Compression mechanism

Abstract

The invention relates to a compression system comprising two pressure gauges (2, 3) mounted on a load-bearing frame (1), the pressure gauges being pushed towards the other pressure gauge by means of respective thrust means (5), the thrust means (5) generating a given thrust (L5); an adjustable stop (60) fastened to the load-bearing frame (1) is arranged opposite the thrust means and interposed between the load-bearing frame (1) and said thrust means in order to act on and unload a portion (L6) of the thrust (L5) onto the frame such that a second portion (L23) of the thrust (L5) is transmitted to the two pressure gauges; -the adjustable stops are connected to the respective position adjustment means (6),-the thrust means comprise at least one first actuator cylinder supplied with a fluid at a preset pressure, said at least one first actuator cylinder having known and predetermined bores,-the adjustable stops are connected to the respective position adjustment means (6),-the thrust means comprise at least one second actuator cylinder supplied with a fluid at a preset pressure; and-the adjusting device for adjusting the adjustable stop comprises at least one further actuator cylinder.

Description

[0001] The present invention relates to a mechanical compression system incorporating a control mechanism.

[0002] More particularly, the control mechanism according to the invention is intended to be incorporated into a system in which two presses, in a cooperative manner, apply a given pressure to a body to be compressed. For example, a system of this type comprises a roller and a counter roller defining a nip through which a web material, such as paper or nonwoven fabric (TNT), passes, applying to this material a pressure provided by two actuators acting on opposite sides of the rollers. Typically, the pressure applied by the presses varies over time due to various factors such as, for example, surface wear of one or both presses; variability in the mechanical properties of the surface coating of one or both presses due to temperature variations associated with prolonged use of the presses; variability in the properties of the material processed by the presses, both due to environmental conditions and due to the nature of the processed material, which does not always have constant physical properties.

[0003] Therefore, the operator responsible for operating the machine using the compression system must perform adjustment operations, but the adjustment operations are usually delayed because they are carried out after the processed material is inspected to check whether it meets the preset production standards. This leads to higher production costs due to the waste generated thereby.

[0004] US2023 / 0085467A1 discloses a roller mill for comminuting bulky materials. The roller mill comprises a pair of pressure rollers connected to a synchronization device comprising two hydraulic actuators, each acting on a corresponding floating bearing supporting one of the two pressure rollers. The synchronization device is arranged behind the pressure rollers, acts on the pressure rollers, and is configured to adjust the relative position of the floating bearings of the rollers to avoid or limit a loss of parallelism between the axes of the two pressure rollers.

[0005] The main object of the present invention is to eliminate or at least significantly reduce the above-mentioned disadvantages.

[0006] This result has been achieved according to the invention by adopting the concept of providing a control mechanism for a mechanical compression system having the features of claim 1. Further features of the invention are subject matter of the dependent claims.

[0007] By means of the present invention, it is possible to ensure that the pressure applied to the processed material is more precisely and thus the quality of the process using this pressure can be improved, the quality of the processed material can be increased in line with preset production standards and waste can be reduced, all at very low implementation costs relative to the advantages offered by the control mechanism.

[0008] These and further advantages and features of the present invention will be more and better understood by each person skilled in the art with the help of the following description and the accompanying drawings, which are given by way of example but should not be considered in a limiting sense, in which:

[0009] Figure 1 is a schematic side view of a control mechanism for a mechanical compression system according to the present invention, the control mechanism being applied to an embossing unit for processing web-like materials such as paper or TNT;

[0010] Figure 2 is with Figure 1 The same view as in FIG. 1 , in which the forces L5 , L23 , L6 are shown.

[0011] The following detailed description relates to a possible implementation example of an embossing unit for processing web material, such as facial tissue, which embossing unit uses a control mechanism according to the invention.

