CN106193270A - Urban discharging pipeline blocking Dredge drill bit - Google Patents

Abstract

The dredging bit for urban drainage pipeline blockage includes a front cone, a middle cylinder, a rear cone and a rear cylinder arranged coaxially from front to back. There is a water spray hole for forward rotation drive at the rear of the cylinder, a water spray hole for backward rotation drive at the front of the middle cylinder, a retreat water spray hole at the rear of the front cone, and a forward water spray hole at the front of the rear cone , the inner wall of the middle cylinder is provided with a fixed bracket, and the fixed bracket is provided with a water pressure adjustment linkage mechanism for blocking/opening the four kinds of water spray holes; the front end of the front cone is provided with a jet hole; the rear cylinder is coaxial A water inlet pipe is connected, and a rotary sealing structure is arranged between the outer wall of the water inlet pipe and the inner wall of the rear cylinder. The invention fully reduces the labor intensity of operators, has a high degree of automation, moves forward or backward by adjusting the water pressure, can be used repeatedly, has good dredging effect, and is specially suitable for dredging municipal pipelines.

Description

Drill bit for unblocking urban drainage pipes

technical field

The invention belongs to the technical field of municipal engineering management and maintenance, and in particular relates to a dredging drill bit for blockage of urban drainage pipes.

Background technique

Every summer, heavy rainfall occurs in many places in China, and urban waterlogging problems emerge one after another, directly endangering the safe operation of the city and people's lives, and also causing huge economic losses. There are many reasons for urban waterlogging, such as excessive rainfall, imperfect drainage systems, and damaged drainage pipes. Coupled with the increasing intensity of urban construction, the sand and soil required for the project are easily dropped and accumulated on the road during transportation, and flow into the sewage and rainwater drainage system with the road surface washing, resulting in an increase in the amount of silt in the pipeline and causing pipeline blockage. At the same time, it will also lead to poor drainage in rainy days, further aggravating urban waterlogging, affecting smooth traffic, and even causing traffic paralysis. How to effectively improve the drainage efficiency of urban drainage pipes, reduce pipe siltation or blockage, ensure smooth flow of pipes, and ensure safety during flood seasons are the most effective ways to solve urban waterlogging.

At present, the dredging vehicles of municipal engineering are generally used to dredge urban rainwater and sewage drainage pipes, but most of the operations on site still require manual operation, which not only has harsh working environment, high labor intensity, low work efficiency, but also consumes a lot of water resources. Dredge effect is not good.

Contents of the invention

In order to solve the deficiencies in the prior art, the present invention provides a dredging drill bit for blockage of urban drainage pipes with high degree of automation, high dredging efficiency, good dredging effect and water saving.

In order to solve the above-mentioned technical problems, the present invention adopts the following technical scheme: the dredging drill bit for urban drainage pipe blockage, comprising a front cone, a middle cylinder, a rear cone and a rear cylinder coaxially arranged in sequence from front to back, and the front cone The cylinder has a conical structure with a sharp front and a thick rear. The outer diameter of the rear end of the front cone is equal to the outer diameter of the middle cylinder, and the rear cone is a conical structure with a thick front and a thinner back. diameter, the outer diameter of the rear end of the rear cone is equal to the rear cylinder;

The outer peripheral surface of the middle cylinder is provided with spiral convex ribs along the axial direction, the rear part of the middle cylinder is uniformly provided with at least three forward rotation driving water spray holes along the circumference direction, and the front part of the middle cylinder is uniformly provided with at least three water spray holes along the circumference direction. Three backward rotation driving water spray holes, at least three backward water spray holes are evenly opened in the rear of the front cone along the circumferential direction, and at least three forward water spray holes are evenly opened in the front of the rear cone along the circumferential direction;

The centerlines of all forward rotating drive water spray holes are located on a plane perpendicular to the centerline of the middle cylinder; the centerlines of all backward rotation drive water spray holes are located on another plane perpendicular to the centerline of the middle cylinder. The center line of the rotary drive water spray hole and the center line of the reverse rotary drive water spray hole are parallel to the tangential direction of the middle cylinder, and the outer port of the forward rotation drive water spray hole is in the same direction as the middle cylinder rotates clockwise , the direction of the outer port of the water spray hole driven by the backward rotation is consistent with the direction when the middle cylinder rotates counterclockwise; the center line of the forward water spray hole and the center line of the backward water spray hole are parallel to the center line of the middle cylinder;

