Pre-tightening tool, pre-tightening assembly and pre-tightening method for main frame of heavy hydraulic press

Abstract

The present application relates to heavy hydraulic machine technical field, the present application provides a kind of heavy hydraulic machine main frame's pre-tightening tool, pre-tightening assembly, heavy hydraulic machine main frame and the pre-tightening method of heavy hydraulic machine main frame, wherein pre-tightening tool is used to separately apply set pre-tightening force to each rope, rope is used to single loop around the outside of main frame, pre-tightening tool includes: two clamping tables, one clamping table is used to connect the first end of rope, another clamping table is used to connect the tail end of rope;Two two-link assemblies, each two-link assembly is located between two clamping tables, and the two ends of each two-link assembly are connected to the corresponding clamping table;Driving member, including fixed end and driving end, fixed end is arranged in one clamping table, and driving end is connected with two-link assembly, to drive another clamping table to move to tighten the rope.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of heavy hydraulic machine, in particular to a pre-tightening tool, a pre-tightening assembly and a pre-tightening method for a heavy hydraulic machine frame. BACKGROUND

[0002] The pre-tightening of the heavy hydraulic machine frame has always been a problem. The conventional main pre-tightening approach includes mechanical pre-tightening, and flat steel band winding pre-tightening is one approach of mechanical pre-tightening. However, the entire pre-tightening supporting equipment is high in cost. In addition, the flat steel band winding pre-tightening usually needs to bind hundreds of layers on the main frame, the pre-tightening tension of each layer of flat steel band is different, the construction period is long, and the stress release of each layer of flat steel band during the binding process is difficult to be uniform.

[0003] Therefore, a technical solution is needed to achieve better pre-tightening effect of the heavy hydraulic machine frame. SUMMARY

[0004] The present application provides a new technical solution of a pre-tightening tool, a pre-tightening assembly and a pre-tightening method for a heavy hydraulic machine frame. By improving the pre-tightening assembly, better pre-tightening effect of the heavy hydraulic machine frame can be achieved.

[0005] In one aspect, the present application provides a tool for a heavy hydraulic machine frame, the pre-tightening tool is used to separately apply a set pre-tightening force to each rope, the rope is used to wind around the outside of the main frame in a single turn, and the pre-tightening tool comprises:

[0006] Two clamping tables, one of which is used to connect the first end of the rope, and the other is used to connect the tail end of the rope;

[0007] Two two-link assemblies, each of which is located between two clamping tables, and the two ends of each two-link assembly are connected to the corresponding clamping table;

[0008] A driving member comprising a fixed end and a driving end, the fixed end is arranged on one of the clamping tables, and the driving end is connected to the two-link assembly to drive the other clamping table to move to tighten the rope.

[0009] By adopting the technical scheme in the application, the main frame is pre-tightened by winding a plurality of single turns of the ropes outside the main frame, and the pre-tightening force of each rope applied to the main frame is the same by pre-tightening each rope individually, thereby avoiding the problem that in the pre-tightening scheme of the conventional heavy hydraulic machine main frame, the pre-tightening force of each layer of flat steel bands applied to the main frame is different due to the bundling of hundreds of layers of flat steel bands on the main frame. Meanwhile, since each rope is wound in a single turn outside the main frame, the stress of each rope is uniformly released, thereby avoiding the problem that in the conventional pre-tightening scheme, the stress of each layer of flat steel bands is not uniformly released, and thus a better pre-tightening effect can be achieved by the technical scheme of the application.

[0010] Optionally, each of the two-link assemblies comprises a first link and a second link hingedly connected to each other, and the driving end applies a driving force to a middle position of the total length of the first link and the second link.

[0011] The driving end is pushed outwards to drive the two two-link assemblies to bend towards each other to drive the two clamping tables to move towards each other.

[0012] Optionally, two third links are further included, and the two third links correspond to the two two-link assemblies one by one, and the driving end is drivingly connected to the middle positions of the two-link assemblies through the third links.

[0013] The third links are in an arc shape, and the third links protrude towards the pushing-out side of the driving end.

