Device for cutting elastomer expansion joint residues under bridge floor

Abstract

The utility model relates to the technical field of bridge maintenance equipment, in particular to a device for cutting elastomer expansion joint residues under a bridge floor. Comprising a telescopic rod, a transmission box installed at the end of the telescopic rod and a cutting mechanism installed at the output end of the transmission box, a motor is installed at the near end of the transmission box, an output shaft is installed at the far end of the transmission box, and the output shaft is in transmission connection with the motor; the cutting mechanism comprises a driving shaft mounted at the end part of the output shaft, and a cutting cutterhead fixedly mounted on the driving shaft; the output shaft is inserted into the transmission case in a penetrating mode through a bearing, a spline sleeve is arranged at the end of the output shaft, the driving shaft is installed in the spline sleeve in a matched mode through a spline, and a spring is arranged at the inner end of the driving shaft. The height of the device can be adjusted according to the telescopic rods of different lengths, cutting operation can be conveniently conducted under a bridge floor, the two ends of an elastic body can be cut at the same time, clamping stagnation is avoided during construction operation, and efficiency is high; operation under the bridge can be directly carried out without dismantling railway ballasts or in the railway operation period, and the problem that a traditional expansion joint cutting device is low in cutting efficiency on the bridge floor is solved.

Description

Technical Field

[0001] This utility model relates to the technical field of bridge maintenance equipment, specifically a device for cutting the residue of elastomeric expansion joints under the bridge deck. Background Technology

[0002] Expansion joints are structural joints installed along the construction joint direction of a building to prevent structural damage caused by thermal expansion and contraction due to climate temperature changes. To prevent rainwater from entering the bridge through expansion joints and causing problems such as grout leakage and frost heave, polyurethane elastomers with expansion properties are added to the expansion joints. However, due to various factors such as weather conditions and construction quality, some elastomer expansion joints may experience cracking or even detachment between the elastomer and the concrete at the beam end. In such cases, the expansion joint needs to be replaced to restore its waterproof sealing function. Replacing an expansion joint requires cutting the damaged elastomer to remove it. Existing expansion joint cutting devices are bulky and can only operate on the bridge deck. When there is track maintenance, work can only be done during railway downtime, and the ballast and steel cover plates must be removed before work can be done on the bridge, resulting in low efficiency. Furthermore, in existing technology, the cutting blades in expansion joint cutting devices are single-blade, meaning they can only cut one end of the elastomer expansion joint before cutting the other end, further reducing cutting efficiency. For example, Chinese Patent 2024214815261 discloses "A Cutting Device for Expansion Joints" (authorization announcement number CN222730362U). This device includes a horizontally placed base plate, with a rotating wheel arranged front and back along an axis fixed around each of the four sides of the lower end face of the base plate. A handle is fixed to the upper right side of the base plate. A through groove extending from the upper end face of the base plate to the lower end face is provided. A cover with an opening at the lower end is mounted on the upper side of the base plate. The lower side of the left end of the cover is hinged to the base plate, and the right end of the cover can swing up and down. A rotating shaft is installed inside the cover, and two cutting blades coaxial with the rotating shaft are fixed on the rotating shaft. There is a gap between the two cutting blades, and the cutting blades can be positioned below the rotating wheel as the cover moves downward. This device is used to solve the problems of skewed cutting position and broken cutting teeth. Utility Model Content

[0003] To address the shortcomings of existing technologies, this utility model provides a device for cutting remnants of elastic expansion joints under bridge decks. It solves the problems of existing expansion joint cutting devices being unable to operate under bridges, and being unable to simultaneously cut both ends of the elastic material while allowing for free expansion and contraction. This device allows for adjustment of the equipment height according to expansion joints of different heights; it can simultaneously cut both ends of the elastic material; and it allows for direct operation under bridges without the need to remove ballast or during railway operation, thus solving the problem of low cutting efficiency on bridge decks with traditional expansion joint cutting devices.