There is a fixed bracket on the inner wall of the middle part of the middle cylinder, and a fixed cylinder with an open front end is arranged on the fixed bracket. There is a compression spring between the right side wall of the fixed cylinder, and the front side of the slider is fixedly connected with the front linkage rod along the axis direction. The front end of the front linkage rod is connected by bolts and nuts. There is a front permeable hole on the top, a front sealing bracket is arranged on the outer circumference of the front blocking plate, a front sliding sealing ring and a front conical sealing ring located on the rear side of the front sliding sealing ring are arranged on the outer circumference of the front sealing bracket, and the front sliding sealing ring Sliding and sealing connection with the inner wall of the middle cylinder, the front conical sealing ring corresponds to the front and rear of the retreat water spray hole and is adapted to the inner wall of the front cone cylinder; the rear side of the slider is fixedly connected along the axial direction with a rearward pass through the compression spring and the fixed cylinder The rear linkage rod on the rear side wall, the rear end of the rear linkage rod is connected by bolts and nuts to a disc-shaped rear blocking plate, the rear blocking plate is provided with a rear permeable hole, and the outer periphery of the rear blocking plate is provided with a rear sealing bracket , the outer circumference of the rear sealing bracket is provided with a rear sliding sealing ring and a rear conical sealing ring located on the rear side of the rear sliding sealing ring. The holes correspond to the front and back and are adapted to the inner wall of the rear cone. The diameter of the water spray hole driven by forward rotation is smaller than the width of the rear sliding sealing ring, and the diameter of the water spray hole driven by backward rotation is smaller than the width of the front sliding sealing ring;

A jet hole is provided at the front end of the front cone; a water inlet pipe is coaxially connected in the rear cylinder, and a rotary sealing structure is arranged between the outer wall of the water inlet pipe and the inner wall of the rear cylinder.

The rotary sealing structure includes a limit ring plate at the front end of the inner wall of the rear cylinder, the front end of the rear cylinder is inserted into the limit ring plate, a positioning sleeve is provided on the outer wall of the water inlet pipe, and a gap is formed between the inner wall of the rear cylinder and the outer wall of the water inlet pipe. The bearing chamber with the rear end open, the bearing chamber is provided with the first thrust bearing, the inner ball bearing, the second thrust bearing and the fixed sealing ring from front to rear, and the first thrust bearing, the second thrust bearing and the fixed sealing ring are set in the On the water inlet pipe, the inner ring of the inner ball bearing is set on the positioning sleeve, the first support ring set on the positioning sleeve is set between the first thrust bearing and the inner ball bearing, the second thrust bearing and the inner ball bearing There is a second support ring set on the positioning sleeve; the rear end of the rear cylinder is provided with a bearing gland for pressing the second thrust bearing and fixing the sealing ring. The bearing gland is connected to the rear cylinder through screws. The rear end face is tightly connected.

A sealing ring is arranged between the inner ring of the limiting ring plate and the outer wall of the water inlet pipe, between the inner wall of the fixed cylinder and the outer wall of the slider, and between the outer wall of the rear linkage rod and the rear side wall of the fixed cylinder.

The middle cylinder includes a first cylinder and a second cylinder, the rear end of the first cylinder is threadedly connected with the front end of the second cylinder, the first cylinder and the front cone are integrated, the rear cylinder and the rear cone integrated structure.