[0014] In a second aspect, the application further provides a pre-tightening assembly of a heavy hydraulic machine main frame, comprising the above-mentioned pre-tightening tool and at least one of the ropes.

[0015] A connecting piece is further included to connect the first end and the tail end of the tightened rope to form a closed ring structure.

[0016] Optionally, the first end and the tail end of the rope are provided with a rigging.

[0017] Each of the clamping tables is provided with a clamping groove portion, a part of the rope can be clamped into the clamping groove portion from the slot of the clamping groove portion, and the rigging is located outside the clamping groove portion and forms a stop cooperation with the end face of the clamping groove portion.

[0018] Optionally, the rigging comprises a first section and a second section, the first section is used to be clamped with the clamping groove portion, and the second section is used to be pinned with the connecting piece.

[0019] Optionally, each of the second segments comprises two opposite clamping plates, each of which is provided with a through hole, and the two clamping plates are clamped on both sides of the connecting piece in the thickness direction of the connecting piece and are pinned with the corresponding positions of the connecting piece.

[0020] In a third aspect, the application further provides a heavy hydraulic machine main frame, which is used to be matched with the pre-tightening assembly of the heavy hydraulic machine main frame as described above, and the outer circumferential surface of the main frame is configured with a guide assembly, each of which is used to be matched with one of the ropes;

[0021] Each of the guide assemblies comprises two opposite guide segments, each of which is provided with a guide groove in which the rope can move, and the connecting piece is arranged between the two guide segments.

[0022] The height of the guide groove gradually increases from the side far away from the connecting piece to the side close to the connecting piece.

[0023] In a fourth aspect, the application further provides a pre-tightening method of a heavy hydraulic machine main frame, which comprises the following steps:

[0024] Rope winding, a plurality of ropes are arranged around the circumference of the main frame;

[0025] Connecting piece connection, one end of the rope is connected with the connecting piece;

[0026] Pre-tightening, the pre-tightening tool tightens both ends of each of the ropes;

[0027] Connecting piece connection, the other end of the rope is connected with the connecting piece, and the rope and the connecting piece jointly form a closed ring structure.

[0028] Optionally, the pre-tightening step comprises: two clamping tables are respectively clamped with the head end and the tail end of the rope.

[0029] Controlling the driving end to push out the two-link assembly to drive the two-link assembly to move in the direction away from each other, so as to drive the two clamping tables to move in the direction close to each other to tighten the rope.

[0030] Other features of the present application and its advantages will become apparent from the following detailed description of exemplary embodiments thereof, taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0031] The accompanying drawings incorporated in and forming a part of the specification, illustrate embodiments of the present application and, together with the description, serve to explain the principles of the present application.

[0032] Figure 1 is a schematic diagram of the tensioned state of the heavy hydraulic machine main frame in the embodiment of the present application.

[0033] Figure 2 is a state diagram of the pre-tightening of the main frame of the heavy hydraulic press in the embodiment of the application, a first view;

[0034] Figure 3 is a structural diagram of the pre-tightening tool in the initial state in the embodiment of the application;

[0035] Figure 4 is a structural side view of the pre-tightening tool in the pre-tightening state in the embodiment of the application;

[0036] Figure 5 is a structural top view of the pre-tightening tool in the pre-tightening state in the embodiment of the application;

[0037] Figure 6 is a state diagram of the pre-tightening of the main frame of the heavy hydraulic press in the embodiment of the application, a second view;

[0038] Figure 7 is a flow chart of the pre-tightening method of the main frame of the heavy hydraulic press in the embodiment of the application.

[0039] Explanation of reference signs:

[0040] 1, main frame; 11, guide section;

[0041] 2, rope;

[0042] 3, pre-tightening tool;

[0043] 4, connecting piece;

[0044] 5, clamping table; 51, clamping groove; 51a, notch; 51b, side opening;

[0045] 6, two-link assembly; 61, first link; 62, second link; 63, third link;

[0046] 7, driving piece; 71, fixed end; 72, driving end;

[0047] 8, rigging; 81, first section; 82, second section; 82a, clamping plate. DETAILED DESCRIPTION

[0048] In order to make the person skilled in the art better understand the application scheme, the application will be further described in detail below in combination with the drawings and specific embodiments.

