Internal expansion type elastic polishing and grinding tool for lubricating oil path of marine diesel engine part as well as use method and application of internal expansion type elastic polishing and grinding tool

Abstract

The invention discloses an internal expansion type elastic polishing and grinding tool for a lubricating oil way of a marine diesel engine part. The internal expansion type elastic polishing and grinding tool comprises an air expansion shaft, a retainer, an elastic grinding disc, a butyl rubber pipe and other core components. Compressed gas is injected through the gas nozzle to enable the butyl rubber tube to expand radially, the elastic abrasive discs evenly distributed on the circumference are pushed to be tightly attached to the inner wall of an oil way, and meanwhile the pneumatic air mill drives the tool to rotate to achieve polishing. The air pressure self-adaptive adjusting technology is adopted, so that the abrasive disc and the inner wall of the oil way keep constant pressure all the time, and the problems that a traditional tool is poor in attaching performance and insufficient in grinding pressure are effectively solved.

Description

Technical Field

[0001] This invention belongs to the field of mechanical manufacturing technology, and specifically relates to an internal expansion elastic polishing tool for lubricating oil circuits of marine diesel engine parts, as well as its use and application. This tool uses pneumatic pressure to drive the radial expansion of an elastic grinding disc, achieving efficient polishing of the inner wall of the oil circuit. It is particularly suitable for eliminating cutting marks caused by deep hole machining, improving surface quality, and ensuring oil circuit cleanliness. Background Art

[0002] The lubricating oil circuits of marine diesel engine parts typically utilize deep-hole machining. Due to poor chip removal, lubrication, and heat dissipation during machining, deep cutting marks often remain on the inner walls of the oil circuits. These marks easily accumulate foreign particles and are difficult to thoroughly clean. If these impurities enter the bearings along with the lubricating oil during operation, they can cause scratches on the bearing surface, shorten its lifespan, or even lead to serious failures.

[0003] Traditional polishing methods (such as flap wheels or grinding wheels) have significant drawbacks: the grinding head struggles to fully conform to the hole wall, and the excessively long extension rods of air mills result in insufficient grinding pressure and low efficiency. Girder grinding tools, however, have limited oilstone travel, resulting in material removal efficiencies that fail to meet production requirements. Furthermore, the poor precision and surface quality of oil circuit processing further limit the applicability of traditional tools.

[0004] Therefore, there is an urgent need for a tool that can efficiently fit the inner wall of the oil circuit, provide stable grinding pressure and significantly improve polishing efficiency to solve the above technical problems.

[0005] The present invention realizes radial adaptive expansion of the elastic grinding disc through the air pressure internal expansion design, effectively improving the polishing effect and production efficiency. Summary of the Invention

[0006] The purpose of the present invention is to solve the problem of low polishing efficiency of the inner hole surface of the oil circuit, and to provide an internal expansion elastic polishing tool for the lubricating oil circuit of marine diesel engine parts and its use method and application. The elastic grinding disc is pushed to move radially by internal expansion of air pressure, so that on the one hand it fits the surface to be polished, and on the other hand it also provides the contact pressure necessary for cutting, thereby improving the polishing and cutting efficiency.

[0007] The technical solutions of the present invention are as follows:

[0008] A marine diesel engine part lubricating oil circuit internal expansion type elastic polishing tool, which is characterized by including:

[0009] The air expansion shaft has an external thread on one end and an air nozzle mounting hole on the other end;

[0010] A retainer, the center of which is provided with an internal thread that matches the external thread of the gas expansion shaft and is locked and fixed by a fastening nut;

[0011] A plurality of elastic grinding discs are evenly distributed in the mounting grooves around the circumference of the retainer;

[0012] A butyl rubber tube is sleeved on the outer surface of the gas expansion shaft, and its two ends are sealed and fixed by rubber tube compression terminals and fastening screw plugs, and is used to expand radially under the action of gas pressure to push the elastic grinding plate to fit the inner wall of the oil circuit;

[0013] A butyl rubber ring is provided between the bottom of the elastic grinding disc and the butyl rubber tube;

[0014] A fastening nut is used to limit the axial displacement of the elastic grinding disc;

[0015] Among them, the gas is injected through the air nozzle to cause the butyl rubber tube to expand radially, pushing the elastic grinding disc to expand outward and close to the inner wall of the oil circuit. At the same time, the air expansion shaft is connected to the pneumatic wind mill to drive the retaining frame to rotate, thereby achieving efficient polishing.

