FI115618B - Apparatus and method for effecting sealing movement in a bed casting machine - Google Patents

Description

115618

Arrangement and Method for Compacting Movement in Concrete Molding Machine 5 Elongated concrete products, such as hollow core slabs, are generally manufactured by extruder molding or sliding molding machines. The casting machine consists of a conical hopper with one or more screws underneath. The screw-thread helix is often followed by a mandrel, which continues as an auxiliary mandrel supporting the cavity made into the product above. The mold mandrel has a vibrator or other compacting device for compacting the concrete to be molded into the shape specified by the mold and mandrel. In addition, the casting machine has an upper roll bar forming the upper edge of the mold, and generally the mold edges 15 are formed by lateral rolling bars. The trusses compact the mass to be cast and finish the surface of the cast piece. Alternatively, vibration may be used in addition to or instead of the massage. Extruder casting machines are continuous casting machines which move forward on the die face by the reaction force caused by the feed screws.

Vibration of other concrete boundaries in the mold, or hollow core slabs in the manufacture of vibrators located in a hollow mandrel are used to compact the concrete mass to be poured. Instead of vibration-25, relatively slow movements of the various V 'parts of the casting machine affecting the casting mass have been used. The compaction movement is the transverse rotation of the mandrel after the feed screw and the 'deformation of the mandrel, whereby by varying the mandrel cross section' · ['30] the concrete is compacted. For non-circular mandrels, the reciprocal rotation of the mandrel -; * · _ is used for compaction. All of these devices are characterized by 2 115618 that the compacting of the concrete mass is effected by low-frequency mechanical movements in which the pulp particles are moved relative to one another by the thrust of the movements of the machine parts and not by the average impact forces of the pulp particles.

The compaction method described above is commonly referred to as shear compaction or shear compaction and has the advantage that the mass particle movements and displacements are already small at low motion, i.e., low frequency, and the machine is noiseless.

The principle of low-frequency compacting movements has been further developed in a device in which conical or wedge-shaped surfaces are formed in the cavity tower, whereby the slow casting movements of the mandrels compact the concrete. Compaction is done by slow movements with a stroke of 5 to 50 mm and a frequency of 1 to 10 Hz compared to vibration. The machine employs wedge-shaped or conical surfaces to provide frictional seals, which provide flow-expanding and shrinking constrictions that • create sealing spaces.

Sealing plays an important role in the final quality of the product. In sealing, it is essential to move the constituent parts of the concrete: the mass particles, relative to each other, so that they become in a position such that different par- · '·! · The dots require the smallest possible space and the concrete ··· is compacted. The pressure of the mechanical parts and the force of gravity are used for this. The amplitudes and frequencies of the compaction movements vary greatly, and it is attempted to adjust the compaction to the particular product and mass to be cast. In mechanical sealing devices, the frequency 3 115618 may be from 1 to 200 Hz and the amplitude from 50 to 0.005 mm. Usually, at higher frequencies smaller amplitude is used and vice versa.

5 The effect of compaction on the mass to be cast can vary within wide limits and good results can be obtained with different amplitudes under different conditions. In the compaction of concrete mass, it is typical that large mass particles are compacted at very low frequencies and high amplitudes and correspondingly smaller particles are better compacted at high frequencies and small amplitudes. Normal concrete contains a wide distribution of particles of different sizes, from very dusty binder particles to large particles up to 16 - 32 mm. Particles of varying sizes and types can produce products suitable for a variety of applications. However, in order to obtain the best possible end product from the pulp made for a particular application, the pulp must be compacted in a suitable manner, 20 that is, for a given pulp type, the correct sealing amplitude and frequency should be used. Concrete sealing has a significant effect on the strength and uniformity of the end product.

: »V v 25 Adjusting and changing the frequency of the compaction is quite easy nowadays, because electric motors using vibrating devices can be adjusted, for example, by frequency converters •» i.i: over a wide speed range. However, when compacting concrete, you have to make compromises of * 1 * 30, that is, choose the frequency and amplitude that will give a good enough result. Compaction parameters are typically kept constant regardless of the concrete. · *. proportion, that is to say, the proportions of the various constituents and grain sizes 4 115618 in the mass used or other characteristics of the concrete mass or their changes. When the seal is not adapted to the properties of the mass to be poured, the sealing result is poor or a very high sealing power 5 must be used to achieve sufficient sealing. High compaction power consumes and burdens the equipment, which requires more frequent maintenance and the design of the casting machine for heavy loads already at the design stage.

