A sand core clamp with automatic balancing holding force

Abstract

The embodiment of the present invention discloses a sand core clamp with automatic balanced holding force, including: a main frame, a plurality of hand-cranked sand core positioning devices and a clamping claw device; the hand-cranked sand core positioning device includes: a positioning frame, an elastic rubber pad inside the positioning frame and a hand-cranked threaded connecting rod, the hand-cranked threaded connecting rod applies an inward force to the positioning frame and the elastic rubber pad after rotating through the corresponding column; the part of the load-bearing plate located inside the main frame in the clamping claw device is directly connected to the sand core, the cone head of the cone head suspension rod passes through the keyway from the bottom of the load-bearing plate, so that the load-bearing plate and the cone head suspension rod are connected in a movable manner, and an installation platform is provided on the outside of the main frame, and the balanced load-bearing mechanism passes through the installation platform and contacts the load-bearing plate position to provide a balanced load-bearing effect. The technical solution provided by the embodiment of the present invention solves the problem that the existing sand core clamp structure is difficult to achieve uniform force on the sand core during transportation, which makes it very easy for the sand core to crack or even break during transportation.

Description

Technical Field

[0001] The invention relates to the field of but not limited to the technical field of sand core loading fixture structure design, in particular to a sand core fixture with automatic balancing holding force. Background Art

[0002] With the continuous development of casting technology, the use of 3D printed sand cores in alloy casting production has become more and more extensive. Compared with traditional sand cores, 3D printed sand cores can achieve the purpose of integrated molding of complex structures, improve the precision of casting products, improve the quality of castings, and speed up production efficiency. In addition, thanks to the advantages of flexible modification of model design, this process has a very prominent effect on reducing the sand-iron ratio, and is particularly suitable for the production of castings with complex internal structures.

[0003] However, when the 3D printed sand core structure is large and complex, the existing clamp structure cannot ensure that the sand core is evenly stressed during transportation, causing the sand core to easily crack or even break during transportation, greatly affecting the quality of the sand core, causing the sand core to eventually be scrapped and reducing the production efficiency of the sand core. Summary of the invention

[0004] Purpose of the present invention: An embodiment of the present invention provides a sand core clamp with automatic balancing holding force to solve the problem that it is difficult to achieve uniform force on the sand core during transportation, which causes the sand core to easily crack or even break during transportation, greatly affecting the quality of the sand core, thereby eventually causing the sand core to be scrapped and reducing the production efficiency of the sand core.

[0005] The technical solution of the present invention: The embodiment of the present invention provides a sand core clamp with automatic balanced holding force, comprising: a main frame 101, at least 8 hand-cranked sand core positioning devices 102 and at least 8 clamping claw devices 103;

[0006] The main frame 101 includes a U-shaped frame arranged at the top, a plurality of columns vertically fixedly arranged along the circumference of the U-shaped frame, the at least 8 hand-cranked sand core positioning devices 102 are evenly and symmetrically arranged along the circumference of the U-shaped frame and installed on the columns at corresponding positions, and the at least 8 clamping devices 103 are arranged along the circumference of the U-shaped frame and installed on the columns at corresponding positions;

[0007] Each of the hand-cranked sand core positioning devices 102 comprises: a positioning frame 1 penetrating the corresponding column, an elastic rubber pad 2 bonded to the inner side of the positioning frame 1 and arranged close to the sand core 104, and a hand-cranked threaded connecting rod 3, wherein the hand-cranked threaded connecting rod 3 is rotated through the corresponding column and then applies an inward force to the positioning frame 1 and the elastic rubber pad 2, so that the elastic rubber pad 2 abuts against the outer side of the sand core 104, thereby preventing the sand core 104 from being relatively displaced from the main frame 101 during transportation;

[0008] Each of the clamping jaw devices 103 includes: a height adjustment rod 5, a cone head suspension rod 6, a load-bearing plate 8 and a balanced load-bearing mechanism; wherein the load-bearing plate 8 is located on the inner side of the main frame 101 and is directly connected to the sand core 104. As a load-bearing component of the clamp, the load-bearing plate 8 is provided with a conical through keyway 7, and the cone head of the cone head suspension rod 6 passes through the keyway 7 from the bottom of the load-bearing plate 8, so that the load-bearing plate 8 and the cone head suspension rod 6 are connected in a movable manner. One end of the height adjustment rod 5 is screwed to the external thread at the top end of the cone head suspension rod 6 through an internal thread, and the other end passes through the U-shaped frame and is fixedly connected to the main frame 101; an installation platform is vertically arranged on the outer side of the column of the main frame 101, and the balanced load-bearing mechanism passes through the threaded hole of the installation platform from the upper end and then contacts the end face of the load-bearing plate 8 located outside the main frame 101, so as to provide a balanced load-bearing effect when the sand core connected to the load-bearing plate 8 shakes.

