Cutting and boring machine for machining sealing surface of valve seat

Abstract

The invention relates to the technical field of cutting boring machines, in particular to a cutting boring machine for machining a sealing surface of a valve seat. The fixing device comprises an upper fixing plate and a lower fixing plate, and a sliding rod is fixedly connected between the upper fixing plate and the lower fixing plate. According to the cutting boring machine for machining the sealing face of the valve seat, the limiting mechanism is located in the flange fixing piece, limiting pieces with different calibers can be automatically formed in the vertical moving process, and when the limiting mechanism ascends, the caliber of the limiting mechanism is gradually reduced to be matched with a boring cutter handle, so that boring cutters with different calibers are fixed; the compatibility of equipment to different boring cutters is enhanced, a large number of adaptive parts do not need to be frequently replaced, the production cost is remarkably reduced, and meanwhile the universality and machining flexibility of the equipment are improved; meanwhile, the flange fixing piece is operated through the eight studs, accurate adjustment of the longitudinal position of the boring cutter is conveniently achieved, and adjustment deviation caused by part abrasion and assembly errors is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of cutting boring machines, and more specifically, to a cutting boring machine for machining the sealing surface of a valve seat. Background Art

[0002] A cutting boring machine for machining the sealing surface of a valve seat is a mechanical device specifically designed for precision boring and cutting of the sealing surface of a valve seat ring. This device aims to ensure that the valve seat sealing surface reaches the required dimensional accuracy and surface finish by precisely controlling the position and movement of the boring tool, thereby guaranteeing the good sealing performance and long service life of the valve.

[0003] When using a cutting boring machine for machining the sealing surface of a valve seat, it is necessary to first select a boring tool suitable for machining the valve seat sealing surface. The diameter of the boring tool usually has a specific specification. After selecting the appropriate boring tool, the user generally inserts the boring tool into the driving shaft and then fixes the boring tool to the driving shaft using bolts. This fixing method means that only a specific boring tool can be used to machine a specific valve seat sealing surface. When machining other different valve seat sealing surfaces, the valve seat has to be transported to the area of the cutting boring machine for machining the specific valve seat sealing surface. The entire process of fixing the boring tool is extremely cumbersome. Each time when changing to machine different valve seat sealing surfaces, a large amount of time is consumed in selecting the boring tool, fixing the boring tool, and transporting the valve seat. The frequent operation process prolongs each processing cycle, resulting in a sharp reduction in the number of valve seats that can be machined per unit time and seriously slowing down the overall production progress. In view of this, we propose a cutting boring machine for machining the sealing surface of a valve seat. Summary of the Invention

[0004] The purpose of the present invention is to provide a cutting boring machine for machining the sealing surface of a valve seat to solve the problems raised in the above background art.

[0005] To achieve the above purpose, the present invention provides a cutting boring machine for machining the sealing surface of a valve seat, including an upper fixing plate and a lower fixing plate. A sliding rod is fixedly connected between the upper fixing plate and the lower fixing plate. A moving plate is slidably connected to the sliding rod. A driving shaft is rotatably connected to the inside of the moving plate through a bearing, and a boring tool is installed at the bottom end of the driving shaft.

[0006] A flange fixing member and a limiting mechanism are respectively provided below the lower fixing plate. When fixing and disassembling the flange fixing member with eight double-headed bolts, the longitudinal position of the boring tool is adjusted. The limiting mechanism is located inside the flange fixing member. Different-sized limiting members are formed during the up and down movement of the limiting mechanism. During the upward movement of the limiting mechanism, the diameter of the limiting mechanism gradually decreases to form a diameter adapted to the shank of the boring tool, realizing the fixation of boring tools with different diameters.

[0007] As a further improvement of the technical solution, a transmission mechanism is provided above the upper fixing plate. The transmission mechanism includes a first gear rotatably connected to the middle of the top surface of the upper fixing plate. A chain is meshed with the surface of the first gear. Second gears are meshed with the inner parts at both ends of the chain. The bottom end of the second gear is fixedly connected with a threaded lead screw, and the threaded lead screw penetrates through the upper fixing plate and is rotatably connected with the inner wall of the upper fixing plate.