Using the above technical scheme, the rear end of the water inlet pipe is connected to a high-pressure water source (the high-pressure water source can be a dredging vehicle commonly used in municipal engineering), and the present invention is placed at the blockage of the drainage pipe, and the high-pressure water is injected into the middle cylinder from the water inlet pipe, and the high-pressure water Push the rear blocking plate to move forward, the rear sliding sealing ring on the outer edge of the rear blocking plate is separated from the forward rotation driving water spray hole, the rear tapered sealing ring is separated from the forward water spray hole, and the rear blocking plate passes through the rear linkage rod, slider and The front linkage rod pushes the front blocking plate to move forward, the front sliding sealing ring on the outer edge of the front blocking plate will move backward and rotate to drive the water spray hole to block, and the front conical sealing ring will block the backward water spray hole, and at the same time, the water flow passes through the water spray hole. After the hole, the fixed bracket and the front permeable hole, it is sprayed out through the jet hole at the front end of the front cone, and the high-pressure water jetted through the jet hole sprays the blockage, which plays a certain role in dredging the jet flow. At the same time, the high-pressure water flows from the forward rotation Drive the water spray hole and the forward water spray hole to spray, the impulse generated by the high-pressure water jet sprayed out of the forward rotation drive water spray hole drives the dredging drill to rotate clockwise, and the impulse generated by the high-pressure water jet sprayed out of the forward water spray hole Drive the dredging drill bit forward, because the middle cylinder is provided with spiral convex ribs, and the convex ribs also rotate with the dredging bit to generate a spiral thrust to the dredging drill bit. When the drill bit rotates again, it also moves forward, thereby dredging the blockage in the drainage pipe, and the high-pressure water also plays a good role in dredging the blockage.

Because the drainage pipe is relatively long, it is difficult to withdraw directly after the present invention is screwed in. When the present invention needs to be withdrawn, the pressure of the high-pressure water is increased. After the water pressure of the high-pressure water increases, the high-pressure water will drive the slider to overcome the elastic force of the compression spring Move backward along the inner wall of the fixed cylinder. With the increase of water pressure, the slider moves backward all the time. The slider pulls the front blocking plate forward through the front linkage rod to move backward. At the same time, the slider pushes forward through the rear linkage rod. The blocking plate moves backward until the rear sliding sealing ring and the rear cone sealing ring block the forward rotation drive water spray hole and the forward water spray hole respectively, and the water pressure no longer rises. At this time, the backward rotation drives the water spray hole and the backward The water spray hole is opened, and the high-pressure water is sprayed from the water spray hole driven by the backward rotation and the water spray hole. The impulse generated by the jetted high-pressure water jet drives the dredging bit to retreat. Since the middle cylinder is provided with spiral ribs, the ribs also rotate with the dredging bit to generate a helical thrust on the dredging bit. When the helical thrust and high-pressure water flow The combined effect of forward driving force promotes the dredging drill bit to rotate and also moves backward, so that the dredging drill bit is withdrawn from the drainage pipe.

Due to the setting of the rotary sealing structure, the water inlet pipe remains motionless when the rear cylinder rotates at high speed. The first thrust bearing and the second thrust bearing play a good supporting role when the water inlet pipe and the middle cylinder are subjected to axial force. There is a sealing ring between the inner wall of the rear cylinder and the outer wall of the water inlet pipe, between the inner wall of the fixed cylinder and the outer wall of the slider, and between the outer wall of the rear linkage rod and the rear side wall of the fixed cylinder to provide a good seal and prevent high-pressure water from entering into the bearing chamber and the fixing cylinder.

The rear end of the first cylinder is threadedly connected to the front end of the second cylinder, the first cylinder and the front cone are integrally structured, and the rear cylinder and the rear cone are integrally structured. In this way, it is convenient to disassemble, repair and maintain the various internal components.

The center line of the water spray hole driven by the forward rotation and the center line of the water spray hole driven by the backward rotation are parallel to the tangential direction of the middle cylinder, so that the dredging drill bit can be driven to rotate clockwise or counterclockwise under the action of high-pressure water), The center line of the forward water spray hole and the center line of the retreat water spray hole are all parallel to the center line of the middle cylinder, and under the action of high-pressure water, the power to advance and retreat in the axial direction is provided for the dredging drill bit. The forward rotation driving water spray hole, the backward rotation driving water spray hole, the forward water spray hole and the retreating water spray hole are all convenient for processing and manufacturing.

In addition, two connecting rings are arranged symmetrically at the position adjacent to the bearing gland on the side of the water inlet pipe, and there are pull ropes connected to the connecting rings. Make the present invention exit the drain pipe faster and easier.

In summary, the present invention is novel in design, simple and compact in structure, easy to operate, fully reduces the labor intensity of operators, and has a high degree of automation. Forward or backward during the dredging process, and can be reused many times, the dredging effect is good, and it is specially suitable for the dredging operation of municipal pipelines.

