Expansion type lifting device

Abstract

The utility model provides an expansion type lifting device which comprises a sleeve, an expansion head connected to one end of the sleeve, an inner rod arranged in the sleeve and an adjusting assembly used for adjusting the stroke of the inner rod. The inner rod can slide relative to the sleeve to enable the expansion head to expand. When the expansion type lifting device is used for extracting an extracted object such as a packing and a valve seat, the extracted object can be conveniently and quickly taken out from the valve, and the disassembly efficiency of the valve is improved. Meanwhile, the stroke of the inner rod can be adjusted through the adjusting assembly, so that the lifting device is suitable for extracting the extracted objects at various depths and positions.

Description

Technical Field

[0001] The utility model belongs to the technical field of nuclear power, and more specifically relates to an expansion type pulling device. Background Art

[0002] Valves are important components of nuclear power plants. Each unit has tens of thousands of valves. During each overhaul, hundreds of valves need to be disassembled. When disassembling valves, it is necessary to remove the old packing and replace it with a new one. However, the packing of some valves is very difficult to remove. For example, the packing is not installed on the valve cover but on the valve body, the horizontal position of the valve body is poor, the packing has multiple layers, there is a lantern ring in the middle, and the packing is pure graphite packing, which is hard and fragile and very difficult to remove. Moreover, the valve dosage is very high, and it takes about 20 minutes to remove the packing each time, which is time-consuming.

[0003] In addition to the packing being difficult to remove during disassembly, the valve seats of some valves are also difficult to remove due to limited space and lack of traction points. The packing cavity is small and deep, and the valve seat cannot be removed directly by hand. After long-term operation, some valve seats are adsorbed to the valve seat gasket, and a large force is required to pull out the valve seat. Utility Model Content

[0004] The purpose of the embodiment of the utility model is to provide an expansion type pulling device to solve the technical problem that packing, valve seat and the like are difficult to remove in the prior art.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the utility model is: to provide an expansion type lifting device, including a sleeve, an expansion head connected to one end of the sleeve, an inner rod arranged inside the sleeve, and an adjustment component for adjusting the stroke of the inner rod, the expansion head is used to press and pull the object to be pulled outward, and the inner rod can slide relative to the sleeve to expand the expansion head.

[0006] In the above scheme, the expansion type pulling device includes a sleeve, an expansion head, an inner rod and an adjustment component. The inner rod can slide inside the sleeve and expand the expansion head. The adjustment component can adjust the sliding stroke of the inner rod. When it is necessary to remove the pulled objects such as packing and valve seats, the expansion head is extended to the pulled objects, the inner rod is moved to expand the expansion head and press against the pulled objects, and then the sleeve is pulled outward. The pulled objects can be pulled out through the limiting effect of the expansion head on the pulled objects. When the expansion type pulling device is used to extract the extracted objects such as packing and valve seats, the extracted objects can be conveniently and quickly removed from the valve, thereby improving the efficiency of valve disassembly. At the same time, the stroke of the inner rod can also be adjusted by the adjustment component, so that the pulling device is suitable for extracting the extracted objects at various depths and positions.

[0007] Optionally, the adjustment assembly includes a threaded member threadedly connected to the inner rod, and the axial movement of the inner rod is limited by the cooperation between the head of the threaded member and one end of the sleeve to form an axial limit for the inner rod.

[0008] In the above scheme, by setting the threaded member, the relative position between the threaded member and the inner rod can be adjusted, and then the distance between the head of the threaded member and the end of the sleeve can be changed to adjust the stroke of the inner rod.

[0009] Optionally, the adjustment assembly further comprises an elastic member, the inner wall of the sleeve is provided with a limiting protrusion, one end of the elastic member is connected to the limiting protrusion, and the other end is connected to the head of the threaded member.

[0010] In the above solution, by providing the elastic member, the inner rod can be automatically returned to its original position without manually pulling the inner rod to return to its original position.

[0011] Optionally, a first handle is fixedly provided on the head of the threaded member for easy handholding.

[0012] In the above scheme, by providing the first handle, the space occupied by the head of the threaded member is increased, and the operator can more easily rotate, press, and perform other operations on the threaded member, thereby saving the operator effort when using the lifting device.

[0013] Optionally, the outer peripheral wall of the sleeve is provided with a second handle for convenient handholding.

