A sealing structure of a deviation rectifying section of a rectangular pipe jacking machine

Abstract

A sealing structure of a deviation rectification section of a rectangular pipe jacking machine, comprising a front shell and a rear shell, the rear shell being provided with a deviation rectification section extending into the front shell, the deviation rectification section being provided with at least two sealing rings and corresponding sealing grooves, the partition groove wall between adjacent sealing rings being higher than the outer side groove wall to reserve a displacement allowance; the rear shell being provided with a first injection channel communicating with the sealing grooves, and a second injection channel communicating with the gap between the deviation rectification section and the front shell, the rear end annular baffle of the deviation rectification section and the outer side soil body and the gap jointly enclosing a closed space, and the cross section of the baffle being inclined outward along the axial direction from front to back. The structure avoids single point failure through multiple sealing, reduces sealing ring loss by reserving displacement allowance, replenishes sealing material through the injection channel, strengthens the closure through the annular baffle, adapts to the multidirectional displacement and complex stress of the rectangular pipe jacking machine, improves the sealing reliability and deviation rectification flexibility, and ensures construction safety.

Description

Technical Field

[0001] This utility model relates to the field of building construction equipment technology, specifically to a sealing structure for the correction section of a rectangular pipe jacking machine. Background Technology

[0002] In the construction of rectangular pipe jacking projects such as urban underground utility tunnels and subway sections, the sealing structure of the correction section (the hinged joint between the front and rear shells) is a key component to ensure the dryness of the equipment's interior and prevent the infiltration of underground mud and water. Compared to circular pipe jacking machines, rectangular pipe jacking machines are affected by their cross-sectional shape, resulting in multi-directional displacement and more complex stress during the correction process. Traditional rectangular pipe jacking machines often use a single-seal design for the correction section, relying on only one sealing ring for sealing. This poses a risk of "leakage due to single-point failure." Once the seal is damaged, underground mud and water can easily seep into the equipment, damaging the drive and correction systems, and even causing ground subsidence, making it difficult to meet long-term construction safety requirements.

[0003] To address this issue, several sealing optimization solutions adapted to pipe jacking machines have emerged within the industry. For example, Chinese invention patent application number 202011434849.1 (publication number CN112392500A) discloses a "High-strength Rock Crushing Pipe Jacking Machine for Composite Strata," which sets a shell hinge sealing ring between the front and rear shells of the pipe jacking machine. The sealing ring elastically deforms and fits against the hinge surface to block mud and water. Simultaneously, it works with a correction cylinder to adjust the machine's posture, thus improving the sealing reliability of the circular pipe jacking machine to a certain extent.

[0004] However, the sealing structure of this pipe jacking machine still has significant shortcomings when applied to rectangular pipe jacking machines: First, it is not adapted to the multi-directional displacement characteristics of the correction section of the rectangular pipe jacking machine. The sealing ring and the shell are rigidly fitted. During correction, the swinging and translation of the shell will cause uneven compression and stretching of the sealing ring. The long side wears faster, while the short side is prone to cracking due to excessive compression, which greatly shortens the sealing life. Second, there is no design for movement space. The groove wall of the sealing ring installation groove in this scheme is a uniform height structure, which does not reserve movement margin for the multi-directional displacement of the correction section of the rectangular pipe jacking machine. When the shell moves, it is easy to interfere with the groove wall, which not only limits the correction accuracy but also aggravates the friction wear of the sealing ring. Third, there is no protective design adapted to the rectangular cross section. The cross section of the rectangular pipe jacking machine is subjected to uneven stress. A single sealing ring cannot fully cover all stress areas. In complex formations, formation pressure fluctuations can easily lead to the expansion of local sealing gaps, significantly increasing the risk of leakage.

[0005] Therefore, based on the existing sealing technology of pipe jacking machines, how to optimize the structure to adapt to the multi-directional displacement and complex stress characteristics of the correction section of rectangular pipe jacking machines, and improve the sealing reliability while ensuring the correction flexibility, has become a technical problem that technicians in this field urgently need to solve. Utility Model Content

[0006] The technical problem to be solved by this utility model is to provide a sealing structure for the correction section of a rectangular pipe jacking machine that adopts a multi-seal structure and a design with unequal height of the groove walls to adapt to the multi-directional displacement of the shell and the stress on the balanced cross section, in view of the above-mentioned technical status.