[0012] Figure 1 A stamping unit (UG) for web material is shown, comprising a carrier frame (1), a steel roller (2) mounted on the carrier frame (1), the steel roller (2) being provided with a cutout on its outer surface (20); and an antagonist roller (3), the antagonist roller (3) having an outer surface (30) covered with rubber, the steel roller (2) and the antagonist roller (3) defining a stamping portion (nip) (N) for a web material (MN) to pass through, and the web material (MN) being stamped as a result of the web material (MN) passing through the stamping portion (N). The roller (2) and the antagonist roller (3) are arranged with respective axes transverse to the frame (1) and parallel to each other. The roller (2) is rotated around the axis (A2) of the roller (2) at a preset angular velocity by a respective drive unit (M2). The axis (A2) of the roller (2) is fixed. On each of its sides, the antagonist roller (3) is supported by a rod (4) connected to a corresponding thrust cylinder (5). Figure 1 In the diagram, a single rod (4) and a single thrust cylinder (5) are visible because Figure 1: is a side view of the laminating unit (U). Each rod (4) is locked at the corresponding end (3E) of the counter roller (3) by means of a half collar (40) which grips said end in cooperation with the concave surface (41) of the same rod. The thrust cylinder (5) is integral with the frame (1).

[0013] Via a lever (4), the cylinder (5) pushes the counter roller (3) towards the roller (2).

[0014] The thrust cylinder (5) is supplied with a working fluid at a preset pressure (P) associated with the thrust that the counter roller (3) must exert on the roller (2) according to a programmed process. Figure 1 , the supply of working fluid to the cylinder (5) is indicated by arrow "FL".

[0015] The travel of the rod (50) of each cylinder (5) is limited by a corresponding adjustable stop (60).

[0016] Each stopper (60) is formed by the free end of the rod of a further cylinder (6) which is integral with the frame (1) and is arranged horizontally coaxially with the rod (50) of the thrust cylinder (5). The further cylinder (6) is configured to generate a thrust (L6) of a predetermined value. The function of the thrust (L6) will be described below.

[0017] For example, the additional cylinder (6) is supplied with fluid at the same pressure (P) as the thrust cylinder (5), and the additional cylinder (6) has a hole (A6) that is smaller than the hole (A5) of the thrust cylinder (5). Therefore, the thrust (L5) generated by the thrust cylinder (5) is greater than the thrust (L6) generated by the additional cylinder (6).

[0018] It will be appreciated that the further cylinder (6) is supplied with a corresponding fluid that is different from the fluid supplying the thrust cylinder (5) and that is at a pressure sufficient to generate the thrust (L6).

[0019] In operation, under the condition of symmetrical forces, the thrust (L5) applied by each cylinder (5) via the corresponding rod (50) is:

[0020] L5=1 / 2*L23+L6, wherein L23 is the load acting between the roller (2) and the roller (3), and L23 is a known value, so L23 is used as a preset processing parameter.

[0021] In this regard, it should be noted that the load ( L6 ) is an additional load compared to the load ( L23 ) which serves to stiffen the stamping unit so that vibrations normally generated during operation of the same unit are reduced.

[0022] Each stop (6) opposing the advancement of the rod (50) of the corresponding cylinder (5) releases a force (L6) on the frame (1).

[0023] Since the forces (L5) and (L6) do not change, due to the fact that they are related to the constant pressure (P) and the invariable apertures of the cylinders (5) and (6), the thrust (L23) is also constant, even if the surface properties of the pressure rollers (2, 3) are subject to changes (e.g. due to changes in the elasticity and / or geometrical properties of the rubber covering of the rollers 3 due to wear or overheating). In this way, a self-regulating system is achieved. In the event of an increase or decrease in the pressure (P), the thrust (L23) will be automatically adjusted, since it is defined by the difference between the thrusts (L5) and (L6), which are directly dependent on the pressure (P) and on the invariable geometrical properties (in particular the apertures) of the cylinders (5) and (6).

