Abstract:
The invention concerns a cooling and molding water tank for a plastic complicated profile. A plurality of molding blocks and water collection plates are provided along the length inside the tank, and they are spaced each other. The advantage of this invention is that: the cooling water flows alternately in cycle or periphery-inner-periphery. It makes the complicated profile cool homogeneously and efficiently upon the high speed extrusion pulling and provides the profile with good molding effect and quality.

Description:
TECHNICAL FIELD 
   This invention relates to a cooling tank for extrusion of a plastic complicated profile, and particularly to a cooling and molding water tank for extrusion of a plastic complicated profile for the purpose of cooling and molding of various kinds of plastic complicated profiles manufactured in a continuous manner. 
   BACKGROUND  
   Molding die structures for extrusion of plastic complicated profiles have been developed from entirely dry molding structures in the earlier time to molding structures with the combination of dry and wet states, so that a manufacturing speed of plastic profiles is greatly increased. As a dispensable part of the whole system of an extrusion die, a cooling water tank plays a more and more important role in strengthening the cooling effect of plastic profiles, increasing the extrusion speed, and keeping the intrinsic quality of plastic profiles. Presently, extrusion die is developed to have higher speed and better performance. A cooling water tank of plastic complicated profiles, such as Chinese Patent of Utility Model “a molding and cooling mechanism for extrusion of a plastic complicated profile” (Patent No. ZL01237399.0, Announcement No. CN2472911Y) and Chinese Patent of Utility Model “a molding die mechanism for a plastic complicated profile” (Patent No. ZL0322110.0, Announcement No. CN2594001Y), is processed and provided with a water slot or a water hole in locations where a molding block approaches a profile cavity plate inside a water tank, in order to homogeneously cool a local part of a profile or obtain eddy flow of the cooling water. Although both mechanisms mentioned above overcome the defect of poor heat exchange in dry molding structures, the cooling ability still remains restricted. Obviously, the existing molding and cooling mechanisms cannot meet the needs for high speed and excellent efficiency of an extrusion die. As shown in Chinese Patent of Utility Model “a cooling water tank for the production of a plastic complicated profile” (Patent No. ZL01262430.6, Announce No. CN2491214Y), which provides with a cooling water tank which is disposed with a set of molding plates inside the tank body of a water tank, said set of molding plates are arranged so that they are spaced more and more away from each other from an inlet to an outlet of the water tank. In this way, the manufacturing cost of a water tank is reduced, however the problems of homogeneously cooling of the profiles and promoting cooling efficiency still exist. Therefore, it has become one of urgent technical problems to be solved in the technical field to develop a new cooling and molding water tank with better cooling ability and cooling characteristics of high efficiency and homogeneity. 
   SUMMARY OF THE INVENTION  
   The invention aims to overcome the defects and shortcomings existing in the prior art, and provide a cooling and molding water tank for continuous extrusion of a complicated profile, in order to promote the cooling efficiency and the cooling homogeneity during the extrusion of a plastic complicated profile, and sufficiently guarantee the efficiency and quality of a profile molding during a high speed extrusion. 
   To obtain the objects mentioned above, it is provided a cooling and molding water tank for extrusion of a plastic complicated profile, comprising a tank body, said tank body including front and rear end blocks, a top cover of, two side plates, a bottom plate and a plurality of foot plates which are in bolted or hinged joint. An inlet pipe is provided on the side plate near the front end block, and an outlet pipe is provided on the side plate near the rear end block. A vacuum valve and a vacuum, gauge are provided on the top cover. A plurality of molding blocks and water collection plates are provided along the length direction inside the tank body, said molding blocks and water collection plates being spaced from each other, and the intervals therebetween becoming wider from the front end to the rear end. 
   Said molding blocks and water collection plates are inserted into a receptacle at the internal side of the side plates of the water tank, which have a limited freedom of motion in the longitudinal, transverse and vertical directions. 
