Marine engine connecting rod stud bolt removal and installation tool

Abstract

The utility model discloses a disassembly and installation tool for connecting rod studs of marine engines, comprising an elastic nut, a locking sleeve, a locking cover, a guide cylindrical pin and an adjusting ball screw, wherein the elastic nut is screwed on the outer end of the connecting rod stud. The locking sleeve is located between the locking cover and the elastic nut, and the conical surfaces of the locking sleeve and the elastic nut abut against each other. One end of the guide cylindrical pin is fixed in one side of the through hole of the locking sleeve, and the other end is embedded and positioned in the guide groove of the elastic nut. One end of the adjusting ball screw abuts against the center hole of the connecting rod stud. The utility model significantly improves assembly efficiency, reduces labor intensity of assembly, avoids damage to the end thread of the connecting rod stud, and thus improves the assembly quality of marine engines.

Description

Technical Field

[0001] The utility model relates to a disassembly and installation tool for stud bolts, in particular to a disassembly and installation tool for connecting rod stud bolts fixed on the big end of a connecting rod of a marine engine, and belongs to the technical field of benchwork. Background Art

[0002] The connecting rod assembly is a key part of a marine engine. It converts the up and down motion of the cylinder piston into the rotational motion of the crankshaft. The connecting rod big end and the connecting rod cover are positioned by two diagonally arranged locating pins, and the connecting rod cover is fixed to the connecting rod bearing shell on the crankshaft neck by two connecting rod stud bolts and nuts on both sides of the connecting rod big end and the connecting rod cover.

[0003] When assembling or repairing the connecting rod assembly, the connecting rod stud bolts need to be removed or installed from the connecting rod big end. For example, the threads at both ends of the connecting rod stud bolts of a certain type of marine engine are M33×2, with a large thread diameter and no wrench opening, which makes it difficult to remove with general tools. The existing process of disassembling the connecting rod stud bolts is as follows: Figure 1 As shown, two nuts 20 are screwed on the end of the connecting rod stud 10, with a washer 30 between the two nuts 20, and two open-end wrenches are used to respectively turn the nuts 20 on both sides of the washer 30, and the two nuts 20 are turned in opposite directions until they cannot be turned, so that the two nuts 20, the washer 30 and the connecting rod stud 10 are temporarily fixed together, and the nuts can be turned counterclockwise with an electric wrench or a pneumatic wrench to loosen the connecting rod stud 10. This process needs to be repeated many times before the connecting rod stud can be removed. The operation is cumbersome, the labor intensity is high, the work efficiency is very low, and the thread of the connecting rod stud is easily damaged. In serious cases, a new connecting rod stud needs to be replaced, which increases the installation or maintenance cost of the marine engine. Utility Model Content

[0004] The utility model aims to provide a disassembly and installation tool and method for a connecting rod stud bolt of a marine engine, which can reduce the labor intensity of disassembly, improve the disassembly efficiency and ensure that the connecting rod stud bolt will not be damaged.

[0005] The utility model is realized through the following technical solutions:

[0006] A tool for disassembling and installing a connecting rod stud bolt for a marine engine, comprising an elastic nut, a locking sleeve, a locking cover, a guide cylindrical pin and an adjusting ball screw, wherein the elastic nut is a combination of an upper annular body, a middle hollow frustum body and a lower annular body, a plurality of elastic grooves are evenly distributed radially on the lower part of the combination, a guide groove is provided on one side of the radial outer edge of the upper part of the combination, and the elastic nut is screwed on the lower end of the connecting rod stud bolt; the locking sleeve is located between the radial direction of the locking cover and the radial direction of the elastic nut, the outer peripheral surface of the locking sleeve is an external thread structure, and the upper part of the locking cover is provided with a guide groove. The internal thread is screwed into the external thread of the locking sleeve, the locking sleeve through hole is a combination hole of the upper circular hole and the lower frustum body hole, the lower frustum body hole and the outer conical surface of the hollow frustum body in the middle of the elastic nut abut against each other; one end of the horizontally placed guide cylindrical pin is fixed in the pin hole on one side of the upper circular hole of the locking sleeve through hole, and the other end of the guide cylindrical pin is embedded in the guide groove positioned at the radial outer edge of the elastic nut; the adjusting ball screw is screwed into the central threaded hole of the locking cover, and the ball head at one end of the adjusting ball screw abuts against the central hole of the connecting rod stud bolt.

