Method for preventing valve shaft of low-speed diesel engine one-way valve from falling off

Abstract

According to the method for preventing the valve shaft of the one-way valve of the low-speed diesel engine from falling off, the one-way valve comprises a guide block and the valve shaft, and the method is characterized in that the guide block and the valve shaft are fixed together through a fixing pin so as to prevent the valve shaft from falling off due to vibration in the operation process of the low-speed diesel engine. A shaft pin hole is drilled in the radial direction of the valve shaft; 2) drilling a pin hole which penetrates through the guide block and is communicated with the shaft hole in the guide block along the radial direction of the shaft hole, wherein the diameter is the same as that of the shaft pin hole; and (3) the valve shaft is inserted into the shaft hole of the guide block, fixing pins with the same diameter penetrate into the pin hole and the shaft pin hole at the same time, so that the valve shaft and the guide block are fixed together, then the fastening bolt is screwed, and finally the guide block is fixedly connected to the scavenging collecting pipe through the fixing bolt. The reliability of the one-way valve is improved. The device has the advantages of simple structure, convenience in maintenance and convenience in operation.

Description

Technical Field

[0001] The invention relates to a low-speed diesel engine, in particular to a method for preventing a valve shaft of a one-way valve of a low-speed diesel engine from falling off, belonging to the technical field of low-speed ship diesel engines. Background Art

[0002] Currently, scavenge air manifolds on low-speed marine diesel engines are typically equipped with a check valve. This device restricts fluid flow to the inlet direction, preventing backflow at the outlet. To prevent backflow of scavenge air, the check valve is installed after the drip separator. When air flows normally forward, the check valve opens in response to the airflow. If air flows in the reverse direction, the check valve closes, preventing backflow.

[0003] See also Figure 2 The structure of the one-way valve includes a valve plate 1, a guide block 2, a valve shaft 3 and a baffle 6. Figure 3 The guide block 2 includes an axial hole 4 and an open slot 5 at the top. The valve shaft 3 is inserted into the axial hole 4 and fixed to the guide block 2 by a set bolt 8 passing through the open slot 5. The guide block 2 is fixedly connected to the scavenging manifold 11 by a fixing bolt 7. The upper part of the valve plate 1 is rolled into a circular tube, wrapping the valve shaft 3 inside. The lower part of the valve plate 1 can rotate around the valve shaft 3. When the air flows forward, the valve plate 1 opens the opening on the scavenging manifold 11 forward to allow air to pass through. If the air flows in the reverse direction, the valve plate 1 rotates backward to fit closely to the scavenging manifold 11. Figure 1 , close the opening to prevent air from flowing back. Figure 2 The baffle 6 is fixed to the guide block 2 by bolts 9 and nuts 10 to limit the rotation of the valve plate 1.

[0004] The existing one-way valve has the following shortcomings: when the main engine is running, the valve shaft 3 of the one-way valve often moves and falls due to excessive vibration. The main reasons are analyzed as follows:

[0005] 1) When the valve shaft 3 is installed, it may not fully contact or partially contact the shaft hole 4. The main engine will vibrate during operation, causing the valve shaft 3 to slowly shift to one side and eventually fall out. 2) There is an open slot 5 above the guide block 2. From an assembly perspective, it cannot achieve the same fixed size as a fully closed type, and a gap will be generated. From a processing perspective, although the shaft hole 4 on the guide block 2 has size requirements, if the processing deviation of the valve shaft 3 is too large, a larger gap will be generated, causing the valve shaft 3 to fall off. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the shortcomings of the existing technology and provide a method for preventing the valve shaft of a one-way valve of a low-speed diesel engine from falling off, so that the valve plate is reliably fixed on the valve shaft to prevent the valve shaft from falling off from the guide block due to vibration when the main engine is running, thereby achieving the purpose of improving the reliability of the one-way valve.

[0007] Based on the above purpose, the technical solution adopted by the present invention is:

[0008] A method for preventing a valve shaft from falling off in a one-way valve of a low-speed diesel engine, the one-way valve comprising a guide block and a valve shaft, the end of the valve shaft being inserted into an axial hole of the guide block and fixed to the guide block by a fixing bolt passing through an open groove, the guide block being fixedly connected to a scavenging manifold by a fixing bolt; the method being characterized in that the guide block and the valve shaft are fixed together by a fixing pin to prevent the valve shaft from falling off due to vibration during operation of the low-speed diesel engine, thereby improving the reliability of the one-way valve.

