A segment lifting device and method

Abstract

The present invention relates to a segment lifting device and method. The segment lifting device includes a grasping arm assembly, which includes a frame, a pair of left and right grasping arms, and a driving mechanism. The driving mechanism includes a cam and an unidirectional intermittent transmission mechanism. The cam is in transmission connection with the grasping arm. The unidirectional intermittent transmission mechanism includes a push rod and a driven member. The unidirectional intermittent transmission mechanism is used to convert the up-and-down movement of the push rod along with the segment into a rotational movement of a set angle of one-way rotation each time, so that the cam changes its working position under the action of the unidirectional intermittent transmission mechanism, and the grasping arm changes its opening and closing state under the action of the cam. The lifting method provided by the present invention relies on the gravity of the entire grasping arm assembly itself, and only needs to perform the operation of lifting and lowering the segment lifting device to achieve the grasping and releasing of the segment. It neither requires external power supply nor complex control systems and control processes. The design is simple, reasonable, and low in cost. The lifting process does not require personnel to participate, reducing the labor intensity of workers.

Description

Technical Field

[0001] The present invention relates to the technical field of shield construction, and particularly to a segment lifting device and a lifting method for transporting segments for a shield machine in a lifting manner. Background Art

[0002] During the tunnel shield construction process, the shield machine needs to assemble segments at the shield tail with an erector while tunneling. These segments can be assembled into a pipeline to support the tunnel wall, and the shield machine also relies on the assembled segments as a jacking fulcrum to move forward. Before segment installation, the segments need to be lifted to a designated position (segment temporary storage area, segment assembly area of the erector, or segment feeder), and then segment assembly is carried out. Therefore, segment lifting is a key step in shield tunnel construction.

[0003] Existing segment lifting technologies include: For example, a Chinese invention patent with the authorization announcement number CN212225263U discloses a lifting device for shield segments. The segments are reserved with segment bolt holes. When lifting the segments, the segment bolts are first screwed into the segment bolt holes, and then the segment bolts are hung on the lifting tool. The lifting tool lifts the segments through the cooperation with the segment bolts. Such a lifting tool is a pure mechanical structure. Screwing the segment bolts into the segment bolt holes and hanging the segment bolts on the lifting tool both need to be completed manually, resulting in problems such as low automation, low efficiency, and potential installation hazards in manual operation. Another example is a Chinese invention patent application with the application publication number CN113443551, which discloses a rapid segment lifting device and a lifting method for shield segments. The segment lifting device includes a rapid grasping mechanism, a slewing mechanism, and a hoisting and traveling mechanism. The telescopic member (oil cylinder or air cylinder) of the rapid grasping mechanism drives the grasping arm group to open and close to grasp the segments, and the segments are lifted by the slewing mechanism and the hoisting and traveling mechanism to realize segment transfer. This kind of lifting tool uses an oil cylinder or an air cylinder to drive the grasping arm to open and close, so a hydraulic power source and pipelines need to be provided and a complex control system needs to be equipped, resulting in a relatively high cost. Summary of the Invention

[0004] The purpose of the present invention is to provide a segment lifting device and a segment lifting method using the segment lifting device, so as to achieve automatic grasping and lifting at a relatively low cost.

[0005] A segment hoisting device of the present invention includes a hoisting and traveling mechanism and a grasping arm assembly. The hoisting and traveling mechanism is used to drive the grasping arm assembly to lift and travel and shift. The grasping arm assembly includes a frame, a pair of left and right grasping arms, and a driving mechanism. The lower end of the grasping arm has a grasping hook. The grasping arm has two states: open and closed. The grasping hook can lift the segment when the grasping arm is closed and avoid the segment when the grasping arm is open. There is an activity space above the grasping hook. The activity space allows the grasping arm assembly to move up and down relative to the segment supported at the bottom; the grasping arm assembly includes a reset device, and the reset device is used to provide a reset force to drive the grasping arm to be in the reset state. One of the open and closed states is the reset state, and the other is defined as the non-reset state; the driving mechanism includes a cam and a one-way intermittent transmission mechanism; the cam is rotationally assembled on the frame, and the cam is directly or through a transmission component in transmission cooperation with the grasping arm. And the cam has a set edge shape so that when the cam rotates, there are cam working positions that appear alternately with a set angle difference: a force application position and a release position. The cam in the force application position provides a reverse reset force opposite to the reset force to keep the grasping arm in the non-reset state, and the cam in the release position releases the reverse reset force to make the grasping arm return to the reset state; the one-way intermittent transmission mechanism is used to convert a linear reciprocating motion into a rotational motion that rotates a set angle in one direction each time, including a driving part and a driven part. The driving part is a push rod that is vertically movably assembled on the frame. The lower end of the push rod is used for abutting and cooperating with the top surface of the segment in the activity space, and the upper end of the push rod is used for cooperating with the driven part. When the push rod moves upward, it drives the driven part to rotate. When the push rod moves downward, the one-way intermittent transmission mechanism is self-locking; the driven part is in transmission cooperation with the cam and is used to convert one up and down reciprocating motion of the push rod into one rotational motion that drives the cam to rotate a set angle in one direction, so that the cam working position is converted once; in a reciprocating motion process of the grasping arm assembly relative to the segment first downward and then upward, the segment in the activity space reciprocates up and down relative to the grasping arm assembly, so that the push rod is pushed upward by the segment moving upward and moves downward under the action of gravity when the segment moves downward. At the same time, the cam is converted to a working position under the action of the driven part, and the grasping arm is converted to a state under the action of the cam.