[0016] Furthermore, the air expansion shaft is provided with an axial through hole connected to the air nozzle, and the gas enters the inner cavity of the butyl rubber tube through the through hole; the fastening screw plug is threadedly connected to the end of the air expansion shaft, and cooperates with the rubber tube clamping terminal to realize double-end sealing of the butyl rubber tube.

[0017] Furthermore, the mounting grooves of the retaining frame are evenly distributed radially, and the width of the grooves is slightly smaller than the thickness of the elastic grinding plate; the fastening nut is threadedly connected to the end of the retaining frame, limiting the axial movement of the elastic grinding plate but allowing radial sliding.

[0018] Furthermore, the butyl rubber ring is an annular structure and is sleeved on the root of the elastic grinding plate to provide radial elastic pre-tightening force; when the butyl rubber tube expands, the pressure is evenly transmitted to each elastic grinding plate through the butyl rubber ring.

[0019] Furthermore, the driving end of the pneumatic shaft is provided with a standard clamping structure, which can be quickly connected to the extension rod of the pneumatic wind mill; the retaining frame is axially positioned by the step surface of the pneumatic shaft and transmits the rotational torque through a threaded connection.

[0020] Furthermore, the working surface of the elastic grinding disc is provided with a wear-resistant abrasive layer with a thickness of 0.5-2 mm; the radial stroke of the elastic grinding disc is 3-8 mm, which is suitable for oil circuit polishing of different apertures.

[0021] Furthermore, the working pressure of the butyl rubber tube is 0.2-0.6 MPa, and the outer diameter can be increased by 3-10 mm after expansion; the gas nozzle is provided with a one-way valve structure to prevent gas leakage.

[0022] At the same time, the present invention also provides a method for using the polishing tool, comprising the steps of:

[0023] a) Select the elastic grinding disc combination of corresponding size according to the oil channel aperture;

[0024] b) Inject gas through the air nozzle to slightly expand the grinding disc and then insert it into the oil passage;

[0025] c) Continue to apply pressure until the grinding disc is completely in contact with the inner wall of the oil circuit;

[0026] d) Start the wind mill to drive the tool to rotate and move it axially at a constant speed;

[0027] e) After polishing is completed, release the pressure, remove the tool, and check the surface quality.

[0028] Furthermore, the polishing speed is 2000-5000 rpm, and the axial feed speed is 10-30 mm / s;

[0029] When polishing in multiple times, increase the air pressure by 0.1-0.3MPa each time.

[0030] Third, a method for manufacturing a lubricating oil circuit for a marine diesel engine includes polishing the machined oil circuit using the above-mentioned tool to remove cutting lines with a depth of ≥0.05 mm and to make the surface roughness Ra ≤0.8 μm.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] 1) The elastic grinding disc is driven by air pressure to expand radially, achieving efficient polishing of the inner wall of the oil circuit. It is especially suitable for eliminating cutting lines caused by deep hole processing, improving surface quality and ensuring the cleanliness of the oil circuit.

[0033] 2) It can polish and eliminate deeper cutting lines, and the amount of material removal is relatively large compared with other polishing technologies.

[0034] 3) Particularly suitable for the manufacture and maintenance of marine diesel engine lubricating oil circuits, it can significantly reduce the failure rate of bearings caused by impurities in the oil circuits and improve the overall reliability of the engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a front view of the internal expansion elastic polishing tool for the lubricating oil circuit of a marine diesel engine part according to the present invention;

[0036] Figure 2 This is an exploded view of the assembly of the internal expansion elastic polishing tool for the lubricating oil circuit of a marine diesel engine part according to the present invention. DETAILED DESCRIPTION

[0037] The technical solution of the present invention will be clearly and completely described below in conjunction with application cases of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0038] See also Figure 1 and Figure 2 , Figure 1 This is a front view of the internal expansion elastic polishing tool for the lubricating oil circuit of a marine diesel engine part according to the present invention; Figure 2 This is an exploded view of the assembly of the internal expansion elastic polishing tool for the lubricating oil circuit of marine diesel engine parts of the present invention. As shown in the figure, the tool is assembled as follows:

[0039] Installation of the gas expansion shaft assembly: The butyl rubber tube 10 is sleeved on the outer surface of the gas expansion shaft 5 and fixed at both ends with rubber tube compression terminals 9; screw the fastening screw plug 2 into one end of the gas expansion shaft 5 to ensure that the butyl rubber tube 10 is sealed; install the air nozzle 3 at the other end of the gas expansion shaft 5 and tighten it with threads to form a closed air pressure channel.