[0009] Furthermore, the end of the valve shaft is provided with a radial axis pin hole, the guide block is provided with a pin hole along the radial direction of the axis hole, and the fixing pin is inserted into the pin hole and the axis pin hole at the same time to fix the guide block and the valve shaft together.

[0010] Furthermore, the shaft pin hole and the pin hole are smooth holes and their diameters are the same as the diameter of the fixing pin.

[0011] Furthermore, the pin hole is a through hole that passes through the guide block and is connected to the shaft hole.

[0012] Furthermore, the pin hole is a threaded through hole, and the fixing pin is provided with an external thread matching the threaded through hole.

[0013] Furthermore, the axle pin hole is a blind hole.

[0014] Furthermore, the method for preventing the valve shaft from falling off includes the following specific steps:

[0015] 1) Drilling a shaft pin hole at the end of the valve shaft along the radial direction of the valve shaft, wherein the shaft pin hole is a smooth hole;

[0016] 2) drilling a pin hole on the guide block along the radial direction of the shaft hole, the pin hole being a light hole that passes through the guide block and communicates with the shaft hole, and the diameter of the pin hole being the same as the diameter of the shaft pin hole;

[0017] 3) Insert the valve shaft into the shaft hole of the guide block, and use a fixing pin with the same diameter as the pin hole and the shaft pin hole to simultaneously penetrate the pin hole and the shaft pin hole to fix the valve shaft and the guide block together, then tighten the fixing bolt passing through the open groove, and finally use the fixing bolt to fix the guide block to the scavenging manifold.

[0018] Furthermore, in the step 2), the pin hole is a threaded through hole, and in the step 3), the fixing pin is provided with an external thread matching the threaded through hole.

[0019] Compared with the prior art, the present invention has achieved the following beneficial effects:

[0020] 1) Practical verification shows that the technical measure of using a fixing pin to fix the guide block and the valve shaft can greatly avoid the occurrence of the valve shaft falling off, improve the working reliability of the one-way valve, and reduce the probability of damage.

[0021] 2) The present invention maintains the original structure of the one-way valve as much as possible without making major changes, and has the advantage of convenient operation.

[0022] 3) The present invention has the characteristics of simple structure and easy maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the installation of a one-way valve.

[0024] Figure 2 It is a structural diagram of an existing one-way valve.

[0025] Figure 3 Schematic diagram of the existing guide block.

[0026] Figure 4 This is a cross-sectional view of an existing valve shaft.

[0027] Figure 5 It is a structural schematic diagram of the present invention.

[0028] Figure 6 Schematic diagram of the valve shaft of the present invention.

[0029] Figure 7 Schematic diagram of the guide block of the present invention.

[0030] Figure 8 Flow chart of the method of the present invention.

[0031] In the figure,

[0032] 1—valve plate, 2—guide block, 3—valve shaft, 4—shaft hole, 5—opening slot, 6—baffle, 7—fixing bolt, 8—tightening bolt, 9—bolt, 10—nut, 11—scavenging manifold, 12—fixing pin, 13—shaft pin hole, 14—pin hole. DETAILED DESCRIPTION

[0033] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but this should not be used to limit the scope of protection claimed in the present invention.

[0034] The present invention is used to prevent the valve shaft of a one-way valve of a low-speed diesel engine from falling off. The one-way valve includes a guide block 2 and a valve shaft 3. Figure 5 The end of the valve shaft 3 is inserted into the shaft hole 4 of the guide block 2 and is fixed to the guide block 2 by a fastening bolt 8 passing through the open groove 5. The guide block 2 is fixedly connected to the scavenging manifold 11 by a fixing bolt 7.

[0035] The present invention optimizes and improves the existing one-way valve structure. The guide block and the valve shaft are fixed together by a fixing pin, and the entire one-way valve is fixed to the scavenging manifold by bolts, thereby preventing the valve shaft from falling off due to vibration during the operation of the main engine and improving the reliability of the one-way valve.

[0036] See also Figure 6 The end of the valve shaft 3 is provided with a radial axis pin hole 13, and the axis pin hole 13 is a smooth hole and a blind hole.

[0037] See also Figure 7 The guide block 2 is provided with a pin hole 14 along the radial direction of the shaft hole 4. The pin hole 14 is a through hole that passes through the guide block 2 and is connected to the shaft hole 4. The pin hole 14 can be a smooth hole or a threaded through hole, and its diameter is the same as that of the shaft pin hole 13.

[0038] See also Figure 5 The fixing pin 12 is inserted into the pin hole 14 of the guide block 2 and the shaft pin hole 13 of the valve shaft 3 to fix the guide block 2 and the valve shaft 3 together.

