Auxiliary tool for improving perpendicularity of marine diesel engine body bolt hole

Abstract

The auxiliary tool for improving the perpendicularity of the marine diesel engine body bolt hole comprises a screw tap extension rod used for connecting a screw tap and a drilling machine and a positioning sleeve used for limiting deflection of the screw tap extension rod when an internal thread section of the bolt hole is machined, and the upper end of the screw tap extension rod is connected with a tapping cutter handle of the drilling machine. The lower end of the screw tap extension rod is connected with the upper end of the screw tap in a matched mode, the positioning sleeve is matched with the opening position of the upper end of the unthreaded hole, and the screw tap penetrating out of the positioning sleeve is driven by the tapping cutter handle to coaxially machine a threaded hole along the bottom of the unthreaded hole under the anti-deviation guiding effect of the positioning sleeve on the screw tap extension rod. The positioning sleeve is arranged at the hole opening position of the machined unthreaded hole, the screw tap and the drilling machine are connected through the screw tap extension rod, the screw tap coaxially machines the threaded hole along the hole bottom of the unthreaded hole in the state that the screw tap extension rod is matched with the positioning sleeve, and the quality problem that the perpendicularity of a bolt hole is out of tolerance in a traditional machining mode is solved. The perpendicularity requirement of the bolt hole is ensured, the machining quality of products is improved, and smooth production is ensured.

Description

Technical Field

[0001] The utility model belongs to the technical field of diesel engine body bolt hole processing, and particularly relates to an auxiliary tool for improving the verticality of the bolt holes of a marine diesel engine body. Background Art

[0002] Marine diesel engines feature high thermal efficiency, good economy, easy starting, and wide adaptability to various types of vessels, making them widely used in marine propulsion systems and power plants. The engine fuselage is a key component and serves as the engine's foundation, with all fixed and moving parts bolted to it. Key bolt holes in the engine fuselage are the main bearing and cylinder head bolt holes. These bolt holes are stepped, with threaded holes at the bottom and smooth holes at the top. The thread diameter must be at least M36, and the required perpendicularity must be 0.20 / 100. The traditional, economical machining method involves pre-drilling with a gantry boring and milling machine followed by tapping with a drill press. However, the high flexibility of the drill press can lead to irregular perpendicularity in the main bearing and cylinder head bolt holes. The main bearing and cylinder head bolts on a marine diesel engine are approximately 1000 mm long, and irregular perpendicularity in these bolt holes can directly impact the installation of the main bearing and cylinder heads, causing interference. During the tapping process of key bolt holes, the verticality of the thread is mainly guaranteed by the accuracy of the drilling machine. However, as the equipment ages, the accuracy of the drilling machine decreases, and it is impossible to perform accuracy compensation like a CNC machine tool. This system error directly affects the processing accuracy of the key bolt holes of the fuselage, and the processing quality is unstable, resulting in the main bearing cover and cylinder head being unable to be installed smoothly, affecting the production progress. Therefore, it is necessary to make improvements to the above problems. Utility Model Content

[0003] The technical problem solved by the utility model is to provide an auxiliary tool for improving the verticality of the bolt hole of the marine diesel engine fuselage, by arranging a positioning sleeve at the position of the processed light hole hole mouth, and connecting the tap and the drilling machine by a tap extension rod, the tap is used to coaxially process the threaded hole along the bottom of the light hole when the tap extension rod and the positioning sleeve are adapted, thereby solving the quality problem of excessive verticality of the bolt hole under the traditional processing method, ensuring the verticality requirement of the bolt hole, improving the processing quality of the product, and ensuring smooth production.

[0004] The technical solution adopted by the utility model is an auxiliary tool for improving the verticality of the bolt hole of the marine diesel engine fuselage, comprising a tap extension rod for connecting the tap and the drilling machine and a positioning sleeve for limiting the deflection of the tap extension rod when processing the threaded section in the bolt hole, the upper end of the tap extension rod is connected to the tapping tool holder of the drilling machine, and the lower end of the tap extension rod is adaptively connected to the upper end of the tap, the positioning sleeve is adapted to the position of the upper end of the light hole, and the tap that passes through the positioning sleeve is driven by the tapping tool holder to coaxially process the threaded hole along the bottom of the light hole under the anti-deflection guiding effect of the positioning sleeve on the tap extension rod.

[0005] The positioning sleeve is a T-shaped sleeve, the small diameter section at the lower end of the positioning sleeve is adapted to the upper end of the light hole, and the step surface formed by the large diameter section and the small diameter section of the positioning sleeve contacts and positions the plane on the fuselage at the position of the light hole opening.

[0006] Furthermore, a plurality of shallow grooves are evenly distributed on the circumference of the inner hole wall of the positioning sleeve and are parallel to the axial direction thereof and are used to guide cutting fluid or cutting oil.

