A split rail module for a jumbo with adjustable gap
Patent Information
- Application Number
- CN202522042191.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-23
- Publication Date
- 2026-09-18
- Estimated Expiration
- 2035-09-23
AI Technical Summary
[0003]推进梁与滑块模块与之间应留有适当的间隙,随着耐磨块不断磨损,间隙逐渐变大,此间隙不易调整
[0016]综上所述,本实用新型至少具有以下有益之处中的一个:
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Figure CN224770152U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of mining equipment technology, specifically to a split track module with adjustable clearance for a rock drilling rig. Background Technology
[0002] As an important piece of mining machinery, the propulsion beam of the rock drilling rig is usually connected by a slider module. The slider module is equipped with wear-resistant blocks, and the wear-resistant blocks rub against the propulsion beam (the slider module will shake during the sliding process, causing the wear-resistant blocks to come into contact with the propulsion beam).
[0003] An appropriate gap should be left between the propulsion beam and the slider module. As the wear-resistant blocks continue to wear, the gap gradually increases, and this gap is not easy to adjust.
[0004] Traditionally, the gap between the slider and the wear-resistant block is adjusted using a long slot. When one end of the slider is tapped inward, the other end of the slider will rotate in the opposite direction, making it difficult to adjust the gap between the wear-resistant block and the propulsion beam. Summary of the Invention
[0005] In order to overcome the problem of "difficulty in adjusting the gap between the traditional wear-resistant block and the propulsion beam" in the above-mentioned background technology, this utility model provides a split track module with adjustable gap for rock drilling rigs.
[0006] The technical solution adopted by this utility model to solve the above-mentioned technical problems is: A split-type track module for an adjustable clearance rock drilling rig includes a track assembly and a slider assembly. The slider assembly includes a top plate, a first mounting block, a second mounting block, and a through bolt. The track assembly includes a main beam and a support strip disposed on the outer wall of the main beam. The first and second mounting blocks are Y-shaped and fitted to the support strip. The first and second mounting blocks are mounted below the edge of the top plate and are capable of lateral movement. The through bolt is used to limit the movement of the first and second mounting blocks. The first mounting block has a first mounting hole, and the second mounting block has a second mounting hole that fits the first mounting hole. Both the first and second mounting holes are inclined strip holes, and the stud of the through bolt is inserted into the first and second mounting holes. The top plate end has a limiting component for abutting against the end faces of the first and second mounting blocks.
[0007] As a further optimization of this utility model, the limiting component includes a lower extension protrusion and an abutment stud; the lower extension protrusion has a horizontally arranged screw hole, and the abutment stud is inserted into the screw hole and connected by threads; the first end face of the abutment stud can abut against the end face of the first mounting block and the end face of the second mounting block, and the second end face of the abutment stud is located outside the upper projection range of the top plate.
[0008] As a further optimization of this utility model, the end of the abutting stud is provided with a plug hole.
[0009] As a further optimization of this utility model, the insertion hole is a cross-shaped insertion hole and / or an internal hexagonal insertion hole.
[0010] As a further optimization of this utility model, the angle between the length direction of the first mounting hole and the length direction of the support strip is a degrees, and the angle between the length direction of the second mounting hole and the length direction of the support strip is b degrees; 20≤a=b≤45.
[0011] As a further optimization of this utility model, the top plate has an Ω-shaped cross section, and the top plate includes a connecting plate, a lower extension fixedly installed at the bottom edge of the connecting plate, and edge fins fixedly installed at the bottom of the outer side wall of the lower extension.
[0012] As a further optimization of this utility model, the edge fin is provided with a positioning hole, and the stud of the through bolt is inserted into the positioning hole.
[0013] As a further optimization of this utility model, the support bar is provided with an upper inclined surface and a lower inclined surface; the first mounting block is provided with a first adapting inclined surface, which is arranged parallel to the upper inclined surface; the second mounting block is provided with a second adapting inclined surface, which is arranged parallel to the lower inclined surface.
[0014] As a further optimization of this utility model, a first wear-resistant strip is snapped onto the first adapter inclined surface; a second wear-resistant strip is snapped onto the second adapter inclined surface.