[0004] The technical solution adopted by this utility model to solve the technical problem is:

[0005] This utility model discloses a device for cutting the residue of an elastomer expansion joint under a bridge deck. It includes a telescopic rod, a transmission box installed at the end of the telescopic rod, and a cutting mechanism installed at the output end of the transmission box. A motor is installed at the near end of the transmission box, and an output shaft is installed at the far end of the transmission box. The output shaft is connected to the motor for transmission. The cutting mechanism includes a drive shaft installed at the end of the output shaft and a cutting disc fixedly installed on the drive shaft. The output shaft is inserted into the transmission box through a bearing, and a spline sleeve is provided at the end of the output shaft. The drive shaft is installed in the spline sleeve through a spline fit, and a spring is provided at the inner end of the drive shaft.

[0006] This solution allows the device to adjust its height according to the different lengths of the telescopic rods, facilitating cutting operations under the bridge deck. It can cut both ends of the elastic body simultaneously and can operate directly under the bridge without removing ballast or during railway operation, solving the problem of low cutting efficiency on the bridge deck by traditional expansion joint cutting devices.

[0007] Preferably, a set of cutting mechanisms is provided at each end of the output shaft, and the outer end of the drive shaft is provided with a shaft head for mounting the cutting disc and a screw coaxially arranged with the shaft head. The cross-sectional shape of the shaft head is a non-circular irregular structure, and a nut and a hemispherical end cap are installed on the screw.

[0008] With this solution, the cutting disc is less prone to slipping or jamming, which facilitates smooth cutting operations.

[0009] Preferably, the transmission box includes a left side wall and a right side wall arranged in parallel. The motor is fixedly installed on the left side wall or the right side wall. The motor shaft is fixedly connected to the drive wheel arranged between the left side wall and the right side wall. The drive wheel is drivenly connected to the driven wheel fixedly installed on the output shaft.

[0010] This design results in a simple transmission box structure that is easy to maintain.

[0011] Preferably, the bearing is a thrust bearing.

[0012] This solution allows the thrust bearing to stabilize the axial position of the output shaft and prevent axial displacement of the output shaft.

[0013] Preferably, the telescopic rod includes a fixed rod fixedly connected to the near end of the transmission box and a movable rod connected to the fixed rod by a positioning pin. The movable rod is provided with a plurality of positioning pin holes arranged along its length.

[0014] With this solution, the length of the telescopic rod is adjustable, and its structure is simple and easy to use.

[0015] Thanks to the aforementioned structure, the device can adjust its height according to the different lengths of the telescopic rods, facilitating cutting operations under the bridge deck. It can cut both ends of the elastic body simultaneously, ensuring smooth and efficient construction. It can be used directly under the bridge without removing ballast or during railway operation, solving the problem of low cutting efficiency on the bridge deck caused by traditional expansion joint cutting devices. Attached Figure Description

[0016] Figure 1 This is a front structural diagram of one embodiment of the present invention.

[0017] Figure 2 This is an enlarged schematic diagram of the cutting mechanism.

[0018] Figure 3 This is a schematic diagram of the structure of the outer end face of the drive shaft. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0020] like Figure 1 As shown, the device for cutting remnants of elastomer expansion joints under bridge decks according to this utility model includes a telescopic rod 4, a transmission box 3 installed at the end of the telescopic rod 4, and a cutting mechanism 8 installed at the output end of the transmission box 3. A set of cutting mechanisms 8 is provided at each end of the output shaft 17. A motor 1 is installed at the near end of the transmission box 3, and the output shaft 17 is installed at the far end of the transmission box 3. The output shaft 17 is connected to the motor 1 via a transmission connection. The distance between the two sets of cutting mechanisms 8 is approximately equal to the width of the expansion joint to be cut. In use, the device is lifted from under the bridge deck, and the two sets of cutting mechanisms 8 are respectively aligned with both sides of the polyurethane elastomer in the expansion joint for cutting.