[0007] Furthermore, the positioning sleeve is a two-petal splicing structure, and a plurality of V-shaped shallow grooves are evenly distributed on the circumference of the inner hole wall of the positioning sleeve.

[0008] Furthermore, the positioning sleeve is made of high-quality carbon structural steel through quenching and tempering treatment.

[0009] Furthermore, the tap extension rod is made of CrMo steel through heat treatment, and the heat treatment hardness of the tap extension rod is 40-45HRC.

[0010] Furthermore, the tap extension rod includes a connecting guide section at the lower end, a stepped connecting section at the upper end, and an extended section connected to the connecting guide section and the stepped connecting section as a whole. The lower end surface of the connecting guide section is provided with a square hole that is adapted to be connected to the square column at the upper end of the tap, and the top screw threadedly connected to the connecting guide section through a countersunk screw hole is tightened in the annular groove at the upper end of the tap, and the square column at the upper end of the stepped connecting section is adapted to be connected to the bed tapping tool handle.

[0011] The advantages of this utility model compared with the prior art are:

[0012] 1. This technical solution addresses the quality issue of excessive verticality of bolt holes in traditional machining methods by placing a locating sleeve at the opening of the machined hole and connecting the tap to the drill press with a tap extension rod. With the tap extension rod and locating sleeve in place, the tap coaxially machines the threaded hole along the bottom of the machined hole. This provides a guide for the tap extension rod to prevent swaying during threaded segment machining, ensuring the stability and reliability of the tap when machining the threaded hole at the bottom of the machined hole, thereby guaranteeing the required verticality of the bolt hole.

[0013] 2. This technical solution processes a shallow groove on the inner wall of the positioning sleeve to guide cutting fluid or cutting oil. Cutting fluid or cutting oil can be added during tapping to ensure sufficient lubrication;

[0014] 3. This technical solution has a simple structure, novel design, low cost, stable and reliable positioning and guiding, reduces the difficulty of bolt hole processing, improves the verticality accuracy of bolt holes, improves the processing quality of products, and ensures smooth production. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the utility model in use;

[0016] Figure 2 A schematic diagram of the structure of the two-piece positioning sleeve of the utility model after being spliced together;

[0017] Figure 3 Schematic diagram of bolt hole center deviation. DETAILED DESCRIPTION

[0018] The following is a combination of the embodiments of the present invention Figure 1-3 The technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0019] It should be noted that, in this document, unless otherwise stated, it should be understood that the terms "center," "upper," "lower," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate positions or relationships based on those shown in the accompanying drawings. These are intended only to facilitate the description of the present invention and simplify the description, and are not intended to indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0020] As used herein, the terms "comprises," "comprising," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, the phrase "comprising a..." does not preclude the presence of additional identical elements in the process, method, article, or apparatus that includes the elements.

[0021] Auxiliary tools used to improve the verticality of bolt holes in marine diesel engine bodies, such as Figure 1-3As shown, it includes a tap extension rod 1 for connecting the tap 3 and the drilling machine and a positioning sleeve 2 for limiting the deflection of the tap extension rod 1 when machining the threaded section in the bolt hole. The upper end of the tap extension rod 1 is connected to the tapping handle of the drilling machine, and the lower end of the tap extension rod 1 is adapted to be connected with the upper end of the tap 3, so that the tap 3 rotates with the rotation of the tap extension rod 1. The positioning sleeve 2 is adapted to the position of the upper end of the light hole 4, and the tap 3 that passes through the positioning sleeve 2 is driven by the tapping handle to move along the light hole 4 under the anti-deflection guiding effect of the positioning sleeve 2 on the tap extension rod 1. The threaded hole is coaxially processed at the bottom of the hole 4. In the above structure, a positioning sleeve 2 is provided at the opening of the light hole 4 to be processed, and the tap 3 is connected to the drilling machine by the tap extension rod 1. When the tap extension rod 1 and the positioning sleeve 2 are adapted, the tap 3 coaxially processes the threaded hole along the bottom of the light hole 4. This solves the quality problem of excessive verticality of the bolt hole in traditional processing methods, provides a guide condition for the tap extension rod 1 to prevent swing during thread segment processing, ensures the stability and reliability of the tap when processing the threaded hole at the bottom of the light hole 4, and thus meets the verticality requirements of the bolt hole.