[0015] As a further optimization of this utility model, the first mounting block is fitted with a first insert rod for laterally limiting the first wear-resistant strip; the second mounting block is fitted with a second insert rod for laterally limiting the second wear-resistant strip; the first insert rod and the second insert rod are arranged in a V-shape and their ends abut against each other.
[0016] In summary, this utility model has at least one of the following advantages: (1) The present invention has a simple structure and reliable function. The first mounting hole and the second mounting hole are both strip holes and are inclined. When the user applies a thrust parallel to the length direction of the track assembly to the first mounting block / second mounting block, the distance between the slider assembly and the track assembly can be adjusted conveniently and quickly, avoiding the problem of the first mounting block / second mounting block rotating instead of moving laterally.
[0017] (2) The vertical pressing force of the through bolt is perpendicular to and not collinear with the lateral thrust of the weight, which means that its ability to resist lateral thrust is low. The limiting component abuts against the first mounting block and the second mounting block laterally, and the lateral abutting force of the limiting component is collinear with the lateral thrust of the weight. Therefore, the limiting component and the through bolt work together to improve the stability and load-bearing capacity of this utility model.
[0018] (3) When the user inserts an electric screwdriver into the internal hex socket, the stud can be driven to rotate rapidly. This solution is suitable for new production, assembly and debugging of this utility model in clean environments such as production workshops when the rotational friction of the stud is small.
[0019] (4) The user inserts one end of the pry bar into the cross-shaped socket and uses manpower, a mechanical arm, a hydraulic cylinder, or a counterweight to pull the other end of the pry bar to rotate the stud. This solution is suitable for dusty environments such as construction sites, where the rotational friction of the stud is large, and this utility model can be adjusted accordingly. Attached Figure Description
[0020] The present application will be further explained below with reference to the accompanying drawings: Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a structural sectional view of the present invention; Figure 3 A schematic diagram of the installation structure of the first mounting block, the second mounting block, and the support strip; Figure 4 This is a schematic diagram of the installation structure of the first wear-resistant strip; Figure 5 This is a schematic diagram of the installation structure for the second wear-resistant strip; Figure 6 This is a schematic diagram showing the position of the first insertion slot and the structure from an oblique upward view. Figure 7 This is a top-view diagram showing the location of the second insertion slot and the structure. Figure 8 This is a top-view diagram showing the location and structure of the third insertion slot; Figure 9 This is a schematic diagram showing the location of the fourth insertion slot and the structure from an oblique upward view. Figure 10 A front view diagram showing the first and second inserts in contact. Figure 11 A vertical sectional view of the first mounting hole, the second mounting hole, and the positioning hole; Figure 12 This is a schematic diagram showing the rotation state of the first mounting block; Figure 13 A top view of the structure of the first mounting hole and the first mounting block; Figure 14 A top view of the structure of the second mounting hole and the second mounting block; Figure 15 Top view of the position setting for the limit component; Figure 16 This is a side view of the vertical section structure of the limiting component.
[0021] Explanation of reference numerals in the attached figures: In the picture, 1. Track assembly; 11. Top plate; 111. Connecting plate; 112. Lower extension; 113. Edge fins; 1131. Positioning hole; 12. First mounting block; 121. First adapting inclined surface; 1211. First slot; 1212. First insertion slot; 1213. First insertion rod; 122. First mounting hole; 13. Second mounting block; 131. Second adapting inclined surface; 1311. Second slot; 1312. Third insertion slot; 1313. Second insertion rod; 132. Second mounting hole; 14. Through bolt; 141. Stud; 15. First wear-resistant strip; 151. First snap-fit strip; 152. Second insertion slot; 16. Second wear-resistant strip; 161. Second snap-fit strip; 162. Fourth insertion slot; 2. Slider assembly; 21. Main beam; 22. Support bar; 221. Upper inclined surface; 222. Lower inclined surface; 3. Limiting component; 31. Lower extension protrusion; 311. Screw hole; 32. Abutment stud; 321. Cross socket; 322. Socket socket. Detailed Implementation
[0022] Based on the above-described structural features of this application, the implementation methods of this application will be further described as follows: Reference Figures 1-3 This embodiment provides a split-type track module for an adjustable clearance rock drilling rig, including a slider assembly 2 and a track assembly 1. The slider assembly 2 can be fastened to the upper part of the track assembly 1 and can reciprocate laterally along the length direction of the track assembly 1.