   The number of said molding blocks is 5-30. 
   The number of said water collection plates is 3-28. 
   U-shape water passage slots are provided on the four peripheral sides of said molding blocks. 
   The width of said U-shape water passage slot is 0.2-0.8 of the side length of said molding block, the depth of which is ranged 2-15 mm according to the size of the molding blocks. 
   An adjusting mechanism is provided on the long side of the profile cavity passage of said molding block. The adjusting mechanism includes a through kurf which is parallel to and 1-8 mm from the plane of the long side of the profile cavity passage, and at least one through screw hole which is provided on and perpendicular to the plane of the long side and intersects with the low side of the kurf, wherein an adjusting screw is engaged with the screw hole and the top of the adjusting screw may extend against the upper side of said kurf. 
   The width of said kurf is 0.1-2.0 mm, and the length of said kurf is equal to that of the long side of the profile cavity passage, or a little longer or shorter. 
   The shape of an internal cavity of said water collection plate is the shape of an outwardly expanded section of a plastic complicated profile which expands 0.5-8 mm in the radial direction. The shape of some parts of the internal cavity where are overlapped, adjacent, or complicated can be simplified. 
   Said water collection plates can be made of stainless steel, alloy aluminum, organic glass, or other stainless and corrosion resistant materials. 
   The advantages of the invention is that, by using a water collection plate and incorporating a molding block with a novel structure, the water flow state is changed and form a special alternate cycle flow of cooling water so as to accelerate the heat exchange between a profile and the cooling water. In contrast to the prior art, very high cooling efficiency and very good cooling homogeneity is obtained and the efficiency and quality of a profile molding during a high speed extrusion is guaranteed. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a front view of an embodiment in accordance with the invention; 
       FIG. 2  is a top view of an embodiment in accordance with the invention; 
       FIG. 3  is a left view of in the direction of B shown in  FIG. 1  in accordance with the invention; 
       FIG. 4  is a front view, a bottom view and a left view of a molding block; 
       FIG. 5  is a front view and a bottom view of a water collection plate. 
   

   DESCRIPTION OF THE REFERENCE NUMBERS IN THE DRAWINGS 
   
       
         1 —tank body 
         11 —front end block and rear end block 
         12 —top cover 
         121 —vacuum valve 
         122 —vacuum gauge 
         13 —side plate 
         14 —bottom plate 
         15 —foot plate 
         16 —inlet pipe 
         17 —outlet pipe 
         2 —molding block 
         21 —U-shape water passage slot 
         22 —adjusting mechanism 
         221 —kurf 
         222 —screw hole 
         223 —adjusting screw 
         3 —water collection plate 
         31 —internal cavity 
     
  
   DETAILED DESCRIPTION  
   An embodiment of the present invention will be described by reference to the following detailed description of an embodiment in accordance with the present invention when taken in conjunction with the accompanying drawings. 
   As shown in  FIGS. 1 ,  2  and  3 , which are respectively a front view, a bottom view and a left view in the B direction according to an embodiment of the invention, a cooling and molding water tank for extrusion of a plastic complicated profile includes a tank body  1  including front and rear end block  11 , top cover  12 , two side plates  13 , a bottom plate  14  and a plurality of foot plates  15  which are in bolted or hinged joint. An inlet pipe  16  is provided on the side plate  13  near the front end block  11 , and an outlet pipe  17  is provided on the side plate  13  near the rear end block  11 . A vacuum valve  121  and a vacuum gauge  122  are provided on the top cover  12 . A plurality of molding blocks  2  and water collection plates  3  are provided along the length direction inside the tank body  1 , said molding blocks and water collection plates being spaced from each other, wherein the intervals therebetween becoming wider from the front end to the rear end. 
   As shown in  FIGS. 1 and 2 , said molding blocks  2  and water collection plates  3  are respectively inserted into receptacles at the internal side of the side plates  13  of the water tank, which have a limited freedom of motion in the longitudinal transverse and vertical directions. 
