Positioning tool and mounting method for marine low-speed diesel engine air cooler seawater pipe

Abstract

According to the positioning tool and the installation method for the marine low-speed diesel engine air cooler seawater pipe, the positioning tool comprises a connecting support, a plurality of positioning flanges and rib plates, the two ends of the connecting support are fixed to the lower portion of the bottom plane of a scavenging box through close-fitting bolts and common bolts respectively, and the positioning flanges are horizontally and fixedly welded to the connecting support; the positioning flanges correspond to the standard positions of the seawater pipes in position, the positioning flanges are connected with connecting flanges of the seawater pipes so as to position the seawater pipes, and the rib plates are vertically connected between the positioning flanges and the connecting support; the upper plane of the connecting support and the bottom plane of the scavenging box are tightly attached and aligned, installation of the positioning tool is completed through the close-fitting bolts and the common bolts, the connecting flange of the seawater pipe and the positioning flange are connected through the connecting bolts, and positioning of the seawater pipe is completed. Based on the positioning reference of the bottom surface of the scavenging box, the positioning precision of the interface of the seawater pipe is within + / -2mm, manual measurement errors are eliminated, reworking is avoided, the positioning precision of the seawater pipe flange is improved, the operation efficiency is improved, and the production cost is reduced.

Description

Technical Field

[0001] The present invention relates to a ship diesel engine manufacturing process, in particular to a positioning tool and an installation method for a seawater pipe of an air cooler of a ship low-speed diesel engine, belonging to the technical field of diesel engine manufacturing. Background Art

[0002] In the dual-fuel main engine version 2.0, the air cooler housing is larger, with its lower portion pre-assembled with the engine frame, while the seawater pipe is pre-installed with the cylinder block. Because the cylinder block and frame are installed separately, the interface between the seawater pipe and the air cooler core is prone to spatial misalignment during assembly. This requires on-site rework, including cutting, welding, or adjusting the seawater pipe (typically exceeding 500mm in diameter). This process is not only time-consuming and labor-intensive, but also compromises sealing.

[0003] Traditional installation methods rely on manual measurement and positioning, which has low accuracy and poor efficiency. Summary of the Invention

[0004] The purpose of the present invention is to provide a positioning tool and installation method for the seawater pipe of the air cooler of a marine low-speed diesel engine, so as to solve the problem of alignment deviation between the seawater pipe and the air cooler core when the cylinder body and the frame are closed. The bottom surface of the scavenge air box is used as the positioning reference, and the interface position of the seawater pipe is accurately fixed during the pre-assembly stage of the cylinder body, so as to ensure that the interface of the air cooler core is accurately aligned when it is closed with the frame, thereby avoiding the need for additional piping on site after closing.

[0005] The technical solutions of the present invention are as follows:

[0006] A positioning fixture for the seawater pipe of an air cooler of a marine low-speed diesel engine is installed on the bottom plane of the scavenge air box of the marine low-speed diesel engine, characterized in that the positioning fixture includes a connecting bracket, a plurality of positioning flanges and a rib plate; the two ends of the connecting bracket are respectively fixed to the bottom plane of the scavenge air box by tight-fitting bolts and ordinary bolts, and a plurality of positioning flanges are horizontally fixed and welded to the connecting bracket, and the positions correspond to the standard positions of each seawater pipe. The positioning flange is connected to the connecting flange of the seawater pipe to position the seawater pipe, and the rib plate is vertically connected between the positioning flange and the connecting bracket.

[0007] Furthermore, a positioning hole is provided at one end of the connecting bracket, which is connected to the bottom plane of the scavenging box by the tight-fitting bolts to accurately position the connecting bracket and the positioning flange of the positioning tooling. A fixing hole is provided at the other end of the connecting bracket, which is connected to the bottom plane of the scavenging box by the ordinary bolts to fix the positioning tooling.

[0008] Furthermore, the positioning hole of the connecting bracket forms a sliding fit with the tight-fitting bolt.

[0009] Furthermore, the rib plate is made of H-shaped steel and has reinforcing ribs welded thereon to prevent positioning deformation.

[0010] Furthermore, the connection flange is provided with connection holes corresponding in position to the bolt holes of the connection flange of the seawater pipe.

[0011] Furthermore, the connecting bracket is made of H-shaped steel.

[0012] Another technical solution of the present invention is as follows:

[0013] A method for installing a seawater pipe of an air cooler of a marine low-speed diesel engine using the positioning fixture comprises the following steps:

[0014] 1) Align the upper plane of the connecting bracket closely with the bottom plane of the scavenging box;

[0015] 2) Using the tightening bolts to connect one end of the connecting bracket to the bottom plane of the scavenging box for reference positioning, and then connecting the other end of the connecting bracket to the bottom plane of the scavenging box using the ordinary bolts to complete the installation of the positioning tool;

[0016] 3) Align the connecting flange of the seawater pipe with the positioning flange and connect them with connecting bolts to complete the positioning of the seawater pipe.

[0017] The beneficial technical effects of the present invention are as follows:

[0018] 1. Improved precision: The positioning fixture uses the bottom plane of the scavenging box as the positioning reference, eliminating the error caused by manual measurement and ensuring that the alignment accuracy of the seawater pipe flange is within ±2mm.

[0019] 2. Efficiency optimization: The seawater pipe can be positioned successfully in one go during the pre-installation phase, saving more than 70% of the man-hours required for adjustment after closure.

[0020] 3. Cost reduction: avoids material waste and rework costs caused by on-site preparation of pipe fittings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the present invention.

[0022] Figure 2 It is an installation schematic diagram of the present invention.