[0023] Reference Figures 1-3 The slider assembly 2 includes a top plate 11, a first mounting block 12, a second mounting block 13, and a through bolt 14.
[0024] Reference Figure 2The track assembly 1 includes a main beam 21 and support bars 22 disposed on the outer side wall of the main beam 21; the main beam 21 and the support bars 22 are fixedly connected (e.g., by bolts or by an integral fixed connection). At least one support bar 22 is installed on each of the left and right side walls of the main beam 21, thereby applying a tensile force to both sides of the slider assembly 2, preventing the slider assembly 2 from falling off the track assembly 1, and improving the operational stability of this invention.
[0025] Reference Figures 3-5 The first mounting block 12 and the second mounting block 13 are connected in a Y-shape and adapted to fasten the support strip 22. The first mounting block 12 and the second mounting block 13 are installed below the edge of the top plate 11 and can move laterally, thereby adjusting the distance between the first mounting block 12 / second mounting block 13 and the support strip 22, and further adjusting the distance between the first wear-resistant strip 15 / second wear-resistant strip 16 and the track assembly 1, so as to improve the sliding stability and smoothness of the slider assembly 2.
[0026] Reference Figures 3-5 The through bolt 14 is used to limit the first mounting block 12 and the second mounting block 13. When the nut or column head of the through bolt 14 is loosened (e.g., the nut / column head disengages from the top surface of the top plate 11), the user can move the first mounting block 12 and the second mounting block 13 laterally so that the distance between the first mounting block 12 / second mounting block 13 and the support bar 22 reaches the required level; when both ends (nuts and / or columns) of the through bolt 14 are tightened, the first mounting block 12 and the second mounting block 13 are fixed.
[0027] Reference Figure 11 , Figure 13 and Figure 14 The first mounting block 12 has a first mounting hole 122, and the second mounting block 13 has a second mounting hole 132 that matches the first mounting hole 122. Both the first mounting hole 122 and the second mounting hole 132 are inclined strip holes, and the stud 141 of the through bolt 14 is inserted into the first mounting hole 122 and the second mounting hole 132. The first mounting hole 122 and the second mounting hole 132 are arranged in the same direction, so the user can push the first mounting block 12 and the second mounting block 13 to move back and forth along the length direction of the first mounting hole 122 / the length direction of the second mounting hole 132, thereby adjusting the distance between the first mounting block 12 / the second mounting block 13 and the support strip 22.
[0028] Reference Figure 12If the length direction of the strip hole is perpendicular to the length direction of the top plate 11, when the user pushes one end of the first mounting block 12 / second mounting block 13 inward, the other end of the first mounting block 12 / second mounting block 13 will move outward (a gap will inevitably be generated between the stud 141 and the first mounting hole 122 / second mounting hole 132), thus causing rotation. This will result in different distances between the two ends of the first mounting block 12 and the support bar 22, reducing the smoothness of movement of the slider assembly 2. Similarly, this will also result in different distances between the two ends of the second mounting block 13 and the support bar 22, reducing the smoothness of movement of the slider assembly 2.
[0029] Reference Figure 13 and Figure 14 Applying a thrust (parallel to the length direction of the track assembly 1) to the end face of the first mounting block 12 / the end face of the second mounting block 13 can prevent the first mounting block 12 / the second mounting block 13 from rotating instead of moving laterally.
[0030] Reference Figure 15 The top plate 11 has a limiting component 3 at its end for abutting against the end face of the first mounting block 12 and the end face of the second mounting block 13. The limiting component 3 is used to abut against the end face of the first mounting block 12 and the end face of the second mounting block 13 laterally, so as to prevent the first mounting block 12 and the second mounting block 13 from moving outward when the through bolt 14 is loose, thereby preventing the relative sliding stability from decreasing due to the increased distance between the slider assembly 2 and the track assembly 1.
