Heating device of laminating machine and control method thereof
Technical Field
The invention relates to the technical field of hot pressing, in particular to a heating device of a laminating machine and a control method thereof.
Background
The laminating machine is widely applied to the laminating and packaging of various flat plate materials. The temperature uniformity of the heating plate has a direct influence on the quality of the packaged product. If the temperature is not uniform, the problems of local expansion with heat and contraction with cold can occur, and the problems of bubbles, bending, even crushing and the like can occur. In the prior art, in order to obtain a heating plate with high temperature uniformity, high-temperature heat conduction oil is generally used for circularly flowing in a coil pipe in the heating plate to heat the heating plate. However, the heat conduction oil has thermal attenuation in the heating plate, so that the inlet temperature and the outlet temperature of the heat conduction oil cannot be consistent, the temperature difference of the heating plate cannot be reduced to be less than 0.7 ℃ per square meter, and the technical bottleneck of the laminating machine is formed.
Disclosure of Invention
The technical problem to be solved by the invention is to provide a heating device of a laminating machine and a control method thereof, which can solve the defects of the prior art and further reduce the temperature difference of the heating device of the laminating machine.
In order to solve the technical problems, the technical scheme adopted by the invention is as follows.
The utility model provides a heating device of laminator, which comprises an outer shell, parallel arrangement has three-layer heating pipe in the shell, the heating pipe of top layer and the heating pipe symmetry setting of bottom, the heating pipe in intermediate level sets up rather than the heating pipe of both sides is crisscross, be provided with a temperature sensor between two adjacent heating pipes in intermediate level, the shell intussuseption is filled with heat conduction silica gel layer, the position that heat conduction silica gel layer is located top layer heating pipe and bottom heating pipe is provided with the arc recess, top layer heating pipe and bottom heating pipe are located the arc recess, the heating pipe is including concentric outer tube and the interior sleeve pipe that sets up, be filled with the conduction oil.
Preferably, the electric heating wires in the inner sleeve are divided into a plurality of sections which are arranged in parallel, all the electric heating wires are divided into two groups, the two groups of electric heating wires are alternately arranged in the inner sleeve at intervals, the electric heating wires in the same group are mutually parallel, the included angle of the axes of the adjacent electric heating wires is 13-degree 28', the adjacent electric heating wires are partially overlapped in the radial direction of the inner sleeve, and the overlapped part accounts for 20% of the total length of the electric heating wires.
Preferably, the inner wall of the outer sleeve is provided with a first heat-sensitive metal heat-conducting layer, the outer wall of the inner sleeve is provided with a second heat-sensitive metal heat-conducting layer, a heat-conducting insulating elastic rubber layer is arranged between the first heat-sensitive metal heat-conducting layer and the second heat-sensitive metal heat-conducting layer, and the thermal expansion coefficient of the first heat-sensitive metal heat-conducting layer is larger than that of the second heat-sensitive metal heat-conducting layer.
Preferably, a plurality of concave parts are uniformly arranged on the first heat-sensitive metal heat-conducting layer, convex parts which correspond to the concave parts one by one are arranged on the second heat-sensitive metal heat-conducting layer, and hard metal supports are connected between the concave parts and the convex parts.
Preferably, the temperature sensor is positioned between the top layer heating pipe and the middle layer heating layer, and the ratio of the distance from the temperature sensor to the plane where the top layer heating pipe is located to the distance from the temperature sensor to the plane where the middle layer heating pipe is located is 1: 2.
Preferably, the flow cross-sectional area of the heat transfer oil and the distance between the flow cross-section and the liquid inlet end of the heating pipe satisfy the following functional relationship,
wherein k 1-k 3 are proportionality constants, L is the distance between the flow section and the liquid inlet end of the heating pipe, and s is the flow section.
Preferably, it is mentioned.
Preferably, a wire mesh layer is provided at a connection between the third pump body and the first flow valve.