[0014] In the above scheme, the outer periphery of the sleeve is convexly arranged by setting the second handle, which makes it easier for the operator to pull the sleeve axially outward, making it more labor-saving for the operator to use the pulling device.

[0015] Optionally, the sleeve is detachably connected to the expansion head.

[0016] In the above scheme, by setting the expansion head to be detachably connected to the sleeve, different expansion heads can be selected for replacement according to the object to be pulled, and the axial length of the expansion pulling device during transportation can be reduced, thereby reducing transportation costs.

[0017] Optionally, one of the sleeve and the expansion head is provided with an external thread, and the other is provided with an internal thread, so that the sleeve and the expansion head are threadedly connected.

[0018] In the above solution, the sleeve and the expansion head are threadedly connected, the structure is simple and reliable, and no additional disassembly tools are required for disassembly and assembly, so disassembly and assembly are convenient.

[0019] Optionally, the expansion head includes a connecting tube and an expansion part, one end of the connecting tube is connected to the sleeve, and the other end of the connecting tube is connected to the expansion part, and the expansion part extends radially outward to form a claw part, and the claw part is used to press and fit with the object to be pulled.

[0020] In the above scheme, by setting the expansion head as a connecting tube and an expansion part, the connecting tube provides a connection space for the expansion head and the sleeve, and the axial length of the pulling device can be lengthened to a certain extent, so that the pulling device is suitable for objects to be pulled at a deeper position.

[0021] Optionally, the expansion portion includes a plurality of expansion units that are circumferentially spaced apart, and the inner rod is used to extend into the center of the expansion portion to cause each of the expansion units to deform radially outward.

[0022] In the above solution, by providing the expansion part with a plurality of circumferentially arranged expansion units, the expansion part can hook the extractable object at each circumferential position, so that the force applied to the extractable object is more uniform.

[0023] Optionally, the inner rod has a conical shape at one end close to the expansion head.

[0024] In the above scheme, by setting one end of the expansion head to be conical, firstly, the inner rod can be automatically guided so that the conical section of the inner rod gradually enters the expansion head; secondly, the expansion head can be gradually expanded by the conical section, and the expansion head is not easy to crack. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 A cross-sectional view of the expansion-type lifting device provided by an embodiment of the utility model when not expanded;

[0027] Figure 2 A cross-sectional view of the expansion-type lifting device provided in an embodiment of the utility model when expanded;

[0028] Figure 3 A cross-sectional view of a first expansion head provided in an embodiment of the utility model;

[0029] Figure 4 A cross-sectional view of a second expansion head provided by an embodiment of the utility model;

[0030] Figure 5A side view of an expansion head provided in an embodiment of the utility model.

[0031] Among them, the reference numerals in the figure are:

[0032] 10-sleeve; 20-expansion head; 21-connecting tube; 22-expansion part; 221-expansion unit; 222-claw part; 30-inner rod; 31-second handle; 32-limiting protrusion; 40-adjusting assembly; 41-threaded member; 42-elastic member; 43-first handle. DETAILED DESCRIPTION

[0033] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0034] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0035] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0036] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0037] Valves are important components of nuclear power plants. Each unit has tens of thousands of valves. During each overhaul, hundreds of valves need to be disassembled. When disassembling valves, it is necessary to remove the old packing and replace it with a new one. However, the packing of some valves is very difficult to remove. For example, the packing is not installed on the valve cover but on the valve body, the horizontal position of the valve body is poor, the packing has multiple layers, there is a lantern ring in the middle, and the packing is pure graphite packing, which is hard and fragile and very difficult to remove. Moreover, the valve dosage is very high, and it takes about 20 minutes to remove the packing each time, which is time-consuming.

[0038] In addition to the packing being difficult to remove during disassembly, the valve seats of some valves are also difficult to remove due to limited space and lack of traction points. The packing cavity is small and deep, and the valve seat cannot be removed directly by hand. After long-term operation, some valve seats are adsorbed to the valve seat gasket, and a large force is required to pull out the valve seat.

[0039] In order to solve the above technical problems, the utility model proposes an expansion type pulling device, including a sleeve 10, an expansion head 20, an inner rod 30 and an adjusting assembly 40. After adjusting the stroke of the inner rod 30 by the adjusting assembly 40, the expansion type pulling device is extended into the inner cavity of the object to be pulled, and the inner rod 30 slides relative to the sleeve 10 to expand the expansion head 20. After the expansion head 20 is expanded, it presses against the object to be pulled, and then the pulling device is pulled out as a whole. In this way, the object to be pulled can be extracted, and the packing, valve seat, bushing, etc. can be removed quickly and conveniently even in a narrow space or limited position.