[0009] Optionally, in the sand core clamp with automatic balanced holding force as described above, in the structure of each of the hand-cranked sand core positioning devices 102,

[0010] The positioning frame 1 includes: a longitudinal frame arranged parallel to the columns in the main frame 101, and two transverse frames arranged perpendicularly on the outside of the longitudinal frame. The two transverse frames are fixed to the external threads at the ends of the transverse frames by nuts after passing through the through holes on the corresponding columns from the inside of the main frame 101, so that the positioning frame 1 can move horizontally corresponding to the corresponding columns through the transverse frames; the elastic rubber pad 2 is bonded to the inside of the longitudinal frame, located on the inside of the main frame 101, and parallel to the columns of the main frame 101;

[0011] The hand-cranked threaded connecting rod 3 passes vertically through the rocker arm limiting structure on the corresponding column from the outside of the main frame 101 and is located between the two transverse frames. By rotating the hand-cranked threaded connecting rod 3 inward, the top end of the hand-cranked threaded connecting rod 3 applies a vertical inward force to the longitudinal frame of the positioning frame 1, so as to push the positioning frame 1 and the elastic rubber pad 2 to move in the direction close to the sand core 104 until the elastic rubber pad 2 rests against the outside of the sand core 104.

[0012] Optionally, in the sand core clamp with automatic balancing holding force as described above, each of the hand-cranked sand core positioning devices 102 further comprises: a return spring 4 respectively sleeved on the outer side of a part of each transverse frame extending out of the column in the positioning frame 1;

[0013] One end of the reset spring 4 rests against the outer side wall of the corresponding column, and the other end is limited by a nut fixedly installed at the end of the upper transverse frame; when the hand-cranked threaded connecting rod 3 is rotated outward, the tension of the reset spring 4 causes the positioning frame 1 and the elastic rubber pad 2 to reset.

[0014] Optionally, in the sand core clamp with automatic balanced holding force as described above, the balanced load mechanism comprises: a pre-tightening screw 9 and a balanced load end cover assembly;

[0015] Among them, the pre-tightening screw 9 is screwed from the top through the threaded hole on the mounting platform, perpendicular to the end face of the mounting platform, and a screwing handle is provided at the top of the pre-tightening screw 9, and the bottom screw is screwed with the top threaded hole of the balanced load-bearing component, and the bottom end of the balanced load-bearing component is in contact with the end face of the load-bearing plate 8 located outside the main frame 101, so as to provide a balanced load-bearing effect when the sand core connected to the load-bearing plate 8 shakes.

[0016] Optionally, in the sand core clamp with automatic balanced holding force as described above, the balanced load end cover assembly includes: a balanced load end cover 10, a balanced load sleeve 11, a stopper 12, a ball head pre-tightening sleeve 13 and a balanced load spring 14;

[0017] Among them, the balancing load end cover 10 is arranged above the balancing load sleeve 11, and is connected to the bottom screw of the preload screw 9 through its top threaded hole. The ball head preload sleeve 13 is a top open sleeve structure with an annular flange on the top. It is arranged in the balancing load sleeve 11 through the annular flange, and the bottom end of the balancing load sleeve 11 is provided with a circumferentially inward-buckled limiter 12 for limiting the ball head preload sleeve 13. A balancing load spring 14 is sleeved in the cavity formed by the ball head preload sleeve 13 and the balancing load sleeve 11.

[0018] Optionally, in the sand core fixture with automatic balanced holding force as described above, in the installation structure of the balanced load-bearing end cover assembly,

[0019] The balancing load spring 14 is installed in the cavity formed by the bottom end of the balancing load end cover 10, the balancing load sleeve 11 and the ball head pre-tightening sleeve 13. The top end of the balancing load spring 14 is in contact with the balancing load end cover 10, and the bottom end is in contact with the bottom of the ball head pre-tightening sleeve 13. The ball head at the bottom end of the ball head pre-tightening sleeve 13 is in contact with the end surface of the bearing plate 8 located outside the main frame 101, providing pre-tightening force and balancing load for the bearing plate 8, so that the inner side of the bearing plate 8 directly connected to the sand core 104 provides a balanced lifting force for the sand core 104.

[0020] The balancing load sleeve 11 and the ball head pre-tightening sleeve 13 are used to swing up and down according to the expansion and contraction of the balancing load spring 14 .

[0021] Optionally, in the sand core fixture with automatic balancing holding force as described above,

[0022] The radius of the key slot 7 is larger than the radius of the cone head on the cone head hanger 6. The cone head on the cone head hanger 6 passes through the key slot 7 on the load-bearing plate 8, thereby forming a movable fulcrum in the middle of the load-bearing plate 8, so that the load-bearing plate 8 can tilt with the shaking of the sand core 104, thereby having a swing angle, and the swing angle is controlled by the spring 14 in the balanced load-bearing mechanism, so that the overall clamping jaw device 103 provides a balanced load-bearing effect on the sand core 104.

[0023] Optionally, in the sand core fixture with automatic balancing holding force as described above,

[0024] When installing the balanced load end cover assembly, the balanced load spring 14 has a certain preload force. Under the action of the center of gravity of the sand core 104, the outer sides of the multiple load-bearing plates 8 located on one side of the main frame 101 are pushed up, and the preload force provided by the balanced load springs 14 corresponding to the multiple load-bearing plates 8 on this side makes the bottom ball head of the ball head preload sleeve 13 still press the outer end surface of the load-bearing plate 8; in addition, the outer sides of the multiple load-bearing plates 8 located on the opposite side of the main frame 101 sink, so that the original preload force of the balanced load springs 14 corresponding to the multiple load-bearing plates 8 on this side is partially released, so that the ball head preload sleeve 13 still rests on the outer end surface of the load-bearing plate 8, so that the overall sand core clamp forms a balanced load effect.