[0049] In some embodiments of the present application, as Figure 1As shown, a pre-tightening assembly of a heavy hydraulic machine main frame 1 is provided, which comprises at least one rope 2, a pre-tightening tool 3 and a connecting piece 4. A plurality of ropes 2 are arranged in sequence along the thickness direction of the main frame 1, and each rope 2 is single-wound on the outer side of the main frame 1. The thickness direction of the main frame 1 refers to the direction perpendicular to the paper in the middle. Figure 6

[0050] Before pre-tightening, the leading end and the trailing end of each rope 2 are separated. After pre-tightening each rope 2 separately by the pre-tightening tool 3, the connecting piece 4 connects the leading end and the trailing end of the tightened rope 2 to form a closed loop structure.

[0051] Specifically, as shown in the drawings, the pre-tightening tool 3 comprises two clamping tables 5, two two-link assemblies 6 and a driving piece 7, one clamping table 5 is connected with the leading end of the rope 2, and the other clamping table 5 is connected with the trailing end of the rope 2. Figures 2-5

[0052] Each two-link assembly 6 is located between the two clamping tables 5. That is, the two clamping tables 5 are oppositely arranged in a first direction, and the two two-link assemblies 6 are oppositely arranged in a second direction, and the first direction is perpendicular to the second direction. Each two-link assembly 6 comprises a first link 61 and a second link 62 which are hingedly connected, and one end of the first link 61 away from the second link 62 is hingedly connected to one clamping table 5, and one end of the second link 62 away from the first link 61 is hingedly connected to the other clamping table 5.

[0053] The driving piece 7 comprises a fixed end 71 and a driving end 72, the fixed end 71 is arranged on one clamping table 5, and the driving end 72 can drive the other clamping table 5 to move to tighten the rope 2. At the same time, when the clamping table 5 moves, the two-link assembly 6 can be deformed, and vice versa, when the two-link assembly 6 is deformed, the clamping table 5 can move relative to each other. The driving end 72 is connected with the two-link assembly 6, or connected with the other clamping table 5.

[0054] Thus, the pre-tightening of the main frame 1 can be achieved by the rope 2 single-wound on the outer side of the main frame 1, and the pre-tightening of each rope 2 is performed separately, so that the pre-tightening force of each tightened rope 2 applied to the main frame 1 is the same, thereby avoiding the problem that in the conventional pre-tightening scheme of the heavy hydraulic machine main frame 1, the pre-tightening force of each layer of flat steel belt applied to the main frame 1 is not the same due to the bundling of hundreds of layers of flat steel belts on the main frame 1. At the same time, since each rope 2 is single-wound on the outer side of the main frame 1, the stress of each rope 2 is uniformly released, thereby avoiding the problem that in the conventional pre-tightening scheme, the stress of each layer of flat steel belt is not uniformly released, so that better pre-tightening effect can be achieved by the technical scheme of the present application.

[0055] ​​In addition, by using the pre-tightening tool 3 in the present application, the amplification effect of driving force can be formed by using the two-link assembly 6, thereby saving energy. Meanwhile, the pre-tightening tool 3 in the present application has simple structure and low processing cost.

[0056] The following describes the connection mode of the driving end 72 and the two-link assembly 6. Referring to Figures 3-5 , the driving end 72 applies driving force to the middle position of the total length of the first link 61 and the second link 62. By being in transmission connection with the middle position of the total length of the first link 61 and the second link 62, the driving force of the driving end 72 can be effectively amplified.

[0057] Of course, the driving end 72 can also not be connected to the middle position of the first link 61 and the second link 62, but be connected to the side of the first link 61 away from the second link 62 or the side of the second link 62 away from the first link 61.

[0058] Both of the above two connection modes will reduce the stroke of the driving end 72, but when the pre-tightening tool 3 applies the same pre-tightening force to each rope 2, the driving end 72 needs more tonnage in the mode of being connected to the side of any one of the first link 61 and the second link 62 away from the other, thereby causing the size of the pre-tightening tool 3 to become larger.