[0040] The expansion type lifting device provided by the embodiment of the utility model is now described. The expansion type lifting device is used to extract valve seats, packings, bushings and other components in valves. For the convenience of description, the valve seats, packings, bushings and other components to be extracted are collectively referred to as objects to be lifted.

[0041] Please also read Figure 1 and Figure 2 The expansion lifting device includes a sleeve 10, an expansion head 20, an inner rod 30 and an adjustment assembly 40.

[0042] The sleeve 10 is a hollow cylindrical structure, which can be passed through by the inner rod 30. The length direction of the sleeve 10 is the axial direction, and the direction of the sleeve 10 perpendicular to its axial direction is the radial direction.

[0043] The expansion head 20 is connected to one end of the sleeve 10, and the end of the expansion head 20 away from the sleeve 10 is used to press against the object to be pulled, forming an axial limit for the object to be pulled, so that the expansion head 20 and the object to be pulled can move axially synchronously. The expansion head 20 has a smaller cross-section in the unexpanded state, so it can penetrate into the inner cavity of the object to be pulled. Under the push of the inner rod 30, the cross-section of the expansion head 20 increases, so it can press against the object to be pulled, so that the object to be pulled and the expansion head 20 can move axially synchronously. For example, when the object to be pulled is a bushing or a valve seat, the expansion head 20 passes through the object to be pulled to the end of the object to be pulled, and after the expansion head 20 expands, it abuts against one end of the object to be pulled in the axial direction, and then pulls the sleeve 10 outward, so that the object to be pulled, the sleeve 10 and the expansion head 20 move outward (axially) synchronously. For example, when the object to be pulled is packing, the expansion head 20 extends into the inner cavity of the packing, expands, squeezes the packing, causes the expansion head 20 to sink into the packing, and then pulls the sleeve 10 outward, causing the packing, sleeve 10 and expansion head 20 to move outward (axially) synchronously.

[0044] The inner rod 30 is arranged through the sleeve 10, and the inner rod 30 can slide relative to the sleeve 10. When the inner rod 30 slides toward one end of the expansion head 20 and contacts the expansion head 20, the expansion head 20 can be expanded to form an axial limit for the object being pulled. When the inner rod 30 slides away from one end of the expansion head 20, it separates from the expansion head 20, and the expansion head 20 returns to its initial state.

[0045] The adjustment component 40 is used to adjust the stroke of the inner rod 30, and the stroke of the inner rod 30 is the distance that the inner rod 30 can move in the axial direction. By adjusting the stroke of the inner rod 30 by the adjustment component 40, the expansion lifting device can be applied to valves of different specifications, that is, it can extract extracts of different depths and positions.

[0046] The expansion type lifting device in the above embodiment includes a sleeve 10, an expansion head 20, an inner rod 30 and an adjustment component 40. The inner rod 30 can slide inside the sleeve 10 and expand the expansion head 20. The adjustment component 40 can adjust the sliding stroke of the inner rod 30. When it is necessary to remove the pulled object such as packing and valve seat, the expansion head 20 is extended to the pulled object, the inner rod 30 is moved to expand the expansion head 20 and press against the pulled object, and then the sleeve 10 is pulled outward. Through the limiting effect of the expansion head 20 on the pulled object, the pulled object can be pulled out together. When the expansion type lifting device is used to extract the extracted objects such as packing and valve seat, the extracted objects can be conveniently and quickly removed from the valve, thereby improving the efficiency of valve disassembly. At the same time, the stroke of the inner rod 30 can also be adjusted by the adjustment component 40, so that the lifting device is suitable for extracting the extracted objects at various depths and positions.

[0047] In some embodiments of the present invention, please refer to Figure 1 and Figure 2 The adjustment assembly 40 includes a threaded member 41 threadedly connected to the inner rod 30, and the axial movement of the inner rod 30 is formed by the head of the threaded member 41 and one end of the sleeve 10 cooperating with each other to form an axial limit for the inner rod 30. The threaded member 41 is threadedly connected to the inner rod 30, that is, the threaded member 41 can rotate relative to the inner rod 30, and axial movement occurs during the rotation process, and the relative position of the threaded member 41 and the inner rod 30 is adjustable. The axial limit of the inner rod 30 is formed between the head of the threaded member 41 and the end of the sleeve 10, that is, when the inner rod 30 moves to the point where the head of the threaded member 41 is close to the sleeve 10, the head of the threaded member 41 will abut against the sleeve 10, so that the inner rod 30 cannot continue to move, thereby forming an axial limit for the inner rod 30. The size of the head of the threaded member 41 is larger than the inner diameter of the sleeve 10, so that the head of the threaded member 41 cannot enter the interior of the sleeve 10.