[0025] Optionally, the sand core clamp with automatic balancing holding force as described above specifically includes:

[0026] 8 hand-cranked sand core positioning devices 102, 2 hand-cranked sand core positioning devices 102 are evenly arranged on each side of the main frame 101;

[0027] There are 16 clamping jaw devices 103 , with 4 clamping jaw devices 103 evenly distributed on each side of the main frame 101 .

[0028] The beneficial effects of the present invention are as follows: since the sand core 104 is a large and complex structure, its weight is relatively large, and its weight is not evenly distributed due to its complex structure, and the existing clamps are inevitably rigidly connected to the sand core 104, resulting in uneven force on various parts of the sand core 104 during the process of lifting the sand core 104 by the existing clamps, making the fragile sand core 104 more likely to crack or even break completely.

[0029] In view of the problems existing in the above-mentioned existing clamps for transporting sand cores, in order to make the sand core 104 be evenly stressed during the transport process, the embodiment of the present invention provides a sand core clamp with automatic balanced clamping force, ... The structure of the sand core clamp consists of a main frame 101, a hand-cranked sand core positioning device 102 and a clamping jaw device 103. Before transporting the sand core, the main frame 101 is firstly put on the sand core 104, and then the bearing plate 8 on the clamping jaw device 103 is inserted into the corresponding bearing hole of the sand core 104, and the threaded connecting rod on the clamping jaw device 103 is rotated so that the ball head pre-tightening sleeve 13 contacts the bearing plate 8 and has an appropriate downward pressure. In addition, it is necessary to ensure that the ball head pre-tightening sleeves on each clamping jaw device 103 exert the same downward pressure on the bearing plate as much as possible. Finally, the hand-cranked threaded connecting rod on the hand-cranked sand core positioning device 102 is rotated so that the elastic rubber pad 2 on the hand-cranked sand core positioning device 102 is slightly in contact with the wall of the sand core 104, so as to achieve the effect of stabilizing the sand core 104 during the transport process. During the process of transporting the easily cracked sand core 104, since there is a balanced load spring 14 in the clamping jaw device 103 and the load-bearing plate 8 can rotate within a small angle range, the sand core 104 presents a non-rigid connection with the overall sand core clamp during the transportation process, which greatly alleviates the uneven force phenomenon and improves the production efficiency of the sand core. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings are used to provide a further understanding of the technical solution of the present invention and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present invention and do not constitute a limitation on the technical solution of the present invention.

[0031] Figure 1 A top view of a sand core clamp with automatic balancing holding force provided by an embodiment of the present invention;

[0032] Figure 2 for Figure 1 A structural schematic diagram of a sand core clamp with automatic balancing holding force provided by the illustrated embodiment from one perspective;

[0033] Figure 3 for Figure 2 A schematic diagram of a partial structure of a hand-cranked sand core positioning device in a sand core clamp with automatic balanced holding force provided by the illustrated embodiment;

[0034] Figure 4 for Figure 1 A schematic structural diagram of a sand core clamp with automatic balancing holding force provided by the illustrated embodiment from another perspective;

[0035] Figure 5 for Figure 4 The illustrated embodiment is a schematic diagram of the partial structure of a clamping jaw device in a sand core clamp with automatic balanced clamping force.

[0036] Reference numerals:

[0037] 101-main frame, 102-hand-cranked sand core positioning device, 103-clamping device, 104-sand core, 1-positioning frame, 2-elastic rubber pad, 3-hand-cranked threaded connecting rod, 4-reset spring, 5-height adjustment rod, 6-cone head suspension rod, 7-keyway, 8-load-bearing plate, 9-preload screw, 10-balanced load end cover, 11-balanced load sleeve, 12-limiter, 13-ball head preload sleeve, 14-balanced load spring. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the present invention more clear, the embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other arbitrarily without conflict.

[0039] As described in the above background technology, when the current 3D printed sand core structure is large and complex, the existing clamp structure cannot achieve uniform force on the sand core during transportation, which will make the sand core very easy to crack or even break during transportation, greatly affecting the quality of the sand core, causing the sand core to be eventually scrapped and reducing the production efficiency of the sand core.

[0040] In order to solve the problem of balanced force during the transportation of sand cores, an embodiment of the present invention provides a sand core clamp with automatic balanced holding force, which can improve the stability of the sand cores during transportation, prevent the sand cores from being damaged due to uneven force, and ultimately improve the production efficiency of the sand cores.

[0041] The present invention provides the following specific embodiments which can be combined with each other. The same or similar concepts or processes may not be described in detail in some embodiments.

[0042] Figure 1 A top view of a sand core clamp with automatic balancing holding force provided by an embodiment of the present invention, Figure 2 for Figure 1 A structural schematic diagram of a sand core clamp with automatic balancing holding force provided by the illustrated embodiment from one perspective; Figure 3 for Figure 2 A schematic diagram of a partial structure of a hand-cranked sand core positioning device in a sand core clamp with automatic balanced holding force provided by the illustrated embodiment; Figure 4 for Figure 1 A schematic structural diagram of a sand core clamp with automatic balancing holding force provided by the illustrated embodiment from another perspective; Figure 5 for Figure 4 The illustrated embodiment is a schematic diagram of the partial structure of a clamping jaw device in a sand core clamp with automatic balanced clamping force.