10 Nowadays the compaction is controlled by changing the frequency of the compaction stroke. Since the amplitude of the compression movement is not changed together with the frequency change, the frequency control can only affect the compaction power, i.e. the amount of energy transferred to the concrete mass. Frequency control 15 takes no account of the properties of the concrete and the grain size or grain size distribution of its various components. Thus, current control methods cannot control the compaction event in such a way that the properties of different concrete masses can be utilized in the best possible way and unnecessarily high energy is required to achieve a good sealing result.

: * Finnish patent application 941608 describes a solution in which the reciprocating sealing movement can be formed by means of eccentrics and that the actuators are preferably:; Adjustable. The eccentrics are used to perform only motion of the same amplitude. The solution is to stand | it is only possible to adjust the frequency of motion by adjusting, for example, the speed of the actuator that is operating.

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The application FI 990130 has twin blades ·] * attached to an axle. These are parallel eccentrics, one of which moves the first leveling member and the second the second leveling member via a support structure.

It is an object of the present invention to provide a method and a device for providing advantageously a reciprocating sealing movement required in a concrete pouring machine, the amplitude of which can be adjusted or changed in a simple manner if necessary.

The invention is based on the fact that the sealing movement is formed by two rotatable axes, the first of which is fitted with a primary and a secondary secondary center. The movement of the primary eccentric is transmitted to the secondary eccentric by the palm, whereby the eccentricity of the eccentric defines the angle of motion of the secondary shaft and the travel of one or more connecting rods attached thereto. The connecting rods are connected to the bodies to which the reciprocating motion is desired, such as, for example, pendulum pendulum movements.

More specifically, the arrangement of the invention '1 is characterized by what is stated in the characterizing part of claim 1:.

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The method according to the invention, in turn, is characterized by what is described in the characterizing part of claim 11.

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* '··: The invention provides considerable advantages.

• · (30 The invention can be used to optimize the sealing power and method for • 111 · different concrete grades. By combining the amplitude control according to the invention with known frequency control, the • 6 · 115618 properties or proportion changes, the amplitude and frequency of the compaction movement can be quickly re-optimized for a new concrete mix; as concrete aggregates or other constituents change, compaction conditions can be adjusted to produce good products immediately or almost immediately after recipe change. As the compaction result improves, cheaper concrete raw materials can be used without compromising on the quality of the final products, since a better compaction result 10 can compensate for the inefficiencies of the raw material properties, thereby saving on production costs. This reduces power consumption and reduces machine strain and wear. Lower power consumption also reduces noise. The solution according to the invention 15 is more advantageous to implement than, for example, the sealing movement by hydraulic cylinders. Hydraulically, a reciprocating amplitude-adjustable sealing movement could be achieved, but would require efficient pressure-generating devices and a sophisticated control system.

The invention will be explained in more detail below with reference to the accompanying drawings.

Figure 1 shows a side view of one embodiment of the invention.

Figure 2 is a sectional view of the S-S of Figure 1.

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Figure 3 is a side view of another embodiment of the invention. Figure 4 is a detail of Figure 3.

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Fig. 5 shows a control flange used in the embodiment of Fig. 3.

Figure 6 is a partial sectional view of the device of Figure 3 from above.

Figure 7 is a table illustrating the relationship between the position of the adjusting flange and the sealing motion.

Fig. 1 shows an extruder casting machine in which one of the compaction movements is the reciprocating movement of the forming mandrels 3. The compaction movement and operation of such an extruder molding machine is described in European Patent Application 0 677 362, which is hereby incorporated by reference. Connected to the body of the casting machine 1 is a casting space 2 defined by the mold walls 7, which has an inlet 8 for feeding the concrete mass into the pouring pit. The feed opening 8 is delimited by a rear wall 9 through which the shafts 10 of the feed screw 3 pass through the ends of the feed screw 3 to form molded mandrels 4 which form cavities of the desired shape in the molded cavity plates. In this embodiment, the sealing is done specifically by the movement of the hollow mandrels 4, but also, for example, by piles or filled slabs ;;; in the manufacture, the sealing movement must be the movement of another member, since no mold is placed in the casting.