[0048] By setting the threaded member 41 , the relative position between the threaded member 41 and the inner rod 30 can be adjusted, and then the distance between the head of the threaded member 41 and the end of the sleeve 10 can be changed to adjust the stroke of the inner rod 30 .

[0049] In some embodiments, one end of the inner rod 30 is provided with an internal thread, and the threaded member 41 has an external thread, so that the inner rod 30 is threadedly connected to the threaded member 41 .

[0050] In some embodiments, one end of the inner rod 30 is provided with an external thread, and the threaded member 41 has an internal thread, so that the inner rod 30 is threadedly connected with the threaded member 41. For example, the threaded member 41 is a nut.

[0051] In other embodiments of the present invention, the adjustment assembly 40 includes a retaining spring, and the inner rod 30 is provided with a plurality of retaining grooves arranged along its axial direction. By adjusting the matching position of the retaining spring and the retaining grooves, the movement stroke of the inner rod 30 can also be adjusted.

[0052] In some embodiments of the present invention, please refer to Figure 1 and Figure 2 The adjustment assembly 40 also includes an elastic member 42. The inner wall of the sleeve 10 is provided with a limiting protrusion 32. One end of the elastic member 42 is connected to the limiting protrusion 32, and the other end is connected to the head of the threaded member 41. One end of the elastic member 42 is connected to the limiting protrusion 32. It can be understood that one end of the elastic member 42 is fixedly connected to the limiting protrusion 32, abuts against each other, or is axially limited. The other end of the elastic member 42 is connected to the head of the threaded member 41. It can be understood that the other end of the elastic member 42 is fixedly connected to the head of the threaded member 41, abuts against each other, or is axially limited. When the head of the threaded member 41 is pressed, the elastic member 42 is compressed and the expansion head 20 is expanded. When the pressing force disappears, the expansion head 20 returns to the unexpanded state, and the elastic member 42 returns to the initial state, so that the inner rod 30 automatically returns to its position.

[0053] By disposing the elastic member 42, the inner rod 30 can be automatically returned to its original position without manually pulling the inner rod 30 to return to its original position.

[0054] In some embodiments, the limiting protrusion 32 is annular. Alternatively, the limiting protrusion 32 includes a plurality of circumferentially arranged limiting units. The specific structure of the limiting protrusion 32 is not limited here, and it only needs to be able to stop the elastic member 42.

[0055] In some embodiments, the elastic member 42 is sleeved on the outer circumference of the inner rod 30 and the threaded member 41 , which has a radial limiting effect on the elastic member 42 , making the telescopic deformation of the elastic member 42 more stable.

[0056] In some embodiments, the elastic member 42 is a cylindrical spring.

[0057] In some embodiments of the present invention, please refer to Figure 1 and Figure 2 The head of the threaded member 41 is fixedly provided with a first handle 43 for convenient hand-holding. The head of the threaded member 41 is fixedly connected to the first handle 43, and the first handle 43 moves synchronously with the threaded member 41. The first handle 43 is larger than the head of the threaded member 41, which is convenient for controlling the threaded member 41. Specifically, when adjusting the stroke of the inner rod 30, the threaded member 41 can be rotated by rotating the first handle 43. When the expansion head 20 is expanded, the first handle 43 is pressed to keep the inner rod 30 in a state of contact with the expansion head 20.

[0058] By providing the first handle 43 , the space occupied by the head of the screw member 41 is increased, and the operator can more easily rotate, press, and perform other operations on the screw member 41 , thereby saving effort when the operator uses the lifting device.

[0059] In some embodiments, the first handle 43 and the threaded member 41 are fixedly connected by welding.

[0060] In some embodiments, the cross-section of the first handle 43 is in a hexagonal, quadrilateral, or other shape, which facilitates the operator to rotate the first handle 43 .