Description of drawings

Fig. 1 is a structural representation of the present invention's profile;

Fig. 2 is A-A sectional view among Fig. 1;

Fig. 3 is a B-B sectional view in Fig. 1 .

detailed description

As shown in Fig. 1, Fig. 2 and Fig. 3, the dredging drill bit for blockage of urban drainage pipes of the present invention comprises a front cone 1, a middle cylinder, a rear cone 2 and a rear cylinder coaxially arranged in sequence from front to back Body 3, the front cone 1 has a conical structure with a sharp front and a thick rear. The outer diameter of the rear end of the front cone 1 is equal to the outer diameter of the middle cylinder. The diameter is equal to the outer diameter of the front end of the rear cone 2, and the outer diameter of the rear end of the rear cone 2 is equal to the rear cylinder 3; the middle cylinder includes the first cylinder 4 and the second cylinder, and the rear end of the first cylinder 4 is connected to the The front end of the second cylinder 5 is screwed, the first cylinder 4 and the front cone 1 are integrated, and the rear cylinder 3 and the rear cone 2 are integrated.

The outer peripheral surface of the middle cylinder is provided with spiral convex ribs 6 along the axial direction, at least three forward rotation driving water spray holes 7 are uniformly opened along the circumferential direction at the rear of the middle cylinder, and the front part of the middle cylinder is uniformly opened along the circumferential direction. There are at least three backward rotation driving water spray holes 8, the rear portion of the front cone 1 is uniformly provided with at least three retreat water spray holes 40 along the circumferential direction, and the front portion of the rear cone 3 is uniformly provided with at least three forward spray holes along the circumferential direction. Water hole 41.

The centerlines of all forward rotation driving spray holes 7 are located on a plane perpendicular to the centerline of the middle cylinder; the centerlines of all backward rotation drive water spray holes 8 are located on another plane perpendicular to the centerline of the middle cylinder , the center line of the forward rotation driving water spray hole 7 and the center line of the backward rotation driving water spray hole 8 are all parallel to the tangential direction of the middle cylinder body, and the outer port of the forward rotation drive water spray hole 7 faces clockwise with the middle cylinder body The direction of rotation is the same, and the direction of the outer port of the water spray hole 8 driven by the backward rotation is consistent with the direction when the middle cylinder rotates counterclockwise; the center line of the forward water spray hole 41 and the center line of the backward water spray hole are all parallel to the middle cylinder body centerline.

A fixed bracket 9 is provided on the inner wall of the middle part of the middle cylinder, and a fixed cylinder 10 with an open front end is arranged on the fixed bracket 9. The center line of the fixed cylinder 10 coincides with the center line of the middle cylinder body, and a slider is provided for sliding inside the fixed cylinder 10. 11. A compression spring 12 is provided between the rear side of the slider 11 and the right side wall of the fixed cylinder 10. The front side of the slider 11 is fixedly connected with the front linkage rod 13 along the axis direction, and the front end of the front linkage rod 13 is connected by a bolt and nut. A disc-shaped front blocking plate 14 is provided with a front permeable hole 15, a front sealing bracket 16 is provided on the outer periphery of the front blocking plate 14, and a front sliding sealing ring 17 is provided on the outer circumference of the front sealing bracket 16. And the front conical sealing ring 42 that is positioned at the rear side of the front sliding sealing ring 17, the front sliding sealing ring 17 is in sliding and sealing connection with the inner wall of the middle cylinder, and the front conical sealing ring 42 corresponds to the front and back of the retreating water spray hole 40 and is connected to the front cone. 1, the inner wall is compatible; the rear side of the slider 11 is fixedly connected along the axial direction with a rear linkage rod 18 that passes through the compression spring 12 and the rear side wall of the fixed cylinder 10 backwards, and the rear linkage rod 18 is connected by a bolt and nut. Disc-shaped rear blocking plate 19, the rear blocking plate 19 is provided with a rear permeable hole 20, the outer periphery of the rear blocking plate 19 is provided with a rear sealing support 21, and the outer circumference of the rear sealing support 21 is provided with a rear sliding sealing ring 22 And the rear tapered sealing ring 43 that is positioned at the back side of the rear sliding sealing ring 22, the rear sliding sealing ring 22 is in sliding sealing connection with the inner wall of the middle cylinder, the rear tapered sealing ring 43 corresponds to the front and rear of the forward spray hole 41 and is connected to the rear cone 2 inner walls are compatible; the aperture of the forward rotation driving water spray hole 7 is less than the width of the rear sliding seal ring 22, and the aperture of the backward rotation driving water spray hole 8 is less than the width of the front sliding seal ring 17.