[0008] As a further improvement of the technical solution, the bottom end of the threaded lead screw is rotatably connected to the top surface of the lower fixing plate. The sliding rod is fixedly connected to the top surface of the lower fixing plate. The threaded lead screw and the sliding rod form a rectangle between the upper fixing plate and the lower fixing plate to ensure the stability of the up-and-down movement of the moving plate.

[0009] As a further improvement of the technical solution, the moving plate is in threaded connection with the threaded lead screw and is slidably connected with the sliding rod. A bearing seat is fixedly connected to the top of the moving plate to fix the bearing connecting the moving plate and the driving shaft. Insertion holes are longitudinally arranged in a linear array on the surface of the driving shaft for installing boring tools.

[0010] As a further improvement of the technical solution, a power component is provided at one end of the driving shaft close to the lower fixing plate. The power component includes a worm gear fixedly connected to the outer wall of the driving shaft. A worm is meshed with the outer edge of the worm gear, and one end of the worm is fixedly connected with a driving motor. A fixing bin is fixedly connected to the outside of the driving motor. The fixing bin is used for installing the worm gear, the worm and the driving motor, and the fixing bin is fixedly connected to the bottom surface of the lower fixing plate.

[0011] As a further improvement of the technical solution, one end of the worm away from the driving motor is rotatably connected with a fixing piece, and the fixing piece is connected to one side of the bottom surface of the lower fixing plate. The worm gear is rotatably connected to the middle of the bottom surface of the lower fixing plate.

[0012] As a further improvement of the technical solution, the flange fixing part includes a stabilizing sleeve fixedly connected to the bottom surface of the fixing bin, and the stabilizing sleeve is rotatably connected with the driving shaft. A first flange is fixedly installed on the bottom surface of the stabilizing sleeve. A second flange is fixedly connected to the lower part of the first flange through eight double-headed bolts.

[0013] As a further improvement of the technical solution, the limiting mechanism includes fixing blocks on both sides of the bottom of the stabilizing sleeve. The bottom surface of the fixing block is fixedly connected with an upper fixing clamp. A lower fixing clamp is slidably connected to one side of the fixing block, and the lower fixing clamp is fixedly connected to the fixing block through a bolt.

[0014] Compared with the prior art, the beneficial effects of the present invention:

[0015] In the cutting boring machine for machining the valve seat sealing surface, the limiting mechanism is located inside the flange fixing part and can automatically form limiting parts with different diameters during the up and down movement. When the limiting mechanism rises, the diameter of the limiting mechanism gradually shrinks to match the boring tool shank, thereby realizing the fixation of boring tools with different diameters, enhancing the compatibility of the equipment with different boring tools, eliminating the need to frequently replace a large number of matching parts, significantly reducing the production cost, and at the same time improving the versatility and processing flexibility of the equipment;

[0016] Meanwhile, by operating on the flange fixing part through eight double-headed bolts, it is convenient to accurately adjust the longitudinal position of the boring tool, reducing the adjustment deviation caused by component wear and assembly errors, and being able to more quickly and accurately adjust the depth of the boring tool according to the processing requirements of different valve seat sealing surfaces, greatly improving the processing accuracy and efficiency.

[0017] In addition to the purposes, features, and advantages described above, the present invention has other purposes, features, and advantages. The following will refer to the drawings to further elaborate on the present invention in detail. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is the overall structure assembly schematic diagram of the present invention;

[0019] Figure 2 is the flange fixing part assembly schematic diagram of the present invention;

[0020] Figure 3 is the limiting mechanism assembly schematic diagram of the present invention;

[0021] Figure 4 is the transmission mechanism schematic diagram of the present invention;

[0022] Figure 5 is the flange fixing part and limiting mechanism schematic diagram of the present invention;

[0023] Figure 6 is of the present invention Figure 5 schematic diagram at position A;

[0024] Figure 7 is the sectional view of the limiting mechanism, flange fixing part, and power part of the present invention;

[0025] Figure 8 is of the present invention Figure 7 schematic diagram at position B.

