Replaceable tearing knife

Abstract

The utility model relates to the technical field of shield tunneling machines, in particular to a replaceable tearing knife which comprises a knife shaft, a knife holder and a tearing knife head, the knife holder is sleeved on the knife shaft, a self-lubricating copper sleeve is arranged between the knife holder and the knife shaft, and the self-lubricating copper sleeve is sleeved on the knife shaft. Sleeves are arranged on the two sides of the tool apron and fixedly arranged on the tool shaft in a sleeving mode. The tearing cutter head is fixedly arranged on a cutter holder, and wedge-shaped tensioning blocks are detachably connected to the two ends of the cutter holder. According to the replaceable tearing cutter, the risks that alloy of the cutter head of the tearing cutter collapses and falls off and the cutter shaft is broken can be effectively reduced, so that premature failure of the cutter head and the cutter shaft of the tearing cutter is avoided, the service life of the replaceable tearing cutter is prolonged, the shutdown time of a shield tunneling machine is shortened, and the tunneling efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of shield machines, in particular to a replaceable tearing knife. Background Art

[0002] Shield machines are widely used in tunnel construction for subways, highways, municipal engineering, hydropower, and other fields due to their high degree of automation, rapid excavation speeds, minimal ground disturbance, and high construction safety. The basic operating principle of a shield machine is that a cylindrical steel component advances along the tunnel axis, excavating the soil while simultaneously advancing. The shell of this cylindrical component, the shield, provides temporary support for the excavated, unlined tunnel section, bearing the pressure of the surrounding soil and, in some cases, groundwater pressure, thereby keeping it out. Excavation, soil removal, and lining operations are carried out under the protection of the shield; tunneling is primarily accomplished by cutting soil or rock using tools mounted on the shield machine's cutterhead.

[0003] The main cutting tools commonly used in shield machines are disc cutters and ripping cutters. These are typically configured based on the lithology of the formation. Disc cutters are suitable for hard rock or composite formations, but are difficult to start in soft rock formations and are prone to eccentric wear and failure. Therefore, replaceable ripping cutters are often used in soft rock formations (uniaxial compressive strength ≤ 25 MPa). These cutters slide and rub against the rock mass, eliminating the risk of eccentric wear. The base of the ripping cutter is inlaid with cemented carbide to ensure wear resistance. Existing replaceable ripping cutters often use a rigid connection between the cutterhead and the cutter shaft. In high-impact formations such as gravel and pile formations, the cutter head and cutter shaft are prone to alloy chipping, alloy shedding, and cutter shaft fracture and failure. This can lead to premature failure of the cutter head and cutter shaft, increasing shield machine downtime and affecting tunnel excavation efficiency. Summary of the Invention

[0004] The utility model aims to solve the problem that the replaceable tearing knife in the prior art, in which the knife seat and the knife shaft are rigidly connected, and the tearing knife head and the knife shaft are prone to premature failure, and provides a replaceable tearing knife. The tearing knife can effectively reduce the risk of alloy collapse and falling of the tearing knife head and the risk of the knife shaft breaking, thereby avoiding premature failure of the tearing knife head and the knife shaft, extending the life of the replaceable tearing knife, thereby reducing the downtime of the shield machine and improving the efficiency of tunnel excavation.

[0005] To achieve the above objectives, the present invention provides a replaceable ripping knife comprising a blade shaft, a blade holder, and a ripping knife head. The blade holder is mounted on the blade shaft, and a self-lubricating copper sleeve is disposed between the blade holder and the blade shaft. The self-lubricating copper sleeve is mounted on the blade shaft. The self-lubricating copper sleeve acts as a buffer, effectively reducing the risk of alloy fragmentation and dislodging of the ripping knife head and the risk of blade shaft breakage.

[0006] The blade holder is provided with sleeves on both sides, which are fixedly mounted on the blade shaft. The tearing blade head is fixedly mounted on the blade holder, and wedge-shaped tension blocks are detachably connected to both ends of the blade holder. The sleeves restrict the axial movement of the blade holder, while the wedge-shaped tension blocks secure the blade holder and the blade box, limiting the blade holder's circumferential rotational movement.