The front end of the front cone 1 is provided with a jet hole 23; the rear cylinder 3 is coaxially connected with a water inlet pipe 24, and a rotary sealing structure is arranged between the outer wall of the water inlet pipe 24 and the inner wall of the rear cylinder 3.

The inner port of the forward rotation driving water spray hole 7 is located at the front side of the outer port of the forward rotation driving water spray hole 7, and the center line of the forward rotation driving water spray hole 7 deviates from the center line of the middle cylinder; the backward rotation drives the water spray hole 8 The inner port of the inner port is positioned at the rear side of the outer port of the reverse rotation drive water spray hole 8, the center line of the reverse rotation drive water spray hole 8 deviates from the center line of the dredging drill bit, the center line of the forward rotation drive water spray hole 7 and the retreat rotation drive spray hole 8 The centerlines of the water holes 8 all form an angle of 40-50° with the centerline of the middle cylinder.

The rotary sealing structure includes a limit ring plate 25 provided with the front end of the inner wall of the rear cylinder body 3. A bearing chamber with an open rear end is formed between the outer wall of the water inlet pipe 24. The bearing chamber is provided with a first thrust bearing 27, an inner ball bearing 28, a second thrust bearing 29 and a fixed sealing ring 30 from front to back. The first thrust bearing The bearing 27, the second thrust bearing 29 and the fixed sealing ring 30 are set on the water inlet pipe 24, the inner ring of the inner ball bearing 28 is set on the positioning sleeve 26, and a sleeve is arranged between the first thrust bearing 27 and the inner ball bearing 28. The first support ring 31 provided on the positioning sleeve 26, the second support ring 32 set on the positioning sleeve 26 is provided between the second thrust bearing 29 and the inner ball bearing 28; the rear end of the rear cylinder 3 is provided with a The bearing cover 32 is used to press and limit the second thrust bearing 29 and fix the sealing ring 30, and the bearing cover 32 is fastened to the rear end surface of the rear cylinder 3 through screws.

A sealing ring 34 is provided between the inner ring of the limit ring plate 25 and the outer wall of the water inlet pipe 24, between the inner wall of the fixed cylinder 10 and the outer wall of the slider 11, and between the outer wall of the rear linkage rod 18 and the rear side wall of the fixed cylinder 10.

The working process of the present invention is as follows: the rear end of the water inlet pipe 24 is connected to a high-pressure water source (the high-pressure water source can adopt a dredging vehicle commonly used in municipal engineering), the present invention is placed on the blockage of the drainage pipe, and the high-pressure water is injected into the center by the water inlet pipe 24 Inside the cylinder, the high-pressure water is moved forward by pushing the rear blocking plate 19, the rear sliding sealing ring 22 on the outer edge of the rear blocking plate 19 is separated from the forward rotation driving water spray hole 7, the rear tapered sealing ring 43 is separated from the forward water spray hole 41, and the rear The blocking plate 19 pushes the front blocking plate 14 to move forward through the rear linkage rod 18, the slider 11 and the front linkage rod 13 in turn, and the front sliding sealing ring 17 on the outer edge of the front blocking plate 14 will retreat and rotate to drive the spray hole 8 to block, The front cone sealing ring 42 blocks the retreat water spray hole 40. At the same time, after the water flow passes through the rear water permeable hole 20, the fixed bracket 9 and the front water permeable hole 15, it is sprayed out through the jet hole 23 at the front end of the front cone tube 1, and passes through the jet hole. The high-pressure water flow ejected from 23 sprays the clogged part, which plays a certain role in dredging the jet flow. At the same time, the high-pressure water is sprayed from the forward rotation driving water spray hole 7 and the forward water spray hole 41, and the forward rotation drives the water spray hole 7. The impulse generated by the ejected high-pressure water jet drives the dredging bit to rotate clockwise, and the impulse generated by the high-pressure water jet ejected from the forward water spray hole 41 drives the dredged bit to advance. , the convex rib 6 also produces a helical thrust to the dredging bit as the dredging bit rotates, and the helical thrust and the water flow act together to push the dredging bit to rotate while also moving forward, thereby dredging the blockage in the drainage pipe, and the high-pressure water also Play a good dredging effect on blockages.