[0031] Reference Figure 3 The top plate 11 has an Ω-shaped cross-section and includes a connecting plate 111, a lower extension 112 fixedly installed at the bottom edge of the connecting plate 111, and edge fins 113 fixedly installed at the bottom of the outer side wall of the lower extension 112. The connecting plate 111, the lower extension 112, and the edge fins 113 are integrally fixedly connected. There are two lower extensions 112, each connected to one of the two edges of the connecting plate 111; there are two edge fins 113, each connected to one of the two lower extensions 112.
[0032] Reference Figure 2 and Figure 3 Two first mounting blocks 12 are provided and are respectively located below the two edge fins 113, and two second mounting blocks 13 are provided and are respectively located below the two edge fins 113. The first mounting blocks 12 are located above the second mounting blocks 13.
[0033] Reference Figure 11 The edge fin 113 is provided with a positioning hole 1131. The stud 141 of the through bolt 14 is inserted into the positioning hole 1131. The positioning hole 1131 plays a limiting role for the stud 141, so that the relative position of the stud 141 and the mounting plate is fixed.
[0034] Reference Figure 3 , Figure 4 and Figure 5 The support bar 22 has an upper inclined surface 221 and a lower inclined surface 222, which are arranged in a V-shape. The first mounting block 12 has a first adapting inclined surface 121, which is parallel to the upper inclined surface 221; the second mounting block 13 has a second adapting inclined surface 131, which is parallel to the lower inclined surface 222. A first wear-resistant strip 15 is snapped onto the first adapting inclined surface 121; a second wear-resistant strip 16 is snapped onto the second adapting inclined surface 131. The first mounting block 12 is fixedly connected to the first wear-resistant strip 15, so moving the position of the first mounting block 12 can adjust the distance between the first wear-resistant strip 15 and the upper inclined surface 221; similarly, the second mounting block 13 is fixedly connected to the second wear-resistant strip 16, so moving the position of the second mounting block 13 can adjust the distance between the second wear-resistant strip 16 and the upper inclined surface 221.
[0035] Reference Figure 4 The first adapter inclined surface 121 is provided with a first slot 1211. A first snap-fit strip 151 is fixedly installed on the back of the first wear-resistant strip 15 (e.g., through an integrated fixed connection). The first snap-fit strip 151 is adapted to be inserted into the first slot 1211 to realize the connection between the first mounting block 12 and the first wear-resistant strip 15. The second adapter inclined surface 131 is provided with a second slot 1311. A second snap-fit strip 161 is fixedly installed on the back of the second wear-resistant strip 16 (e.g., through an integrated fixed connection). The second snap-fit strip 161 is adapted to be inserted into the second slot 1311 to realize the connection between the second mounting block 13 and the second wear-resistant strip 16.
[0036] Reference Figure 4 and Figure 5 The cross-sections of the first slot 1211, the second slot 1311, the first snap-fit strip 151, and the second snap-fit strip 161 are all in the shape of an isosceles trapezoid.
[0037] Reference Figures 6-9 The first mounting block 12 is connected to a first insert rod 1213 for laterally limiting the first wear-resistant strip 15; the second mounting block 13 is connected to a second insert rod 1313 for laterally limiting the second wear-resistant strip 16; thereby preventing the first wear-resistant strip 15 from laterally dislodging from the first slot 1211 and preventing the second wear-resistant strip 16 from laterally dislodging from the second slot 1311.
[0038] Reference Figure 6 and Figure 7, a first inserting groove (1212) is provided at the first adaptive inclined surface (121), and the first inserting groove (1212) and the first clamping groove (1211) are arranged in a丰-shaped configuration; a second inserting groove (152) is provided in the first clamping strip (151), the first inserting grooves (1212) and the second inserting grooves (152) are in one-to-one correspondence, and the mutually corresponding first inserting groove (1212) and second inserting groove (152) are coaxially arranged and communicated with each other; the first inserting rod (1213) is inserted into the first inserting groove (1212) and the second inserting groove (152), so as to realize transverse limiting of the first wear-resistant strip (15).