[0006] Advantageous effects: The present invention only relies on the up and down movement operation of the grasping arm assembly, and the driving mechanism of the grasping arm assembly can realize the switching of the opening and closing states of the grasping arm, so as to perform the grasping and releasing operations on the segment. It neither requires external power supply nor a complex control system, and has a simple and reasonable structure design and low cost.

[0007] Preferably, the follower is a dial wheel assembly, which includes a shaft seat, a lever, and an elastic member. The shaft seat is fixedly connected to the cam and has a common axis of revolution. The levers correspond to the work positions of the cam one by one and are evenly distributed along the circumference around the axis of revolution. The lever is hinged to the shaft seat. The lever reciprocates and has two states: a driving state and an avoiding state. In the driving state, the lever presses against a stop member provided on the shaft seat and can apply a torque to the shaft seat. In the avoiding state, the lever disengages from the stop member in the reverse direction and cannot apply a torque to the shaft seat. The elastic member is used to drive the lever to press against the stop member. The lever has a stop surface that cooperates with the stop member and a pressing surface that cooperates with the ejector rod. The orientations of the stop surface and the pressing surface are opposite. When each lever rotates around the axis of revolution with the shaft seat, it has two lever work positions that are reached successively: a preparatory position and a completion position. The preparatory position and the completion position are distributed from bottom to top on the moving path of the ejector rod. The pressing surface of the lever in the preparatory position faces downward and corresponds to the upper end of the ejector rod. When the gripper arm assembly moves up and down, the segment in the active space has an upper position and a lower position. When the segment moves from the lower position to the upper position, the ejector rod is pushed up by the segment. When the segment moves from the upper position to the lower position, the ejector rod under the action of gravity moves downward. When the ejector rod moves upward, the lever in the preparatory position is pushed by the ejector rod to maintain the driving state and continues to rotate around the axis of revolution to reach the completion position. At the same time, the lever drives the shaft seat and the cam to rotate, thereby switching the cam work position and changing the state of the gripper arm. And the next lever reaches the preparatory position. When the ejector rod moves downward, the one-way intermittent transmission mechanism is self-locked. The lever in the preparatory position is temporarily pushed away to the avoiding state by the ejector rod and returns to the driving state under the action of the elastic member after the ejector rod leaves. The lever in the preparatory position always stays in the preparatory position to achieve the self-locking of the one-way intermittent transmission mechanism, so that the cam work position and the state of the gripper arm remain unchanged. Using the dial wheel assembly as the main component of the one-way intermittent transmission mechanism can closely cooperate with the cam, improve the transmission efficiency, and save the space occupied by the driving mechanism.

[0008] Preferably, the shaft seat includes a disc-shaped dial and a rotating shaft fixed to the center of the dial. The lever is hinged to the outer peripheral surface of the rotating shaft. The stop member is a stop block protruding from the outer peripheral surface of the rotating shaft. The elastic member is a lever spring, and the lever spring is connected between the outer peripheral surface of the rotating shaft and the lever.

[0009] Preferably, positioning grooves are provided on the outer peripheral surface of the dial. The positioning grooves correspond to the cam work positions one by one. A positioning spring and a positioning block that cooperate with the positioning grooves are also provided on the frame. The positioning block is used to insert into the positioning groove to block the rotation of the cam and keep the cam work position unchanged, and withdraws from the groove when the one-way intermittent transmission mechanism drives the cam to rotate. The positioning spring is used to apply an elastic force to the positioning block. The cooperation between the positioning groove and the positioning block can achieve the locking of the cam work position and avoid misoperation of the mechanism.

[0010] Preferably, two force-applying rods are movably assembled on the frame in the left-right direction: a left force-applying rod and a right force-applying rod. The two force-applying rods are symmetrically arranged on the left and right sides of the cam. The cam is in transmission cooperation with the gripper arm through the two force-applying rods.