[0007] The technical solution adopted by this utility model to solve the above-mentioned technical problems is as follows: a sealing structure for the correction section of a rectangular pipe jacking machine, including a front shell and a rear shell, wherein the front end of the rear shell is provided with a correction section extending into the inner wall of the rear end of the front shell, characterized in that: at least two spaced sealing rings are provided on the outer periphery of the correction section, the sealing rings are correspondingly embedded in the sealing grooves on the outer periphery of the correction section, and a partition groove wall is formed between two adjacent sealing rings, the height of the partition groove wall is higher than the side groove wall outside the two outermost sealing rings, so as to reserve the movement margin for multi-directional displacement of the correction section.

[0008] In order to flexibly replenish grease or sealing material into the sealing groove, reduce frictional wear of the sealing ring, and promptly seal any small gaps in the seal, preferably, the rear housing is provided with a first injection channel, the outlet end of the first injection channel is connected to the sealing groove, and the inlet end extends to the inner peripheral wall of the rear housing for selective injection of grease or sealing material.

[0009] In order to ensure that the grease or sealing material can evenly cover the circumferential sealing groove of the correction section and avoid local sealing failure due to lack of lubrication or insufficient sealing material, preferably, the first injection channel is provided in multiple ways, and the multiple first injection channels are distributed at intervals along the circumference of the rear housing.

[0010] In order to deliver grease or sealing material to multiple adjacent sealing grooves in a single injection operation and ensure that multiple sealing grooves are adequately replenished, preferably, the first injection channel includes a first through hole and a connecting channel. The first through hole radially penetrates the partition groove wall, and the connecting channel extends axially and connects two adjacent sealing grooves, and the connecting channel is connected to the first through hole.

[0011] In order to ensure the connectivity of the connecting channel while facilitating the observation of the channel status during installation or maintenance, preferably, the connecting channel is a groove formed on the outer periphery of the partition groove wall.

[0012] In order to promptly replenish sealing material at the gap between the rear end of the side groove wall and the front housing in the event of a broken sealing ring, forming a secondary sealing protection and further preventing underground mud and water from seeping into the equipment through the gap, preferably, a gap is formed between the correction section of the rear housing, the outer periphery of the rear end of the side groove wall and the front housing, and a second injection channel is provided on the rear housing. The outlet end of the second injection channel is connected to the gap, and the inlet end extends to the inner peripheral wall of the rear housing.

[0013] To simplify the structure of the second injection channel, facilitate processing and maintenance, and ensure that the channel can stably penetrate the rear housing and achieve effective communication between the gap and the inner peripheral wall of the rear housing, preferably, the second injection channel is a second through hole, which penetrates the rear housing radially.

[0014] In order to ensure that the sealing material can be evenly filled into all circumferential areas of the gap, avoid local leakage points due to insufficient sealing material, and improve the overall sealing of the gap, preferably, multiple second through holes are provided, and the multiple second through holes are distributed at intervals along the circumference of the rear housing.

[0015] In order to isolate the outer soil from the gap and form a closed space, so as to avoid the soil directly squeezing the gap and causing the seal to fail, and at the same time to provide a space for the sealing material injected into the second injection channel to ensure that the sealing material can stably play a sealing role, preferably, the rear end of the correction section is provided with a ring baffle, which together with the outer soil and the gap forms a closed space.

[0016] In order to make it easier for the annular baffle to cut into the soil during the jacking process, reduce resistance and facilitate the rapid formation of a closed space, and at the same time reduce the impact pressure of the soil on the baffle, preferably, the cross-section of the annular baffle is inclined and tilted outward from the front end to the rear end along the axial direction of the correction section.

[0017] Compared with the prior art, the advantages of this utility model are as follows: By setting at least two spaced sealing rings on the outer periphery of the correction section and embedding the sealing rings into the sealing grooves on the outer periphery of the correction section, and by making the height of the partition groove wall formed between two adjacent sealing rings higher than the side groove wall outside the two outermost sealing rings, the redundant sealing design of multiple sealing rings avoids the risk of "single-point failure leading to leakage" in traditional single-seal systems, thus significantly improving sealing reliability. Furthermore, the height difference between the partition groove wall and the side groove wall provides sufficient space for multi-directional displacement of the correction section. The dynamic margin effectively avoids interference between the shell displacement and the trench wall during correction, ensuring the correction accuracy of the rectangular pipe jacking machine while reducing uneven compression, stretching, and friction loss of the sealing ring, thus extending the seal life. At the same time, the multi-seal structure adapts to the uneven stress characteristics of the rectangular pipe jacking machine cross-section, and can fully cover all stress areas. Even if the ground pressure fluctuation in the composite stratum causes local gap changes, the multiple seals can still prevent underground mud and water from seeping in, protecting the internal drive and correction system of the equipment from damage, reducing the risk of ground collapse, and meeting the long-term construction safety requirements. Attached Figure Description