[0043] like Figures 1 to 5The specific structure of the sand core clamp with automatic balanced holding force is shown. The main structure of the sand core clamp with automatic balanced holding force provided by the embodiment of the invention includes: a main frame 101, at least 8 hand-cranked sand core positioning devices 102 and at least 8 clamping claw devices 103.

[0044] In an embodiment of the present invention, the main frame 101 includes a U-shaped frame arranged at the top, and a plurality of columns vertically fixedly arranged along the circumference of the U-shaped frame. The at least 8 hand-cranked sand core positioning devices 102 are evenly and symmetrically arranged along the circumference of the U-shaped frame and installed on the columns at corresponding positions. The at least 8 clamping devices 103 are arranged along the circumference of the U-shaped frame and installed on the columns at corresponding positions; that is, at least 2 hand-cranked sand core positioning devices 102 and at least 2 clamping devices 103 are arranged on each side of the U-shaped structure main frame 101.

[0045] In a possible implementation of the embodiment of the present invention, specifically provided are: 8 hand-cranked sand core positioning devices 102 and 16 clamping devices 103, 2 hand-cranked sand core positioning devices 102 are evenly arranged on each side of the main frame 101; 4 clamping devices 103 are evenly arranged on each side of the main frame 101, such as Figure 1 Installation location shown.

[0046] like Figure 2 and Figure 3 As shown, the specific structure of the hand-cranked sand core positioning device 102 is schematically shown. Each of the hand-cranked sand core positioning devices 102 includes: a positioning frame 1 that passes through the corresponding column, an elastic rubber pad 2 that is bonded to the inner side of the positioning frame 1 and is arranged close to the sand core 104, and a hand-cranked threaded connecting rod 3. The hand-cranked threaded connecting rod 3 is rotated through the corresponding column and then applies an inward force to the positioning frame 1 and the elastic rubber pad 2, so that the elastic rubber pad 2 is against the outside of the sand core 104, thereby preventing the sand core 104 from being relatively displaced with the main frame 101 during transportation.

[0047] It can be seen that the function of the hand-cranked sand core positioning device 102 uniformly arranged around the main frame 101 in the embodiment of the present invention is to provide soft protection for the sand core 104. If the sand core 104 tends to be relatively displaced with the main frame 101 during transportation, the innermost elastic rubber pad 2 of the hand-cranked sand core positioning device 102 will be in contact with the sand core 104.

[0048] like Figure 4 and Figure 5As shown, the specific structure of the clamping device 103 is schematically shown. Each of the clamping devices 103 includes: a height adjustment rod 5, a cone head suspension rod 6, a bearing plate 8 and a balanced load-bearing mechanism; wherein the bearing plate 8 is located on the inner side of the main frame 101 and is directly connected to the sand core 104. As the load-bearing component of the clamp, the bearing plate 8 is provided with a conical through keyway 7. The cone head of the cone head suspension rod 6 passes through the keyway 7 from the bottom of the bearing plate 8, so that the bearing plate 8 and the cone head suspension rod 6 are connected in a movable manner. One end is screwed to the external thread at the top of the cone-head suspension rod 6 through an internal thread, and the other end passes through the U-shaped frame and is fixedly connected to the main frame 101, that is, the height adjustment rod 5 is parallel to the column of the main frame 101; an installation platform is vertically arranged on the outside of the column of the main frame 101, and the balanced load-bearing mechanism passes through the threaded hole of the installation platform from the upper end and contacts the end face of the load-bearing plate 8 located outside the main frame 101, so as to provide a balanced load-bearing effect when the sand core connected to the load-bearing plate 8 shakes.

[0049] It can be seen that the function of the clamping device 103 evenly arranged circumferentially on the main frame 101 in the embodiment of the present invention is: to provide bearing capacity to the sand core 104 through the load-bearing plate 8 directly connected to the sand core 104 in the clamping device 103, and to provide a balanced bearing effect in the circumferential direction through multiple balanced load-bearing mechanisms evenly arranged circumferentially, so that during the transportation process, the load situation can be adjusted in real time by multiple balanced load-bearing mechanisms, so that the sand core 104 and the main frame 101 can always maintain a balanced load-bearing state.

[0050] In one implementation of the embodiment of the present invention, Figure 2 and Figure 3 In the specific structure of the hand-cranked sand core positioning device 102 shown, the positioning frame 1 includes: a longitudinal frame arranged parallel to the column in the main frame 101, and two transverse frames arranged perpendicularly on the outside of the longitudinal frame, that is, the transverse frame of the positioning frame 1 is arranged perpendicularly to the column of the main frame 101, and the two transverse frames are passed through the through holes on the corresponding columns from the inside of the main frame 101, and are fixed to the external threads at the ends of the transverse frames by nuts, so that the positioning frame 1 can move horizontally corresponding to the corresponding columns through the transverse frames; the elastic rubber pad 2 is bonded to the inner side of the longitudinal frame, located on the inner side of the main frame 101, and parallel to the columns of the main frame 101;

[0051] The hand-cranked threaded connecting rod 3 vertically passes through the rocker arm limiting structure on the corresponding column from the outside of the main frame 101, and is located between the two transverse frames, and is vertically arranged with the column of the main frame 101. By rotating the hand-cranked threaded connecting rod 3 inward, the top end of the hand-cranked threaded connecting rod 3 applies a vertical inward force to the longitudinal frame of the positioning frame 1, so as to push the positioning frame 1 and the elastic rubber pad 2 to move in the direction close to the sand core 104 until the elastic rubber pad 2 rests against the outside of the sand core 104.