[0021] like Figure 2As shown, the cutting mechanism 8 includes a drive shaft 20 mounted on the end of the output shaft 17 and a cutting disc 19 fixedly mounted on the drive shaft 20. The output shaft 17 is inserted into the transmission housing 3 through a bearing 16, which is a thrust bearing, allowing the output shaft 17 to rotate but not move axially. A spline sleeve 171 is provided at the end of the output shaft 17, and the drive shaft 20 is installed in the spline sleeve 171 through a spline fit, allowing the drive shaft 20 to rotate with the output shaft 17 and slide axially. A spring 9 is provided at the inner end of the drive shaft 20, with hanging rings at both ends. One end of the spring 9 is connected to the inner end of the drive shaft 20, and the other end is connected to the bottom of the spline sleeve 171. In this way, the spring 9 can hold the drive shaft 20 in place to prevent it from falling out of the spline sleeve 171. On the other hand, when the drive shaft 20 is compressed and retracted into the spline sleeve 171, it applies a restoring elastic force to the drive shaft 20. When the external force disappears, it pushes the drive shaft 20 back to its original position.

[0022] Furthermore, as a further improvement of this utility model, the outer end of the drive shaft 20 is provided with a shaft head 201 for mounting the cutting blade disc 19 and a screw 202 coaxially arranged with the shaft head 201. The cross-sectional shape of the shaft head 201 is a non-circular irregular structure. A nut 18 and a hemispherical end cap 21 are mounted on the screw 202. The shaft head 201 is a non-circular columnar structure, for example, it can adopt a square cross-section or a pentagonal or hexagonal cross-section. Alternatively, it can adopt... Figure 3 The structure shown involves cutting a cross-section slightly smaller than the diameter on each side of a cylinder with a larger diameter, forming an irregularly shaped cylinder with two parallel cross-sections. The shape of the mounting hole at the center of the cutting disc 19 matches the cross-sectional shape of the shaft head 201, and is a non-circular irregular structure. This ensures that the cutting disc 19 will not slip as the shaft head 201 rotates after being mounted on it. Tightening the nut 18 on the screw 202 can press the cutting disc 19 tightly from the outside, preventing it from loosening. The end cap 21 has a semi-circular outer contour and an internal thread at its center that matches the screw 202. In use, after tightening the nut 18, the end cap 21 is screwed onto the outer end of the screw 202. This protects the external threads on the screw 202 from damage during cutting, and the hemispherical end cap 21 provides good passage when moving close to the inner wall of the expansion joint, preventing jamming that could prevent the cutting mechanism 8 from moving.

[0023] like Figure 1As shown, the transmission box 3 includes a left side wall 31 and a right side wall 32 arranged in parallel. Both the left side wall 31 and the right side wall 32 are U-shaped groove structures that are fastened together by snap-fit ​​or fastening bolts, forming a cavity between the left side wall 31 and the right side wall 32. The motor 1 is fixedly installed on the left side wall 31 or the right side wall 32. The rotating shaft 13 of the motor 1 is fixedly connected to the driving wheel 12 located between the left side wall 31 and the right side wall 32. The driving wheel 12 is driven by the driven wheel 15 fixedly installed on the output shaft 17. The driving wheel 12 and the driven wheel 15 can be connected by a belt 6 or by other transmission methods such as a chain. When the motor 1 is working, it drives the driving wheel 12 to rotate through the rotating shaft 13. The driving wheel 12 drives the driven wheel 15 and the output shaft 17 to rotate through the transmission mechanism. The output shaft 17 drives the cutting disc 19 to rotate through the drive shaft 20. The cutting edge of the cutting disc 19 cuts the polyurethane elastomer in the expansion joint. The structure and shape of the cutting disc 19 and the blade are existing technologies and will not be described in detail here.

[0024] Additionally, the telescopic rod 4 includes a fixed rod 41 fixedly connected to the near end of the transmission box 3, and a movable rod 42 connected to the fixed rod 41 via positioning pins. The movable rod 42 has multiple positioning pin holes 11 arranged along its length. Both the fixed rod 41 and the movable rod 42 are rectangular square tubes. One end of the fixed rod 41 is fixedly connected to the left side wall 31 and right side wall 32 of the transmission box 3 via clamping bolts 22, or it can be directly welded to the left side wall 31 and right side wall 32. The other end of the fixed rod 41 has mounting holes for the positioning pins. In use, aligning the positioning pin holes 11 on the movable rod 42 with the mounting holes on the fixed rod 41 and inserting the positioning pins connects the movable rod 42 and the fixed rod 41. Different alignments of the positioning pin holes 11 with the mounting holes result in telescopic rods 4 of varying lengths. The other positioning pin holes on the movable rod 42 can be used to connect it to a traveling machine, facilitating stable support and smooth movement of the cutting mechanism 8 during cutting operations.