[0023] In the figure, 1 is the connecting bracket, 2 is the positioning flange, 3 is the stiffener, 4 is the tight-fitting bolt, 5 is the ordinary bolt, 6 is the seawater pipe, 11 is the positioning hole, and 12 is the fixing hole. DETAILED DESCRIPTION

[0024] The present invention will be described in further detail below with reference to the accompanying drawings and embodiments, but the scope of protection claimed in the present invention shall not be limited thereby.

[0025] The invention is used for positioning operation of a seawater pipe of an air cooler of a low-speed marine diesel engine; the low-speed marine diesel engine comprises a scavenging box and a seawater pipe.

[0026] Example

[0027] Figure 2 The marine low-speed diesel engine shown is a large low-speed two-stroke diesel engine dual-fuel main engine version 2.0.

[0028] like Figure 1 As shown, the positioning fixture is installed on the bottom plane of the scavenge air box of the marine low-speed diesel engine, and includes a connecting bracket 1, a plurality of positioning flanges 2 and a rib plate 3.

[0029] The connecting bracket 1 is made of H-shaped steel, with its ends secured to the underside of the scavenge box's bottom plane via clamping bolts 4 and standard bolts 5, respectively. One end of the connecting bracket 1 has a positioning hole 11, which connects to the scavenge box's bottom plane via the clamping bolts 4 to precisely position the connecting bracket 1 and the positioning flange 2 of the positioning fixture. The positioning hole 11 forms a sliding fit with the clamping bolts 4. The other end of the connecting bracket 1 has a fixing hole 12, which connects to the scavenge box's bottom plane via standard bolts 5 to secure the positioning fixture.

[0030] Several positioning flanges 2 are horizontally fixed and welded to the connecting bracket 1, and their positions correspond to the standard positions of each seawater pipe 6. The connecting flanges 2 are provided with connection holes corresponding to the bolt holes of the connecting flanges of the seawater pipes 6. The positioning flanges 2 are connected to the connecting flanges of the seawater pipes 6 to position the seawater pipes 6.

[0031] The rib plate 3 is made of H-shaped steel and is vertically connected between the positioning flange 2 and the connecting bracket 1. Reinforcing ribs are welded on the rib plate 3 to prevent positioning deformation.

[0032] The method for installing a seawater pipe for an air cooler of a low-speed marine diesel engine according to the present invention comprises the following specific steps:

[0033] 1. Align the connecting bracket 1 with the bottom plane of the scavenge air box and install it.

[0034] 2. Use the tight-fitting bolt 4 to connect one end of the connecting bracket 1 to the bottom plane of the scavenging box to ensure the reference positioning. Connect one end of the connecting bracket 1 to the bottom plane of the scavenging box with the ordinary bolt 5 to complete the installation of the positioning tooling.

[0035] 3. Align the connecting flange of the air cooler seawater pipe 6 with the positioning flange 2 on the positioning fixture, and connect them with bolts to complete the positioning of the seawater pipe 6.

[0036] The above is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. All equivalent changes and modifications made according to the content of the patent application of the present invention should fall within the technical scope of the present invention.

Claims

1. A positioning fixture for a seawater pipe of an air cooler of a low-speed marine diesel engine, mounted on the bottom plane of a scavenge air box of the low-speed marine diesel engine, characterized in that: The positioning fixture includes a connecting bracket, several positioning flanges and a rib plate; the two ends of the connecting bracket are fixed to the bottom plane of the scavenging box by tight bolts and ordinary bolts respectively, and several positioning flanges are horizontally fixed and welded to the connecting bracket, and the positions correspond to the standard positions of each seawater pipe. The positioning flange is connected to the connecting flange of the seawater pipe to position the seawater pipe, and the rib plate is vertically connected between the positioning flange and the connecting bracket.

2. The positioning fixture for seawater pipes of marine low-speed diesel engine air coolers according to claim 1, characterized in that: One end of the connecting bracket is provided with a positioning hole, which is connected to the bottom plane of the scavenging box by the tight-fitting bolts to accurately position the connecting bracket and the positioning flange of the positioning tooling. The other end of the connecting bracket is provided with a fixing hole, which is connected to the bottom plane of the scavenging box by the ordinary bolts to fix the positioning tooling.

3. The positioning fixture for seawater pipes of marine low-speed diesel engine air coolers according to claim 2, characterized in that: The positioning hole of the connecting bracket forms a sliding fit with the tight-fitting bolt.

4. The positioning fixture for seawater pipes of marine low-speed diesel engine air coolers according to claim 1, characterized in that: The rib plate is made of H-shaped steel and is welded with reinforcing ribs to prevent positioning deformation.

5. The positioning fixture for seawater pipes of marine low-speed diesel engine air coolers according to claim 1, characterized in that: The connecting flange is provided with connecting holes whose positions correspond to the bolt holes of the connecting flange of the seawater pipe.

6. The positioning fixture for seawater pipes of marine low-speed diesel engine air coolers according to claim 1, characterized in that: The connecting bracket is made of H-shaped steel.

7. A method for installing seawater pipes for a marine low-speed diesel engine air cooler using the positioning fixture of claim 1, characterized in that: The installation method comprises the following steps: 1) Align the upper plane of the connecting bracket closely with the bottom plane of the scavenging box; 2) Using the tightening bolts to connect one end of the connecting bracket to the bottom plane of the scavenging box for reference positioning, and then connecting the other end of the connecting bracket to the bottom plane of the scavenging box using the ordinary bolts to complete the installation of the positioning tool; 3) Align the connecting flange of the seawater pipe with the positioning flange and connect them with connecting bolts to complete the positioning of the seawater pipe.

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