Front clamping type hydraulic jack tool anchor allowing clamping piece to be continuously separated from anchor disc

Abstract

The invention discloses a front clamping type hydraulic jack tool anchor allowing a clamping piece and an anchor disc to be continuously separated, and relates to the field of pre-stress tensioning of precast beams. Comprising a tool anchor disc, an elastic tool clamping piece and an axial linkage assembly, an anchor hole of the tool anchor disc is of a three-section structural design comprising a guide section, a conical surface section and a matching section, and the tool clamping piece achieves axial displacement through magnetic linkage of a second electromagnet, a telescopic sleeve and a telescopic rod. In the tensioning stage, the tool clamping piece is in contact with the conical surface section under the elastic force of the spring to form one-way locking; and during return stroke, the steel strand pushes the telescopic assembly to be linked, so that the tool clamping piece is separated from the conical surface section to release locking, and the steel strand can be freely withdrawn. Manual participation is not needed in the whole working process, intelligent automatic control is achieved, the working process is stable and reliable, the problem that a tool clamping piece and an anchor hole cannot be separated is solved, smooth separation is achieved without additionally arranging a specific device, therefore, the reserved length of the steel strand can be shortened as much as possible, and cost is reduced.

Description

Technical Field

[0001] The present invention relates to the field of precast beam prestress tensioning, and specifically to a front-loading hydraulic jack tool anchor that allows the wedge grip to continuously separate from the anchor plate. Background Art

[0002] The jack used for traditional prestressed beam tensioning is a rear-loading jack. When it works, the steel strand, working anchor, and wedge grip will be encapsulated in the prestressed component after tensioning. Before encapsulation, the steel strand exceeding the wedge grip will leave 5 - 10 mm outside the wedge grip, and the rest will be cut off. The cut-off steel strand is treated as scrap steel. Since the steel strand is expensive, assuming a medium-sized highway beam yard that needs to perform 30,000 times of steel strand tensioning per year, for each 100 mm of length saved at the single-side end of the steel strand, 6,000 meters of steel strand can be saved, and the actual length of the steel strand saved at the end far exceeds 100 mm.

[0003] Based on this, the improved front-loading jack tool anchor, such as the one described in the patent with the publication number CN221590467U, describes an internal-loading hydraulic jack tool anchor. Although it achieves the effect of saving steel strand, its design has great limitations. It can only loosen the wedge grip in a short period before the jack returns, and cannot ensure that the wedge grip separates from the tool anchor plate within a specific period during the jack's return.

[0004] In the overall design of the hydraulic jack and the tool anchor, the patent with the publication number CN109269884B describes a front-loading jack and tool anchor device for prestress tensioning. Using the relative displacement generated by the hydraulic jack during its return, a "return push rod" is adopted to separate the wedge grip from the tool anchor plate, still unable to ensure that the wedge grip separates from the tool anchor plate within a specific period during the jack's return. The above problems will cause wear on the internal thread of the wedge grip, and in severe cases, the steel strand will not be able to separate from the wedge grip. In addition, the above patent adds a specific device between the tool anchor plate and the limit plate to assist in separating the wedge grip from the tool anchor plate, and this process will occupy the length of the steel strand, which is not conducive to the ultimate goal of the front-loading jack to save steel strand. In the field of prestressed beam tensioning equipment, especially the tool anchor, it has been developing towards automation in recent years, and higher design requirements for the ability to save steel strand have been put forward. General front-loading hydraulic jack tool anchors are difficult to meet these requirements. Therefore, we provide a front-loading hydraulic jack tool anchor that allows the wedge grip to continuously separate from the anchor plate. Summary of the Invention

[0005] The purpose of the present invention is to provide a front-loading hydraulic jack tool anchor that allows the wedge grip to continuously separate from the anchor plate.

[0006] The technical problem solved by the present invention is that in the prior art, it is difficult to reduce the reserved length of the end of the steel strand and ensure that the tool wedge and the tool anchor plate continuously maintain contact fit or separation state under corresponding working conditions without increasing the working length of the tool anchor.

[0007] The present invention can be realized by the following technical solutions: A front-loading hydraulic jack tool anchor that allows the wedge and the anchor plate to continuously separate, including a tool anchor plate and tool wedges arranged in its anchor holes. The tool anchor plate is provided with at least two anchor holes penetrating through it, and the tool wedges are slidably installed in the anchor holes.