Because the drainage pipe is relatively long, it is difficult to withdraw directly after the present invention is screwed in. When the present invention needs to be withdrawn, the pressure of the high-pressure water is increased. After the hydraulic pressure of the high-pressure water increases, the high-pressure water will drive the slider 11 to overcome the compression spring 12 The elastic force moves backward along the inner wall of the fixed cylinder 10. With the increase of water pressure, the slider 11 has been moving backward. The slider 11 pulls the front blocking plate 14 forward through the front linkage rod 13 and moves backward. At the same time, the slider 11 The rear blocking plate 19 is pushed forward by the rear linkage rod 18 and moves backward until the rear sliding sealing ring 22 and the rear tapered sealing ring 43 respectively block the forward rotation driving water spray hole 7 and the forward water spray hole 41. No longer rising, at this time, the reverse rotation drives the water spray hole 8 and the retreat water spray hole 40 to open. The impulse generated by the high-pressure water jet drives the dredging bit to rotate counterclockwise, and the impulse generated by the high-pressure water jet ejected from the retreating water spray hole 40 drives the dredged bit to retreat. Rib 6 also produces helical thrust to dredging drill bit along with the dredging drill bit rotation, and when spiral thrust and current act together, also moves backward when promoting dredging drill bit to rotate, so just makes dredging drill bit withdraw from drainpipe.

Due to the setting of the rotary sealing structure, the water inlet pipe 24 remains motionless when the rear cylindrical body 3 rotates at a high speed. The first thrust bearing 27 and the second thrust bearing 29 play a good supporting role when the water inlet pipe 24 and the middle cylinder are subjected to axial force. A sealing ring 34 is arranged between the inner wall of the rear cylinder body 3 and the outer wall of the water inlet pipe 24, between the inner wall of the fixed cylinder 10 and the outer wall of the slider 11, and between the outer wall of the rear linkage rod 18 and the rear side wall of the fixed cylinder 10 to play a good role. The sealing can prevent high-pressure water from entering the bearing chamber and the fixed cylinder 10.

The rear end of the first cylinder 4 is threadedly connected to the front end of the second cylinder 5, the first cylinder and the front cone are integrally structured, and the rear cylinder body 3 and the rear cone 2 are integrally structured. In this way, it is convenient to disassemble, repair and maintain the various internal components.

The center line of the forward rotation driving water spray hole 7 and the center line of the backward rotation driving water spray hole 8 are both parallel to the tangential direction of the middle cylinder, so that the dredging drill bit can be driven to rotate clockwise or counterclockwise under the action of high pressure water ), the center line of the forward water spray hole 41 and the center line of the retreat water spray hole 40 are all parallel to the center line of the middle cylinder, and under the action of high-pressure water, the power to advance and retreat in the axial direction is provided for the dredging drill bit. The water spray hole 7 driven by forward rotation, the water spray hole 8 driven by the backward rotation, the water spray hole 41 advanced and the water spray hole 40 retreated are all convenient for processing and manufacturing.

In addition, two connecting rings are arranged symmetrically near the position of the bearing gland 32 on the side of the water inlet pipe 24. The connecting rings are connected with pull ropes. rope, making the present invention exit the drain faster and more easily.

This embodiment does not impose any formal restrictions on the shape, material, structure, etc. of the present invention. All simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention belong to the protection of the technical solution of the present invention. scope.

Claims (4)