[0024] For example, the further cylinder (6) is supplied via a hydraulic accumulator (8) which is supplied with the same fluid as the fluid supplying the thrust cylinder (5), and the hydraulic accumulator (8) supplies the further cylinder (6) with a different fluid at the outlet of the hydraulic accumulator (8), but at the same supply pressure (P) as the thrust cylinder (5). The presence of the accumulator (8) stabilizes the supply pressure of the further cylinder (6) in a known manner.

[0025] Preferably, a flow regulator (7) is inserted on the supply line (F6) of the further cylinder (6), the function of which is to slow down the movement of the stopper (60) and to hinder the return of fluid from the further cylinder (6) to the pressure accumulator (8) due to the effect of mechanical vibrations transmitted through the stopper (60).

[0026] In a simplified embodiment of the system according to the invention, the thrust means may comprise only one cylinder (5), and the number of cylinders (5) may in any case differ from the examples described above, depending on the specific practical application of the system. Similarly, the adjustable stop means for absorbing part of the thrust generated by the thrust means may comprise a single adjustable stop constructed as described above or more than two adjustable stops constructed as described above.

[0027] exist Figure 1 and Figure 2In the embodiment shown by way of example in FIG, the carrying frame (1) has a horizontal side and two opposite vertical sides, the horizontal side connecting the lower parts of the vertical sides to form a support on which the rollers (2) and the counter rollers (3) are located. A thrust cylinder (5) is mounted on one vertical side of the carrying frame (1), while a further cylinder (6) is mounted on the opposite vertical side.

[0028] More generally, the thrust cylinder (5) and the further cylinder (6) may be mounted on opposite parts of the carrying frame (1).

[0029] Therefore, according to the present invention, a system is provided, comprising a first press (2) and a second press (3), the first press (2) and the second press (3) being mounted on a carrier frame (1) and having respective counter-faced compression surfaces (20, 30), wherein

[0030] - one of the two pressers is pushed towards the other of the two pressers by means of a corresponding thrust device (5), which is configured to generate a thrust (L5) having a preset value,

[0031] - an adjustable stop device (60) connected to the carrying frame (1) is arranged opposite the thrust device (5) and is placed between the carrying frame (1) and the thrust device (5) to absorb a portion (L6) of the thrust (L5) and unload the portion (L6) of the thrust (L5) onto the frame (1), so that a second portion (L23) of the thrust (L5) is transmitted to the two pressers,

[0032] - the adjustable stop means (60) are connected to corresponding adjustment means (6) which adjust the position of the adjustable stop means (60) relative to the thrust means (5),

[0033] - the thrust means (5) comprises at least one first actuator cylinder supplied with fluid at a preset pressure (P), said at least one first actuator cylinder having a known and predetermined orifice (A5); and

[0034] The adjusting device (6) for adjusting the adjustable stop comprises at least one further actuator cylinder.

[0035] The system according to the invention may also have one or more of the following features, even in combination with one another:

[0036] - said at least one further actuator cylinder is also supplied with fluid at said preset pressure (P), said at least one further actuator cylinder having an orifice (A6) smaller than the orifice (A5) of said at least one first actuator cylinder;

[0037] - the pressers (2, 3) are rollers parallel to each other and one of said two rollers is connected to a respective motor member (M2) which controls the rotation of said one roller around its axis (A2) at a preset angular speed;

[0038] - the pressers (2, 3) are rollers parallel to each other, and one of the two rollers is connected to a corresponding motor member (M2) that controls the rotation of the one roller around its axis (A2) at a preset angular speed, the outer surface of one of the two rollers being engraved and the outer surface of the other roller being smooth, preferably the outer surface of the other roller being made of a rubber coating;

[0039] - the pressers (2, 3) are rollers parallel to each other, and one of the two rollers is connected to a corresponding motor member (M2) that controls the rotation of the one roller at a preset angular speed around its axis (A2), and the outer surfaces of the two rollers are smooth;