[0008] On one side of the tool anchor plate, a baffle and a guide cylinder are coaxially fixed in sequence, and through holes communicating with the anchor holes are provided on both the baffle and the guide cylinder to form a communication cavity, and an axial linkage assembly is installed in the communication cavity.

[0009] The axial linkage assembly includes a positioning boss formed on the side of the baffle close to the tool wedge. A sliding hole is coaxially provided in the middle of the positioning boss. A spring with both ends abutting against the baffle and the tool wedge respectively is sleeved outside the positioning boss. An electromagnet two is slidably arranged in the sliding hole; A telescopic sleeve and a telescopic rod are slidably nested in sequence in the guide cylinder. One side of the electromagnet two always remains in contact with the tool wedge, and the other end of the electromagnet two is in contact with the telescopic sleeve or the baffle.

[0010] One end of the telescopic rod close to the tool wedge is fixed with an electromagnet one for maintaining connection with the end of the steel strand. The telescopic rod slides relative to the telescopic sleeve within a certain range, and slides synchronously with the telescopic sleeve beyond this range.

[0011] A further technical improvement of the present invention is that the anchor holes of the tool anchor plate are provided with a guiding section, a conical section, and a mating section, and the sizes of the three sections increase in sequence. When one side of the tool wedge contacts the conical section, the size of the central through hole of the tool wedge is smaller than the size of the central through hole of the tool wedge in its natural state.

[0012] A further technical improvement of the present invention is that during the tensioning preparation and tensioning execution processes, the tool wedge remains in contact with the conical section under the action of the spring force, and the end of the electromagnet two away from the tool wedge is in contact connection with the telescopic sleeve; During the return stroke of the hydraulic jack, the end of the electromagnet two away from the tool wedge is in contact connection with the stop block.

[0013] A further technical improvement of the present invention is that an inner limit protrusion is provided in the middle of the inner side wall of the telescopic sleeve, and an outer limit protrusion is provided at the end of the telescopic rod away from the electromagnet one. When the outer limit protrusion is between the left end hole wall of the telescopic sleeve and the inner limit protrusion, the telescopic rod moves independently relative to the telescopic sleeve. When the outer limit protrusion contacts the left end hole wall of the telescopic sleeve or the inner limit protrusion, the telescopic sleeve moves synchronously with the telescopic rod.

[0014] A further technical improvement of the present invention lies in that: the inner hole size of the telescopic sleeve is the same as the inner diameter of the central through hole of the second electromagnet and the inner diameter of the steel strand through hole of the tool clamping piece in the natural state.

[0015] A further technical improvement of the present invention lies in that: the magnetic force generated between the second electromagnet and the baffle, the tool clamping piece or the telescopic sleeve is greater than the elastic force of the spring.

[0016] A further technical improvement of the present invention lies in that: the magnetic force between the first electromagnet and the steel strand is greater than the magnetic force between the second electromagnet and the baffle.

[0017] A further technical improvement of the present invention lies in that: the second electromagnet and the first electromagnet are always in the energized state.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The present invention utilizes the relative movement relationship between the end of the steel strand and the tool anchor plate, and drives the second electromagnet to move through the axial linkage assembly, so as to automatically switch the contact state and non-contact state between the tool clamping piece and the conical surface section of the anchor hole, so that the tool clamping piece maintains the contact and cooperation state with the conical surface section when the steel strand moves relatively to the left, and maintains the non-contact state with the conical surface section when moving relatively to the right; and finally, after the hydraulic jack moves left as a whole, the end of the steel strand exits the anchor hole, and drives the axial linkage assembly under the drive of the first electromagnet to make the tool clamping piece return to the contact state with the conical surface section of the anchor hole. The whole process does not require manual participation, realizes intelligent automatic control, the working process is stable and reliable, there will be no problem that the tool clamping piece cannot be separated from the anchor hole, and there is no additional specific device to achieve smooth separation, so that the reserved length of the steel strand can be shortened as much as possible, and the cost is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] For the convenience of those skilled in the art to understand, the present invention will be further described below with reference to the accompanying drawings.

[0021] Figure 1 It is a schematic cross-sectional view of the overall structural state in the tensioning preparation and execution stages of the present invention;

[0022] Figure 2 It is a schematic cross-sectional view of the state of the first node position of the telescopic rod in the return stroke stage of the hydraulic jack of the present invention;

[0023] Figure 3 It is a schematic cross-sectional view of the state of the second node position of the telescopic rod in the return stroke stage of the pressing jack of the present invention.