[0011] Preferably, the cam stations are four consecutive positions with a 90-degree difference. The first and third positions are the force application positions, and the second and fourth positions are the release positions; there are four lever arms, which are hinged to the shaft seat with a 90-degree difference.

[0012] Preferably, the reset device is a reset spring. The open state of the grasping arm is the reset state, and the closed state of the grasping arm is the non-reset state.

[0013] Preferably, the frame includes a grasping disc. The grasping disc and the grasping hook are arranged at an interval up and down to form the moving space, and the ejector rod passes through the through hole provided on the grasping disc.

[0014] Preferably, the ejector rod includes an upper end portion of the ejector rod, a lower end portion of the ejector rod, and an ejector rod spring. The upper end portion and the lower end portion of the ejector rod are connected by the ejector rod spring. The ejector rod spring can reduce the overall length required for the ejector rod to move upward after being lifted by the segment, that is, the length of the ejector rod is shorter when moving upward than when moving downward, so that the thickness of the grasping disc in the up and down direction required to accommodate the ejector rod can be reduced.

[0015] A method for hoisting segments of the present invention uses the aforementioned segment hoisting device and includes the following steps:

[0016] (1) Move the grasping arm assembly to the segment taking position and be above the segment to be taken. The grasping arm assembly moves downward when its grasping arm is in the open state. The ejector rod of the grasping arm assembly is pushed upward by the segment, and the ejector rod drives the cam to rotate through the follower, thereby converting the cam station. Furthermore, the grasping arm is converted from the open state to the closed state under the action of the cam, so that the grasping hook on the grasping arm can lift the segment upward; after the grasping arm of the grasping arm assembly is converted to the closed state, it continues to move upward, and the segment is lifted by the grasping hook on the grasping arm, and the ejector rod moves downward under the action of gravity; at the segment taking position, during the process of the segment reciprocating up and down once in the moving space, the cam is converted under the action of the one-way intermittent transmission mechanism, and the grasping arm is converted from the open state to the closed state under the action of the cam;

[0017] (2) The grasping arm assembly moves from the segment taking position to the segment placing position. The grasping arm assembly moves downward when its grasping arm is in the closed state. The bottom of the segment is supported and moves upward relative to the grasping arm assembly and disengages from the grasping hook; the ejector rod of the grasping arm assembly is pushed upward by the segment, and the ejector rod drives the cam to rotate through the follower, thereby converting the cam station. Furthermore, the grasping arm is converted from the closed state to the open state under the action of the cam, so that the grasping hook on the grasping arm can avoid the segment; at the segment placing position, during the process of the segment reciprocating up and down once in the moving space, the cam is converted under the action of the one-way intermittent transmission mechanism, and the grasping arm is converted from the closed state to the open state under the action of the cam;

[0018] (3) After the gripping arm assembly continues to move upward after its gripping arm is converted to the open state, the segment continues to move downward relative to the gripping arm assembly and disengages from the gripping arm assembly.

[0019] The segment lifting method provided by the present invention relies on the self-gravity of the gripping arm assembly to achieve the gripping and releasing of the segment. During the lifting process, only the operation of lifting and lowering the gripping arm assembly is required. It neither requires external power supply nor complex control systems and control processes. The design is simple, reasonable, and low-cost. The lifting process does not require human participation, reducing the labor intensity of workers. Description of the Drawings

[0020] Figure 1 is a schematic structural view of an embodiment of the segment lifting device of the present invention;

[0021] Figure 2 is Figure 1 the A-A view in

[0022] Figure 3 is a schematic view of the lifting process of an embodiment of the segment lifting of the present invention;

[0023] Figure 4 is a schematic structural view of the drive mechanism in an embodiment of the segment lifting device of the present invention;

[0024] Figure 5 is Figure 4 the E-E view in

[0025] Figure 6 is Figure 4 the enlarged view of part I of

[0026] In the figure:

[0027] 1. Chain; 2. Gripping arm; 3. Gripping disk; 4. Proximity switch; 5. Camera; 6. Gripping hook; 7. Push rod; 8. Push rod spring; 9. Cam; 10. Return spring; 11. Segment; 9-1. Rotating shaft; 9-2. Dial; 9-3. Lever; 9-4. Upper end of the push rod; 9-5. Force-applying rod; 9-6. Stopper; 9-7. Lever spring; 9-8. Positioning block; 9-9. Positioning spring; 9-10. Positioning spring seat. Detailed Embodiment

[0028] An embodiment of the segment lifting device of the present invention is as shown in Figures 1-6As shown, it includes a lifting and traveling mechanism and a grabbing arm assembly. The lifting and traveling mechanism includes a chain 1, which is used to drive the grabbing arm assembly to rise and fall and move. The grabbing arm assembly includes a frame, a pair of grabbing arms 2 on the left and right, a driving mechanism, and a reset spring 10. The grabbing disc 3 constitutes the main body of the frame, and the chain 1 is fixed on the grabbing disc 3. There are two pairs of grabbing arms 2, and the grabbing arms 2 are hingedly mounted on the ears on both sides of the grabbing disc 3. The grabbing arms 2 have two states: open and closed. The reset spring 10 is used to provide a reset force to drive the grabbing arm 2 to be in a reset state. The reset spring 10 in this embodiment is used to drive the grabbing arm 2 to open, so the reset state of the grabbing arm in this embodiment is the closed state, and the non-reset state is the open state. Of course, in other embodiments, the reset state of the grabbing arm can also be an open state, and the non-reset state is a closed state.