   The number of said molding blocks  2  is 5-30. As shown in  FIGS. 1 and 2 , the number of said molding blocks  2  is 14 according to this embodiment. 
   The number of said water collection plates is 3-28. As shown in  FIGS. 1 and 2 , the number of said water collection plates  3  is 9 according to this embodiment. 
   As shown in  FIG. 4 , a flat U-shape water passage slot  21  is provided on each periphery side of said molding blocks  2 . 
   The width of said U-shape water passage slot  21  is 0.2-0.8 of the side length of the molding block  2 , the depth of which is ranged 2-15 mm according to the size of the molding blocks. In this embodiment, the width of said U-shape water passage slot  21  is about 0.7 of the side length of the molding block  2 , the depth of which is designated as 8 mm. 
   As shown in  FIG. 4 , an adjusting mechanism  22  is provided on the long side of the profile cavity passage of said molding block  2 . The adjusting mechanism  22  includes a through kurf  221  which is parallel to and 1-8 mm from the plane of the long side of the profile cavity passage, and at least one through screw hole  222  which is provided on the plane of the long side, such as a screw hole  222  according to this embodiment. Said screw hole  222  is perpendicular to the plane of the long side and intersects with the lower side of the kurf  221 , wherein an adjusting screw  223  is engaged with the screw hole  222  and the top of the adjusting screw  223  may extend against the upper side of said kurf  221 . When the profile cavity passage of the molding block  2  does not have a long side, an adjusting mechanism  22  may not be provided. When the profile cavity passage of a molding block  2  has more than one long sides, more than one adjusting mechanisms  22  may be provided respectively according to the locations of the long sides. When a long side is very long, a kurf  221  is very long too, so two or more screw holes  222  and adjusting screws  223  may be provided. 
   The width of said kurf is 0.1-2.0 mm, and the length of said kurf is equal to that of the long side of the profile cavity passage, or a little longer or shorter. 
   As shown in  FIG. 5 , the shape of an internal cavity  31  of said water collection plate  3  is the shape of an outwardly expanded section of a plastic complicated profile (profile cavity passage) which expands 0.5-8 mm in the radial direction. The shape of some parts of the internal cavity  31  of the water collection plate  3  where are overlapped, adjacent, or complicated can be simplified. In the present embodiment, the radial expansion distance is 5 mm, and the shape of the internal cavity is simplified so as to facilitate water passage, as is the simplified shape of an internal cavity shown in  FIG. 5 . 
   Said water collection plate  3  can be made of stainless steel, alloy aluminum, organic glass, or other stainless and corrosion resistant materials. In the present embodiment, the water collection plate  3  is made of stainless steel. 
   In extrusion, a plastic complicated profile enters the front end block  11  of the water tank  1  along the A direction shown in  FIG. 1 . When the profile gradually becomes shaped through molding blocks  2  and water collection plates  3 , the cooling water firstly passes through the U-shape water passage slots  21  disposed around the molding plate  2 , then through a gap with a width of 0.5-8 mm between the profile and the internal cavity  31  of the water collection plate  3 , then through the U-shape water passage slots  21  disposed around the next molding plate  2 , then through a gap with a width of 0.5-8 mm between the profile and the internal cavity  31  of a water collection plate  3 , and continues to circulate as described above, as is shown using arrows in  FIG. 1  and  FIG. 2 , because molding plates  2  and water collection plates  3  are spaced from each other in the tank body  1 , and the intervals therebetween become wider from the front end to the rear end. Thus, the cooling water flow forms an periphery-inner circle-periphery alternate flow cycle. Also, because the cooling water passes evenly along the outer surface of the profile when passing through the internal cavity  31  of the water collection plate  3 , the profile can be cooled homogeneously and high efficiently in a high-speed extrusion. Good profiled effect and quality can be sufficiently guaranteed in a high-speed extrusion because of the high cooling efficiency.