[0007] The purpose of the utility model can be further achieved by the following technical measures.

[0008] Furthermore, the taper of the lower frustum hole of the locking sleeve through hole and the taper of the hollow frustum body in the middle of the elastic nut are both 7:24.

[0009] Furthermore, a positioning step is retracted in the bottom of the threaded hole of the elastic nut, and the lower end of the connecting rod stud bolt abuts against the positioning step.

[0010] Furthermore, the locking cover is provided with a stepped countersunk hole, the upper threaded hole of the stepped countersunk hole is screwed with the external thread of the locking sleeve, the bottom of the locking sleeve is against the bottom surface of the upper threaded hole, and a single-side clearance δ1=0.2-0.3mm is left between the lower countersunk hole of the stepped countersunk hole and the lower annular body of the elastic nut in the radial direction. The radial single-side clearance δ2=0.10-0.15mm between the guide cylindrical pin and the guide groove.

[0011] Furthermore, the elastic nut is made of 60Si2CrA spring steel, and the allowable stress of the elastic nut is [σ]=270-302Mpa.

[0012] Furthermore, when used to remove the connecting rod stud bolts, the center screw hole thread of the locking cover and the external thread of the adjusting ball screw are both left-handed threads; when used to install the connecting rod stud bolts, the center screw hole thread of the locking cover and the external thread of the adjusting ball screw are both right-handed threads.

[0013] The utility model adopts a structure in which the elastic nut, the locking sleeve and the locking cover are threadedly connected with the taper and the ball head of the adjusting ball screw is tightened against the center hole of the end of the connecting rod stud bolt. Only a small torque is needed to rotate the adjusting ball screw, so that a large normal force can be generated between the elastic nut and the locking sleeve due to the close contact of the conical surface, so that the utility model is fixed on the end of the connecting rod stud bolt, thereby realizing that the connecting rod stud bolt can be removed from or installed on the connecting rod big head with a small rotation torque. The structure is simple and compact, easy to operate, time-saving and labor-saving, significantly improving the assembly efficiency, reducing the labor intensity of assembly, avoiding damage to the end thread of the connecting rod stud bolt, and thus improving the assembly quality of marine engine products.

[0014] Advantages and features of the present invention will be illustrated and explained by the following non-limiting description of preferred embodiments, which are given as examples only with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the existing installation and removal of the connecting rod stud bolt;

[0016] Figure 2 It is a structural diagram of the utility model tooling;

[0017] Figure 3 yes Figure 2 A magnified view of part I;

[0018] Figure 4 yes Figure 3 AA section enlarged view. DETAILED DESCRIPTION

[0019] The utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0020] like Figure 1 to Figure 3 As shown, the disassembly and installation tool for connecting rod studs of the marine engine of the utility model comprises an elastic nut 1, a locking sleeve 2, a locking cover 3, a guide cylindrical pin 4 and an adjusting ball screw 5. The elastic nut 1 is a combination of an upper annular body 11, a middle hollow frustum body 12 and a lower annular body 13. Four elastic grooves 14 are evenly distributed radially at the lower part of the combination. A guide groove 15 is opened on one side of the radial outer edge of the upper part of the combination. The elastic nut 1 is screwed on the lower end of the connecting rod stud 10. The elastic nut 1 is made of 60Si2CrA spring steel with an allowable stress [σ] = 270-302Mpa, so that the elastic nut 1 has good elasticity, which is convenient for the elastic nut 1 to be clamped and fixed on the end of the connecting rod stud 10 through the locking sleeve 2. It is also convenient to loosen the elastic nut 1 and remove the tool.

[0021] The locking sleeve 2 is located between the radial direction of the locking cover 3 and the radial direction of the elastic nut 1. The outer peripheral surface of the locking sleeve 2 is an external thread structure. The internal thread of the upper part of the locking cover 3 is screwed with the external thread of the locking sleeve 2. The locking sleeve through hole is a combination hole of the upper circular hole 21 and the lower frustum body hole 22. The lower frustum body hole 22 and the outer conical surface of the hollow frustum body 12 in the middle of the elastic nut 1 abut against each other. The taper of the lower frustum body hole 22 of the locking sleeve through hole and the taper of the hollow frustum body 12 in the middle of the elastic nut 1 are both 7:24. When the elastic nut 1 and the locking sleeve 2 are axially displaced, the elastic nut 1 and the locking sleeve 2 can be quickly combined into one, and can also be quickly separated and disassembled, thereby realizing the rapid connection or rapid separation of the utility model with the end of the connecting rod stud bolt 10.