1. The dredging drill bit for urban drainage pipeline blockage is characterized in that: it includes a front cone, a middle cylinder, a rear cone and a rear cylinder arranged coaxially from front to back, and the front cone is pointed at the front and thick at the back. Cone structure, the outer diameter of the rear end of the front cone is equal to the outer diameter of the middle cylinder, and the rear cone is a conical structure with a thick front and a thinner back. The external diameter is equal to the rear cylinder; The outer peripheral surface of the middle cylinder is provided with spiral convex ribs along the axial direction, the rear part of the middle cylinder is uniformly provided with at least three forward rotation driving water spray holes along the circumference direction, and the front part of the middle cylinder is uniformly provided with at least three water spray holes along the circumference direction. Three backward rotation driving water spray holes, at least three backward water spray holes are evenly opened in the rear of the front cone along the circumferential direction, and at least three forward water spray holes are evenly opened in the front of the rear cone along the circumferential direction; The centerlines of all forward rotating drive water spray holes are located on a plane perpendicular to the centerline of the middle cylinder; the centerlines of all backward rotation drive water spray holes are located on another plane perpendicular to the centerline of the middle cylinder. The center line of the rotary drive water spray hole and the center line of the reverse rotary drive water spray hole are parallel to the tangential direction of the middle cylinder, and the outer port of the forward rotation drive water spray hole is in the same direction as the middle cylinder rotates clockwise , the direction of the outer port of the water spray hole driven by the backward rotation is consistent with the direction when the middle cylinder rotates counterclockwise; the center line of the forward water spray hole and the center line of the backward water spray hole are parallel to the center line of the middle cylinder; There is a fixed bracket on the inner wall of the middle part of the middle cylinder, and a fixed cylinder with an open front end is arranged on the fixed bracket. There is a compression spring between the right side wall of the fixed cylinder, and the front side of the slider is fixedly connected with the front linkage rod along the axis direction. The front end of the front linkage rod is connected by bolts and nuts. There is a front permeable hole on the top, a front sealing bracket is arranged on the outer circumference of the front blocking plate, a front sliding sealing ring and a front conical sealing ring located on the rear side of the front sliding sealing ring are arranged on the outer circumference of the front sealing bracket, and the front sliding sealing ring Sliding and sealing connection with the inner wall of the middle cylinder, the front conical sealing ring corresponds to the front and rear of the retreat water spray hole and is adapted to the inner wall of the front cone cylinder; the rear side of the slider is fixedly connected along the axial direction with a rearward pass through the compression spring and the fixed cylinder The rear linkage rod on the rear side wall, the rear end of the rear linkage rod is connected by bolts and nuts to a disc-shaped rear blocking plate, the rear blocking plate is provided with a rear permeable hole, and the outer periphery of the rear blocking plate is provided with a rear sealing bracket , the outer circumference of the rear sealing bracket is provided with a rear sliding sealing ring and a rear conical sealing ring located on the rear side of the rear sliding sealing ring. The holes correspond to the front and back and are adapted to the inner wall of the rear cone. The diameter of the water spray hole driven by forward rotation is smaller than the width of the rear sliding sealing ring, and the diameter of the water spray hole driven by backward rotation is smaller than the width of the front sliding sealing ring; A jet hole is provided at the front end of the front cone; a water inlet pipe is coaxially connected in the rear cylinder, and a rotary sealing structure is arranged between the outer wall of the water inlet pipe and the inner wall of the rear cylinder. 2. The dredging bit for urban drainage pipe blockage according to claim 1, characterized in that: the rotary sealing structure includes a limit ring plate provided with the front end of the inner wall of the rear cylinder, and the front end of the rear cylinder is inserted into the limit ring plate , a positioning sleeve is provided on the outer wall of the water inlet pipe, and a bearing chamber with an open rear end is formed between the inner wall of the rear cylinder and the outer wall of the water inlet pipe. Bearings and fixed sealing rings, the first thrust bearing, the second thrust bearing and the fixed sealing ring are set on the water inlet pipe, the inner ring of the inner ball bearing is set on the positioning sleeve, and there is a sleeve between the first thrust bearing and the inner ball bearing. The first support ring set on the positioning sleeve, the second support ring sleeved on the positioning sleeve is set between the second thrust bearing and the inner ball bearing; 2. The thrust bearing and the bearing gland for fixing the sealing ring, the bearing gland is tightly connected with the rear end surface of the rear cylinder by screws. 3. The dredging bit for urban drainage pipe blockage according to claim 2, characterized in that: between the inner ring of the limiting ring plate and the outer wall of the water inlet pipe, between the inner wall of the fixed cylinder and the outer wall of the slider, between the outer wall of the rear linkage rod and the outer wall of the fixed A sealing ring is arranged between the rear side walls of the barrel. 4. The dredging drill bit for urban drainage pipe blockage according to claim 1 or 2, characterized in that: the middle cylinder comprises a first cylinder and a second cylinder, and the rear end of the first cylinder is connected to the second cylinder. The front end is threaded, the first cylinder and the front cone are integrated, and the rear cylinder and the rear cone are integrated.