[0059] It can be understood that the middle position in the present embodiment is approximately the middle position of the total length of the first link 61 and the second link 62. Those skilled in the art can adjust it according to the actual avoidance requirements of the pre-tightening tool 3 and the like.

[0060] Alternatively, in the present embodiment, the lengths of the first link 61 and the second link 62 can be the same or different, and here the lengths of the first link 61 and the second link 62 are not limited.

[0061] In one example, as shown in Figure 3 , the driving member 7 is a hydraulic cylinder, the cylinder body of the hydraulic cylinder is fixed on a clamping table 5, and the push rod of the hydraulic cylinder is in transmission connection with the second link 62 as the aforementioned driving end 72. Figure 3 , the initial state of the pre-tightening tool 3 is shown, in which the push rod is in the retracted position, and the distance between the two clamping tables 5 is the first distance. The first distance is the maximum distance between the two clamping tables 5 of the pre-tightening tool 3.

[0062] Referring to Figure 4In the process of pre-tightening each rope 2 by the pre-tightening tool 3, the driving end 72 pushes out the two-link assemblies 6 to drive the two-link assemblies 6 to bend towards the direction away from each other, so as to drive the two clamping tables 5 to move towards each other to the second distance. The second distance is smaller than the first distance, and the difference between the first distance and the second distance meets the pre-tightening requirement of the rope 2.

[0063] Thus, the pre-tightening tool 3 can pull the two ends of the rope 2 towards each other to apply a set pre-tightening force on the rope 2 to tighten the rope 2.

[0064] Of course, the push rod can also drive the two-link assemblies 6 to bend towards each other to pull the two clamping tables 5 closer to tighten the rope 2 by pulling back. However, the push rod pushing out to pull the two clamping tables 5 closer can avoid increasing the distance between the two-link assemblies 6 in the second direction, thereby avoiding increasing the overall size of the pre-tightening tool 3.

[0065] In the present application, pushing out and pulling back refer to the movement of the push rod relative to the cylinder. Pushing out refers to the process that the two clamping tables 5 move closer to each other, and the length of the push rod extending out of the cylinder increases, and the end of the push rod drivingly connected with the two-link assembly 6 moves away from the cylinder. Conversely, pulling back refers to the process that the length of the push rod extending out of the cylinder decreases, and the end of the push rod drivingly connected with the two-link assembly 6 moves closer to the cylinder.

[0066] In the above embodiment, as shown in Figure 5 The pre-tightening tool 3 further comprises a third link 63. The driving end 72 is drivingly connected with the middle position of the two-link assembly 6 through the third link 63. For example, the pre-tightening tool 3 comprises two third links 63, and the two third links 63 correspond to the two two-link assemblies 6 one by one. One end of each third link 63 is rotatably connected with the driving end 72, and the other end is rotatably connected with the middle position of the corresponding two-link assembly through a pin shaft.

[0067] Optionally, the third link 63 is arc-shaped, and the third link 63 protrudes towards the pushing-out side of the driving end 72.

[0068] In addition, by protruding the third link 63 towards the pushing-out side of the driving end 72, the distance between the two-link assemblies 6 in the second direction can also be reduced. By making the third link 63 arc-shaped, stress concentration of the third link 63 can be effectively avoided, thereby improving the strength of the third link 63, improving the compactness of the structure of the pre-tightening tool 3, and reasonably avoiding other components of the pre-tightening tool 3.

[0069] The connection between the clamping table 5 and the two ends of the rope 2 will be described below.

[0070] In some embodiments of the present application, as shown in Figure 6 Each clamping platform 5 is provided with a clamping groove 51. The clamping groove 51 is located on the side of the clamping platform 5 facing the mainframe 1. The rope 2 is partially arranged in the clamping groove 51, and the fitting 8 extends to the outside of the clamping groove 51 and forms a stop cooperation with the end face of the clamping groove 51.

[0071] Specifically, in combination with Figure 5 and Figure 6 The clamping groove 51 has a slot 51a for entering the rope 2, and the side wall of the clamping groove 51 is provided with two opposite side opening portions 51b, which are arranged in the axial direction of the rope 2. The size of the fitting 8 is larger than the size of the side opening portion 51b. The two fittings 8 are located on the inside of the two clamping grooves 51 and respectively form a stop cooperation with the end face of the side opening portion 51b of the corresponding clamping groove 51.