[0022] One end of the horizontal guide cylindrical pin 4 is fixed in the pin hole 23 on one side of the upper circular hole 21 of the locking sleeve through hole, and the other end of the guide cylindrical pin 4 is embedded in the guide groove 15 positioned at the radial outer edge of the elastic nut 1. The adjusting ball screw 5 is screwed into the central threaded hole 33 of the locking cover 3, and the ball head 51 at one end of the adjusting ball screw 5 abuts against the central hole 101 of the connecting rod stud. The guide cylindrical pin 4 prevents the elastic nut 1 and the locking sleeve 2 from rotating relative to each other, so that the elastic nut 1 is better fixed on the end of the connecting rod stud 10. The bottom of the elastic nut threaded hole is retracted into a positioning step 16, and the lower end of the connecting rod stud 10 abuts against the positioning step 16 to be limited.

[0023] The locking cover 3 is provided with a stepped countersunk hole, the upper threaded hole 31 of the stepped countersunk hole is screwed with the external thread of the locking sleeve 2, the bottom of the locking sleeve 2 is against the bottom surface of the upper threaded hole 31, and a single-side clearance δ1=0.2-0.3mm is left between the lower countersunk hole 32 of the stepped countersunk hole and the lower annular body 13 of the elastic nut 1 in the radial direction. The radial single-side clearance δ2=0.10-0.15mm between the guide cylindrical pin 4 and the guide groove 15.

[0024] When the utility model is used to remove the connecting rod stud bolt 10, the thread of the central screw hole 31 of the locking cover and the external thread of the adjusting ball screw 5 are both left-handed threads; when used to install the connecting rod stud bolt 10, the thread of the central screw hole 31 of the locking cover and the external thread of the adjusting ball screw 5 are both right-handed threads.

[0025] The process of disassembling or installing the connecting rod stud bolts of a marine engine using the utility model is as follows:

[0026] 1) First, drive one end of the guide cylindrical pin 4 into the pin hole 23 on one side of the upper circular hole 21 fixed to the locking sleeve through hole, and make the other end of the guide cylindrical pin 4 embedded in the guide groove 15 at the radial outer edge of the elastic nut 1. Then, put the locking sleeve 2 on the outside of the elastic nut 1, and press the locking sleeve 2 downward, so that the lower cone hole 22 of the locking sleeve through hole and the middle hollow cone body 12 of the elastic nut 1 abut against each other.

[0027] 2) Then tighten the locking cover 3 onto the locking sleeve 2 until the bottom of the locking sleeve 2 abuts against the bottom surface of the upper threaded hole 31 of the locking cover stepped countersunk hole, and then screw the elastic nut 1 clockwise onto the lower end of the connecting rod stud 10 until the lower end of the connecting rod stud 10 abuts against the positioning step 16 at the bottom of the elastic nut threaded hole. Finally, screw the adjusting ball screw 5 counterclockwise into the central threaded hole 31 of the locking cover 3, so that the ball head 51 at one end of the adjusting ball screw 5 is pressed against the central hole 101 of the connecting rod stud, thereby installing the tooling of the utility model on the lower end of the connecting rod stud 10.

[0028] 3) The operator holds the knurled outer circle of the locking cover 3 with one hand, and uses a manual wrench or an electric wrench with the other hand to turn the square handle 52 at the other end of the adjusting ball screw 5 counterclockwise, so that the locking cover 3 and the locking sleeve 2 move in the direction away from the connecting rod stud 10. Due to the combination of the conical surfaces of the locking sleeve 2 and the locking nut 1, the elastic nut 1 radially contracts and locks the lower end thread of the connecting rod stud 10, thereby fixing the disassembly tool and the connecting rod stud 10 into one body; at this time, the operator loosens the knurled outer circle of the locking cover 3 with one hand, and only needs to use a manual wrench or an electric wrench with the other hand to turn the square handle 52 at the other end of the adjusting ball screw 5 counterclockwise, and through the ball head 51 at one end of the adjusting ball screw 5, the conical surface of the center hole 101 of the connecting rod stud 10 is tightened, so that the other end of the connecting rod stud 10 is screwed into the connecting rod big head and the screw and the threaded hole produce relative rotation and loosen. The connecting rod stud bolt 10 can be removed from the connecting rod big end by continuing to turn the square handle 52 at the other end of the adjusting ball screw 5 counterclockwise.