[0025] In use, the telescopic rod 4 is fixedly installed on the lifting arm of the traveling machinery. The lifting arm raises the position of the cutting mechanism 8 so that it is aligned with the expansion joint from below the bridge deck. The cutting discs 19 of the two sets of cutting mechanisms 8 are respectively aligned with the two sides of the expansion joint. The motor 1 is started, and the cutting discs 19 cut the polyurethane elastomer, forming a cutting slit between the polyurethane elastomer and the inner wall of the expansion joint. At this time, the traveling machinery is started and moves along the length of the expansion joint, driving the cutting discs 19 to cut two parallel cutting slits on both sides of the polyurethane elastomer in the expansion joint until the polyurethane elastomer can be removed. During the cutting process, due to the certain error in the width of the expansion joint, when the width becomes narrower, the two inner side walls of the expansion joint may exert a certain lateral squeezing force on the cutting discs 19. This squeezing force pushes the shaft head 201 to move into the spline sleeve 171, so that the distance between the two cutting discs 19 always adapts to the width of the expansion joint, and the cutting discs 19 will not get stuck and can move forward smoothly. When the width of the expansion joint returns to normal, the spring 9 pushes the shaft head 201 to reset, and the distance between the two cutting discs 19 still adapts to the width of the expansion joint, so that the cutting operation can be completed smoothly.

[0026] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A device for cutting the residue of an elastic expansion joint under a bridge deck, comprising a telescopic rod (4), a transmission box (3) installed at the end of the telescopic rod (4), and a cutting mechanism (8) installed at the output end of the transmission box (3), characterized in that: The transmission box (3) is equipped with a motor (1) at its near end and an output shaft (17) at its far end. The output shaft (17) is connected to the motor (1) in a transmission connection. The cutting mechanism (8) includes a drive shaft (20) installed at the end of the output shaft (17) and a cutting disc (19) fixedly installed on the drive shaft (20). The output shaft (17) is inserted through a bearing (16) into the transmission box (3). A spline sleeve (171) is provided at the end of the output shaft (17). The drive shaft (20) is installed in the spline sleeve (171) through a spline fit. A spring (9) is provided at the inner end of the drive shaft (20).

2. The device for cutting the residue of an elastic expansion joint under a bridge deck according to claim 1, characterized in that: A set of cutting mechanisms (8) is provided at each end of the output shaft (17). The outer end of the drive shaft (20) is provided with a shaft head (201) for mounting the cutting disc (19) and a screw (202) coaxially arranged with the shaft head (201). The cross-sectional shape of the shaft head (201) is a non-circular irregular structure. The screw (202) is equipped with a nut (18) and a hemispherical end cap (21).

3. The device for cutting the residue of an elastic expansion joint under a bridge deck according to claim 1 or 2, characterized in that: The transmission box (3) includes a left side wall (31) and a right side wall (32) arranged in parallel. The motor (1) is fixedly installed on the left side wall (31) or the right side wall (32). The rotating shaft (13) of the motor (1) is fixedly connected to the driving wheel (12) arranged between the left side wall (31) and the right side wall (32). The driving wheel (12) is connected to the driven wheel (15) fixedly installed on the output shaft (17).

4. The device for cutting the residue of an elastomer expansion joint under a bridge deck according to claim 1 or 2, characterized in that: The bearing (16) is a thrust bearing.

5. The device for cutting the residue of an elastic expansion joint under a bridge deck according to claim 1 or 2, characterized in that: The telescopic rod (4) includes a fixed rod (41) fixedly connected to the near end of the transmission box (3) and a movable rod (42) connected to the fixed rod (41) by a positioning pin. The movable rod (42) is provided with a plurality of positioning pin holes (11) arranged along its length direction.

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