conveyor belt and rest a base 83. Between the support arms 82, an insulating layer 84 is applied to the base 83, wherein the plates 72, 73 are supported by the support wheels 81 so that an air gap between the upper Surface of the insulating layer 84 and the lower surface of the plate 73 is present.

The top plate 72 is also bounded by a pair of rectangular angles 85, one of which Leg is attached to a side edge surface of the plate 72 and the other leg is an extension the contact surface of the plate 72 in the transverse direction.

The plates 72 and 73 of the press unit 71 have such a thickness that their heat capacity is sufficient about their surface temperature over a certain period of time after the initial heating

at the vulcanization temperature of a rubber-based conveyor belt without a additional heat supply would be necessary. For example, it has been found that the heat capacity of a 7.5 cm thick plate 72, 73 more than sufficient for the purpose of vulcanizing a 2.5 cm thick Conveyor belt is.

The plates 72, 73 are supplied with heat at heating stations in that they are in contact with hot metal plates as will be described below. For reheating the plates 72, 73 also include infrared heating devices or direct heating of the outer surfaces of the plates 72, 73 by gas flames in question.

The use of an intermittent supply of heat has the advantage that the plates 72, 73, before they are brought into contact with the portion 74, can be heated to a temperature, which is higher than the temperature normally used to heat the conveyor belt, so that the heat from the surface of the conveyor belt penetrates faster into its central part, whereby the Vulcanization time is shortened. Due to the heat transfer from the surface of the plate 72, 73 on The surface of the plate is cooled by the conveyor belt, so that overhardening of the conveyor belt is easily avoided can be.

During the movement of the press unit 71 along the support arms 82 during a vulcanization process there will be heat losses on the top surface of the top plate 72 through the use of a stationary Cover 86 kept to a minimum. This cover 86 runs almost over the entire Working path of the pressing units 71 and is provided with a lining 87 made of insulating material.

On both sides of the press unit 71 85 lugs 88 are attached to each bracket, so that the upper Plate 72 lowered and raised as required by external means not shown can be engaged to engage the band section 74 at the beginning and at the end of heating. to disengage.

According to FIG. 2 are successive press units 71 during the vulcanization of the material to be conveyed held together at the front with the aid of coupling devices 100. These coupling devices 100 are shown in FIG. 2 clamping devices that can be screwed in from the outside. Instead of screwable ones Clamping devices can also be arranged at one end of each plate 72, 73, a pivotable cylinder articulated in the plane of the plate will. At the other end of the plates 72, 73 a bolt is then to be arranged with a stop on the free end of the piston rod of the cylinder cooperates. By acting on the cylinder are the following pressing units 71 are drawn together.

A working cycle of the heating process using the pressing units 71 as well as a stationary one Press 89 (FIG. 4) is described below with reference to FIG. 6 described.

There are arranged side by side two conveyor belts 92 to be hardened, their direction of advance through Is indicated by arrows. To the conveyor belts 92 during the vulcanization process constantly under longitudinal tension To hold, clamps 90 are provided, two of which are stationary and two in the direction of the conveyor belt are reciprocable. Each clamp 90 consists of a pair of horizontal jaws, from one of which can be moved vertically to hold the conveyor belt 92 in place or to let it pass freely be able. The stationary clamps 90, which are movable in the direction of the conveyor belt, are alternatively closed or open, depending on whether the assigned conveyor belt 92 is running or at a standstill.

The pressing units 71, of which in FIG. 6 only one is designated, run between four stations S 1 to S 4. In the first station S 1, the conveyor belt 92 lies between the plates 72 and 73 of the pressing unit 71. The edge strips 75 delimit the belt edges. The pressing unit 71 is coupled together with its adjacent pressing unit 71. Alignment pins 101 (Figs. 1-3), one on each side of each press unit 71, which engage through openings at angles 77 and 85, ensure accurate alignment of the plates 72,73.