[0052] In this implementation, each of the hand-cranked sand core positioning devices 102 further includes: a reset spring 4 respectively sleeved on the outer side of the part of each transverse frame extending out of the column in the positioning frame 1; that is, the reset spring 4 is arranged vertically with the column of the main frame 101;

[0053] One end of the reset spring 4 rests against the outer wall of the corresponding column, and the other end is limited by a nut fixedly installed at the end of the upper transverse frame; when the hand-cranked threaded connecting rod 3 is rotated outward, the tension of the reset spring 4 causes the positioning frame 1 and the elastic rubber pad 2 to reset, that is, the positioning frame 1 and the elastic rubber pad 2 move outward and away from the sand core.

[0054] In another implementation of the embodiment of the present invention, Figure 4 and Figure 4 In the specific structure of the clamping device shown, the balanced load mechanism includes: a pre-tightening screw 9 and a balanced load end cover assembly;

[0055] Among them, the pre-tightening screw 9 is screwed from the top through the threaded hole on the mounting platform, perpendicular to the end face of the mounting platform, and a screwing handle is provided at the top of the pre-tightening screw 9, and the bottom screw is screwed with the top threaded hole of the balanced load-bearing component, and the bottom end of the balanced load-bearing component is in contact with the end face of the load-bearing plate 8 located outside the main frame 101, so as to provide a balanced load-bearing effect when the sand core connected to the load-bearing plate 8 shakes.

[0056] The balanced load end cover assembly in this implementation method specifically includes: a balanced load end cover 10, a balanced load sleeve 11, a stopper 12, a ball head pre-tightening sleeve 13 and a balanced load spring 14;

[0057] Among them, the balancing load end cover 10 is arranged above the balancing load sleeve 11, and is connected to the bottom screw of the preload screw 9 through its top threaded hole. The ball head preload sleeve 13 is a top open sleeve structure with an annular flange on the top. It is arranged in the balancing load sleeve 11 through the annular flange, and the bottom end of the balancing load sleeve 11 is provided with a circumferentially inward-buckled limiter 12 for limiting the ball head preload sleeve 13. A balancing load spring 14 is sleeved in the cavity formed by the ball head preload sleeve 13 and the balancing load sleeve 11.

[0058] In this implementation, in the installation structure of the balanced load end cover assembly, the balanced load spring 14 is installed in the cavity formed by the bottom end of the balanced load end cover 10, the balanced load sleeve 11 and the ball head preload sleeve 13. The top end of the balanced load spring 14 is in abutment contact with the balanced load end cover 10, and the lower end is in abutment contact with the bottom of the ball head preload sleeve 13; the bottom ball head of the ball head preload sleeve 13 is in abutment with the end face of the load-bearing plate 8 located outside the main frame 101, providing preload force and balanced load for the load-bearing plate 8, so that the inner side of the load-bearing plate 8 directly connected to the sand core 104 provides a balanced lifting force for the sand core 104.

[0059] Based on the specific structure of the balanced load end cover assembly in this implementation, the balanced load sleeve 11 and the ball head preload sleeve 13 are used to swing up and down according to the expansion and contraction of the balanced load spring 14.

[0060] It should be noted that, in the embodiment of the present invention, the radius of the key slot 7 is larger than the radius of the cone head on the cone head hanger 6, and the cone head on the cone head hanger 6 passes through the key slot 7 on the load-bearing plate 8. In this way, a movable fulcrum can be formed in the middle of the load-bearing plate 8, so that the load-bearing plate 8 can be tilted with the shaking of the sand core 104, thereby having a swing angle, and the swing angle is controlled by the spring 14 in the balanced load-bearing mechanism, so that the overall clamping device 103 provides a balanced load-bearing effect on the sand core 104.

[0061] In addition, when installing the balanced load end cover assembly in the embodiment of the present invention, it is necessary to make the balanced load spring 14 have a certain preload force. Under the action of the center of gravity of the sand core 104, the outer sides of the multiple load-bearing plates 8 located on one side of the main frame 101 are pushed up, and the preload force provided by the balanced load springs 14 corresponding to the multiple load-bearing plates 8 on this side makes the bottom ball head of the ball head preload sleeve 13 still press the outer end surface of the load-bearing plate 8; in addition, the outer sides of the multiple load-bearing plates 8 located on the opposite side of the main frame 101 sink, so that the original preload force of the balanced load springs 14 corresponding to the multiple load-bearing plates 8 on this side is partially released, so that the ball head preload sleeve 13 still rests on the outer end surface of the load-bearing plate 8, so that the overall sand core clamp forms a balanced load effect.