[0029] The grabbing arm 2 has a grabbing hook 6 at the lower end. The grabbing hook 6 can lift the pipe segment 11 when the grabbing arm 2 is folded and avoid the pipe segment 11 when the grabbing arm 2 is opened. A movable space is provided between the grabbing hook 6 and the grabbing plate 3. The movable space allows the grabbing arm assembly to move up and down relative to the pipe segment 11 supported at the bottom. The upper surface of the grabbing hook 6 is designed to be inclined in order to increase the contact area between the upper surface of the grabbing hook 6 and the bottom of the pipe segment 11, and an anti-slip material is provided on the upper surface of the grabbing hook 6 to prevent sliding between the bottom of the pipe segment 11 and the upper surface of the grabbing hook 6. Proximity switches 4 and cameras 5 are also provided on both sides of the bottom of the grabbing plate 3. Figure 1 As shown in the figure, the size of the aperture under the camera 5 is the range that the camera 5 can observe. The proximity switch 4 and the camera 5 are used to monitor whether the pipe segment is safely grasped. The proximity switch 4 can trigger a position signal when the bottom of the pipe segment 11 is in full contact with the upper surface of the grab hook 6. At the same time, the cameras 5 at both ends of the gripping plate 3 can also observe the coordination between the pipe segment 11 and the grab hook 6 in real time to monitor whether the grab arm assembly is safely grasping the pipe segment 11.

[0030] The driving mechanism includes a cam 9 and a one-way intermittent transmission mechanism; the cam 9 is rotatably assembled on the frame, and the cam 9 is transmitted and coordinated with the grabbing arm 2 through the force rod 9-5. Two force rods 9-5 are movably assembled on the frame along the left and right directions: a left force rod 9-5 and a right force rod 9-5. The two force rods 9-5 are symmetrically movably arranged on the left and right sides of the cam 9, and the cam 9 is transmitted and coordinated with the grabbing arm 2 through the two force rods 9-5.

[0031] The cam 9 has a set edge shape, so that when the cam 9 rotates, it has cam positions that are set angles apart and appear alternately: force application position and release position. The cam 9 is specifically elliptical, so the cam positions are four continuous positions that are 90 degrees apart in the rotation direction. The first and third positions are force application positions, corresponding to Figure 3 The elliptical major axis of the cam 9 is in a horizontal state, and the second and fourth positions are release positions, corresponding to Figure 3The major axis of the ellipse of the cam 9 therein is in the vertical state. The cam 9 in the force application position provides a repeated biasing force to the grasping arm 2 through the biasing rod 9-5. The repeated biasing force is a force opposite to the restoring force of the aforementioned restoring spring 10, and the repeated biasing force keeps the grasping arm 2 in the non-restoring state (i.e., the open state of the grasping arm 2 in this embodiment). The cam 9 in the release position releases the repeated biasing force to make the grasping arm 2 return to the restoring state (i.e., the closed state of the grasping arm 2 in this embodiment). Of course, in other embodiments, the contour of the cam 9 can also be other shapes, such as having a plurality of alternately continuous concave and convex portions, and the convex and concave portions differ by a set angle in the rotational direction. The concave portion corresponds to the release position, and the convex portion corresponds to the force application position.

[0032] The one-way intermittent transmission mechanism includes a driving member and a driven member. The driving member is a push rod 7 that is vertically movably assembled in the central hole of the gripping disc 33, and the driven member is a dial assembly. The push rod 7 includes an upper end portion 9-4 of the push rod, a lower end portion of the push rod, and a push rod spring 8. The upper end portion 9-4 of the push rod and the lower end portion of the push rod are connected by the push rod spring 8. The upper and lower ends of the push rod 7 are respectively located on the upper end portion 9-4 of the push rod and the lower end portion of the push rod. The lower end of the push rod 7 is used for abutting and cooperating with the top surface of the segment 11, and the upper end of the push rod 7 is used for cooperating with the dial assembly.