The press unit 71 becomes the stationary press 89 through the support wheels 81 and the guide wheels 80 guided. A piston-cylinder unit 94 supported on a foundation 95 (FIG. 4) presses one there on guide members 97 displaceable lower punch 96 against an upper punch 98, so that heating plates 99, which are isolated from the punches 96, 98 by insulating layers 102, on the plates 72, 73 attack the pressing unit 71 and this is lifted off the support wheels 81.

While the press unit 71 in the stationary press 89 is under pressure, are on each side the pressing unit 71 each two clamping screws 103 inserted through the angle 77 and 85 from the outside, so that when the pressing unit 71 emerges from the press 89, at least part of the compressive force is maintained with which the plates 72, 73 in the press 89 have been acted upon.

After a predetermined interval, the press unit 71 jets the stationary press 89 and moves it step by step towards the second station S 2 . Vulcanization continues because the thick plates 72, 73 maintain the portion 74 with which they are engaged at its vulcanization temperature while the press unit 71 runs along on the support wheels 81 under the cover 86.

At the second station S1 , the press unit 71 is released from the subsequent press unit 71 in that the coupling device 100 is opened. Furthermore, the application of pressure is canceled by loosening the tensioning screws 103. The dowel pins 101 and the pins 76 are disengaged by external means (not shown), whereupon the top plate 72 is lifted off the conveyor belt 92 by engaging the lugs 88. The lower part of the pressing unit 71 is moved transversely by the conveyor belt 92 and reunited with the upper part, whereupon the whole pressing unit 71 becomes the third. Station S 3 is brought. The work sequence just described is repeated at this third station S 3 and the pressing unit 71 moves with the conveyor belt 92 to the fourth station S 4 and from there back to the first station S 1.

By preheating the conveyor belt 92 in devices 93 before it is fed to the presses 89 is increased, the output of the device is increased.

The in F i g. 3 illustrated press unit 104 is in the device according to F i g. 7 and 8 used, where the in F i g. 5 illustrated stationary double

press is used. The device of FIG. 7 and 8 is used when it is inconvenient is to heat two strips at the same time, as these, for example, have different heating times to have.

The pressing unit 104 differs from the pressing unit 71 according to FIGS. 1 and 2 in it as they is designed so that the pressing units 104 of this type at a distance during a heating process are arranged from each other. Accordingly, no coupling device 100 is equivalent to that of the pressing units 71 are provided. Rather, there are 104 at each end of the press unit as a whole four L-shaped end pieces 105 are provided, which have an L-leg over an intermediate insulating layer 106 are attached to the end face of the plates 72, 73. The other L-leg is used to support the Contact surface of the plates 72, 73 with the he ^ to expand warming band in the longitudinal direction, but this leg is shaped so that this elongated surfaces on adjacent end pieces 105 are inclined away from each other.

As the end pieces 105 from the hot plates 72, 73 through the insulating layers. 106 are isolated, remain they are relatively cool (although additional water cooling can be used), which achieves this is that at each end of the press unit 104 there is a transverse strip of tape 107 which is under pressure but not heated. This prevents z. B. hotter, more plastic Rubber is squeezed out at the ends of the press unit 104, thus causing irregularities on the tape surface at the ends of the Pressing unit 104 can be avoided.

The other features of the press unit 104 are practically the same in structure and function as those the in F i g. 1 and 2 shown pressing unit 71 and correspondingly numbered the same.

The stationary press 108 shown in FIG. 5 has a horizontal foundation 109, from which guide members 110 protrude vertically upwards. The top Ends of the support members 110 are connected to one another by a fixed upper punch plate 111. on the guide members 110 are between the foundation 109 and the upper punch plate 111 an upper one Stamp 112 and a lower stamp 113 are displaceable. One operated hydraulically or pneumatically The piston-cylinder unit 114 is installed between the lower punch 113 and that in the foundation 109.