[0026] The meanings of each reference numeral in the drawings are as follows:

[0027] 100, upper fixing plate; 101, lower fixing plate; 102, sliding rod; 103, moving plate; 104, driving shaft; 105, boring tool;

[0028] 200. Flange fixing member; 201. Stabilizing sleeve; 202. First flange; 203. Second flange;

[0029] 300. Limiting mechanism; 301. Fixed block; 302. Upper fixing clamp; 303. Lower fixing clamp;

[0030] 400. Transmission mechanism; 401. First gear; 402. Chain; 403. Second gear; 404. Threaded lead screw;

[0031] 500. Power member; 501. Worm gear; 502. Worm. Detailed implementation manner

[0032] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0033] Embodiment 1

[0034] Please refer to Figure 1 - Figure 8 As shown, this embodiment provides a cutting boring machine for machining the valve seat sealing surface, including an upper fixing plate 100 and a lower fixing plate 101. A sliding rod 102 is fixedly connected between the upper fixing plate 100 and the lower fixing plate 101. A moving plate 103 is slidably connected to the sliding rod 102. A driving shaft 104 is rotatably connected to the inside of the moving plate 103 through a bearing, and a boring tool 105 is installed at the bottom end of the driving shaft 104;

[0035] Below the lower fixing plate 101, a flange fixing member 200 and a limiting mechanism 300 are respectively provided. When fixing and disassembling the flange fixing member 200 with eight double-headed bolts, the longitudinal position of the boring tool 105 is adjusted. The limiting mechanism 300 is located inside the flange fixing member 200. The limiting mechanism 300 forms limiting members with different sizes during the up and down movement. During the upward movement of the limiting mechanism 300, the diameter of the limiting mechanism 300 gradually shrinks to form a diameter adapted to the shank of the boring tool 105, realizing the fixation of boring tools 105 with different diameters.

[0036] When the present invention is in use: on the one hand, when using a cutting boring machine for machining the valve seat sealing surface, it is necessary to first select a boring tool 105 suitable for machining the valve seat sealing surface. The caliber of the boring tool 105 usually has a specific specification. After selecting the appropriate boring tool 105, the user generally inserts the boring tool 105 into the driving shaft 104 and then fixes the boring tool 105 to the driving shaft 104 using bolts. This fixing method means that only a specific boring tool 105 can be used to machine a specific valve seat sealing surface. When machining other different valve seat sealing surfaces, the valve seat has to be transported to the area of the cutting boring machine for machining the specific valve seat sealing surface. The entire process of fixing the boring tool 105 is extremely cumbersome. Each time when changing to machine different valve seat sealing surfaces, a large amount of time is consumed in selecting the boring tool 105, fixing the boring tool 105, and transporting the valve seat. The frequent operation process prolongs each processing cycle, resulting in a sharp reduction in the number of valve seats that can be machined per unit time and seriously slowing down the overall production progress. In view of this, we propose a cutting boring machine for machining the valve seat sealing surface; therefore, through the limiting mechanism 300, limiting members of different sizes and calibers can be automatically formed during the up-and-down movement. When the limiting mechanism 300 rises, the caliber of the limiting mechanism 300 gradually shrinks to match the shank of the boring tool 105, thereby realizing the fixation of boring tools 105 of different calibers, enhancing the compatibility of the equipment with different boring tools 105, eliminating the need to frequently replace a large number of matching parts, significantly reducing the production cost, and at the same time improving the versatility and processing flexibility of the equipment;

[0037] On the other hand, the stabilization method of the moving plate 103 of the traditional cutting boring machine may be relatively single and is easily affected by factors such as vibration during the processing. Therefore, a rectangular structure is formed between the upper fixing plate 100 and the lower fixing plate 101 by using the threaded lead screw 404 and the sliding rod 102. The moving plate 103 is threadedly connected to the threaded lead screw 404 and slidably connected to the sliding rod 102, which can not only effectively resist the lateral force and vibration during the processing, ensure the stability of the up-and-down movement of the moving plate 103, but also ensure the high precision of the movement trajectory of the boring tool 105, thereby improving the processing quality and stability and significantly reducing the processing error.