[0072] In the present embodiment, as shown in Figure 6 The fitting 8 includes a first segment 81 and a second segment 82, the first segment 81 is used to stop cooperation with the clamping groove 51, and the second segment 82 is used to pin with the connecting piece 4.

[0073] For example, in the process of pre-tightening, the second segment 82 of the fitting 8 at the head end is first pin-connected with the first position of the connecting piece 4, and then the rope 2 is pulled tight by the pre-tightening tool 3 to make the second segment 82 of the fitting 8 at the tail end opposite to the second position of the connecting piece 4 and form pin connection.

[0074] The first position is the pre-set position of the connecting piece 4, and the second position is the position of the fitting 8 at the tail end opposite to the connecting piece 4 after the rope 2 is pulled tight. After the connecting piece is drilled at the second position, the fitting 8 at the tail end is pin-connected with the connecting piece 4 at the second position.

[0075] Specifically, as shown in Figure 1 The second segment 82 includes two opposite clamping plates 82a, and each clamping plate 82a is provided with a through hole. The two clamping plates 82a are clamped on both sides of the connecting piece 4 along the thickness direction of the connecting piece 4 and pin-connected with the corresponding positions of the connecting piece 4.

[0076] In some embodiments of the present application, the present application also provides a mainframe 1 of a heavy hydraulic machine matched with the pre-tightening assembly. As shown in Figure 2 and Figure 6As shown, the outer circumferential surface of the mainframe 1 is configured with a guide assembly, each guide assembly is adapted to a rope. Each guide assembly comprises two opposite guide segments 11, the two guide segments 11 are arranged close to the connecting piece 4, and the connecting piece 4 is arranged between the two guide segments 11. The position where each guide segment 11 contacts the rope 2 is provided with a guide groove, the rope 2 is embedded in the guide groove, and the rope 2 can slide along the guide groove. The height of the guide groove arranged on each guide segment 11 gradually increases from the side away from the connecting piece 4 to the side close to the connecting piece 4.

[0077] In this way, the minimum bending diameter of the rope 2 can be matched by the guide segment 11, and the situation of rope 2 breaking caused by excessive bending of the rope 2 can be avoided.

[0078] In addition, by arranging the guide segment 11 on the outer side of the mainframe 1, the structure and shape of the mainframe 1 can avoid limiting the rope 2, thereby improving the application scenarios of the pre-tightening assembly in the present application.

[0079] At the same time, by gradually changing the height of the guide groove of each guide segment 11, the height of the side of the guide groove close to the connecting piece 4 is higher, so that the height of the rope 2, the rigging 8 and the connecting piece 4 can be matched with each other, and the rope 2, the rigging 8 and the connecting piece 4 can still extend in a straight line after pre-tightening, thereby avoiding the situation that the rope 2 is easily damaged due to bending of the rope 2.

[0080] Optionally, the guide groove forms a stop to the side wall of the rope 2, thereby avoiding the situation that the rope 2 is dislocated in the thickness direction of the mainframe 1.

[0081] In some embodiments of the present application, a pre-tightening method of a heavy hydraulic machine mainframe 1 is also provided, as shown in the figure, the pre-tightening method comprises: Figure 7 As shown, the pre-tightening method comprises:

[0082] Step 1: winding a rope, at least one rope 2 is arranged around the circumference of the mainframe 1;

[0083] Step 2: connecting the connecting piece 4 with one end of the rope 2;

[0084] Step 3: pre-tightening, the pre-tightening tool 3 tightens the rope 2;

[0085] Step 4: connecting the connecting piece 4 with the other end of the rope 2, and the rope 2 and the connecting piece 4 together form a closed ring structure.

[0086] In step 3, it further comprises:

[0087] Step 31: one clamping table 5 is clamped with the head end of the rope 2, and the other clamping table 5 is clamped with the tail end of the rope 2;

[0088] Step 32: the control drive end 72 is pushed outwards to drive the two two-link assemblies 6 to move towards each other, thereby driving the two clamping tables 5 to move towards each other to tighten the rope 2.