[0007] Furthermore, the self-lubricating copper sleeve is provided with a plurality of through holes, and graphite blocks are embedded in the through holes. The graphite blocks can reduce the friction coefficient between the self-lubricating copper sleeve and the cutter shaft.

[0008] Furthermore, the outer side of the self-lubricating copper sleeve has an interference fit with the tool holder, and the inner side has a clearance fit with the tool shaft, the purpose of which is to enable the self-lubricating copper sleeve to absorb energy as a buffer.

[0009] Furthermore, the sleeve is welded and fixed on the cutter shaft, and the outer diameter of the sleeve is larger than the outer diameter of the self-lubricating copper sleeve and smaller than the width of the cutter seat, so that the sleeve can simultaneously limit the axial movement of the cutter seat and the self-lubricating copper sleeve.

[0010] Furthermore, the bottoms of both ends of the knife seat are each provided with an inclined portion 1, and the wedge-shaped tensioning block is provided with an inclined portion 2 matching the inclined portion 1.

[0011] Furthermore, a fastening bolt is vertically arranged on the wedge-shaped tensioning block, and the wedge-shaped tensioning block is connected to the tool holder through the fastening bolt. The wedge-shaped tensioning block is fastened to the tool box and the tool holder through the fastening bolt, thereby limiting the circumferential rotation of the tool holder.

[0012] Furthermore, a washer is sleeved on the fastening bolt, and the washer is located between the wedge-shaped tensioning block and the screw head of the fastening bolt. The effect of the washer can improve the fixing effect of the fastening bolt on the wedge-shaped tensioning block.

[0013] Furthermore, a wear-resistant layer is provided on the surface of the tearing knife head, and a hard alloy is inlaid on the top of the tearing knife head. The wear-resistant layer plays a role in protecting the tearing knife head and increasing the wear resistance of the tearing knife head.

[0014] Through the above technical solution, the beneficial effects of the utility model are:

[0015] 1. The utility model has a reasonable structure and good use effect. It solves the problem that the tearing cutter head and cutter shaft of the existing replaceable tearing cutter with a hard connection between the cutter seat and the cutter shaft are prone to premature failure in high-impact formations. It effectively reduces the risk of alloy collapse and falling of the tearing cutter head and breakage of the cutter shaft, thereby avoiding premature failure of the tearing cutter head and cutter shaft, extending the service life of the replaceable tearing cutter, thereby reducing the downtime of the shield machine and improving the efficiency of tunnel excavation.

[0016] 2. When the utility model excavates through large pebbles and reinforced concrete pile foundations, it faces severe vibration and impact. The self-lubricating copper sleeve is installed between the cutter shaft and the cutter seat as a buffer to absorb part of the energy, reduce the risk of alloy collapse and falling of the tearing cutter head and breakage of the cutter shaft, thereby avoiding premature failure of the tearing cutter head and cutter shaft, and extending the service life of the replaceable tearing cutter; at the same time, by inlaying graphite blocks in the through holes of the self-lubricating copper sleeve, the graphite blocks are used to reduce the friction coefficient between the self-lubricating copper sleeve and the cutter shaft, thereby further extending the service life of the replaceable tearing cutter and improving the efficiency of tunnel excavation.

[0017] 3. The utility model limits the axial movement of the tool holder and the self-lubricating copper sleeve through the sleeves located on both sides of the tool holder; the wedge-shaped tensioning block is fastened to the tool box and the tool holder by fastening bolts, thereby limiting the circumferential rotation of the tool holder. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the structure of a replaceable tearing knife of the utility model. Figure 1 ;

[0019] Figure 2 This is a schematic diagram of the structure of a replaceable tearing knife of the utility model. Figure 2 ;

[0020] Figure 3 This is a schematic diagram of the structure of the self-lubricating copper sleeve of the utility model Figure 1 ;

[0021] Figure 4 This is a schematic diagram of the structure of the self-lubricating copper sleeve of the utility model Figure 2 .