[0038] On this basis, the specific structure is disclosed in detail:

[0039] To achieve the movement of the moving plate 103, as Figure 4As shown in the figure, a transmission mechanism 400 is arranged above the upper fixing plate 100. The transmission mechanism 400 includes a first gear 401 rotatably connected to the middle of the top surface of the upper fixing plate 100. (A servo motor is fixedly installed at the top of the first gear 401.) A chain 402 is meshed with the surface of the first gear 401. The inner parts of both ends of the chain 402 are meshed with a second gear 403. The bottom end of the second gear 403 is fixedly connected with a threaded lead screw 404. The threaded lead screw 404 penetrates through the upper fixing plate 100 and is rotatably connected to the inner wall of the upper fixing plate 100. The bottom end of the threaded lead screw 404 is rotatably connected to the top surface of the lower fixing plate 101. A sliding rod 102 is fixedly connected to the top surface of the lower fixing plate 101. The threaded lead screw 404 and the sliding rod 102 form a rectangle between the upper fixing plate 100 and the lower fixing plate 101 to ensure the stability of the up and down movement of the moving plate 103. The moving plate 103 is threadedly connected to the threaded lead screw 404 and is slidably connected to the sliding rod 102. A bearing seat is fixedly connected to the top of the moving plate 103 to fix the bearing connecting the moving plate 103 and the driving shaft 104. Insertion holes are longitudinally and linearly arranged on the surface of the driving shaft 104 for installing the boring tool 105. (The first gear 401 is located at the outer edge of the middle of the chain 402 and is meshed with the chain 402. The first gear 401 and the two second gears 403 form a triangle. The two second gears 403 are respectively meshed with the inner circles at both ends of the chain 402, Figure 4 The figure shows the situation of belt and pulley meshing transmission. This transmission method is a conventional operation in the prior art. Those skilled in the art can understand the purpose and principle of this transmission, so it will not be elaborated in detail here);

[0040] Therefore, the servo motor rotates to drive the first gear 401 to rotate. The first gear 401 transmits power to the second gears 403 at both ends through the chain 402 meshed on its surface. Due to the meshing transmission characteristics of the chain 402, the power can be ensured to be transmitted to the two second gears 403 smoothly and synchronously, realizing the distribution and transmission of power. This gear-chain 402 transmission method has higher transmission efficiency and stability compared with other transmission forms, can accurately control the rotation speed and torque output, and its function is to provide a power source for the vertical movement of the entire cutting boring machine. And through the connection of the chain 402, the two second gears 403 on both sides can rotate synchronously, ensuring the consistency of the equipment operation.

[0041] To realize the rotary operation of the boring tool 105, as Figure 5 - Figure 8As shown in the figure, a power component 500 is provided at one end of the driving shaft 104 close to the lower fixing plate 101. The power component 500 includes a worm gear 501 fixedly connected to the outer wall of the driving shaft 104. A worm 502 is meshed with the outer edge of the worm gear 501. One end of the worm 502 is fixedly connected to a driving motor. A fixing bin is fixedly connected to the outside of the driving motor. The fixing bin is used for installing the worm gear 501, the worm 502 and the driving motor. The fixing bin is fixedly connected to the bottom surface of the lower fixing plate 101. One end of the worm 502 away from the driving motor is rotatably connected to a fixing piece. The fixing piece is connected to one side of the bottom surface of the lower fixing plate 101. The worm gear 501 is rotatably connected to the middle of the bottom surface of the lower fixing plate 101;

[0042] Therefore, by the operation of the driving motor, the worm 502 fixedly connected thereto is driven to rotate. The rotation of the worm 502 will drive the worm gear 501 to rotate, so that the driving shaft 104 can obtain sufficient torque to drive the boring tool 105 for efficient cutting. At the same time, the worm gear 501 and the worm 502 transmission also has good self-locking performance. When the driving motor stops running, the worm gear 501 and the worm 502 can remain stationary, preventing the driving shaft 104 from rotating due to external force, ensuring the safety and stability during the processing. Its function is to provide strong and stable power for the driving shaft 104, so that the boring tool 105 can process the valve seat sealing surface at a suitable rotation speed and torque, meeting the requirements of different processing technologies for the cutting force.