The rocking motion of the shape mandrels 4 is accomplished by the pendulum 5 * · 'Γ. The pendulum 5 is adapted to support the shaft 10 of the feed screw * · d 3 and is secured by the spacers * · .. * of the two fingers 6 to the casting machine body 1. Controlled by the cranks 6 for the formwork 4 is obtained in European Patent Application 0 677 "·" 362 illustrates a typical swinging motion. The pendulum 5 has a connecting rod 11 attached to the shaft 12 via a non-Kesko 13. The shaft 12 is a secondary shaft in the transmission and is fixed to the body 1 via bearings and bearing housings 15. The primary shaft 14 is secured to the body 1 above the secondary shaft 12 also through bearings and bearing housings 16. At one end of the primary shaft 14 there are means 17 for connecting the shaft to an electric motor or other power unit. In this case, the members 17 are V-pulleys, but any known method of transmission can be used for transmission.

The primary shaft 14 has a primary cam center 18 opposite to the V-belt pulley wheels 17 on which is mounted a connecting rod 19. The other end of the connecting rod 19 is supported by an eccentric 20 at the end of the secondary shaft 12, and in this embodiment, The eccentricity may be altered, for example, by screw adjustment by changing the position of the center of the eccentricity relative to the center line of the primary axis, by means of nested eccentric flanges whose position can be adjusted, or as described below ;; with adjusting flange. Usually, it is sufficient that the eccentricity can be adjusted so that when the compression amplitude 'is to be changed, the adjustment is made manually. Eccentricity can-,. Of course, it can be adjusted by remote control or »>« • *> on the machine control panel during operation if a suitable actuator is connected to the adjustable • • Kesko. Remote control more »« *. of course, a little price for a machine, but it's relatively '··· * easy to implement if a machine buyer wants such a feature. The eccentricity of the secondary eccentric 20 * »9 115618 is b and should be greater than the eccentricity of the primary eccentric 18.

The device works as follows. The primary shaft 14 is rotated, for example, by an electric motor. The rotation speed of the primary shaft 14 determines the vibration frequency and the frequency can be easily adjusted in electric motor operation, for example by means of a frequency converter. The end (first end) of the palm 19 attached to the primary epicenter 18 rotates the path defined by the eccentricity a around the centerline of the primary shaft 14 and moves the end of the palm 19 attached to the secondary epicenter 20. The path of motion of the secondary end 20 of the palm 19 is dependent on the eccentricity of each eccentric, the eccentricity of the eccentricity and the eccentric positions. In this case, the eccentricity b of the secondary epicenter 20 is greater than the eccentricity a of the primary eccentric 18, so that the end (the other end) of the secondary 19 is not rotated about the centerline of the secondary shaft 12, but is reciprocating. This reciprocating motion is transmitted to the secondary shaft by the cranks 11 attached to the secondary * eccentric 13, which are attached to the pendulum 5. In this way, the rotational movement of the primary shaft • »* • d 14 is transferred to the reciprocating motion of the pendulum 5 and the mandrel. The crank 'mechanism 6 of the pendulum 5 controls the movement of the mandrels in the European

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* · '* As described in Patent Application 0 677 362.

;; * The rotation angle a of the secondary shaft 12 is determined by the eccentricity a of the primary eccentric i »·; · if the eccentricity b is fixed or vice versa. At a given setting, the amplitude of the pendulum motion is further determined by the lever ratio of the palm 11: * '* attached to the pendulum 5 and the eccentric 13 on its secondary axis 12.

The position of the pendulum crank 11 relative to the secondary shaft 12 also affects the amplitude of the pendulum 5. This phenomenon is utilized in the example below.