[0022] The numbers in the accompanying drawings are: 1 is the knife shaft, 2 is the knife seat, 3 is the tearing knife head, 4 is the sleeve, 5 is the self-lubricating copper sleeve, 6 is the graphite block, 7 is the wedge-shaped tensioning block, 8 is the fastening bolt, and 9 is the washer. DETAILED DESCRIPTION

[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0024] like Figures 1 to 4 As shown, a replaceable ripping knife comprises a blade shaft 1, a blade holder 2, and a ripping knife head 3. The blade holder 2 is sleeved on the blade shaft 1, and a self-lubricating copper sleeve 5 is disposed between the blade holder 2 and the blade shaft 1. The self-lubricating copper sleeve 5 sleeves on the blade shaft 1. In this embodiment, the self-lubricating copper sleeve 5 serves as a buffer and is a key component for the flexible connection between the blade holder 2 and the blade shaft 1. When the ripping knife is subjected to severe vibration and impact, the self-lubricating copper sleeve 5 absorbs some of the energy, reducing the risk of alloy fragmentation and dislodging of the ripping knife head 3 and the risk of fracture of the blade shaft 1.

[0025] Sleeves 4 are provided on both sides of the blade holder 2, fixedly mounted on the blade shaft 1. The ripping blade head 3 is fixedly mounted on the blade holder 2, with wedge-shaped tensioning blocks 7 detachably connected to both ends of the blade holder 2. In this embodiment, two sleeves 4 are provided, each welded to the blade shaft 1 via a fillet weld to restrict axial movement of the blade holder 2. The ripping blade head 3 is welded to the blade holder 2 via a groove. The base of the ripping blade head 3 is constructed of low-alloy, high-strength structural steel to ensure weldability.

[0026] The self-lubricating copper sleeve 5 is provided with a plurality of through holes, and graphite blocks 6 are embedded in the through holes. In this embodiment, the graphite blocks 6 are made of self-lubricating graphite material, and their purpose is to reduce the friction coefficient between the self-lubricating copper sleeve 5 and the blade shaft 1.

[0027] The outer side of the self-lubricating copper sleeve 5 is interference-fitted with the cutter seat 2 and the inner side is clearance-fitted with the cutter shaft 1, ensuring that the self-lubricating copper sleeve 5 acts as a buffer to absorb energy generated by severe vibration and impact.

[0028] The sleeve 4 is welded to the cutter shaft 1. The outer diameter of the sleeve 4 is larger than the outer diameter of the self-lubricating copper sleeve 5 and smaller than the width of the cutter seat 2. In this embodiment, the sleeve 4 is fillet-welded to the cutter shaft 1 to limit the axial movement of the cutter seat 2 and the self-lubricating copper sleeve 6.

[0029] The bottom of both ends of the tool holder 2 is provided with an inclined portion 1, and the wedge-shaped tensioning block 7 is provided with an inclined portion 2 matching the inclined portion 1. The purpose is to make the tool holder 2 fit with the wedge-shaped tensioning block 7 to avoid the tool holder 2 being connected to the wedge-shaped tensioning block 7.

[0030] A fastening bolt 8 is vertically mounted on the wedge-shaped tensioning block 7, which is connected to the tool holder 2 via the fastening bolt 8. In this embodiment, the bottoms of both ends of the tool holder 2 are inclined surfaces with threaded holes that match the fastening bolts 8. The fastening bolts 8 are screwed into the threaded holes. The wedge-shaped tensioning block 7 is also connected to the tool box via the fastening bolts 8. The wedge-shaped tensioning block 7 is fastened to the tool box and tool holder 2 via the fastening bolts 8 to restrict the circumferential rotation of the tool holder 2.

[0031] A washer 9 is sleeved on the fastening bolt 8 and is located between the wedge-shaped tensioning block 7 and the screw head of the fastening bolt 8. In this embodiment, the cooperation between the washer 9, the wedge-shaped tensioning block 7, and the screw head of the fastening bolt 8 improves the fixing effect of the fastening bolt 8 on the wedge-shaped tensioning block 7 and the tool holder 2.