[0062] The working principle of the sand core clamp with automatic balanced holding force provided by the embodiment of the present invention is:

[0063] Before transporting the sand core, first put the main frame 101 on the sand core 104, and make each elastic rubber pad 2 in the multiple hand-cranked sand core positioning devices 102 arranged circumferentially slightly contact with the sand core 104, then insert the load-bearing plate 8 on the clamping jaw device 103 into the load-bearing hole at the corresponding position of the sand core 104, and rotate the pre-tightening screw 9 on the clamping jaw device 103 so that the ball head pre-tightening sleeve 13 contacts with the load-bearing plate 8 and has an appropriate downward pressure. In addition, it is necessary to ensure that the downward pressure of the ball head pre-tightening sleeve 13 on each clamping jaw device 103 on the load-bearing plate 8 is as similar as possible, finally, rotate the hand-cranked threaded connecting rod 3 on the hand-cranked sand core positioning device 102 so that the elastic rubber pad 2 on the hand-cranked sand core positioning device 102 slightly contacts with the wall of the sand core 104, so as to stabilize the sand core 104 during transportation.

[0064] During the process of transporting the easily cracked sand core 104, since there is a balanced load spring 14 in the clamping jaw device 103 and the load-bearing plate 8 can rotate within a small angle range, the sand core 104 presents a non-rigid connection with the clamp during the transportation process, which greatly alleviates the uneven force phenomenon and improves the production efficiency of the sand core.

[0065] When the main frame 101 is lifted, since the overall structure of the main frame 101, the hand-cranked sand core positioning device 102 and the clamping claw device 103 in the sand core clamp are elastically connected, if the center of gravity of the sand core 104 is not at the original center of gravity due to shaking, under the action of the center of gravity of the sand core 104, the outer sides of the multiple load-bearing plates 8 on one side of the main frame 101 are pushed up, and the pre-tightening force provided by the balancing load springs 14 corresponding to the multiple load-bearing plates 8 on this side makes the bottom ball head of the ball head pre-tightening sleeve 13 still press the outer end surface of the load-bearing plate 8; in addition, the outer sides of the multiple load-bearing plates 8 on the opposite side of the main frame 101 sink, so that the original pre-tightening force of the balancing load springs 14 corresponding to the multiple load-bearing plates 8 on this side is partially released, so that the ball head pre-tightening sleeve 13 still rests on the outer end surface of the load-bearing plate 8, so that the overall sand core clamp forms a balanced load effect.

[0066] It should be noted that the sand core 104 is a large and complex structure, and its weight is not evenly distributed due to its complex structure. The existing clamp is inevitably rigidly connected to the sand core 104, resulting in uneven force on various parts of the sand core 104 during the process of lifting the sand core 104 by the existing clamp, making the fragile sand core 104 more prone to cracks or even complete breakage.

[0067] In order to ensure that the sand core 104 is subjected to uniform force during transportation, an embodiment of the present invention provides a sand core clamp with automatic balancing holding force. The structure of the sand core clamp consists of a main frame 101, a hand-cranked sand core positioning device 102 and a clamping jaw device 103. Before transporting the sand core, firstly, the main frame 101 is put on the sand core 104, and then the load-bearing plate 8 on the clamping jaw device 103 is inserted into the load-bearing hole corresponding to the sand core 104, and the threaded connecting rod on the clamping jaw device 103 is rotated so that the ball head pre-tightening sleeve 13 contacts the load-bearing plate 8 and has an appropriate downward pressure. In addition, it is necessary to ensure that the downward pressure of the ball head pre-tightening sleeves on each clamping jaw device 103 on the load-bearing plate is as consistent as possible. Finally, the hand-cranked threaded connecting rod on the hand-cranked sand core positioning device 102 is rotated so that the elastic rubber pad 2 on the hand-cranked sand core positioning device 102 is slightly in contact with the wall of the sand core 104, so as to stabilize the sand core 104 during transportation. During the process of transporting the easily cracked sand core 104, since there is a balanced load spring 14 in the clamping jaw device 103 and the load-bearing plate 8 can rotate within a small angle range, the sand core 104 presents a non-rigid connection with the overall sand core clamp during the transportation process, which greatly alleviates the uneven force phenomenon and improves the production efficiency of the sand core.