[0024] In the figure: 1. Guide cylinder; 2. Telescopic sleeve; 3. Telescopic rod; 4. Electromagnet I; 5. Baffle; 6. Electromagnet II; 7. Cylindrical spring; 8. Tool clamping piece; 9. Tool anchor plate; 201. Inner limit projection; 301. Outer limit projection; 501. Positioning boss; 502. Sliding hole; 901. Guide section; 902. Conical surface section; 903. Fitting section. Detailed implementation manner

[0025] To further elaborate on the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation manner, structure, features and their effects of the present invention as follows.

[0026] Please refer to Figures 1 - 3 As shown, a front - type hydraulic jack tool anchor that allows the clamping piece and the anchor plate to be continuously separated includes a tool anchor plate 9 and tool clamping pieces 8. At least two anchor holes are evenly and penetratingly formed in the working anchor plate 9. Each anchor hole is sequentially provided with a guide section 901, a conical surface section 902, and a fitting section 903 from left to right. The left - hand side dimension of the anchor hole is larger than the right - hand side dimension of the anchor hole.

[0027] Among them, the tool clamping piece 8 is slidably installed in the fitting section 903 of the anchor hole of the tool anchor plate 9. The tool clamping piece 8 is composed of two or three elastic clamping pieces. When the tool clamping piece 8 contacts the conical surface section 902 of the anchor hole, the steel strand through - hole of the tool clamping piece 8 shrinks, forming a one - way extrusion fixation (only going in and not coming out) for the steel strand. When the tool clamping piece 9 disengages from the conical surface end 902 of the anchor hole, the steel strand through - hole of the tool clamping piece 8 resumes the size in the natural state, and the steel strand can smoothly exit through it.

[0028] A baffle 5 and a guide cylinder 1 are sequentially coaxially arranged on the tool anchor plate 9 away from the guide section 901, and the guide cylinder 1 and the baffle 5 are fixed to one side of the tool anchor plate 9 using bolts.

[0029] On the side of the baffle 5 close to the tool anchor plate 9, there is a positioning boss 501 coaxial with the fitting section of the anchor hole. A sliding hole 502 is coaxially formed on one side of the positioning boss 501. A stepped surface for positioning is provided at the bottom of the sliding hole 502. An electromagnet II 6 is slidably arranged in the sliding hole 502. The central through - hole of the electromagnet II 6 has the same inner diameter as the steel strand through - hole of the tool clamping piece 8 in the natural state. Thus, the moving range of the electromagnet II 6 is between the stepped surface of the sliding hole 502 and the left - hand side surface of the tool clamping piece 8. A cylindrical spring 7 is sleeved outside the positioning boss 501, and the two ends of the cylindrical spring 7 are respectively abutted against the baffle 5 and the tool clamping piece 8.

[0030] A telescopic sleeve 2 is slidably arranged in a guide cylinder 1, a telescopic rod 3 is slidably arranged in the telescopic sleeve 2, an electromagnet 4 is fixedly installed at one end of the telescopic rod 3 close to a tool clamping piece 8, an outer limit projection 301 is arranged at the other end of the telescopic rod 3, and an inner limit projection 201 is arranged in the middle of the inner side wall of the telescopic sleeve 2. The sliding range of the outer limit projection 301 of the telescopic rod 3 is between the left end face of the inner hole of the telescopic sleeve 2 and the left side face of the inner limit projection 201. The inner hole diameter of the telescopic sleeve 2 is the same as the inner diameter of the central through hole of the electromagnet 6, and the right limit position of the telescopic sleeve 2 is the left side face of the electromagnet 6.

[0031] When the present invention is in use, it is divided into a tensioning preparation stage, an execution stage and a hydraulic jack return stage:

[0032] In the tensioning preparation stage, as Figure 1 shown, the cylindrical spring 7 is always in a compressed state, the spring force makes the right end of the tool clamping piece 8 contact with the conical surface section 902, the electromagnet 6 is energized, so that magnetic force is generated with the right end of the telescopic sleeve 2 and the left end of the tool clamping piece 8 and they are adsorbed and connected. At this time, the outer limit projection 301 of the telescopic rod 3 contacts the inner limit projection 201 of the telescopic sleeve 2, and the position of the electromagnet 4 is close to the guiding section 901 of the tool anchor plate 9;