[0039] with reference to Figure 8 and Figure 9 , a third inserting groove (1312) is provided at the second adaptive inclined surface (131), and the third inserting groove (1312) and the second clamping groove (1311) are arranged in a丰-shaped configuration; a fourth inserting groove (162) is provided in the second clamping strip (161), the third inserting grooves (1312) and the fourth inserting grooves (162) are in one-to-one correspondence, and the mutually corresponding third inserting groove (1312) and fourth inserting groove (162) are coaxially arranged and communicated with each other; the second inserting rod (1313) is inserted into the third inserting groove (1312) and the fourth inserting groove (162), so as to realize transverse limiting of the second wear-resistant strip (16).
[0040] with reference to Figure 10 , the first inserting rod (1213) and the second inserting rod (1313) are arranged in a V shape, and end portions thereof abut against each other. With reference to Figure 6 , the first inserting groove (1212) is in a configuration with a sealed top end and an open bottom end, so as to prevent the first inserting rod (1213) from coming off upward. With reference to Figure 8 , the third inserting groove (1312) is in a configuration with an open top end and a sealed bottom end, so as to prevent the second inserting rod (1313) from coming off downward.
[0041] with reference to Figure 15 and Figure 16 , the limiting assembly (3) comprises a downward extending projection (31) and an abutting stud (32). The downward extending projection (31) is fixedly mounted at the end portion of the bottom surface of the edge fin (113) (for example, fixedly connected by bolts or integrally formed and fixedly connected). A transversely arranged screw hole (311) is provided in the downward extending projection (31), and the abutting stud (32) is inserted into the screw hole (311) and connected via threads. When the abutting stud (32) rotates around its own axis, transverse movement thereof can be realized. A first end surface of the abutting stud (32) can abut against the end surface of the first mounting block (12) and the end surface of the second mounting block (13), and a second end surface of the abutting stud (32) is located outside the upper projection range of the top plate (11), which facilitates rotation of a pry bar.
[0042] with reference to Figure 16The stud 32 has insertion holes at its end. These insertion holes include a Phillips head insertion hole 321 and a hexagonal head insertion hole 322. The Phillips head insertion hole 321 is located near the second end face, and the hexagonal head insertion hole 322 is located at the center of the second end face. By inserting an electric screwdriver into the hexagonal head insertion hole 322, the user can drive the stud 32 to rotate rapidly (this solution is suitable for new production, assembly, and debugging of this invention in clean environments such as production workshops where the rotational friction of the stud 32 is relatively low). Alternatively, the user can insert one end of a pry bar into the Phillips head insertion hole 321 and use manpower, a robotic arm, a hydraulic cylinder, or a counterweight to pull the other end of the pry bar to rotate the stud 32 (this solution is suitable for adjusting this invention in dusty environments such as construction sites where the rotational friction of the stud 32 is relatively high).
[0043] Reference Figure 13 and Figure 14 The angle between the length direction of the first mounting hole 122 and the length direction of the support bar 22 is a degree, and the angle between the length direction of the second mounting hole 132 and the length direction of the support bar 22 is b degree; 20≤a=b≤45.
[0044] This utility model has a simple structure and reliable function. The first mounting hole 122 and the second mounting hole 132 are both strip-shaped holes and are set at an angle. When the user applies a pushing force parallel to the length direction of the track assembly 1 to the first mounting block 12 / second mounting block 13, the distance between the slider assembly 2 and the track assembly 1 can be adjusted conveniently and quickly, avoiding the problem that the first mounting block 12 / second mounting block 13 rotates instead of moves laterally.
[0045] The through bolt 14 generates friction through vertical pressing, thereby fixing the first mounting block 12 and the second mounting block 13. This fixing method has low stability (mining machinery typically carries heavy loads, and such loads, once eccentrically loaded, will generate a large lateral thrust on the slider assembly 2). The vertical pressing force of the through bolt 14 is perpendicular to and not collinear with the lateral thrust of the load, meaning its ability to resist lateral thrust is low (under overload, the first mounting block 12 and the second mounting block 13 will slide outward, increasing the distance between the slider assembly 2 and the track assembly 1). The limiting component 3 laterally abuts against the first mounting block 12 and the second mounting block 13, and the lateral abutment force of the limiting component 3 is collinear with the lateral thrust of the load. Therefore, the combined action of the limiting component 3 and the through bolt 14 can improve the stability and load-bearing capacity of this invention.
[0046] Both the first wear-resistant strip 15 and the second wear-resistant strip 16 are made of wear-resistant materials (such as titanium alloy).