[0068] The sand core clamp with automatic balanced holding force provided by the embodiment of the present invention comprises a main frame of a U-shaped structure, a hand-cranked sand core positioning device and a clamping claw device. The hand-cranked sand core positioning device consists of a positioning frame, an elastic rubber pad, a hand-cranked threaded connecting rod and a reset spring. The clamping claw device consists of a height adjustment rod, a bearing plate, a pre-tightening screw, a cone head suspension rod, a balanced load end cover, a balanced load sleeve, a limiter, a ball head pre-tightening sleeve and a balanced load spring. The positioning frame is designed to be vertical to the side of the main frame, and the positioning frame can move horizontally relative to the main frame. The elastic rubber pad is connected to the positioning frame and is located on the inner side of the main frame. The hand-cranked threaded connecting rod runs through the main frame and is designed to be vertical to the main frame. The reset spring is sleeved on the skeleton of the positioning frame, one end of which is connected to the side wall of the main frame, and the other end is connected to the positioning frame. One end of the height adjustment rod is threadedly connected to the cone head suspension rod, and the other end is fixedly connected to the main frame. A key groove is provided on the bearing plate, and a key groove is provided below the bearing plate. The keyway of the cone is conical, and its radius is slightly larger than the radius of the cone head on the cone head suspension rod. The cone head on the cone head connecting rod passes through the keyway on the bearing plate, so that the bearing plate and the cone head connecting rod are connected in a movable joint, forming a movable fulcrum in the middle of the bearing plate. The preload screw passes through the platform on the side wall of the main frame and is perpendicular to the platform. The upper end is connected to the platform by a thread, and the lower end is connected to the balance load end cover in a movable joint. The balance load end cover is connected to the balance load sleeve, and the balance load sleeve is connected to the ball head preload sleeve The balance load spring is placed in a cavity composed of a balance load end cover, a balance load sleeve and a ball head pre-tightening sleeve. The upper end of the balance load spring is connected to the balance load end cover, and the lower end is connected to the ball head pre-tightening sleeve. The balance load sleeve and the ball head pre-tightening sleeve can move according to the expansion and contraction of the load spring. The ball head at the lower end of the ball head pre-tightening sleeve is connected to the outer end of the load-bearing plate to provide pre-tightening force and balance load for the load-bearing plate. The inner end of the load-bearing plate is connected to the sand core to provide a balanced lifting force for the sand core. The sand core clamp provided by the embodiment of the present invention can automatically and evenly distribute the lifting force at multiple clamping points during the sand core transportation and core assembly process, thereby solving the problem of sand core fragmentation caused by uneven force during the process, and successfully completing the development of new machine castings.

[0069] Although the embodiments disclosed in the present invention are as above, the contents are only embodiments adopted to facilitate understanding of the present invention and are not intended to limit the present invention. Any technician in the field to which the present invention belongs can make any modifications and changes in the form and details of implementation without departing from the spirit and scope disclosed in the present invention, but the patent protection scope of the present invention shall still be subject to the scope defined in the attached claims.

Claims

1. A sand core clamp with automatic balancing holding force, characterized in that: include: A main frame (101), at least eight hand-cranked sand core positioning devices (102), and at least eight clamping claw devices (103); The main frame (101) comprises a U-shaped frame arranged at the top, a plurality of columns vertically fixedly arranged along the circumference of the U-shaped frame, the at least eight hand-cranked sand core positioning devices (102) are evenly and symmetrically arranged along the circumference of the U-shaped frame and installed on the columns at corresponding positions, and the at least eight clamping claw devices (103) are arranged along the circumference of the U-shaped frame and installed on the columns at corresponding positions; Each of the hand-cranked sand core positioning devices (102) comprises: a positioning frame (1) passing through a corresponding column, an elastic rubber pad (2) bonded to the inner side of the positioning frame (1) and arranged close to the sand core (104), and a hand-cranked threaded connecting rod (3), wherein the hand-cranked threaded connecting rod (3) is rotated through the corresponding column and then applies an inward force to the positioning frame (1) and the elastic rubber pad (2), so that the elastic rubber pad (2) abuts against the outer side of the sand core (104), thereby preventing the sand core (104) from being displaced relative to the main frame (101) during transportation; Each of the clamping jaw devices (103) comprises: a height adjustment rod (5), a cone-head suspension rod (6), a load-bearing plate (8) and a balanced load-bearing mechanism; wherein the portion of the load-bearing plate (8) located inside the main frame (101) is directly connected to the sand core (104) and serves as a load-bearing component of the clamp; the load-bearing plate (8) is provided with a conical through-key groove (7); the cone head of the cone-head suspension rod (6) passes through the key groove (7) from the bottom of the load-bearing plate (8), so that the load-bearing plate (8) and the cone-head suspension rod (6) are connected in a movable manner. One end of the height adjustment rod (5) is screwed to the external thread at the top end of the cone-head suspension rod (6) through an internal thread, and the other end passes through the U-shaped frame and is fixedly connected to the main frame (101); a mounting platform is vertically arranged on the outer side of the column of the main frame (101); the balancing load-bearing mechanism passes through the threaded hole of the mounting platform from the upper end and contacts the end surface of the bearing plate (8) located outside the main frame (101), so as to provide a balancing load-bearing effect when the sand core connected to the bearing plate (8) shakes; The balanced load-bearing mechanism comprises: a pre-tightening screw (9) and a balanced load-bearing end cover assembly; The pre-tightening screw (9) is screwed from the top through the threaded hole on the mounting platform and is perpendicular to the end surface of the mounting platform. A screwing handle is provided at the top of the pre-tightening screw (9). The bottom screw is screwed to the top threaded hole of the balanced load-bearing component. The bottom end of the balanced load-bearing component abuts against the end surface of the bearing plate (8) located outside the main frame (101) to provide a balanced load-bearing effect when the sand core connected to the bearing plate (8) shakes. The balanced load end cover assembly comprises: a balanced load end cover (10), a balanced load sleeve (11), a stopper (12), a ball head pre-tightening sleeve (13) and a balanced load spring (14); The balancing load end cover (10) is arranged above the balancing load sleeve (11) and is connected to the bottom screw of the pre-tightening screw (9) through its top threaded hole. The ball head pre-tightening sleeve (13) is a top open sleeve structure with an annular flange at the top. It is arranged in the balancing load sleeve (11) through the annular flange, and a circumferentially inwardly buckled limiter (12) is arranged at the bottom end of the balancing load sleeve (11) for limiting the ball head pre-tightening sleeve (13). A balancing load spring (14) is sleeved in the cavity formed by the ball head pre-tightening sleeve (13) and the balancing load sleeve (11).