[0033] The steel strand is inserted from the right side of the tool anchor plate 9, passes through the guiding section 901 and enters the central through hole of the tool clamping piece 8 and its end contacts the electromagnet 4. At this time, there is no need to consider the energized state of the electromagnet 4. As the steel strand moves leftward relative to the tool anchor plate 9, its end pushes the telescopic rod 3 to move leftward as well. When the end of the steel strand exceeds the left end of the tool clamping piece 8 by 10 - 20 mm and the left end of the telescopic rod 3 does not reach the left side wall of the inner hole of the telescopic sleeve 2, the telescopic sleeve 2, the electromagnet 6 and the tool clamping piece 8 are not subjected to the axial external force from the telescopic rod 3. Therefore, the right end of the tool clamping piece 8 still contacts the conical surface section 902, so that before the tensioning starts, the tool clamping piece 8 continuously contacts the conical surface section 902 of the tool anchor plate 9;

[0034] In the tensioning execution stage, the relative position between the end of the cylinder strand and the tool anchor plate 9 remains unchanged, and this state lasts until the tensioning process is completed.

[0035] In the hydraulic jack return stage, as Figure 2As shown, the steel strand continues to move leftward relative to the position of the tool anchor plate 9 until the left end of the telescopic rod 3 contacts the left side wall of the inner hole of the telescopic sleeve 2. At this time, the telescopic sleeve 2, the second electromagnet 6, and the tool clamping piece 8 start to receive an axial thrust from the telescopic rod 3. Since the three are connected by the magnetic force of the second electromagnet 6, they have a tendency to move leftward synchronously under the action of the axial thrust. With the continuous action of the axial thrust, the tool clamping piece 8 overcomes the elastic force of the cylindrical spring 7 and compresses it until the left side of the second electromagnet 6 contacts the bottom step surface of the sliding hole 502. At this time, the magnetic forces generated between the second electromagnet 6 and the baffle 5, the tool clamping piece 8, and the telescopic sleeve 2 are all greater than the elastic force of the cylindrical spring 7 to ensure the overall movement of the telescopic sleeve 2, the second electromagnet 6, and the tool clamping piece 8 and the contact state between the second electromagnet 6 and the baffle 5. The tool clamping piece 8 releases the contact state with the tapered surface section 902 and completely enters the mating section 903. Then, the size of the central through hole of the tool clamping piece 8 becomes larger, releasing the extrusion and fixation of the steel strand, and the steel strand can be withdrawn from the tool clamping piece 8.

[0036] The continued leftward movement of the steel strand drives the telescopic rod 3, thereby pushing the telescopic sleeve 2 to overcome the magnetic force of the second electromagnet 6 and release the connection relationship between the two to achieve separation until the return stroke of the hydraulic jack ends. At this time, the telescopic sleeve reaches the leftmost distal position relative to the guide cylinder 1, and the guide cylinder 1 can still stably guide the telescopic sleeve 2.

[0037] Subsequently, the entire hydraulic jack moves leftward and separates from the steel strand. Then the steel strand moves rightward relative to the tool anchor plate 9 until it completely exits the anchor hole of the tool anchor plate 9. During the relative rightward movement of the steel strand, the first electromagnet 4 needs to remain energized to facilitate the movement of the telescopic rod 3 driven by the rightward movement of the steel strand, so that the outer limit protrusion 301 of the telescopic rod 3 first contacts the inner limit protrusion of the telescopic sleeve 2, and then drives the telescopic sleeve 2 to move rightward together until the right end face of the telescopic sleeve 2 contacts the left side of the second electromagnet 6 and continues to move to squeeze the second electromagnet 6 to overcome the magnetic force between it and the baffle 5, thereby pushing the second electromagnet 6 and the tool clamping piece 8 to move rightward until the right tapered surface of the tool clamping piece 8 contacts the tapered surface section 902 of the anchor hole of the tool anchor plate 9, and the entire structure returns to the state as Figure 1 shown.

[0038] It should be noted that although the first electromagnet 4 needs to be energized to generate magnetic force only during the return stroke of the hydraulic jack, in order to avoid complex state switching and reduce the complexity of the system, the first electromagnet 4 can be kept energized all the time. In addition, the magnetic force between the first electromagnet 4 and the steel strand is greater than the magnetic force between the second electromagnet 6 and the baffle 5.