If the primary shaft 14 is rotated at 1500 l / min in the example described above, the frequency of the compaction stroke will be 25 Hz. The adjustment range of the screw or slip adjustment of the eccentricity a of the primary eccentric 18 may be, for example, 0-15 mm, in which case the eccentricity of the secondary eccentric 18 may be 20 mm. The cam ratio of the cranks 11 attached to the secondary shaft 12 and the eccentric 13 is determined such that when the eccentricity a of the primary eccentric is greatest, the desired desired amplitude of sealing movement is obtained. When the eccentricity a of the primary eccentric a is set to zero, the ends of the palm 19 attached to the primary and secondary eccentric centers 18, 20 do not move because the centers of rotation of the primary eccentric and primary axis are the same. In this way, a stepless adjustment is made between zero and the maximum amplitude of compaction required.

In the device of Figures 3-6, the amplitude adjustment is done slightly *: in different ways. In this solution, the eccentricities a, b of the primary eccentric 18 and the secondary eccentric 20 are fixed and amplitude.]; D is adjusted by changing the position of the secondary shaft 12 and its pendulum cranks 11 relative to the secondary eccentric 20 ·. This device is otherwise similar to the embodiment described above, but now the adjusting flange 21 is attached to the secondary eccentric 20. Figure 6 shows the engagement of the pendulum cranks.

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Lille 12. The number of pendulum cranks 11 varies according to the number of feed screws 3 and hollow mandrels 4. Usually there are several feed screws, and on ever wider machines the number of screws increases to make them a multi-

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sharp tiles. In the example of Fig. 3, the pendulum cranks 11 are adapted to move alternately in different phases and the movement of the different feed screws 3 and the hollow mandrels 4 can be varied as necessary by varying their mounting angle with the secondary shaft 12.

Figures 4 and 5 show the adjustment of the length of movement of the mandrel 4 by means of the adjusting flange 21. Both the secondary cam center 20 and the adjusting flange 21 have circumferential rows of holes 22 and 23. The holes are made such that their mutual distances are varied such that by rotating the adjusting flange 21 or the secondary cam center 20, the holes therein can be aligned at different angular positions of these members. The zero angle of the adjustment flange 21 and the secondary cam center 20 is the angle at which the line passing through the center of rotation of the pendulum cam 11 and the center line of the secondary shaft 12 is parallel to the desired direction of the pendulum amplitude. In this case, rotation of the secondary shaft causes the pendulum 5 to move as little as possible in the direction of the pendulum. In practice, this means horizontal or approximately horizontal. The crank eccentric mechanism circumvents this embodiment! · Always produce the secondary shaft 12 at a given angle of rotation α, which in this case is 49, 24 °.

The amplitude of the movement of the pendulum 5 and the associated mandrel 4 is determined by the position of the pendulum crank 11 disposed on the secondary shaft. When the eccentric axis · of the pendulum crank 11 is parallel to the direction of rotation of the pendulum 5 in the center of the rotation angle; If, on the other hand, the center line of the secondary shaft 12 115618 attached to the lille 12 forms a large angle with respect to the direction of sealing movement, the movement of the pendulum pin 11 attached to the eccentric is substantially parallel to the sealing movement. This phenomenon is utilized in amplitude control by rotating the secondary shaft 12 and the adjusting flange 21 attached thereto relative to the secondary shaft eccentric 20. By means of fixing holes 22, 23 made in the secondary eccentric cam 20 and the adjusting flange 21, the secondary shaft 12 can be locked in different positions so that the eccentrics attached thereto are positioned in a position where the rotational angle α of the secondary shaft 12 gives the desired sealing motion amplitude. The zero adjustment angle can be selected, for example, as the upper or lower dead center of the secondary shaft 13 cam and the pendulum cam mechanism, whereby the adjustment angle S is a deviation from the position of the adjustment flange 21.

Figure 7 shows the relationship between amplitude and angle of adjustment β with the dimensioning shown in Figure 5. Of course, this dimensioning is only an example and the adjustment ranges for different machines and mechanisms are different.

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In addition to the above, the present invention has other embodiments.