[0029] 4) The operator suddenly rotates the square handle 52 at the other end of the adjusting ball screw 5 clockwise with a manual wrench to move the locking cover 3 toward the connecting rod stud 10, and drives the locking sleeve 2 to move in the same direction, thereby releasing the threaded lock between the elastic nut 1 and the lower end of the connecting rod stud 10. The operator can then grasp the knurled outer circle of the locking outer cover 3 by hand and rotate it counterclockwise to remove the disassembly tool.

[0030] By changing the mating threads of the adjusting ball screw 5 and the locking outer cover 3 into right-hand threads, the stud bolt and the threaded hole can be installed using the utility model. The steps of screwing the connecting rod stud bolt 10 onto the connecting rod big head using the utility model are the same as the steps of removing the connecting rod stud bolt 10 from the connecting rod big head, except that the rotation direction of the wrench is opposite.

[0031] The utility model can be used for the installation and disassembly of double-head screws above M20 and has good versatility.

[0032] In addition to the above-mentioned embodiments, the present invention may also have other implementation modes. Any technical solutions formed by equivalent replacement or equivalent transformation shall fall within the protection scope required by the present invention.

Claims

1. A tool for removing and installing connecting rod stud bolts for marine engines, characterized in that: It includes an elastic nut, a locking sleeve, a locking cover, a guide cylindrical pin and an adjusting ball screw. The elastic nut is a combination of an upper annular body, a middle hollow frustum body and a lower annular body. A number of elastic grooves are evenly distributed radially on the lower part of the combination. A guide groove is opened on one side of the radial outer edge of the upper part of the combination. The elastic nut is screwed on the outer end of the connecting rod stud bolt; the locking sleeve is located between the radial direction of the locking cover and the radial direction of the elastic nut. The outer peripheral surface of the locking sleeve is an external thread structure. The internal thread on the upper part of the locking cover is connected to the external thread of the locking sleeve. The threads are screwed together, and the locking sleeve through hole is a combination hole of the upper circular hole and the lower frustum body hole. The lower frustum body hole and the outer cone surface of the hollow frustum body in the middle of the elastic nut abut against each other; one end of the horizontally placed guide cylindrical pin is fixed in the pin hole on one side of the upper circular hole of the locking sleeve through hole, and the other end of the guide cylindrical pin is embedded in the guide groove positioned at the radial outer edge of the elastic nut; the adjusting ball head screw is screwed into the central threaded hole of the locking cover, and the ball head at one end of the adjusting ball head screw abuts against the central hole of the connecting rod stud bolt.

2. The marine engine connecting rod stud bolt disassembly and installation tool as claimed in claim 1, characterized in that: The taper of the lower frustum hole of the locking sleeve through hole and the taper of the hollow frustum body in the middle of the elastic nut are both 7:

24.

3. The marine engine connecting rod stud bolt disassembly and installation tool as claimed in claim 1, characterized in that: A positioning step is retracted inwardly from the bottom of the threaded hole of the elastic nut, and the outer end of the connecting rod stud bolt abuts against the positioning step.

4. The marine engine connecting rod stud bolt disassembly and installation tool as claimed in claim 1, characterized in that: The locking cover is provided with a stepped countersunk hole, the upper threaded hole of the stepped countersunk hole is screwed into the external thread of the locking sleeve, the bottom of the locking sleeve is against the bottom surface of the upper threaded hole, and a single-sided gap δ1=0.2~0.3mm is left between the lower countersunk hole of the stepped countersunk hole and the lower annular body of the elastic nut in the radial direction.

5. The marine engine connecting rod stud bolt disassembly and installation tool as claimed in claim 1, characterized in that: The radial single-side clearance between the guide cylindrical pin and the guide groove is δ2=0.10-0.15 mm.

6. The marine engine connecting rod stud bolt disassembly and installation tool as claimed in claim 1, characterized in that: The elastic nut is made of 60Si2CrA spring steel, and the allowable stress of the elastic nut is [σ]=270-302Mpa.

7. The marine engine connecting rod stud bolt disassembly and installation tool as claimed in claim 1, characterized in that: When used to remove the connecting rod stud bolts, the locking cover center screw hole thread and the adjusting ball screw outer thread are both left-hand threads; when used to install the connecting rod stud bolts, the locking cover center screw hole thread and the adjusting ball screw outer thread are both right-hand threads.

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