[0047] In the description of this utility model, it should be noted that the terms "upper", "lower", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model 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 this utility model.
[0048] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect" 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 mechanical connection or an electrical connection; they can refer to a direct connection or a connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0049] In conclusion, for those skilled in the art, any changes, modifications, substitutions, or variations made to this utility model based on its guidance, without departing from its principles and spirit, shall still fall within the protection scope of this utility model.
Claims
1. A split rail module for a drill jumbo with an adjustable gap, characterized in that: Includes a track assembly (1) and a slider assembly (2); The slider assembly (2) includes a top plate (11), a first mounting block (12), a second mounting block (13), and a through bolt (14). The track assembly (1) includes a main beam (21) and a support bar (22) disposed on the outer side wall of the main beam (21). The first mounting block (12) and the second mounting block (13) are connected in a Y-shape and adapted to fasten the support strip (22); the first mounting block (12) and the second mounting block (13) are installed below the edge of the top plate (11) and can move laterally; the through bolt (14) is used to limit the first mounting block (12) and the second mounting block (13). The first mounting block (12) is provided with a first mounting hole (122), and the second mounting block (13) is provided with a second mounting hole (132) adapted to the first mounting hole (122); the first mounting hole (122) and the second mounting hole (132) are both inclined strip holes, and the stud (141) of the through bolt (14) is inserted into the first mounting hole (122) and the second mounting hole (132); The top plate (11) has a limiting component (3) at its end for abutting against the end face of the first mounting block (12) and the end face of the second mounting block (13).
2. The jumbo adjustable gap split rail module of claim 1, wherein: The limiting component (3) includes a lower extension protrusion (31) and an abutment stud (32); the lower extension protrusion (31) is provided with a horizontally arranged screw hole (311), the abutment stud (32) is inserted into the screw hole (311) and connected by threads; the first end face of the abutment stud (32) can abut against the end face of the first mounting block (12) and the end face of the second mounting block (13), and the second end face of the abutment stud (32) is located outside the upper projection range of the top plate (11).
3. The jumbo adjustable gap split rail module of claim 2, wherein: The end of the abutment stud (32) is provided with a insertion hole.
4. The jumbo adjustable gap split rail module of claim 3, wherein: The insertion hole is a cross-shaped insertion hole (321) and / or an internal hexagonal insertion hole (322).
5. The jumbo adjustable gap split rail module of claim 4, wherein: The angle between the length direction of the first mounting hole (122) and the length direction of the support strip (22) is a degree, and the angle between the length direction of the second mounting hole (132) and the length direction of the support strip (22) is b degrees; 20≤a=b≤45.
6. The jumbo adjustable gap split rail module of claim 5, wherein: The top plate (11) has an Ω-shaped cross section. The top plate (11) includes a connecting plate (111), a lower extension (112) fixedly installed at the bottom edge of the connecting plate (111), and an edge fin (113) fixedly installed at the bottom of the outer side wall of the lower extension (112).
7. The jumbo adjustable gap split rail module of claim 6, wherein: The edge fin (113) is provided with a positioning hole (1131), and the stud (141) of the through bolt (14) is inserted into the positioning hole (1131).
8. The jumbo adjustable gap split rail module of claim 7, wherein: The support bar (22) has an upper inclined surface (221) and a lower inclined surface (222); the first mounting block (12) has a first adapting inclined surface (121), which is parallel to the upper inclined surface (221); the second mounting block (13) has a second adapting inclined surface (131), which is parallel to the lower inclined surface (222).
9. The jumbo adjustable gap split rail module of claim 8, wherein: A first wear-resistant strip (15) is snapped onto the first adapter inclined surface (121); a second wear-resistant strip (16) is snapped onto the second adapter inclined surface (131).
10. The adjustable clearance split track module of the rock drilling rig according to claim 9, characterized in that: The first mounting block (12) is fitted with a first insert rod (1213) for laterally limiting the first wear-resistant strip (15); the second mounting block (13) is fitted with a second insert rod (1313) for laterally limiting the second wear-resistant strip (16); the first insert rod (1213) and the second insert rod (1313) are arranged in a V-shape and their ends abut against each other.