Instead of the above-described shaft-mounted eccentrics, crank mechanisms or other mechanisms providing similar movement may be used. Thus, in this text, the eccentric mechanism refers to arrangements whereby the rotational movement of at least one machine member can be * * '·· * altered at a point orbiting a given path, such as a rotary cam! I move the anchorage point. In another embodiment of the invention, the adjusting flange 13 115618 to be connected to the secondary eccentric can be replaced by mounting all eccentricities of the pendulum cranks 11 with adjustable locking means on the secondary shaft. In this case [although it is more difficult to adjust the device, on the other hand, different range of motion amplitudes can be set for different shape mandrels. Of course, the invention can be applied to provide compaction movements other than mere shape mandrel movements. If a sealing movement is required for only one sealing member, for example an upper swivel beam, the crank or arm moving this member may be directly connected to the secondary eccentric, which then functions as both the secondary eccentric and the pendulum cam eccentric. If a connecting rod mechanism is used as the eccentric mechanism, the primary and secondary eccentrics may be located in the center of the axes. There may also be several eccentric mechanisms in parallel where it is necessary to transfer considerable power. The shafts of the arrangement may be considerably shorter than shown in the figures, for example when a sealing motion is required for only one sealing member.

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Claims (12)

Device for effecting a compression stir in a concrete casting machine, comprising a primary shaft (14), a primary eccentric mechanism (18) arranged at the primary shaft (14), - means (17) for rotating the primary shaft (14), - at least means (4) arranged to perform the compression movement, and means (18, 19, 20, 12, 13, 11, 5, 10, 3) for converting the rotary movement of the primary shaft (14) into a first eccentric movement and for transferring - conveying the same to the means (4) arranged to perform the compression movement, characterized by, · · # - a secondary shaft (12),. - a secondary eccentric mechanism (20) provided at the secondary axis (12), - · at least one first crank (19) disposed at the first · 18 (18) and the second (20) eccentric mechanism for transmitting the movement of the first eccentric mechanism (18) to the secondary eccentric mechanism (20), and at least one eccentric mechanism (13) provided at the secondary shaft (12) for transferring the rotary movement of the secondary shaft (12) to the means (4) compression movement. Device according to claim 1, characterized in that the eccentricity (b) of the secondary eccentric mechanism (20) is greater than the eccentricity (a) of the primary eccentric mechanism (18). Device according to claim 1 or 2, characterized in that the eccentricity (a) of the primary eccentric mechanism (18) is adjustable. Device according to claim 1 or 2, characterized in that the eccentricity (b) of the secondary eccentric mechanism (18) is adjustable. * l [ Device according to claim 1 or 2, characterized in that the eccentricity (a) of the primary eccentric mechanism (*) is controllable and the eccentricity (b) of the mechanism of the eccentric (18) is controllable. » Device according to claim 1, characterized in - M · characterized by at least one reading means (21), whereby the angular position of at least one eccentric mechanism (13) arranged at the secondary shaft (12), which is connected to the means (4), are arranged to effect the compression, movement, can be changed relative to the angular position t>> of the secondary eccentric (20). 20 115618 Device according to claim 6, characterized in that a fixed control flange (21) is attached to the secondary shaft (12), whereby the secondary eccentric mechanism (20) is fixed to the secondary shaft (12) and thus the angular position of the shaft can be changed relative to the secondary eccentric (20). Apparatus according to claim 6, characterized by at least one reading means for attaching to the secondary shaft (12) an eccentric mechanism (13) connected to the means (4) arranged to carry out the compression movement, in this way. that its angular position on the shaft (12) can be changed. Device according to claim 6, characterized in that the eccentricity (a, b) of the primary eccentric mechanism (18), the secondary eccentric mechanism (20) or of both of them is adjustable. ; Device according to claim 9, characterized by a remote control device for varying the eccentricity of at least one eccentric mechanism. V · 20 11. A method for effecting a compression movement in a concrete casting machine, in which method * f * * * t - a primary shaft (14) is rotated, ''. - the rotational movement of the primary shaft (14) is converted into a first eccentric movement, the rotary movement of the primary shaft (14) converted to the first eccentric movement is transmitted to means (4) performing the compression movement, characterized in that - the the first eccentric movement is converted by means of a crank (19) and a second eccentric mechanism (20) into a rotational movement of the secondary shaft (12), - the rotational movement of the secondary shaft (20) is converted by a eccentric mechanism (13) to moving the means (4) performing the compression movement. 12. A method according to claim 11, characterized in that the eccentricity of at least one eccentric motion is varied to control the amplitude of the compressive motion. > t »·» ·:::: 20 * * i »*