[0040] Installation of the retainer and grinding discs: Evenly embed multiple elastic grinding discs 4 into the radial mounting grooves of the retainer 6, and place a butyl rubber ring 8 at the bottom of each grinding disc; screw the assembled retainer 6 into the threaded end of the pneumatic shaft 5 and tighten it with the fastening nut 1 to ensure stable torque transmission; install the fastening nut 7 at the other end of the retainer 6 to limit the axial displacement of the grinding disc but allow it to slide radially.

[0041] The inner expansion shaft is connected and fixed to the elastic grinding disc holder through the step end face on the shaft and the fastening nut, thereby transmitting the torque of the pneumatic wind mill. When the holder rotates, it can drive the grinding disc installed in the grinding disc mounting groove to do circular motion, which is the main cutting motion required for polishing.

[0042] Through the air nozzle installed on the designed inner expansion shaft, gas can enter the butyl rubber tube fixed and sealed on the outer circle of the shaft, thereby expanding the rubber tube and causing the diameter of the tube to increase, thereby pushing the grinding wheel installed in the grinding wheel mounting groove of the retainer to move radially, so that it fits closely to the inner hole surface to be polished and provides the contact pressure necessary for cutting.

[0043] When using an internal expansion polishing tool to polish the inner wall of the oil circuit, the rotation of the tool is the main motion of the grinding and cutting, and the axial movement of the wind mill along the oil circuit is the feed motion of the grinding and cutting. The butyl rubber tube is radially expanded by injecting gas into the air nozzle installed on the air expansion shaft, through the air nozzle, a compression screw plug, a butyl rubber tube, and a compression terminal. The radial expansion of the butyl rubber tube promotes the radial movement of the circumferentially arranged grinding discs, thereby contacting the surface to be polished and providing grinding pressure to achieve better grinding efficiency. The retaining frame has symmetrical grinding disc mounting grooves arranged in the circumferential direction for mounting the grinding discs. A locking nut is installed at one end of the opening of the retaining disc mounting groove to limit the freedom of movement of the grinding discs. The air expansion shaft is connected to the retaining frame via a thread on the shaft and is fixed by a step surface on the shaft and a locking nut, thereby transmitting torque. The end of the air expansion shaft protruding from the retaining frame is installed in the chuck section of the pneumatic wind mill extension rod. The torque is transmitted to the retaining frame, which drives the grinding disc to rotate, generating a grinding and cutting motion. The elastic grinding disc uses the elasticity of the butyl rubber ring to make the bottom of the grinding disc contact the surface of the inflated butyl rubber tube. The pneumatic wind mill provides torque and causes the polishing tool to move back and forth within the oil circuit through back and forth movement, thereby generating axial cutting motion.

[0044] The steps to use the tool are as follows:

[0045] 1. Select an elastic grinding disc of the corresponding size according to the diameter of the oil passage to be polished, ensuring that it can completely cover the inner wall of the oil passage after expansion; install it into the inner groove of the retainer together with the butyl rubber sleeve and tighten the M20*1 fastening nut;

[0046] 2. Use a universal air needle to inject a certain amount of air into the air expansion shaft so that the elastic grinding disc can enter the oil passage hole and there is obvious resistance when rotating;

[0047] 3. Install the shank of the internal expansion elastic polishing tool, that is, the longer part protruding from the retainer, into the chuck of the extended rod head of the pneumatic wind mill;

[0048] 4. Place the internal expansion elastic polishing tool into the oil passage hole, start the wind mill to drive the elastic grinding disc to produce cutting motion along the circumference of the oil passage hole, and at the same time move the wind mill along the axial direction of the oil passage hole to polish the hole surface;

[0049] 5. If the grinding disc is worn out and the polishing effect is not good, insert the air needle into the air nozzle to exhaust the air in the butyl rubber sleeve, and then repeat steps 1-4.

[0050] The above is only a specific case implementation process of the present invention and is not intended to limit the present invention. All equivalent changes and modifications made within the scope of the present invention are within the scope of protection required by the present invention.