[0018] Figure 1 This is a three-dimensional structural diagram of this embodiment;

[0019] Figure 2 This is a schematic diagram of the decomposed state structure of this embodiment;

[0020] Figure 3 This is a cross-sectional view of the structure in this embodiment;

[0021] Figure 4 This is a cross-sectional view of the rear housing in this embodiment (the cross-section is located at the first injection channel). Detailed Implementation

[0022] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0023] Figures 1-4 The figure shown is the preferred embodiment of this utility model.

[0024] The sealing structure of the correction section of the rectangular pipe jacking machine in this embodiment mainly includes a front shell 1, a rear shell 2, a correction section 2a, a sealing ring 3, a sealing groove 3a, a partition groove wall 3b, a side groove wall 3c, a first injection channel 4, a second injection channel 6, and an annular baffle 7. The sealing structure of the correction section of the rectangular pipe jacking machine disclosed in this embodiment aims to solve the problems of "single-point failure leading to leakage" of the single seal of the correction section of the traditional rectangular pipe jacking machine, poor adaptability to multi-directional displacement, and lack of emergency sealing protection. It achieves reliable sealing, flexible correction and convenient maintenance in composite strata construction, and ensures the dryness of the equipment interior and construction safety.

[0025] The structure and connection relationships of each component are as follows:

[0026] Front housing 1 and rear housing 2: Reference Figures 1 to 3 As shown, both the front housing 1 and the rear housing 2 are rectangular cross-section steel structures, adapted to the overall cross-sectional dimensions of the rectangular pipe jacking machine. The rear end inner wall of the front housing 1 has an annular mounting cavity machined therein, with a smooth cavity wall surface to ensure a tight seal with the sealing ring 3. The front end of the rear housing 2 has an integrally formed correction section 2a extending into the mounting cavity of the front housing 1. A clearance is reserved between the outer circumference of the correction section 2a and the inner wall of the mounting cavity of the front housing 1 to allow for multi-directional displacement during correction. The side wall of the rear housing 2 has channels adapted to the first injection channel 4 and the second injection channel 6. The inner wall of the channels is tapped for easy connection to grease or glue injection equipment.

[0027] Sealing groove 3a, partition groove wall 3b and side groove wall 3c: Reference Figures 2 to 4As shown, the sealing groove 3a is an annular groove formed on the outer circumference of the correction section 2a. Two grooves are provided to accommodate dual sealing requirements. The groove wall has a regular shape to accurately fit the sealing ring 3. An annular partition wall 3b is formed between the two sealing grooves 3a. The height of the partition wall 3b is higher than the side groove walls 3c on the outer side of the two outer sealing grooves 3a along the radial direction of the correction section 2a. That is, it is higher than the side groove walls 3c near the depth of the front housing 1 and the side groove walls 3c near the rear end of the correction section 2a. This height difference allows for the correction section 2a to swing up and down, left and right, and make slight translations, so as to avoid excessive compression between the sealing ring 3 and the groove wall during displacement. The tops of the partition wall 3b and the two side groove walls 3c are rounded to reduce friction and scratches on the sealing ring 3.

[0028] Sealing ring 3: Reference Figures 2 to 3 As shown, the sealing ring 3 is made of oil-resistant and wear-resistant rubber, with a circular or elliptical cross-section, corresponding one-to-one with the two sealing grooves 3a and forming an interference fit. After the sealing ring 3 is embedded in the sealing groove 3a, its outer circumferential surface extends beyond the outer circumferential surface of the correction section 2a, elastically fitting against the inner wall of the mounting cavity of the front housing 1, forming a double initial seal. The inner circumferential surface of each sealing ring 3 is coated with grease to reduce friction with the corresponding sealing groove 3a wall.