[0040] - the presses (2, 3) are rollers parallel to each other, both of which are motorized, i.e. both are driven in rotation by the same motor or by two different motors; for example, both rollers are motorized and both have a smooth outer surface, or both rollers are motorized and one of the two rollers is engraved and the other is smooth, or both rollers are engraved;

[0041] - the further cylinder (6) is supplied via a hydraulic accumulator (8) which is supplied with the same fluid as the fluid supplying the at least one first actuator cylinder (5), and the hydraulic accumulator (8) supplies the at least one further cylinder (6) with a fluid at an outlet which is different but at the same supply pressure (P) as the first actuator cylinder;

[0042] A flow regulator (7) is inserted in the supply line (F6) of the at least one further cylinder (6).

[0043] However, in practice, the implementation details may vary in an equivalent manner with respect to the various elements described and illustrated, without departing from the idea of ​​the solution adopted and thus still falling within the scope of protection granted by this patent according to the following claims.

Claims

1. A mechanical compression system comprising a first press (2) and a second press (3), the first press (2) and the second press (3) being mounted on a carrier frame (1) and having respective facing and opposing compression surfaces (20, 30), wherein: - one of the two pressers is pushed towards the other of the two pressers by means of a corresponding thrust device (5), the thrust device (5) being configured to generate a thrust (L5) having a preset value, - an adjustable stop device (60) connected to the carrying frame (1) is arranged opposite the thrust device (5) and is placed between the carrying frame (1) and the thrust device (5) to absorb a portion (L6) of the thrust (L5) and unload the portion (L6) of the thrust (L5) onto the frame (1), so that a second portion (L23) of the thrust (L5) is transmitted to the two pressers, - the adjustable stop means (60) are connected to corresponding adjustment means (6), said adjustment means (6) adjusting the position of the adjustable stop means (60) relative to the thrust means (5), - said thrust means (5) comprises at least one first actuator cylinder supplied with fluid at a preset pressure (P), said at least one first actuator cylinder having a known and predetermined orifice (S5), and - The adjustment device (6) for adjusting the adjustable stop comprises at least one further actuator cylinder.

2. The mechanical compression system according to claim 1, wherein: The at least one further actuator cylinder is also supplied with fluid at the preset pressure (P), the at least one further actuator cylinder having an orifice (A6) that is smaller than the orifice (A5) of the at least one first actuator cylinder.

3. The mechanical compression system according to claim 1, wherein: The pressers (2, 3) are rollers parallel to each other, and one of the two rollers is connected to a corresponding motor member (M2) which controls the rotation of the one roller around its axis (A2) at a preset angular velocity.

4. The mechanical compression system according to claim 1, wherein: The pressers (2, 3) are rollers parallel to each other, and one of the two rollers is connected to a corresponding motor component (M2), which controls the rotation of the one roller around the axis (A2) of the one roller at a preset angular velocity, and the outer surface of one of the two rollers is engraved, while the outer surface of the other roller of the two rollers is smooth, preferably, the outer surface of the other roller of the two rollers is made of rubber coating.

5. The mechanical compression system according to claim 1, wherein: The pressers (2, 3) are rollers parallel to each other, and one of the two rollers is connected to a corresponding motor member (M2), which controls the rotation of the one roller around the axis (A2) of the one roller at a preset angular velocity, and the outer surfaces of the two rollers are smooth.

6. The mechanical compression system of claim 1, wherein: The presses (2, 3), (2, 3) are rollers parallel to each other, both of which are motorized.

7. The mechanical compression system of claim 1 , wherein: The further cylinder (6) is supplied via the hydraulic accumulator (8), which is supplied with the same fluid as the fluid supplying the at least one first actuator cylinder and which supplies at an outlet a fluid to the at least one further cylinder which is different but at the same supply pressure (P) as the first actuator cylinder.

8. The mechanical compression system according to claim 1, wherein: A flow regulator (7) is inserted into the supply line (F6) of at least one further cylinder.

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