[0033] As Figures 4-6 shown, the dial assembly includes a shaft seat, a dial rod, a dial rod spring 9-7, and a stopper 9-6. The shaft seat is fixedly connected to the cam 9 and has a common axis of revolution. The shaft seat includes a disc-shaped dial 9-2 and a rotating shaft 9-1 fixed in the center of the dial 9-2. The dial rod is hinged on the outer peripheral surface of the rotating shaft 9-1. The stopper 9-6 protrudes on the outer peripheral surface of the rotating shaft 9-1. The dial rod spring 9-7 is connected between the outer peripheral surface of the rotating shaft 9-1 and the dial rod. There are four dial rods, which thus correspond to the working positions of the cam 9 one by one and are evenly distributed along the circumference around the axis of revolution. The dial rod reciprocally swings and has two states: a driving state and an avoiding state. The dial rod in the driving state presses against the stopper to be able to apply a torque to the shaft seat, and the dial rod in the avoiding state is reversely separated from the stopper and cannot apply a torque to the shaft seat. The dial rod spring 9-7 is used to drive the dial rod to press against the stopper; the dial rod has a stopper surface for cooperating with the stopper and a pressing surface for cooperating with the push rod 7, and the orientations of the stopper surface and the pressing surface are opposite; each dial rod has a dial rod working position that it reaches successively when rotating around the axis of revolution with the shaft seat: a preparatory position and a completion position. The preparatory position and the completion position are distributed from bottom to top on the moving path of the push rod 7. The pressing surface of the dial rod in the preparatory position faces downward and corresponds to the upper end of the push rod 7.

[0034] On the outer peripheral surface of the dial 9-2 of the shaft seat, there are also four positioning grooves with a 90-degree difference. The positioning grooves correspond to the cam workstations one by one. On the frame, there are also a positioning spring 9-9 and a positioning block 9-8 that cooperate with the positioning grooves. One end of the positioning spring 9-9 is fixedly connected to the positioning spring seat 9-10 provided on the frame (the gripping disc 3), and the other end of the positioning spring 9-9 is fixedly connected to the positioning block 9-8. The positioning spring 9-9 is used to apply an elastic force to the positioning block 9-8, and the positioning block 9-8 is used to insert into the positioning groove to block the rotation of the cam 9, keep the cam workstation unchanged and locked, and can withdraw from the groove when the one-way intermittent transmission mechanism drives the cam 9 to rotate. The purpose of setting the positioning block 9-8 and the positioning spring 9-9 is to keep the cam 9 from rotating under a certain torque and avoid the misrotation of the cam 9.

[0035] In the use of the above embodiment of the present invention, the one-way intermittent transmission mechanism is used to convert each up-and-down linear reciprocating motion of the ejector rod 7 into a one-way rotational motion of the cam 9 and switch the workstation once. When the gripping arm assembly moves up and down, the segment 11 in the active space has an upper position and a lower position relative to the overall gripping arm assembly (or relative to the gripping disc 3). When the segment 11 moves from the lower position to the upper position, the ejector rod 7 is pushed upward by the segment 11. When the segment 11 moves from the upper position to the lower position, the ejector rod 7 under the action of gravity moves downward; when the ejector rod 7 moves upward, the lever in the standby position is pushed by the ejector rod 7 to maintain the driving state and continue to rotate around the axis of revolution to reach the completion position. At the same time, the lever drives the shaft seat and the cam 9 to rotate to switch the cam workstation, so that the gripping arm 2 switches states, and the next lever reaches the standby position; when the ejector rod 7 moves downward, the lever in the standby position is temporarily pushed away by the ejector rod 7 to the avoidance state and returns to the driving state under the action of the elastic member after the ejector rod 7 leaves. The lever in the standby position always stays in the standby position to realize the self-locking of the one-way intermittent transmission mechanism, that is, the one-way intermittent rotation mechanism can only rotate in one direction, so that the cam workstation and the state of the gripping arm remain unchanged. Self-locking means that the driven member of the one-way intermittent transmission mechanism cannot rotate in the reverse direction, but only "stops" to prepare for waiting for the next output of the one-way rotation action.

[0036] The use process of the above embodiment of the present invention is an embodiment of a method for lifting segments of the present invention. This method embodiment uses the segment lifting device in the above segment lifting device embodiment. The method includes the following steps:

[0037] (1) Move the grabbing arm assembly to the segment-taking position and position it above the segment 11 to be taken. When the grabbing arm 2 of the grabbing arm assembly is in the open state, it descends. When the segment 11 moves to the active space and moves from the lower position to the upper position, the ejector rod 7 of the grabbing arm assembly is pushed upward by the segment 11. The ejector rod 7 drives the cam 9 to rotate through the dial 9-2 assembly, thereby switching the cam working position. Further, under the action of the cam 9, the grabbing arm 2 is switched from the open state to the closed state, so that the grabbing hook 6 on the grabbing arm 2 can lift the segment 11 upward; after the grabbing arm 2 of the grabbing arm assembly is switched to the closed state, it continues to ascend, and the segment 11 is lifted by the grabbing hook 6 on the grabbing arm 2. The grabbing arm assembly moves from the segment-taking position to the segment-releasing position; during the process of the segment 11 moving from the upper position to the lower position in the active space, the ejector rod 7 of the grabbing arm assembly descends, and the lever of the dial 9-2 assembly in the standby position remains in the standby position, and the cam working position and the state of the grabbing arm remain unchanged;