[0061] In some embodiments of the present invention, please refer to Figure 1 and Figure 2 The outer peripheral wall of the sleeve 10 is provided with a second handle 31 for convenient hand-holding. The second handle 31 is fixedly connected to the outer peripheral wall of the sleeve 10, and the first handle 43 moves synchronously with the sleeve 10. The second handle 31 is larger than the sleeve 10, which is convenient for controlling the sleeve 10. Specifically, when pulling the extracted object, the second handle 31 is held, and an axial force is applied to the second handle 31 to synchronously remove the pulling device and the extracted object.

[0062] By setting the second handle 31, the outer periphery of the sleeve 10 is convex, which makes it easy to apply external force to the sleeve 10, and the operator can more easily pull the sleeve 10 axially outward, so that the operator can save more effort when using the pulling device.

[0063] In some embodiments, the second handle 31 is integrally formed with the sleeve 10 .

[0064] In some embodiments, the second handle 31 and the sleeve 10 are separately formed and are connected and fixed to each other in a fixed direction by welding or the like.

[0065] In some embodiments, the cross-section of the second handle 31 is in a hexagonal, quadrilateral, or other shape, which facilitates the operator to axially move the sleeve 10 .

[0066] In some embodiments of the present invention, please refer to Figures 1 to 4 The sleeve 10 is detachably connected to the expansion head 20. That is, the expansion head 20 can be removed from the sleeve 10 and replaced with a different expansion head 20 to adapt to different objects to be pulled. Figure 3 and Figure 4 As shown, there are two different expansion heads 20. The expansion heads 20 used in conjunction with the sleeve 10 may have different structures and sizes to accommodate various specifications and types of objects to be pulled.

[0067] By arranging the expansion head 20 to be detachably connected to the sleeve 10, different expansion heads 20 can be selected for replacement according to the object to be pulled, and the axial length of the expansion pulling device during transportation can be reduced, thereby reducing transportation costs.

[0068] In some embodiments, see Figures 1 to 3 , the sleeve 10 and the expansion head 20 are threadedly connected. One of the sleeve 10 and the expansion head 20 is provided with an external thread, and the other is provided with an internal thread, so that the sleeve 10 and the expansion head 20 are threadedly connected. Specifically, the following two situations are included: the outer circumferential wall of the sleeve 10 is provided with an external thread, and the inner circumferential wall of the expansion head 20 is provided with an internal thread; the inner circumferential wall of the sleeve 10 is provided with an internal thread, and the outer circumferential wall of the expansion head 20 is provided with an external thread. The threaded connection between the sleeve 10 and the expansion head 20 does not require the use of connectors such as screws, and threads can be directly designed on the sleeve 10 and the expansion head 20. When the expansion head 20 needs to be replaced, the old expansion head 20 is unscrewed, and the new expansion head 20 is rotated and installed.

[0069] The sleeve 10 and the expansion head 20 are threadedly connected, the structure is simple and reliable, and no additional disassembly tools are required for disassembly and assembly, so disassembly and assembly are convenient.

[0070] In some embodiments of the present invention, please refer to Figure 3 and Figure 4The expansion head 20 includes a connecting tube 21 and an expansion portion 22. One end of the connecting tube 21 is connected to the sleeve 10, and the other end of the connecting tube 21 is connected to the expansion portion 22. The expansion portion 22 extends radially outward to form a claw portion 222, and the claw portion 222 is used to press and fit with the object to be pulled. In the axial direction of the expansion head 20, one axial end of the connecting tube 21 is connected to the sleeve 10, and the other axial end of the connecting tube 21 is connected to the expansion portion 22. When the expansion portion 22 is acted upon by the inner rod 30, the expansion portion 22 expands radially outward, and the claw portion 222 and the object to be pulled are clamped or pressed against each other to achieve axial mutual fixation. For example, when the object to be pulled is a valve seat or a sleeve 10, the claw portion 222 moves radially outward, and the claw portion 222 abuts against the end of the object to be pulled, thereby achieving axial limiting. For example, when the object to be pulled is packing, the claw portion 222 extends into the interior of the packing, thereby achieving axial limitation of the packing and the expansion head 20 .

[0071] By configuring the expansion head 20 as a connecting tube 21 and an expansion portion 22, the connecting tube 21 provides a connection space for the expansion head 20 and the sleeve 10, and the axial length of the lifting device can be lengthened to a certain extent, making the lifting device suitable for objects to be lifted at a deeper position.