[0032] The surface of the tearing blade head 3 is provided with a wear-resistant layer, and the top of the tearing blade head 3 is inlaid with cemented carbide. In this embodiment, the wear-resistant layer is iron-based tungsten carbide, which protects the base of the tearing blade head 3 and increases its wear resistance. The cemented carbide ensures the hardness and wear resistance of the tearing blade head 3 for cutting soil or rock.

[0033] When the present invention is used, firstly, a graphite block 6 is embedded in the through hole of the self-lubricating copper sleeve 5, and then the self-lubricating copper sleeve 5 is sleeved in the knife seat 2 so that the self-lubricating copper sleeve 5 and the knife seat 2 are interference connected; wherein a sleeve 4 is first corner-welded on the knife shaft 1, and after the knife seat 2 is sleeved on the knife shaft 1 through the self-lubricating copper sleeve 5 and is fitted and connected with the sleeve 4, another sleeve 4 is sleeved on the knife shaft 1 and fits with one side of the knife seat 2, and then the sleeve 4 is corner-welded on the knife shaft 1, wherein the tearing knife head 3 is welded and fixed on the knife seat 2; finally, the wedge-shaped tensioning block 7 and the knife box are connected by tightening bolts 8.

[0034] When the tearing knife excavates through large pebbles and reinforced concrete pile foundations, it faces severe vibration and impact. The self-lubricating copper sleeve 5 is installed between the knife shaft 1 and the knife seat 2 as a buffer to absorb part of the energy, reduce the risk of alloy collapse and falling off of the tearing knife head 3, and breakage of the knife shaft 1, thereby avoiding premature failure of the tearing knife head 3 and the knife shaft 1, and extending the service life of the replaceable tearing knife.

[0035] The embodiments described above are only preferred embodiments of the utility model and do not limit the scope of implementation of the utility model. Therefore, any equivalent changes or modifications made according to the technical solutions described in the patent scope of the utility model should be included in the scope of the patent application of the utility model.

Claims

1. A replaceable tearing knife, characterized in that: It comprises a knife shaft (1), a knife seat (2) and a tearing knife head (3), wherein the knife seat (2) is sleeved on the knife shaft (1), a self-lubricating copper sleeve (5) is provided between the knife seat (2) and the knife shaft (1), and the self-lubricating copper sleeve (5) is sleeved on the knife shaft (1); Sleeves (4) are provided on both sides of the knife seat (2), and the sleeves (4) are fixedly sleeved on the knife shaft (1); the tearing knife head (3) is fixedly provided on the knife seat (2), and both ends of the knife seat (2) are detachably connected with wedge-shaped tensioning blocks (7).

2. The replaceable tearing knife according to claim 1, characterized in that: The self-lubricating copper sleeve (5) is provided with a plurality of through holes, and graphite blocks (6) are embedded in the interior of the through holes.

3. The replaceable tearing knife according to claim 2, characterized in that: The outer side of the self-lubricating copper sleeve (5) is in interference fit with the knife seat (2), and the inner side is in clearance fit with the knife shaft (1).

4. The replaceable tearing knife according to claim 1, characterized in that: The sleeve (4) is welded and fixed on the knife shaft (1); the outer diameter of the sleeve (4) is larger than the outer diameter of the self-lubricating copper sleeve (5) and smaller than the width of the knife seat (2).

5. The replaceable tearing knife according to claim 1, characterized in that: The bottoms of both ends of the knife seat (2) are each provided with an inclined portion 1, and the wedge-shaped tensioning block (7) is provided with an inclined portion 2 matching the inclined portion 1.

6. The replaceable tearing knife according to claim 5, characterized in that: A fastening bolt (8) is vertically arranged on the wedge-shaped tensioning block (7), and the wedge-shaped tensioning block (7) is connected to the knife seat (2) via the fastening bolt (8).

7. The replaceable tearing knife according to claim 6, characterized in that: A washer (9) is sleeved on the fastening bolt (8), and the washer (9) is located between the wedge-shaped tensioning block (7) and the screw head of the fastening bolt (8).

8. The replaceable tearing knife according to claim 1, characterized in that: The surface of the tearing knife head (3) is provided with a wear-resistant layer, and the top of the tearing knife head (3) is inlaid with hard alloy.

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