[0029] First injection channel 4, first through hole 4a and connecting channel 4b: Reference Figure 2 and Figure 4 As shown, the first injection channel 4 is opened on the side wall of the rear housing 2 and extends to the correction section 2a, and is evenly spaced along the circumference of the rear housing 2. The first through hole 4a is a circular hole opened radially along the rear housing 2, one end of which penetrates the inner circumferential wall of the rear housing 2 and is provided with an internal thread interface to adapt to a standard grease injection connector, and the other end penetrates the partition groove wall 3b between the two sealing grooves 3a and communicates with the connecting channel 4b. The connecting channel 4b is a straight groove opened on the outer circumferential surface of the partition groove wall 3b, extending axially along the correction section 2a, and its two ends are respectively connected to the two adjacent sealing grooves 3a, ensuring that the injected grease or sealing material can be simultaneously distributed to the two sealing grooves 3a through the connecting channel 4b.

[0030] Gap 5, second injection channel 6 and second through hole 6a: Reference Figure 2 and Figure 3 As shown, gap 5 is an annular gap formed between the outer periphery of the rear end of the correction section 2a of the rear housing 2 near the rear end side groove wall 3c and the inner wall of the mounting cavity of the front housing 1, and is continuously distributed circumferentially. The second injection channel 6 is a second through hole 6a, which is evenly spaced along the circumference of the rear housing 2. The second through hole 6a is a circular hole opened radially along the rear housing 2. One end penetrates the inner circumferential wall of the rear housing 2 and is provided with an internal threaded interface to adapt to the standard glue injection connector. The other end is directly connected to gap 5 to ensure that the sealing material can be accurately injected into the gap space.

[0031] Annular baffle 7: Reference Figure 2 and Figure 3As shown, the annular baffle 7 is made of wear-resistant steel plate and has a rectangular annular structure that fits the correction section 2a. The inner ring of the baffle is fixed to the rear end face of the correction section 2a by welding or other fixing methods. The cross-section of the baffle is inclined and slopes outward from the front end to the rear end along the axial direction of the correction section 2a. Its outer edge extends beyond the outer circumference of the correction section 2a. The inner side of the baffle and the outer circumference of the rear end of the side groove wall 3c of the correction section 2a near the rear end form a closed structure, which together with the gap 5 and the outer soil encloses the space for sealing material.

[0032] The working principle of the sealing structure of the correction section of the rectangular pipe jacking machine in this embodiment is as follows:

[0033] 1. Initial sealing and alignment principle

[0034] Before construction, two sealing rings 3 are respectively embedded in the corresponding sealing grooves 3a. Their outer circumferences elastically compress the inner wall of the mounting cavity of the front housing 1, forming a double independent sealing defense line, completely avoiding the risk of "single-point failure leading to leakage" of traditional single seals. When the pipe jacking machine needs to be corrected, the correction cylinder drives the correction section 2a of the rear housing 2 to produce multi-directional displacement relative to the front housing 1. Since the partition wall 3b between the two sealing grooves 3a is higher than the side groove walls 3c on both sides, the two sealing rings 3 only undergo elastic deformation during the displacement process, without rigidly colliding with the groove wall or being excessively stretched. This ensures the correction accuracy, reduces the frictional wear of the sealing rings 3, and extends their service life.

[0035] 2. Lubrication and Conventional Emergency Sealing Principles

[0036] During routine construction, a high-pressure grease gun is connected through the internal thread of the first injection channel 4 to inject grease into the sealing groove 3a. The grease flows into the connecting channel 4b through the first through hole 4a, and is then evenly distributed to the two sealing grooves 3a, forming a lubricating layer between each sealing ring 3 and the inner wall of the mounting cavity of the front housing 1, further reducing relative friction. If a minor leak occurs in a sealing ring 3 due to wear, polymer sealant can be injected through this channel. The sealant simultaneously fills the gap between the two sealing grooves 3a through the connecting channel 4b, and quickly cures to form a conventional emergency seal, restoring the dual sealing performance without stopping the machine for disassembly.

[0037] 3. Emergency sealing and gap protection principle

[0038] The annular baffle 7, on the one hand, forms a closed space with the outer soil and gap 5, preventing soil impurities from entering the gap 5 and blocking the second injection channel 6. On the other hand, its inclined structure can adapt to the soil contour, synchronously conforming to the soil as the correction section 2a moves, always maintaining a closed state and preventing mud and water from directly impacting the front sealing structure. In emergency situations where the two sealing rings 3 are severely damaged and conventional emergency sealing cannot meet the requirements, the injection equipment is connected through the interface of the second injection channel 6 to inject sealing material into the gap 5. After the sealing material fills the gap 5, it forms a rigid emergency seal with the front shell 1 and the rear shell 2, quickly blocking the seepage path of underground mud and water. If the emergency seal is partially damaged, the second injection channel 6 can be used to replenish the sealant, ensuring the reliability of the seal under emergency conditions and buying time for subsequent replacement of the sealing rings 3.