A method for controlling the heating device of the laminator comprises the following steps:
A. the temperature sensor measures the temperature in the shell and adjusts the temperature of the heat conducting oil, so that the temperature at the inlet of the heating pipe is controlled at a set value;
B. the temperature sensors measure the temperatures of the rest positions, and curve fitting is carried out on the measurement results to obtain a temperature change curve;
C. heating and warming the electric heating wires in each heating pipe according to the difference value between the temperature value on the temperature curve of the position where the heating pipe is positioned and the set value, wherein the heating temperature of the electric heating wires is higher than the set value, and the difference value between the heating temperature of the electric heating wires and the set value is equal to the difference value between the temperature value on the temperature curve of the corresponding position and the set value;
D. after the electric heating wire is heated, the heating temperature of the electric heating wire is adjusted in real time according to the temperature change measured by the temperature sensor;
the electric heating wires in the top heating pipe and the bottom heating pipe are adjusted according to the temperature changes measured by the two temperature sensors which are closest to the electric heating wires, the adjusting process follows the following functional relation,
;
the middle layer heating pipe is adjusted according to the temperature change measured by the temperature sensors at the two sides of the middle layer heating pipe, the adjusting process follows the following functional relation,
;
wherein T1 is the temperature change rate of the temperature sensor at the side with larger difference with the set value, T2 is the temperature change rate of the temperature sensor at the side with smaller difference with the set value, k 4-k 7 are proportionality constants, and T is the temperature adjustment variation of the electric heating wire;
E. after the electric heating wire is subjected to heating compensation, secondary compensation adjustment is carried out on fluctuation of the temperature at the inlet of the heating pipe by adjusting the flow velocity of the heat conducting oil, so that the fluctuation rate of the temperature of the whole heating device is reduced.
Adopt the beneficial effect that above-mentioned technical scheme brought to lie in: according to the invention, the heat conduction oil and the electric heating are organically combined, the heat conduction oil heating system is supplemented through the electric heating, and the temperature attenuation problem in the heat conduction oil heating system is effectively compensated. The distribution uniformity of the high-temperature field can be effectively improved by the arrangement structure of the heating pipes. The electric heating wires at different positions carry out heating temperature adjustment in different modes according to the measuring result of the temperature sensor, the temperature adjustment of the electric heating wires adjusts the elastic deformation of the two layers of heat-sensitive metal heat-conducting layers, and the elastic deformation of the two layers of heat-sensitive metal heat-conducting layers simultaneously carries out feedback intervention on the transmission efficiency of the heat productivity of the electric heating wires, so that the hysteresis of the electric heating wires for heating the heat-conducting oil is reduced, the temperature uniformity of the whole heating device is improved, and the temperature difference is further reduced.
Drawings
FIG. 1 is a block diagram of one embodiment of the present invention.
Fig. 2 is a block diagram of the inner cannula according to an embodiment of the invention.
FIG. 3 is a partial cross-sectional view of a heating tube in accordance with an embodiment of the present invention.
In the figure: 1. a housing; 2. a temperature sensor; 3. a heat conductive silica gel layer; 4. an arc-shaped groove; 5. an outer sleeve; 6. an inner sleeve; 7. an electric heating wire; 8. a first heat-sensitive metal heat-conducting layer; 9. a second heat-sensitive metal heat-conducting layer; 10. a heat-conducting insulating elastic rubber layer; 11. a recessed portion; 12. a boss portion; 13. a hard metal bracket; 14. a heat conductive metal sheet; 15. a sliding sleeve; 16. a support rod.
Detailed Description
The standard parts used in the invention can be purchased from the market, the special-shaped parts can be customized according to the description and the description of the attached drawings, and the specific connection mode of each part adopts the conventional means of mature bolts, rivets, welding, sticking and the like in the prior art, and the detailed description is not repeated.