Claims

1. A marine diesel engine parts lubricating oil circuit internal expansion type elastic polishing tool, characterized in that: include: An air expansion shaft (5) having an external thread at one end and an air nozzle (3) mounting hole at the other end; A retaining frame (6) is provided at its center with an internal thread that matches the external thread of the pneumatic shaft (5) and is locked and fixed by a fastening nut (1); A plurality of elastic grinding discs (4) are evenly distributed in the mounting grooves on the circumference of the retaining frame (6); A butyl rubber tube (10) is sleeved on the outer surface of the pneumatic shaft (5), and its two ends are sealed and fixed by rubber tube compression terminals (9) and fastening screw plugs (2), and is used for radial expansion under the action of air pressure to push the elastic grinding disc to fit the inner wall of the oil circuit; A butyl rubber ring (8) is provided between the bottom of the elastic grinding plate (4) and the butyl rubber tube (10); A fastening nut (7) for limiting the axial displacement of the elastic grinding plate (4); Gas is injected through the air nozzle (3) to cause the butyl rubber tube (10) to expand radially, pushing the elastic grinding disc (4) to expand outward and adhere closely to the inner wall of the oil circuit. At the same time, the air expansion shaft (5) is connected to the pneumatic wind mill to drive the retaining frame (6) to rotate, thereby achieving efficient polishing.

2. The internal expansion elastic polishing tool for lubricating oil circuit of marine diesel engine parts according to claim 1 is characterized in that: The air expansion shaft (5) is provided with an axial through hole connected to the air nozzle (3), and the gas enters the inner cavity of the butyl rubber tube (10) through the through hole; the fastening screw plug (2) is threadedly connected to the end of the air expansion shaft (5), and cooperates with the rubber tube clamping terminal (9) to achieve double-end sealing of the butyl rubber tube (10).

3. The internal expansion elastic polishing tool for lubricating oil circuit of marine diesel engine parts according to claim 1, characterized in that: The mounting grooves of the retaining frame (6) are evenly distributed in a radial shape, and the width of the grooves is slightly smaller than the thickness of the elastic grinding plate (4); the fastening nut (7) is threadedly connected to the end of the retaining frame (6), limiting the axial movement of the elastic grinding plate (4) but allowing radial sliding.

4. The internal expansion elastic polishing tool for lubricating oil circuit of marine diesel engine parts according to claim 1, characterized in that: The butyl rubber ring (8) is an annular structure and is sleeved on the root of the elastic grinding disc (4) to provide radial elastic pre-tightening force; when the butyl rubber tube (10) expands, the pressure is evenly transmitted to each elastic grinding disc (4) through the butyl rubber ring (8).

5. The internal expansion elastic polishing tool for lubricating oil circuit of marine diesel engine parts according to claim 1, characterized in that: The driving end of the pneumatic shaft (5) is provided with a standard clamping structure, which can be quickly connected to the pneumatic wind mill extension rod; the retaining frame (6) is axially positioned by the step surface of the pneumatic shaft (5) and transmits the rotational torque through the threaded connection.

6. The internal expansion elastic polishing tool for lubricating oil circuit of marine diesel engine parts according to claim 1, characterized in that: The working surface of the elastic grinding disc (4) is provided with a wear-resistant abrasive layer with a thickness of 0.5-2 mm; the radial stroke of the elastic grinding disc (4) is 3-8 mm, which is suitable for oil circuit polishing of different apertures.

7. The internal expansion elastic polishing tool for lubricating oil circuit of marine diesel engine parts according to claim 1, characterized in that: The working pressure of the butyl rubber tube (10) is 0.2-0.6 MPa, and the outer diameter can be increased by 3-10 mm after expansion; the gas nozzle (3) is provided with a one-way valve structure to prevent gas leakage.

8. A method for using the polishing tool according to any one of claims 1 to 7, comprising the steps of: a) selecting a combination of elastic grinding discs (4) of corresponding sizes according to the oil passage aperture; b) injecting gas through the air nozzle (3) to slightly expand the grinding disc (4) and then inserting it into the oil passage; c) Continue to apply pressure until the grinding disc (4) is completely in contact with the inner wall of the oil passage; d) Start the wind mill to drive the tool to rotate and move it axially at a constant speed; e) After polishing is completed, release the pressure, remove the tool, and check the surface quality.

9. The method according to claim 8, characterized in that: The polishing speed is 2000-5000rpm, and the axial feed speed is 10-30mm / s; When polishing in multiple times, increase the air pressure by 0.1-0.3MPa each time.

10. A method for manufacturing a lubricating oil circuit for a marine diesel engine, comprising polishing the machined oil circuit using the tool according to claims 1-7 to remove cutting lines with a depth of ≥ 0.05 mm and to reduce the surface roughness Ra to ≤ 0.8 μm.

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