[0043] To realize the position adjustment of the boring tool 105, as Figure 5 shown, the flange fixing member 200 includes a stabilizing sleeve 201 fixedly connected to the bottom surface of the fixing bin. The stabilizing sleeve 201 is rotatably connected to the driving shaft 104. A first flange 202 is fixedly installed on the bottom surface of the stabilizing sleeve 201. A second flange 203 is fixedly connected to the lower part of the first flange 202 by eight double-headed bolts. Therefore, by arranging the stabilizing sleeve 201 around the driving shaft 104, it not only provides rotational support for the driving shaft 104, but also enhances the stability of the whole structure in the vertical direction. The setting of the first flange 202 and the second flange 203 further strengthens the stability of the structure. The eight double-headed bolts are evenly distributed between the flanges. This multi-point connection method can evenly bear various forces from the driving shaft 104 and the processing process, preventing structural deformation or loosening caused by uneven force, ensuring the structural stability of the driving shaft 104 and related components during the working process of the whole cutting boring machine, ensuring that the boring tool 105 can maintain a stable running state during the processing, reducing the processing error caused by structural instability, and improving the processing quality.

[0044] To realize the fixation of boring tools 105 with different diameters, as Figure 5As shown in the figure, the limiting mechanism 300 includes fixing blocks 301 located on both sides of the bottom of the stable sleeve 201. (The fixing blocks 301 are fixedly connected to the driving shaft 104 through collar rings.) The bottom surface of the fixing blocks 301 is fixedly connected with upper fixing clips 302. A lower fixing clip 303 is slidably connected to one side of the fixing blocks 301, and the lower fixing clip 303 is fixedly connected to the fixing blocks 301 through bolts. Therefore, since the lower fixing clip 303 is slidably connected to the fixing blocks 301, when fixing the tool shanks of boring tools 105 with different diameters, the bolts can be loosened first, allowing the lower fixing clip 303 to slide on one side of the fixing blocks 301 to adjust the opening size between the upper and lower fixing clips 303 to match the outer diameter of the tool shank of the boring tool 105. After adjustment, the bolts are tightened to fix the position of the lower fixing clip 303. This self-adaptive adjustment method greatly improves the compatibility of the limiting mechanism 300 with boring tools 105 of different specifications, enhances the versatility of the equipment, eliminates the need to equip special fixing devices for boring tools 105 with different diameters, reduces production costs, and at the same time improves the flexibility of the equipment under different processing requirements.

[0045] The working principle of the present invention:

[0046] The upper fixing plate 100 and the lower fixing plate 101 are fixedly connected through the sliding rod 102. A bearing is installed in the moving plate 103 to connect the driving shaft 104. After starting the servo motor, the servo motor drives the first gear 401 to rotate. As the first gear 401 rotates, it drives the chain 402 to rotate synchronously. The movement of the chain 402 further causes the second gear 403 to rotate. The second gear 403 is connected to the threaded lead screw 404, causing the threaded lead screw 404 to also start rotating. Under the coordinated action of the threaded lead screw 404 and the sliding rod 102, the moving plate 103 can move up and down smoothly along a predetermined trajectory, thereby driving the driving shaft 104 to move to a suitable position;

[0047] The first flange 202 is installed on the bottom surface of the stable sleeve 201. Then, the tool shank of the boring tool 105 is inserted into the insertion hole on the driving shaft 104. The lower fixing clip 303 is slid upward. When the outer wall of the boring tool 105 is completely in contact with the inner walls of the upper fixing clip 302 and the lower fixing clip 303, the bolts on the fixing blocks 301 are tightened to fix the boring tool 105. The second flange 203 is connected through eight double-headed bolts;

[0048] After confirming that the position and fixing condition of the boring tool 105 are correct, the transmission mechanism 400 is started. The driving motor drives the worm 502 to rotate, causing the worm gear 501 and the driving shaft 104 to rotate at high speed. The boring tool 105 starts cutting and machining the valve seat sealing surface. After the machining is completed, the driving motor is first turned off to stop the rotation of the driving shaft 104 and the boring tool 105. The eight double-headed bolts are loosened, the second flange 203 is disassembled, the boring tool 105 is removed, and the debris inside the equipment is cleaned for maintenance and preparation for the next machining.

[0049] The foregoing has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and the above embodiments and descriptions in the specification are only preferred examples of the present invention and are not used to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements fall within the scope of the present invention claimed. The scope of the present invention claimed is defined by the appended claims and their equivalents.