[0039] 4. Overall sealing reliability assurance principle

[0040] The two sealing rings 3, the conventional emergency seal of the first injection channel, the emergency seal of the second injection channel, and the annular baffle 7 together constitute a "three-level sealing protection system": the first level consists of two sealing rings 3, which undertake the main sealing function in daily use; the second level is the conventional emergency seal of the first injection channel, which deals with minor leakage of the sealing rings 3; the third level is the emergency seal of the second injection channel and the annular baffle 7. The former solves the emergency sealing problem in case of severe damage to the sealing rings 3, while the latter isolates soil interference and protects the sealing structure. Even under the condition of pressure fluctuation in complex strata or sudden seal failure, it can still ensure that the inside of the equipment is dry, avoid damage to the drive system and correction cylinder due to mud and water seepage, reduce the risk of strata collapse, and meet the long-term safe construction requirements.

[0041] It should be noted that in the description of this embodiment, the terms "front," "rear," "left," "right," "up," "down," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings. They are merely for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. The terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in the present invention can be understood according to the specific circumstances.

Claims

1. A sealing structure for the correction section of a rectangular pipe jacking machine, comprising a front housing (1) and a rear housing (2), wherein the front end of the rear housing (2) is provided with a correction section (2a) extending into the inner wall of the rear end of the front housing (1), characterized in that: The outer periphery of the correction section (2a) is provided with at least two spaced sealing rings (3), which are correspondingly embedded in the sealing groove (3a) on the outer periphery of the correction section (2a). A partition wall (3b) is formed between two adjacent sealing rings (3), and the height of the partition wall (3b) is higher than the side groove wall (3c) outside the two outermost sealing rings (3) to allow for the movement of the correction section (2a) in multiple directions.

2. The sealing structure of the correction section of the rectangular pipe jacking machine according to claim 1, characterized in that: The rear housing (2) is provided with a first injection channel (4), the outlet end of the first injection channel (4) is connected to the sealing groove (3a), and the inlet end extends to the inner peripheral wall of the rear housing (2) for selective injection of grease or sealing material.

3. The sealing structure of the correction section of the rectangular pipe jacking machine according to claim 2, characterized in that: The first injection channel (4) is provided in multiple ways, and the multiple first injection channels (4) are distributed circumferentially along the rear housing (2).

4. The sealing structure of the correction section of the rectangular pipe jacking machine according to claim 2, characterized in that: The first injection channel (4) includes a first through hole (4a) and a connecting channel (4b). The first through hole (4a) radially penetrates the partition groove wall (3b). The connecting channel (4b) extends axially and connects two adjacent sealing grooves (3a). The connecting channel (4b) is connected to the first through hole (4a).

5. The sealing structure of the correction section of the rectangular pipe jacking machine according to claim 4, characterized in that: The connecting channel (4b) is a groove formed on the outer periphery of the partition wall (3b).

6. The sealing structure of the correction section of the rectangular pipe jacking machine according to claim 1, characterized in that: A gap (5) is formed between the rear housing (2) and the front housing (1) at the outer periphery of the correction section (2a) and the side groove wall (3c). The rear housing (2) is provided with a second injection channel (6). The outlet end of the second injection channel (6) is connected to the gap (5), and the inlet end extends to the inner peripheral wall of the rear housing (2).

7. The sealing structure of the correction section of the rectangular pipe jacking machine according to claim 6, characterized in that: The second injection channel (6) is a second through hole (6a), which penetrates the rear housing (2) radially.

8. The sealing structure of the correction section of the rectangular pipe jacking machine according to claim 7, characterized in that: The second through hole (6a) is provided in multiple ways, and the multiple second through holes (6a) are distributed at intervals along the circumferential direction of the rear housing (2).

9. The sealing structure of the correction section of the rectangular pipe jacking machine according to claim 6, characterized in that: The rear end of the correction section (2a) is provided with a ring baffle (7), which together with the outer soil and the gap (5) forms a closed space.

10. The sealing structure of the correction section of the rectangular pipe jacking machine according to claim 9, characterized in that: The cross-section of the annular baffle (7) is inclined and is inclined outward from the front end to the rear end along the axial direction of the correction section (2a).

Images