[0089] When the main frame 1 is wound with a plurality of ropes 2, the pre-tightening of each rope 2 is the same. Therefore, the pre-tightening of one of the ropes 2 by the pre-tightening tool 3 is taken as an example for description.

[0090] In step 1, one of the ropes 2 is embedded in the guide groove and wound along the outer side of the main frame 1, and the rigging 8 arranged at the head end and tail end of the rope 2 is left between the higher sides of the guide grooves of the two guide sections 11.

[0091] In step 2, the connecting piece 4 is embedded between the two clamping plates 82a of the rigging 8 at the head end, and the connecting piece 4 is pinned with the rigging 8 at the head end.

[0092] In step 3, the pre-tightening tool 3 is lifted by the crane, and the first section 81 of the rigging 8 at the head end and tail end is clamped with the corresponding clamping groove 51 of the pre-tightening tool 3. The drive end 72 is pushed outwards to drive the two two-link assemblies 6, thereby narrowing the distance between the two clamping tables 5 to tighten the rope 2.

[0093] After pre-tightening, the position of the through hole on the two clamping plates 82a of the rigging 8 at the tail end corresponding to the connecting piece 4 is the second position. The connecting piece 4 is drilled at the second position, and then the two clamping plates 82a of the rigging 8 at the tail end are pinned with the connecting piece 4 at the second position.

[0094] Finally, the pre-tightening tool 3 is lifted away from the rope 2, and the pre-tightening of one of the ropes 2 is completed. The above pre-tightening method is repeated to complete the pre-tightening of the main frame 1.

[0095] By using the pre-tightening method in the present application, the pre-tightening cost of the pre-tightening tool 3 is significantly reduced, the pre-tightening period of the heavy hydraulic machine main frame 1 is shortened, and the pre-tightening effect of the main frame 1 is significantly improved.

[0096] The principles and implementation modes of the present application are described by using specific examples in this paper, and the above examples are only used to help understand the method and core idea of the present application. It should be pointed out that for ordinary skilled persons in the technical field, some improvements and modifications can be made without departing from the principles of the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. A pre-tensioning assembly of a main frame of a heavy hydraulic press, characterized in that, The utility model relates to a heavy hydraulic machine main frame pre-tightening assembly, which comprises at least one rope, a pre-tightening tool for tensioning each rope, and a connector for connecting the head and tail of each tensioned rope to form a closed loop structure. The pre-tightening tool is used to apply a set pre-tightening force to each rope individually, and the rope is wound around the outside of the main frame in a single loop. The pre-tightening tool comprises two clamping tables, one for connecting the head of the rope and the other for connecting the tail of the rope. Each two-link assembly is connected to the corresponding clamping table at both ends. The driving member comprises a fixed end and a driving end, the fixed end is arranged on one clamping table, and the driving end is connected to the two-link assembly to drive the other clamping table to move and tighten the rope. The head and tail of the rope are provided with a rigging. Each clamping table of the pre-tightening tool is provided with a clamping groove, and the local part of the rope can be clamped into the clamping groove. The rigging is located outside the clamping groove and forms a stop cooperation with the end face of the clamping groove. Each two-link assembly comprises a first link and a second link that are hinged to each other. The driving end is pushed outwards to drive the two two-link assemblies to bend towards each other to drive the two clamping tables to move towards each other. The driving end is connected to the middle position of the two-link assembly through the third link.

2. The pre-tension assembly of the main frame of a heavy hydraulic press according to claim 1, characterized in that, The third link is arc-shaped and protrudes towards the push-out side of the driving end. The rigging comprises a first segment and a second segment, the first segment is stop cooperated with the clamping groove, and the second segment is used to be pinned with the connector.

3. The pre-tension assembly of the main frame of a heavy hydraulic press according to claim 2, characterized in that, Each second segment comprises two opposite clamping plates, each clamping plate is provided with a through hole, and the two clamping plates are clamped on both sides of the connector along the thickness direction of the connector and are pinned with the corresponding position of the connector. The utility model relates to a heavy hydraulic machine main frame pre-tightening assembly, which comprises at least one rope, a pre-tightening tool for tensioning each rope, and a connector for connecting the head and tail of each tensioned rope to form a closed loop structure.