[0038] In step (1), as Figure 3 shown at position A, before grabbing the segment 11, the return spring 10 is in a contracted state, and the lower end of the grabbing arm 2 is in an outwardly open state to facilitate grabbing the segment 11. As Figure 3 shown at position B, when the segment 11 is located below the grabbing arm 2, the chain 1 elongates downward, and the entire grabbing arm assembly moves downward. The grabbing hook 6 at the lower end of the grabbing arm 2 moves to the bottom of the segment 11. At the same time, the lower end of the ejector rod 7 contacts the upper surface of the segment 11, and the ejector rod 7 ascends, driving the dial 9-2 to rotate counterclockwise by 90 degrees, and at the same time driving the cam 9 to rotate counterclockwise by 90 degrees. The cam 9 is switched to the force-applying position, and a return force is applied to the grabbing arm 2 through the force-applying rod 9-5 to drive the grabbing arm 2 to close to grab the segment 11. When both ends of the segment 11 contact the inner surface of the grabbing arm 2, the proximity switch 4 will transmit a position signal to ensure that the bottom of the segment 11 is in full contact with the upper surface of the grabbing hook 6. At the same time, through the cameras 5 at both ends of the gripping disc 3, it can be observed whether the segment 11 is safely grabbed.

[0039] (2) The gripping arm assembly moves from the segment picking position to the segment placing position. When the gripping arm 2 of the gripping arm assembly is in the retracted state, it descends, and the bottom of the segment 11 is supported and moves upward relative to the gripping arm assembly and disengages from the gripping hook 6. During the process of the segment 11 moving from the lower position to the upper position in the moving space, the ejector rod 7 of the gripping arm assembly is pushed upward by the segment 11, and the ejector rod 7 drives the cam 9 to rotate through the dial 9-2 assembly, thereby switching the cam working position. Further, under the action of the cam 9, the gripping arm 2 is switched from the retracted state to the open state, so that the gripping hook 6 on the gripping arm 2 can avoid the segment 11. After the gripping arm 2 of the gripping arm assembly is switched to the open state, it continues to ascend, and the segment 11 continues to descend relative to the gripping arm assembly and disengages from the gripping arm 2. During the process of the segment 11 moving from the upper position to the lower position in the moving space, the ejector rod 7 of the gripping arm assembly descends, and the lever in the standby position of the dial 9-2 assembly remains in the standby position, and the cam working position and the state of the gripping arm remain unchanged.

[0040] In step (2), as Figure 3 shown at position C, after the gripping arm 2 grabs the segment 11, the gripping arm 2 is lifted upward, the gripping disc 3 is separated from the segment 11, the segment 11 descends, and the ejector rod 7 moves downward under the action of gravity and the spring (because the ejector rod spring 8 can be compressed, and the ejector rod spring 8 is to reduce the overall length required for the ejector rod 7 to move upward after being pushed up by the segment 11, that is, the length of the ejector rod 7 is shorter when moving upward than when moving downward, so as to reduce the thickness of the gripping disc 3 in the up-down direction required to accommodate the ejector rod 7). At this time, the one-way intermittent transmission mechanism is in the self-locking state and will not rotate to change the working position of the cam 9. The gripping arm 2 is always in the retracted state and always maintains a safe gripping state for the segment 11. As Figure 3 shown at position D, after the gripping arm assembly carries the segment 11 to the designated segment placing position (specifically the track), the chain 1 descends, the gripping arm assembly places the segment 11 on the track, and continues to descend until the lower surface of the gripping disc 3 is in full contact with and presses the upper surface of the segment 11, so that the ejector rod 7 contracts and moves upward as a whole. The upper end of the ejector rod 7 drives the dial 9-2 to rotate counterclockwise by 90 degrees, and at the same time drives the cam 9 to rotate counterclockwise by 90 degrees. The cam 9 is switched to the release position and no longer applies a repeated force to the gripping arm 2. The gripping arm 2 returns to the open state under the action of the return spring 10 and completely releases the segment 11 on the track.

[0041] (3) As Figure 3 shown at position E, after the gripping arm 2 of the gripping arm assembly is switched to the open state, it continues to ascend, and the segment 11 continues to descend relative to the gripping arm assembly and disengages from the gripping arm assembly.