[0039] See also Figure 8 The method for preventing the valve shaft from falling off of a one-way valve of a low-speed diesel engine according to the present invention comprises the following steps:

[0040] 1) First, drill a 5.5mm diameter pin hole 13 along the radial direction of the valve shaft 3 at the end of the valve shaft 3 with a diameter of 18mm. Figure 6 The shaft pin hole 13 is a light hole, and the shaft pin hole 13 is a blind hole with a depth of 8mm.

[0041] 2) Drill a pin hole 14 with the same diameter of 5.5 mm on the guide block 2 along the radial direction of the shaft hole 4. Figure 7 The pin hole 14 is a through hole that passes through the guide block 2 and is connected to the shaft hole 4. It can be a plain hole or a threaded through hole.

[0042] 3) Finally, insert the valve shaft 3 into the shaft hole 4 of the guide block 2, and use the fixing pin 12 to simultaneously penetrate the pin hole 14 and the shaft pin hole 13 to fix the valve shaft 3 and the guide block 2 together, then tighten the fastening bolt 8 that passes through the opening groove 5, and finally use the fixing bolt 7 to fix the guide block 2 to the scavenging manifold 11; the diameter of the fixing pin 12 is the same as the diameter of the shaft pin hole 13 and the pin hole 14.

[0043] After being verified in practice, the present invention and method have the characteristics of simple structure, convenient operability, and easy maintenance. They play a role in the operation of the machine and reduce the probability of damage.

[0044] The protection scope of the present invention is not limited to the above-mentioned embodiments, but should also include other obvious changes and alternatives to the present invention.

Claims

1. A method for preventing a valve shaft from falling off in a one-way valve of a low-speed diesel engine, the one-way valve comprising a guide block and a valve shaft, the end of the valve shaft being inserted into an axial hole of the guide block and fixed to the guide block by a set bolt extending through an open slot, the guide block being fixedly connected to a scavenging manifold by a fixing bolt; characterized in that: The guide block is fixed to the valve shaft by a fixing pin to prevent the valve shaft from falling off due to vibration during the operation of the low-speed diesel engine, thereby improving the reliability of the one-way valve.

2. The method for preventing the valve shaft from falling off of a one-way valve of a low-speed diesel engine according to claim 1, characterized in that: The end of the valve shaft is provided with a radial shaft pin hole, the guide block is provided with a pin hole along the radial direction of the shaft hole, and the fixing pin is inserted into the pin hole and the shaft pin hole at the same time to fix the guide block and the valve shaft together.

3. The method for preventing the valve shaft from falling off of a one-way valve of a low-speed diesel engine according to claim 2, characterized in that: The shaft pin hole and the pin hole are smooth holes and their diameters are the same as the diameter of the fixing pin.

4. The method for preventing the valve shaft from falling off of a one-way valve of a low-speed diesel engine according to claim 2, characterized in that: The pin hole is a through hole that passes through the guide block and is connected to the shaft hole.

5. The method for preventing the valve shaft from falling off of a one-way valve of a low-speed diesel engine according to claim 4, characterized in that: The pin hole is a threaded through hole, and the fixing pin is provided with an external thread matching the threaded through hole.

6. The method for preventing the valve shaft from falling off of a one-way valve of a low-speed diesel engine according to claim 2, characterized in that: The axle pin hole is a blind hole.

7. The method for preventing the valve shaft from falling off of a one-way valve of a low-speed diesel engine according to claim 2, characterized in that: The method for preventing the valve shaft from falling off comprises the following specific steps: 1) Drilling a shaft pin hole at the end of the valve shaft along the radial direction of the valve shaft, wherein the shaft pin hole is a smooth hole; 2) drilling a pin hole on the guide block along the radial direction of the shaft hole, the pin hole being a light hole that passes through the guide block and communicates with the shaft hole, and the diameter of the pin hole being the same as the diameter of the shaft pin hole; 3) Insert the valve shaft into the shaft hole of the guide block, and use a fixing pin with the same diameter as the pin hole and the shaft pin hole to simultaneously penetrate the pin hole and the shaft pin hole to fix the valve shaft and the guide block together, then tighten the fixing bolt passing through the open groove, and finally use the fixing bolt to fix the guide block to the scavenging manifold.

8. The method for preventing the valve shaft from falling off of a one-way valve of a low-speed diesel engine according to claim 7, characterized in that: In the step 2), the pin hole is a threaded through hole, and in the step 3), the fixing pin is provided with an external thread matching the threaded through hole.

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