Referring to fig. 1-3, a specific embodiment of the present invention includes a housing 1, three layers of heating pipes are arranged in parallel in the housing 1, the heating pipes at the top layer and the heating pipes at the bottom layer are symmetrically arranged, the heating pipes at the middle layer are arranged in a staggered manner with the heating pipes at both sides thereof, a temperature sensor 2 is arranged between two adjacent heating pipes at the middle layer, a heat-conducting silica gel layer 3 is filled in the housing 1, arc-shaped grooves 4 are arranged at positions of the heat-conducting silica gel layer 3 at the top layer and the bottom layer, the top layer and the bottom layer heating pipes are arranged in the arc-shaped grooves 4, the heating pipes include an outer sleeve 5 and an inner sleeve 6 which are concentrically arranged, heat-conducting oil. The electric heating wires 7 in the inner sleeve 6 are divided into a plurality of sections which are arranged in parallel, all the electric heating wires 7 are divided into two groups, two groups of electric heating wires 7 are alternately arranged in the inner sleeve 6 at intervals, the electric heating wires 7 in the same group are mutually parallel, the included angle of the axes of the adjacent electric heating wires 7 is 13 degrees 28', the adjacent electric heating wires 7 are partially overlapped in the radial direction of the inner sleeve 6, and the overlapped part accounts for 20 percent of the total length of the electric heating wires 7. The inner wall of the outer sleeve 5 is provided with a first heat-sensitive metal heat-conducting layer 8, the outer wall of the inner sleeve 6 is provided with a second heat-sensitive metal heat-conducting layer 9, a heat-conducting insulating elastic rubber layer 10 is arranged between the first heat-sensitive metal heat-conducting layer 8 and the second heat-sensitive metal heat-conducting layer 9, and the thermal expansion coefficient of the first heat-sensitive metal heat-conducting layer 8 is larger than that of the second heat-sensitive metal heat-conducting layer 9. A plurality of concave parts 11 are uniformly arranged on the first heat-sensitive metal heat-conducting layer 8, convex parts 12 which are in one-to-one correspondence with the concave parts 11 are arranged on the second heat-sensitive metal heat-conducting layer 9, and hard metal supports 13 are connected between the concave parts 11 and the convex parts 12. The temperature sensor 2 is positioned between the top layer heating pipe and the middle layer heating layer, and the ratio of the distance from the temperature sensor 2 to the plane where the top layer heating pipe is positioned to the distance from the temperature sensor 2 to the plane where the middle layer heating pipe is positioned is 1: 2.
The flow sectional area of the heat-conducting oil and the distance between the flow sectional area and the liquid inlet end of the heating pipe satisfy the following functional relationship,
wherein k 1-k 3 are proportionality constants, L is the distance between the flow section and the liquid inlet end of the heating pipe, and s is the flow section.
In addition, a heat conducting metal sheet 14 penetrates through the inner sleeve 6, the top of the heat conducting metal sheet 14 is fixedly connected with the top end of the boss 12, two sliding sleeves 15 are slidably arranged on the heat conducting metal sheet 14, a support rod 16 is hinged on the sliding sleeves 15, and the top of the support rod 16 is in sliding pressure joint with the boss 12. The heat conducting metal sheet 14 changes the local deformation of the second heat-sensitive metal heat conducting layer 9 through direct heat transfer, and can effectively reduce the nonlinearity of the temperature transfer process.
A method for controlling the heating device of the laminator comprises the following steps:
A. the temperature sensor 2 measures the temperature in the shell 1 and adjusts the temperature of the heat-conducting oil, so that the temperature at the inlet of the heating pipe is controlled at a set value;
B. the temperature sensor 2 measures the temperatures of the rest positions, and curve fitting is carried out on the measurement result to obtain a temperature change curve;
C. the electric heating wires 7 in each heating pipe are heated according to the difference value between the temperature value on the temperature curve of the position where the heating pipe is located and the set value, the heating temperature of the electric heating wires 7 is higher than the set value, and the difference value between the heating temperature of the electric heating wires 7 and the set value is equal to the difference value between the temperature value on the temperature curve of the corresponding position and the set value;
D. after the electric heating wire 7 is heated, the heating temperature of the electric heating wire 7 is adjusted in real time according to the temperature change measured by the temperature sensor;
the electric heating wires 7 in the top heating pipe and the bottom heating pipe are adjusted according to the temperature changes measured by the two temperature sensors closest to the electric heating wires, the adjusting process follows the following functional relation,
;
the middle layer heating pipe is adjusted according to the temperature change measured by the temperature sensors at the two sides of the middle layer heating pipe, the adjusting process follows the following functional relation,
;
wherein T1 is the temperature change rate of the temperature sensor on the side with a larger difference from the set value, T2 is the temperature change rate of the temperature sensor on the side with a smaller difference from the set value, k 4-k 7 are proportionality constants, and T is the temperature adjustment variation of the electric heating wire 7;
E. after the electric heating wire 7 is subjected to heating compensation, secondary compensation adjustment is carried out on fluctuation of the temperature at the inlet of the heating pipe by adjusting the flow velocity of the heat conducting oil, so that the fluctuation rate of the temperature of the whole heating device is reduced.
In addition, in step C, the two groups of electric heating wires 7 in the same inner sleeve 6 are alternately turned on for heating. The heating mode can form the circulation movement of the temperature field in the inner sleeve, thereby reducing the hysteresis of the relative elastic deformation amount of the two heat-sensitive metal heat-conducting layers.
The invention can reduce the temperature difference of the laminating machine to be below 0.25 ℃ per square meter.
The foregoing shows and describes the general principles and broad features of the present invention and advantages thereof. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.