[0042] In addition, in other embodiments of the present invention, the one-way intermittent transmission mechanism is not limited to the ejector rod 7 and the dial assembly, and can also be other one-way intermittent transmission mechanisms that can convert linear reciprocating motion into a single-way rotation of a set angle each time, such as a ratchet mechanism.

[0043] Meanwhile, in other embodiments of the present invention, the hinge axis of the lever of the dial wheel assembly may also be coaxial with the revolution axis. In this case, it is only necessary to ensure that the stopper is eccentrically arranged. It should also be noted that in other embodiments of the present invention, the transmission cooperation between the cam and the grasping arm is not limited to the force application rod. The cam may also be directly engaged with the grasping arm. For example, a convex portion may be fixed at an appropriate position of the grasping arm. Furthermore, the force application direction of the cam on the grasping arm is not limited to pushing outwards. In other embodiments, the cam may convert the force application direction through a rocker mechanism and then apply a force to the grasping arm. At this time, the cam may apply a pulling force that pulls inwards rather than a pushing force that pushes outwards to the grasping arm.

Claims

1. A pipe segment lifting device, comprising a lifting and walking mechanism and a grab arm assembly, wherein the lifting and walking mechanism is used to drive the grab arm assembly to lift and move, and the grab arm assembly comprises a frame, a pair of left and right grab arms and a driving mechanism, wherein a grab hook is provided at the lower end of the grab arm, and the grab arm has two states: open and closed, and the grab hook can lift the pipe segment when the grab arm is closed and avoid the pipe segment when the grab arm is opened; It is characterized in that The frame includes a gripping plate, and the gripping plate and the gripping hook are arranged at intervals up and down to form an activity space, and the activity space is used for the gripping arm assembly to move up and down relative to the pipe segment supported at the bottom; the gripping arm assembly includes a resetter, and the resetter is used to provide a reset force to drive the gripping arm to a reset state, one of the open and closed states is the reset state, and the other is defined as a non-reset state; The driving mechanism includes a cam and a one-way intermittent transmission mechanism; the cam is rotatably assembled on the frame, the cam is directly or through a transmission component to cooperate with the grabbing arm in transmission, and the cam has a set edge shape so that when the cam rotates, it has cam positions that are different by a set angle and appear alternately: a force application position and a release position. The cam in the force application position provides a repetitive force opposite to the resetting force to keep the grabbing arm in a non-resetting state, and the cam in the release position releases the repetitive force to return the grabbing arm to a resetting state. The one-way intermittent transmission mechanism is used to convert the linear reciprocating motion into a rotational motion of a set angle for each one-way rotation, and includes an active member and a driven member. The active member is a push rod that moves up and down and passes through the center hole of the gripping disk. The push rod includes an upper end portion of the push rod, a lower end portion of the push rod, and a push rod spring. The upper end portion of the push rod and the lower end portion of the push rod are connected by the push rod spring. The lower end of the push rod is used to cooperate with the top surface stopper of the pipe segment in the active space. The upper end of the push rod is used to cooperate with the driven member. When the push rod moves upward, the driven member is driven to rotate. When the push rod moves downward, the one-way intermittent transmission mechanism is self-locking; the driven member cooperates with the cam transmission to convert one up and down reciprocating motion of the push rod into a rotational motion that drives the cam to rotate unidirectionally at a set angle, so that the cam station is converted once; During a reciprocating motion of the grabbing arm assembly relative to the pipe segment, first downward and then upward, the pipe segment in the active space reciprocates up and down once relative to the grabbing arm assembly, so that the push rod is pushed upward by the ascending pipe segment and moves downward due to gravity when the pipe segment moves downward. At the same time, the cam changes its working position under the action of the follower, and the grabbing arm changes its state under the action of the cam.