[0039] The above are only the preferred embodiments of the present invention and do not impose any formal limitations on the present invention. Although the present invention has been disclosed above in preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to equivalent embodiments by using the above-disclosed technical content without departing from the technical solution of the present invention. However, as long as it does not depart from the technical solution content of the present invention, any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A front - clamping hydraulic jack tool anchor that allows the wedge grip to continuously separate from the anchor plate, comprising a tool anchor plate (9) and tool wedge grips (8) arranged in its anchor holes, characterized in that, The tool anchor plate (9) is provided with at least two anchor holes penetrating therethrough, and the tool wedge (8) is slidably installed in the anchor holes; One side of the tool anchor plate (9) is fixedly provided with a baffle plate (5) and a guide cylinder (1) coaxially in sequence, and through holes communicating with the anchor holes are provided on both the baffle plate (5) and the guide cylinder (1) to form a communication cavity, and an axial linkage assembly is installed in the communication cavity; The axial linkage assembly includes a positioning boss (501) formed on one side of the baffle plate (5) close to the tool wedge (8). A sliding hole (502) is coaxially provided in the middle of the positioning boss (501). A spring with both ends abutting against the baffle plate (5) and the tool wedge (8) respectively is sleeved outside the positioning boss (501). An electromagnet two (6) is slidably arranged in the sliding hole (502); A telescopic sleeve (2) and a telescopic rod (3) are slidably nested in sequence in the guide cylinder (1). One side of the electromagnet two (6) is always in contact with the tool wedge (8), and the other end of the electromagnet two (6) is in contact with the telescopic sleeve (2) or the baffle plate (5); One end of the telescopic rod (3) close to the tool wedge (8) is fixedly provided with an electromagnet one (4) for maintaining connection with the end of the steel strand. The telescopic rod (3) slides relative to the telescopic sleeve (2) within a certain range, and slides synchronously with the telescopic sleeve (2) beyond this range.

2. The front - clamping hydraulic jack tool anchor according to claim 1, which allows the wedge grip to be continuously separated from the anchor plate, is characterized in that The anchor holes of the tool anchor plate (9) are provided with a guiding section (901), a conical section (902) and a matching section (903), and the sizes of the three sections increase in sequence. When one side of the tool wedge (8) contacts the conical section (903), the size of the central through hole of the tool wedge (8) is smaller than the size of the central through hole of the tool wedge (8) in its natural state.

3. The front-mounted hydraulic jack tool anchor according to claim 2, which allows the wedge grip to be continuously separated from the anchor plate, is characterized in that, During the tensioning preparation and tensioning execution processes, the tool wedge (8) is in contact with the conical section (902) under the action of the spring force, and the end of the electromagnet two (6) far from the tool wedge (8) is in contact connection with the telescopic sleeve (2); During the return stroke of the hydraulic jack, the end of the electromagnet two (6) far from the tool wedge (8) is in contact connection with the baffle (5).

4. The front-loading hydraulic jack tool anchor according to claim 1, which allows the wedge grip to be continuously separated from the anchor plate, is characterized in that, An inner limit protrusion (201) is provided in the middle of the inner side wall of the telescopic sleeve (2), and an outer limit protrusion (301) is provided at one end of the telescopic rod (3) far from the electromagnet one (4). When the outer limit protrusion (301) is between the left end hole wall of the telescopic sleeve (2) and the inner limit protrusion (201), the telescopic rod (3) moves independently relative to the telescopic sleeve (2). When the outer limit protrusion (301) contacts the left end hole wall of the telescopic sleeve (2) or the inner limit protrusion (201), the telescopic sleeve (2) moves synchronously with the telescopic rod (3).

5. A front - mounted hydraulic jack tool anchor that allows the wedge jaws to continuously separate from the anchor plate, characterized in that, The inner hole size of the telescopic sleeve (2) is the same as the inner diameter of the central through hole of the electromagnet two (6) and the inner diameter of the steel strand through hole of the tool wedge (6) in its natural state.

6. A front - type hydraulic jack tool anchor that allows the wedge grip and the anchor plate to be continuously separated according to claim 1, wherein, The magnetic force generated between the electromagnet two (6) and the baffle plate (5), the tool wedge (8) or the telescopic sleeve (2) is greater than the elastic force of the spring.

7. A front - mounted hydraulic jack tool anchor that allows the wedge grip to be continuously separated from the anchor plate according to claim 1, characterized in that, The magnetic force between the electromagnet one (4) and the steel strand is greater than the magnetic force between the electromagnet two (6) and the baffle plate (5).

8. A front-loading hydraulic jack tool anchor that allows the wedge grip and the anchor plate to be continuously separated, as described in claim 1, characterized in that The electromagnet two (6) and the electromagnet one (4) are always in the energized state.

Images