Claims

1. A cutting boring machine for machining the valve seat sealing surface, comprising an upper fixing plate (100) and a lower fixing plate (101), wherein a sliding rod (102) is fixedly connected between the upper fixing plate (100) and the lower fixing plate (101), and is characterized in that: A moving plate (103) is slidably connected to the sliding rod (102). A driving shaft (104) is rotatably connected to the inside of the moving plate (103) through a bearing, and a boring tool (105) is installed at the bottom end of the driving shaft (104). A flange fixing member (200) and a limiting mechanism (300) are respectively arranged below the lower fixing plate (101). When fixing and disassembling the flange fixing member (200) with eight double-headed bolts, the longitudinal position of the boring tool (105) is adjusted. The limiting mechanism (300) is located inside the flange fixing member (200). The limiting mechanism (300) forms limiting members with different sizes during the up and down movement. During the upward movement of the limiting mechanism (300), the diameter of the limiting mechanism (300) gradually decreases to form a diameter adapted to the shank of the boring tool (105), realizing the fixation of boring tools (105) with different diameters.

2. The cutting boring machine for machining the valve seat sealing surface according to claim 1, wherein: A transmission mechanism (400) is arranged above the upper fixing plate (100). The transmission mechanism (400) includes a first gear (401) rotatably connected to the middle of the top surface of the upper fixing plate (100). A chain (402) is meshed with the surface of the first gear (401). Second gears (403) are meshed with the inside of both ends of the chain (402). A threaded lead screw (404) is fixedly connected to the bottom end of the second gear (403), and the threaded lead screw (404) penetrates through the upper fixing plate (100) and is rotatably connected to the inner wall of the upper fixing plate (100).

3. The cutting boring machine for machining the valve seat sealing surface according to claim 2, characterized in that: The bottom end of the threaded lead screw (404) is rotatably connected to the top surface of the lower fixing plate (101). The sliding rod (102) is fixedly connected to the top surface of the lower fixing plate (101). The threaded lead screw (404) and the sliding rod (102) form a rectangle between the upper fixing plate (100) and the lower fixing plate (101) to ensure the stability of the up and down movement of the moving plate (103).

4. The cutting boring machine for machining the valve seat sealing surface according to claim 1, characterized in that: The moving plate (103) is in threaded connection with the threaded lead screw (404), and the moving plate (103) is slidably connected to the sliding rod (102). A bearing seat is fixedly connected to the top of the moving plate (103) for fixing the bearing connecting the moving plate (103) and the driving shaft (104). Insertion holes are longitudinally and linearly arranged on the surface of the driving shaft (104) for installing the boring tool (105).

5. The cutting boring machine for machining the valve seat sealing surface according to claim 1, characterized in that: A power member (500) is arranged at one end of the driving shaft (104) close to the lower fixing plate (101). The power member (500) includes a worm gear (501) fixedly connected to the outer wall of the driving shaft (104). A worm (502) is meshed with the outer edge of the worm gear (501), and a driving motor is fixedly connected to one end of the worm (502). A fixing bin is fixedly connected to the outside of the driving motor. The fixing bin is used for installing the worm gear (501), the worm (502) and the driving motor, and the fixing bin is fixedly connected to the bottom surface of the lower fixing plate (101).

6. The cutting boring machine for machining the valve seat sealing surface according to claim 5, characterized in that: One end of the worm (502) away from the driving motor is rotatably connected with a fixing piece, and the fixing piece is connected to one side of the bottom surface of the lower fixing plate (101), and the worm gear (501) is rotatably connected to the middle of the bottom surface of the lower fixing plate (101).

7. The cutting boring machine for machining the valve seat sealing surface according to claim 1, characterized in that: The flange fixing member (200) includes a stabilizing sleeve (201) fixedly connected to the bottom surface of the fixing bin, and the stabilizing sleeve (201) is rotatably connected to the driving shaft (104). A first flange plate (202) is fixedly installed on the bottom surface of the stabilizing sleeve (201), and a second flange plate (203) is fixedly connected below the first flange plate (202) by eight double-headed bolts.

8. The cutting boring machine for machining the valve seat sealing surface according to claim 1, characterized in that: The limiting mechanism (300) includes fixing blocks (301) located on both sides of the bottom of the stabilizing sleeve (201). An upper fixing clamp (302) is fixedly connected to the bottom surface of the fixing block (301). A lower fixing clamp (303) is slidably connected to one side of the fixing block (301), and the lower fixing clamp (303) is fixedly connected to the fixing block (301) by bolts.

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