2. The segment lifting device according to claim 1, It is characterized in that The driven member is a dial assembly, which includes a shaft seat, a dial rod, and an elastic member. The shaft seat is fixedly connected to the cam and has a common axis of revolution. The dial rods correspond to the working positions of the cam one by one and are evenly distributed along the circumference around the axis of revolution. The dial rods are hinged to the shaft seat and have two states when reciprocally swinging: a driving state and an avoidance state. In the driving state, the dial rod presses against a stop member provided on the shaft seat and can apply a torque to the shaft seat. In the avoidance state, the dial rod disengages from the stop member in the reverse direction and cannot apply a torque to the shaft seat. The elastic member is used to drive the dial rod to press against the stop member. The dial rod has a stop surface that cooperates with the stop member and a pressing surface that cooperates with the ejector rod. The orientations of the stop surface and the pressing surface are opposite. When each dial rod rotates around the axis of revolution with the shaft seat, there are successively reached dial rod working positions: a preparatory position and a completion position. The preparatory position and the completion position are distributed from bottom to top on the moving path of the ejector rod. The pressing surface of the dial rod in the preparatory position faces downward corresponding to the upper end of the ejector rod. When the grasping arm assembly moves up and down, the segment in the active space has an upper position and a lower position. When the segment moves from the lower position to the upper position, the ejector rod is pushed upward by the segment. When the segment moves from the upper position to the lower position, the ejector rod under the action of gravity moves downward. When the ejector rod moves upward, the dial rod in the preparatory position is pushed by the ejector rod to maintain the driving state and continues to rotate around the axis of revolution to reach the completion position. At the same time, the dial rod drives the shaft seat and the cam to rotate, thereby switching the cam working position and changing the state of the grasping arm, and the next dial rod reaches the preparatory position. When the ejector rod moves downward, the one-way intermittent transmission mechanism is self-locked. The dial rod in the preparatory position is temporarily pushed away to the avoidance state by the ejector rod and returns to the driving state under the action of the elastic member after the ejector rod leaves. The dial rod in the preparatory position always remains in the preparatory position to realize the self-locking of the one-way intermittent transmission mechanism, so that the cam working position and the state of the grasping arm remain unchanged.

3. The segment hoisting device according to claim 2, characterized in that the shaft seat includes a disc-shaped dial and a rotating shaft fixed in the center of the dial. The dial rod is hinged on the outer peripheral surface of the rotating shaft. The stop member is a stop block protruding on the outer peripheral surface of the rotating shaft. The elastic member is a dial rod spring, and the dial rod spring is connected between the outer peripheral surface of the rotating shaft and the dial rod.

4. The segment hoisting device according to claim 3, characterized in that positioning grooves are provided on the outer peripheral surface of the dial. The positioning grooves correspond to the cam working positions one by one. A positioning spring and a positioning block that cooperate with the positioning grooves are further provided on the frame. The positioning block is used to insert into the positioning groove to block the rotation of the cam to keep the cam working position unchanged and withdraw from the groove when the one-way intermittent transmission mechanism drives the cam to rotate. The positioning spring is used to apply an elastic force to the positioning block.

5. The segment hoisting device according to claim 1, characterized in that two force-applying rods are movably assembled on the frame in the left-right direction: a left force-applying rod and a right force-applying rod. The two force-applying rods are symmetrically arranged on the left and right sides of the cam. The cam is in transmission cooperation with the grasping arm through the two force-applying rods.

6. The segment hoisting device according to claim 2, characterized in that the cam working positions are four consecutive positions that differ by 90 degrees. The first and third positions are force-applying positions, and the second and fourth positions are release positions. There are four dial rods, which are hinged to the shaft seat with a difference of 90 degrees.

7. The segment lifting device according to claim 1, characterized in that, the reset device is a reset spring, the open state of the grasping arm is the reset state, and the closed state of the grasping arm is the non-reset state.

8. A segment lifting method, using the segment lifting device according to any one of claims 1-7, comprising the following steps: (1) Move the grasping arm assembly to the segment taking position and position it above the segment to be taken. When the grasping arm of the grasping arm assembly is in the open state, it descends. The ejector rod of the grasping arm assembly is pushed upward by the segment, and the ejector rod drives the cam to rotate through the follower, thereby switching the cam working position. Then, under the action of the cam, the grasping arm switches from the open state to the closed state, so that the grasping hook on the grasping arm can lift the segment upward. After the grasping arm of the grasping arm assembly switches to the closed state, it continues to ascend, and the segment is lifted by the grasping hook on the grasping arm. The ejector rod descends under the action of gravity. At the segment taking position, during the process of the segment reciprocating up and down once in the moving space, the cam switches the working position under the action of the one-way intermittent transmission mechanism, and the grasping arm switches from the open state to the closed state under the action of the cam; (2) The grasping arm assembly moves from the segment taking position to the segment placing position. When the grasping arm of the grasping arm assembly is in the closed state, it descends. The bottom of the segment is supported and ascends relative to the grasping arm assembly and disengages from the grasping hook. The ejector rod of the grasping arm assembly is pushed upward by the segment, and the ejector rod drives the cam to rotate through the follower, thereby switching the cam working position. Then, under the action of the cam, the grasping arm switches from the closed state to the open state, so that the grasping hook on the grasping arm can avoid the segment. At the segment placing position, during the process of the segment reciprocating up and down once in the moving space, the cam switches the working position under the action of the one-way intermittent transmission mechanism, and the grasping arm switches from the closed state to the open state under the action of the cam; (3) After the grasping arm of the grasping arm assembly switches to the open state, it continues to ascend, and the segment continues to descend relative to the grasping arm assembly and disengages from the grasping arm assembly.

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