4. The pre-tension assembly of the main frame of a heavy hydraulic press according to claim 1, characterized in that, The pre-tightening tool is used to apply a set pre-tightening force to each rope individually, and the rope is wound around the outside of the main frame in a single loop.

5. The pre-tension assembly of the main frame of a heavy hydraulic press according to claim 4, characterized in that, The pre-tightening tool comprises two clamping tables, one for connecting the head of the rope and the other for connecting the tail of the rope.

6. A heavy hydraulic press main frame, characterized by, Each two-link assembly is connected to the corresponding clamping table at both ends. The driving member comprises a fixed end and a driving end, the fixed end is arranged on one clamping table, and the driving end is connected to the two-link assembly to drive the other clamping table to move and tighten the rope. The head and tail of the rope are provided with a rigging.

7. A method of pre-tensioning a main frame of a heavy hydraulic press, characterized by, Each clamping table of the pre-tightening tool is provided with a clamping groove, and the local part of the rope can be clamped into the clamping groove. The rigging is located outside the clamping groove and forms a stop cooperation with the end face of the clamping groove. Each two-link assembly comprises a first link and a second link that are hinged to each other. The driving end is pushed outwards to drive the two two-link assemblies to bend towards each other to drive the two clamping tables to move towards each other. The driving end is connected to the middle position of the two-link assembly through the third link. The third link is arc-shaped and protrudes towards the push-out side of the driving end. The rigging comprises a first segment and a second segment, the first segment is stop cooperated with the clamping groove, and the second segment is used to be pinned with the connector. Each second segment comprises two opposite clamping plates, each clamping plate is provided with a through hole, and the two clamping plates are clamped on both sides of the connector along the thickness direction of the connector and are pinned with the corresponding position of the connector. The utility model relates to a heavy hydraulic machine main frame pre-tightening assembly, which comprises at least one rope, a pre-tightening tool for tensioning each rope, and a connector for connecting the head and tail of each tensioned rope to form a closed loop structure. The pre-tightening tool is used to apply a set pre-tightening force to each rope individually, and the rope is wound around the outside of the main frame in a single loop. The pre-tightening tool comprises two clamping tables, one for connecting the head of the rope and the other for connecting the tail of the rope. Each two-link assembly is connected to the corresponding clamping table at both ends. The driving member comprises a fixed end and a driving end, the fixed end is arranged on one clamping table, and the driving end is connected to the two-link assembly to drive the other clamping table to move and tighten the rope. The head and tail of the rope are provided with a rigging. Each clamping table of the pre-tightening tool is provided with a clamping groove, and the local part of the rope can be clamped into the clamping groove. The rigging is located outside the clamping groove and forms a stop cooperation with the end face of the clamping groove. Each two-link assembly comprises a first link and a second link that are hinged to each other. The driving end is pushed outwards to drive the two two-link assemblies to bend towards each other to drive the two clamping tables to move towards each other. The driving end is connected to the middle position of the two-link assembly through the third link. The third link is arc-shaped and protrudes towards the push-out side of the driving end. The rigging comprises a first segment and a second segment, the first segment is stop cooperated with the clamping groove, and the second segment is used to be pinned with the connector. Each second segment comprises two opposite clamping plates, each clamping plate is provided with a through hole, and the two clamping plates are clamped on both sides of the connector along the thickness direction of the connector and are pinned with the corresponding position of the connector. Pre-tensioning, a pre-tensioning tool pulls each of the ropes tight; The connecting member is connected with the other one of the head end or the tail end of the rope, and the rope and the connecting member jointly enclose a closed loop structure.

8. The method of pre-tensioning a heavy hydraulic press main frame according to claim 7, wherein, The step of pre-tensioning comprises: One of the clamping tables is clamped with the head end of each of the ropes, and the other clamping table is clamped with the tail end of the rope; The driving end is controlled to push outwards to drive the two two-link assemblies to move towards the direction of moving away from each other, thereby driving the two clamping tables to move towards the direction of moving close to each other to pull the ropes tight.

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