Abstract:
A mold turnover system for turning over the rotating side mold over the fixed side mold includes a turnover device and a quick releasing mechanism, characterized in that the quick releasing mechanism comprises a hook associated with the turnover device and an engaging member associated with the rotating side mold, wherein the hook can be quick engaged onto or disengaged from the engaging member.

Description:
TECHNICAL FIELD OF THE INVENTION 
     The present invention relates to a mould turnover system for large moulds composed of a fibre-reinforced resin matrix composite material, particularly suitable for wind turbine blade moulds, which allows convenient and totally automatic disconnection of the mould from the turnover device. 
     BACKGROUND OF THE INVENTION 
     For some time there have existed hydraulic and mechanical turnover devices for rotating large composite moulds, particularly wind turbine blade moulds, which usually are a fixed side mould and a turning or rotating side mould. In most cases the turnover device has been connected to the rotating side mould with pins or, in some cases, bolts. When the turnover action is finished and the rotating side mould is turned over to the fixed side mould, it is normally required to remove the pins or bolts to release the mould. Due to the enormity of the moulds, which can exceed 30 tons in weight and 50 meters in length, removing these pins or bolts is frequently difficult, time consuming and somewhat dangerous. 
     SUMMARY OF THE INVENTION 
     An aim of the present invention is to overcome the above-mentioned problems and allow fully automatic connection and release of the turning mould to be realized without any manual intervention. The release may be partial or complete. In the case of partial release of the mould, it may be freed to move in slots, rather than being totally disconnected. 
     The present invention model provides a mould turnover system for turning a rotatable mould over a fixed side mould including a turnover device and a quick releasing mechanism, characterized in that the quick releasing mechanism comprises a hook associated with the turnover device and an engaging member associated with the rotatable mould, wherein the hook can be selectively engaged onto or disengaged from the engaging member. 
     Preferably, the quick releasing mechanism further includes a driving mechanism for the hook. 
     Preferably, the driving mechanism is a hydraulic cylinder that is connected to the hook at one end and fixed to the turnover device at the opposite end. 
     Preferably, the hook is rotated around a pin that is anchored on the turnover device. 
     Preferably, the engaging member is a shelf welded to the rotatable mould and has a cutout or slot that rides on a pin fixed to the turnover device. 
     Preferably, the hydraulic cylinder is equipped with a pressure holding valve to prevent accidental releasing. 
     Preferably, the hook is equipped with one or more proximity sensors, which can be used to signal to a control system whether the hook is engaged or disengaged. 
     Preferably, the hook is equipped with two proximity sensors. 
     Preferably, the rotatable mould is provided with further hooks or ears to allow free movement of the rotatable mould in the vertical direction when the hook is disengaged from the engaging member. 
     This novel design eliminates the labor of inserting or removing pins and ensures efficient and safe production of the large composite parts, especially wind turbine blades. 
     An aim of this new device is to ensure a robust operation even in cases where the environment is extremely dirty and the possibility of fouling with resin, glue, etc. exists. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will now be described in greater detail by way of a non-limiting example and with reference to the accompanying drawings, in which: 
         FIG. 1  shows an illustrative view of a mold turnover system according to an embodiment of the present invention; 
         FIG. 2  shows a perspective view of a quick releasing mechanism according to an embodiment of the present invention; 
         FIG. 3  shows an exploded perspective view of the quick releasing mechanism of  FIG. 2 ; 
         FIG. 4  shows another exploded perspective view of the quick releasing mechanism of  FIG. 2 ; 
         FIG. 5  shows a side view of the quick releasing mechanism of  FIG. 2  in a locked position; and 
         FIG. 6  shows a side view of the quick releasing mechanism of  FIG. 2  in a released or opened position. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Now the turnover device and system according to the present invention will be described with reference to the accompanying drawings, which are only for the illustrative purpose and will not intend to the limit the scope of the present invention. 
       FIG. 1  shows a mold turnover system  100  for turning a rotating side mould laid on a second attachment frame  30  over a fixed side mould laid on a first attachment frame  20 . The mold turnover system  100  generally includes a turnover device  10  and, as shown in  FIG. 2 , a quick releasing mechanism  90 . The quick releasing mechanism  90  connects the second frame  20  for the turning side mould to the turnover device  10  when the mechanism  90  is locked. In this situation, the second frame  30  for the turning side mould can be turned over the first frame  20  for the fixed mould so that two moulds can be clamped together. 
     With reference to  FIG. 2  which illustrates the quick releasing mechanism  90  in a perspective view, the mechanism  90  includes a hook  91 , a hydraulic cylinder  94  and a mould attachment shelf  97  which is welded to the second attachment frame  30  for the turning mould. The output member, or piston, of the cylinder  94  is connected to the hook  91  by means of a pivot pin  92  so that the cylinder  94  can drive the hook  91  and the hook  91  can rotate relative to the output member of the cylinder  94 . The cylinder  94  is fixed to a cylinder anchor point  93  on the turnover device  10  at its opposite end. The mould attachment shelf  97  is provided with a cutout or slot, which rides on a mould side force carrying pin  96 . The pin  96  is fixedly mounted to the turnover device  10 . The hook  91  can rotate around a sizeable pivot pin  95 , which is anchored on the turnover device  10  by passing through suitable holes or bushings, to adopt a locked position, in which the hook  91  engages onto the shelf  97  or a released position in which the hook  91  is disengaged from the shelf  97  under the drive of the cylinder  94 . 
     It is apparent that the hook  91  can be engaged onto or disengaged from the shelf  97  by means of any other driving mechanism and the cylinder  94  is just one of the examples. 
     When the hook  91  is engaged onto the shelf  97 , that is, the hook  91  is in the locked position shown in  FIG. 1  and  FIG. 5 ; the turnover device  10  can be operated to turn the rotating side mould over the fixed side mould. When the hook  91  is disengaged from the shelf  97 , that is, the hook  97  is in the released or opened position shown in  FIG. 6 , the rotating side mould can be moved vertically in the direction as indicated by the arrow A in  FIG. 1  by lifting the hooks or slotted ears provided to the mould. 
     As can be seen that the connection and/or the release of the rotating side mould can be accomplished by only manipulating the cylinder  94  and it is not necessary for the operator to insert or remove any pins. Therefore, the operation is very simple and easy. Of course, if the cylinder  94  is not provided for saving the cost, the engagement or release of the hook  91  can be accomplished manually. 
     Preferably, the hydraulic cylinder  94  is equipped with a pressure holding valve to prevent accidental releasing in case of hose breakage or pressure loss. 
     Preferably, the hook  91  is equipped with one or more proximity sensors, which can be used to signal the control system whether the hook  91  is closed or open. This can be used to prevent operation of the turnover system in case the hook  91  is not properly locked. It is especially preferred to use two proximity sensors in order to ensure a redundant function for higher safety. 
     A person skilled in the art can contemplate many modifications within the scope of the present invention. For example, the shelf  97  can be replaced by any other members that are fixed to the mould and can be engaged by the hook  91 . These modifications all fall in the scope of the present invention defined by the attached claims.