As the F i g. 7 and 8 show a band 115 runs in an upper run by tension clamps 116, a strip preheating station 117, a first station 51, further through the upper work space of the stationary press 108 provided with two work spaces a second station 5 2 to rollers 118 and in a lower run of the rollers 118 by preheating 119, a third station 5 3, through the lined work area of the stationary press 108 and finally to the fourth station 54 and tension clamps 120. The first and second stations 51 and 5, respectively 2 are thus on the same level, as are the third and fourth stations 5 3 and 5 4, respectively.

The tension clamps 116 and 120 operate in the same Manner like the clamps 90 of FIG. 6. After the tape 115 is detected in the station 51, the Press unit 104 with the preheated plates 72, 73 on the upper working space of the stationary press 108 moved to where their plates 72, 73 pressed together by the piston-cylinder unit 114 and clamped together will. The pressing unit 104 is then gradually fed to the station 5 2, where it detached from the tape Ϊ15 and then in the transverse direction is transported to the station 121. Then the press unit 104 becomes the reheating station 122 out, which lies on the level of the lower belt run and in which their plates 72, 73 again to be warmed up. At the station 5 3, the pressing unit 104 detects a section that has not yet hardened of the belt 115, whereupon it runs to the lower workspace of the stationary press 108, where its Plates 72, 73 are clamped together again and a further curing process begins. At the station 54, the press unit 104 is released from the belt 115 and over the station 123 and the reheating station 124 transported back to the upper run and to station 5 1, where another work cycle begins.

As a result of the workflow just described, a belt 115 emerges from station 5 2, which is a row has fully cured sections 74 separated from one another by uncured parts the length of which is slightly smaller than a press unit 104. In the lower work area of the stationary press 108, these non-hardened parts are hardened, after which a completely hardened band 115 is present.

The number and the size of the pressing units 71,104 depend primarily on the one necessary for heating Time, the available space and the required output. By a large number from pressing units 71, 104 a larger output is obtained than by a small number, but is required more space and more frequent advancement of the press units 71, 104. An advantageous number for the Press units 71, 104 is four to ten.

The greater the length of the pressing units 71,104 in the direction of the longitudinal axis of the strip to be heated is, the greater the output, but the transport of the press units 71, 104 requires greater effort.

The devices can be operated continuously; H. without interrupting operations, when a section 74 is finished and a new part is started. The tape is in the process of being made continuously under pressure until heating is complete. The devices for forming the strip edges and to adjust the belt thickness can, if desired, be exchanged automatically.

For this purpose 3 sheets of drawings

Claims (6)

Patent claims: 1. Apparatus for pressing and heating a belt, in particular a drive belt or conveyor belt, with plates that can be connected to one another in the longitudinal direction of the belt, can be moved step by step and are attached to the belt by a locking device and a pressing device in the area of a working section from the top and bottom can be pressed, characterized in that the pressing device consists of a stationary press (89, 108) and the locking device consists of fastening parts which act directly on the plates (72, 73) over the area of the working path after the plates (72, 73) have been pressed together. 2. Apparatus according to claim 1, characterized in that the plates (72, 73) are assigned a coupling device (100) for their successive connection at their end faces in the region of the working section. 3. Apparatus according to claim 2, characterized in that the coupling device (100) consists of one at one end of each plate (72, 73) articulated, pivotable in the plane of the cylinder with a piston rod having a stop at its free end and a bolt on the other end of the plate (72, 73), when the latter engages the stop of the following plate (72, 73), the two plates (72, 73) can be drawn together by the action of the cylinder. 4. Device according to one of claims 1 to 3, characterized in that each pair Plates (72, 73) edge strips (75) are assigned, which are actuated by a pressure medium can be brought into position relative to the plates (72, 73) and have openings in the pin (76) connected to the top plate (72) for locking the edge strips (75) in intervene in their location. 5. Device according to one of claims 1 to 4, characterized in that the plates (72, 73) have a sufficient heat capacity for sufficient heating of the strip (115) over the working distance after initial heating without further heat supply. 6. Device according to one of claims 1 to 5, characterized in that the working section is preceded by a device (93) for preheating the strip to be heated (115) .