2. The sand core clamp with automatic balanced holding force according to claim 1, characterized in that: In the structure of each of the hand-cranked sand core positioning devices (102), The positioning frame (1) comprises: a longitudinal frame arranged parallel to the columns in the main frame (101), and two transverse frames arranged perpendicularly on the outside of the longitudinal frame, wherein the two transverse frames are passed through the through holes on the corresponding columns from the inside of the main frame (101) and are fixed to the external threads at the ends of the transverse frames by nuts, so that the positioning frame (1) can move horizontally corresponding to the corresponding columns through the transverse frames; the elastic rubber pad (2) is bonded to the inside of the longitudinal frame, located on the inside of the main frame (101), and parallel to the columns of the main frame (101); The hand-cranked threaded connecting rod (3) vertically passes through the rocker arm limiting structure on the corresponding column from the outside of the main frame (101) and is located between the two transverse frames. By rotating the hand-cranked threaded connecting rod (3) inward, the top end of the hand-cranked threaded connecting rod (3) applies a vertical inward force to the longitudinal frame of the positioning frame (1), so as to push the positioning frame (1) and the elastic rubber pad (2) to move in a direction close to the sand core (104) until the elastic rubber pad (2) abuts against the outside of the sand core (104).

3. The sand core clamp with automatic balancing holding force according to claim 2, characterized in that: Each of the hand-cranked sand core positioning devices (102) further comprises: a return spring (4) respectively sleeved on the outside of a portion of each transverse frame extending out of the column in the positioning frame (1); One end of the return spring (4) abuts against the outer side wall of the corresponding column, and the other end is limited by a nut fixedly mounted on the end of the upper transverse frame; when the hand-cranked threaded connecting rod (3) is rotated outward, the tension of the return spring (4) causes the positioning frame (1) and the elastic rubber pad (2) to return to their original position.

4. The sand core clamp with automatic balanced holding force according to claim 3, characterized in that: In the installation structure of the balanced load-bearing end cover assembly, The balancing load spring (14) is installed in a cavity formed by the bottom end of the balancing load end cover (10), the balancing load sleeve (11) and the ball head pre-tightening sleeve (13); the top end of the balancing load spring (14) is in abutment contact with the balancing load end cover (10), and the bottom end is in abutment contact with the bottom of the ball head pre-tightening sleeve (13); the ball head at the bottom end of the ball head pre-tightening sleeve (13) is in abutment with the end surface of the bearing plate (8) located outside the main frame (101), providing a pre-tightening force and a balancing load for the bearing plate (8), so that the inner side of the bearing plate (8) directly connected to the sand core (104) provides a balanced lifting force for the sand core (104); The balancing load sleeve (11) and the ball head pre-tightening sleeve (13) are used to perform up and down swinging motion according to the expansion and contraction of the balancing load spring (14).

5. The sand core clamp with automatic balanced holding force according to claim 4, characterized in that: The radius of the keyway (7) is greater than the radius of the cone head on the cone head suspension rod (6), and the cone head on the cone head suspension rod (6) penetrates the keyway (7) on the load-bearing plate (8), thereby forming a movable fulcrum in the middle of the load-bearing plate (8), so that the load-bearing plate (8) can tilt with the shaking of the sand core (104), thereby having a swing angle, and the swing angle is controlled by the balance load spring (14) in the balance load mechanism, so that the overall clamping jaw device (103) provides a balance load effect on the sand core (104).

6. The sand core clamp with automatic balanced holding force according to claim 5, characterized in that: When the balanced load end cover assembly is installed, the balanced load spring (14) has a certain preload force. Under the action of the center of gravity of the sand core (104), the outer sides of the multiple load-bearing plates (8) located on one side of the main frame (101) are pushed up, and the preload force provided by the balanced load spring (14) corresponding to the multiple load-bearing plates (8) on this side makes the bottom ball head of the ball head preload sleeve (13) still press the outer end surface of the load-bearing plate (8); in addition, the outer sides of the multiple load-bearing plates (8) located on the opposite side of the main frame (101) sink, so that the original preload force of the balanced load spring (14) corresponding to the multiple load-bearing plates (8) on this side is partially released, so that the ball head preload sleeve (13) still abuts against the outer end surface of the load-bearing plate (8), so that the overall sand core clamp forms a balanced load effect.

7. The sand core clamp with automatic balancing holding force according to any one of claims 1 to 6, characterized in that: Specifically include: 8 hand-cranked sand core positioning devices (102), with 2 hand-cranked sand core positioning devices (102) evenly arranged on each side of the main frame (101); 16 clamping claw devices (103), with 4 clamping claw devices (103) evenly distributed on each side of the main frame (101).

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