[0072] In some embodiments, see Figure 5 , Figure 5 The left middle picture is a side view of the expansion head 20 when it is not expanded, and the right middle picture is a side view of the expansion head 20 after expansion. The expansion portion 22 includes a plurality of expansion units 221 arranged at circumferential intervals, and the inner rod 30 is used to extend into the center of the expansion portion 22 to deform each expansion unit 221 radially outward. When the inner rod 30 presses the expansion head 20 from the inside of the expansion head 20, each expansion unit 221 is subjected to the force of the inner rod 30 and deforms radially outward, thereby increasing the diameter of the expansion portion 22 and hooking the extract.

[0073] By providing the expansion part 22 with a plurality of circumferentially arranged expansion units 221, the expansion part 22 can hook the extractable object at each circumferential position, so that the force applied to the extractable object is more uniform.

[0074] Optionally, the number of expansion units 221 is two, three, four, etc., and the specific number is not limited here.

[0075] Optionally, the connecting tube 21 is provided with a plurality of notches arranged in sequence in the circumferential direction, so that the connecting tube 21 forms a plurality of tube units, and the notches extend from one end of the connecting tube 21 to the middle of the connecting tube 21, and each tube unit is connected to a corresponding expansion unit 221. When the inner rod 30 pushes the expansion unit 221, the tube unit is also deformed accordingly, so that the expansion unit 221 is more likely to produce radial displacement.

[0076] In some embodiments, the wall thickness of the connecting tube 21 is smaller than the wall thickness of the expansion part 22, so that the connecting tube 21 is easy to deform, and the expansion unit 221 of the expansion part 22 is easier to produce radial displacement and expand, and the expansion head 20 is not easy to be damaged after repeated use.

[0077] In some embodiments of the present invention, please refer to Figure 1 and Figure 2 The inner rod 30 is conical at one end close to the expansion head 20. When the inner rod 30 pushes the expansion head 20, the tip of the cone first extends into the center of the expansion head 20 and gradually moves toward the expansion head 20. Under the action of the cone, the expansion head 20 gradually expands.

[0078] By setting one end of the expansion head 20 to be conical, firstly, the inner rod 30 can be automatically guided so that the conical section of the inner rod 30 gradually enters the expansion head 20; secondly, the expansion head 20 can be gradually expanded by the conical section, and the expansion head 20 is not easy to crack.

[0079] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An expansion type lifting device, characterized in that: It includes a sleeve, an expansion head connected to one end of the sleeve, an inner rod arranged inside the sleeve, and an adjustment component for adjusting the stroke of the inner rod. The expansion head is used to press and pull the object to be pulled outward, and the inner rod can slide relative to the sleeve to expand the expansion head.

2. The expansion lifting device according to claim 1, characterized in that: The adjustment assembly includes a threaded member threadedly connected to the inner rod, and the axial movement of the inner rod is limited by the head of the threaded member cooperating with one end of the sleeve to form an axial limit for the inner rod.

3. The expansion lifting device according to claim 2, characterized in that: The adjustment component also includes an elastic member, and a limiting protrusion is provided on the inner wall of the sleeve. One end of the elastic member is connected to the limiting protrusion, and the other end is connected to the head of the threaded member.

4. The expansion lifting device according to claim 2, characterized in that: The head of the threaded member is fixedly provided with a first handle which is convenient for holding.

5. The expansion lifting device according to any one of claims 1 to 4, characterized in that: The outer peripheral wall of the sleeve is provided with a second handle which is convenient for holding.

6. The expansion lifting device according to any one of claims 1 to 4, characterized in that: The sleeve is detachably connected to the expansion head.

7. The expansion lifting device according to claim 6, characterized in that: One of the sleeve and the expansion head is provided with an external thread, and the other is provided with an internal thread, so that the sleeve and the expansion head are threadedly connected.

8. The expansion lifting device according to any one of claims 1 to 4, characterized in that: The expansion head includes a connecting tube and an expansion part, one end of the connecting tube is connected to the sleeve, and the other end of the connecting tube is connected to the expansion part. The expansion part extends radially outward to form a claw part, and the claw part is used to press and fit with the object to be pulled.

9. The expansion lifting device according to claim 8, characterized in that: The expansion portion includes a plurality of expansion units spaced apart from each other in the circumferential direction, and the inner rod is used to extend into the center of the expansion portion to cause each of the expansion units to deform radially outward.

10. The expansion lifting device according to any one of claims 1 to 4, characterized in that: The inner rod has a conical shape at one end close to the expansion head.

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