[0022] like Figure 1-2 As shown, the specific structure of the positioning sleeve 2 is as follows: the positioning sleeve 2 is a T-shaped sleeve, the small diameter section at the lower end of the positioning sleeve 2 is adapted to the upper end of the light hole 4, and the step surface formed by the large diameter section and the small diameter section of the positioning sleeve 2 is in contact with the plane on the body at the position of the light hole 4; specifically, a plurality of shallow grooves 5 are evenly distributed on the circumference of the inner hole wall of the positioning sleeve 2 and are parallel to its axial direction and are used to guide cutting fluid or cutting oil to facilitate lubrication of the tap; specifically, as Figure 2 As shown, in order to facilitate the installation of the positioning sleeve 2, the positioning sleeve 2 can be designed as a two-petal splicing structure, and a plurality of V-shaped shallow grooves 5 are evenly distributed on the circumference of the inner hole wall of the positioning sleeve 2; in the above structure, by processing the shallow grooves 5 for guiding cutting fluid or cutting oil on the inner hole wall of the positioning sleeve 2, cutting fluid or cutting oil can be added during tapping to ensure sufficient lubrication;

[0023] The positioning sleeve 2 is made of high-quality carbon structural steel after quenching and tempering. Specifically, the tap extension rod 1 is made of 42CrMo steel after heat treatment, and the heat treatment hardness of the tap extension rod 1 is 40-45HRC.

[0024] The specific structure of the tap extension rod 1 is as follows: the tap extension rod 1 includes a connecting guide section 1-1 at the lower end, a stepped connecting section 1-3 at the upper end, and an extension section 1-2 connected to the connecting guide section 1-1 and the stepped connecting section 1-3 as a whole. The lower end surface of the connecting guide section 1-1 is provided with a square hole adapted to connect with the square column at the upper end of the tap 3, and the top screw threadedly connected to the connecting guide section 1-1 through a countersunk screw hole is pressed against the annular groove at the upper end of the tap 3. The square column at the upper end of the stepped connecting section 1-3 is adapted to connect with the bed tapping tool handle; in the above structure, the tap 3 When machining a threaded hole from the bottom of the light hole 4, the connecting guide section 1-1 cooperates with the center hole of the positioning sleeve 2, and the cooperation clearance is selected to be 0.2 to 0.25 mm. Moreover, the length of the connecting guide section 1-1 is greater than the length of the positioning sleeve 2, and is also greater than the machining depth of the threaded hole, thereby ensuring that the positioning sleeve 2 always cooperates with the connecting guide section 1-1 before and after the threaded hole machining, ensuring the verticality requirement of the threaded hole machining. The positioning sleeve 2 that cooperates with the tap extension rod 1 and the light hole 4 of the bolt hole limits the swing position of the tap extension rod 1 during tapping, thereby well ensuring the verticality of the bolt hole.

[0025] According to the structural characteristics of the fuselage bolt hole, the tap extension rod 1 and the positioning sleeve 2 are designed. The tap extension rod 1 is used to connect the tap 3 and the drill press, and the positioning sleeve 2 is used to limit the deflection of the tap extension rod 1 during thread processing. Design principle: if the design center deviation is less than the theoretical center deviation δ, the verticality requirements of the screw hole in the drawing can be met. Figure 3 As shown, the bolt hole design center deviation = the fitting clearance between the tap extension rod 1 and the locating sleeve 2 / 2 + the fitting clearance between the locating sleeve 2 and the bolt hole / 2 < δ; generally, for ease of operation, each fitting clearance is selected to be between 0.2 and 0.25 mm, the orifice size of the fuselage bolt hole is controlled according to the outer diameter of the locating sleeve 2, and the inner hole size of the locating sleeve 2 (to ensure that the sleeve wall thickness is ≥4 mm) is determined according to the size of the positioning part of the tap extension rod 1 (i.e., the connecting guide section 1-1) to meet the fitting clearance requirements; for ease of installation, the locating sleeve 2 can be linearly cut into two parts from the center position, and the inner hole wall of the locating sleeve 2 should be machined with a shallow V-shaped groove 5. Cutting fluid or cutting oil can be added during tapping to ensure adequate lubrication. The material of the positioning sleeve 2 is 45GB / T699, quenched and tempered; the material of the tap extension rod is 42CrMoGB / T3077, heat-treated to a hardness of 40-45HRC. Chip removal can be achieved by setting an axial center hole on the tap extension rod 1. This is the same chip removal method as our company's original design of the tap extension rod, so it will not be repeated here.

[0026] This technical solution has a simple structure, novel design, low cost, stable and reliable positioning and guiding, reduces the difficulty of bolt hole processing, improves the verticality accuracy of bolt holes, improves the processing quality of products, and ensures smooth production.

[0027] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the present invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be encompassed within the present invention. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

[0028] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A tool for improving the verticality of bolt holes in a marine diesel engine body, characterized by: The invention comprises a tap extension rod (1) for connecting a tap (3) to a drilling machine and a positioning sleeve (2) for limiting the deflection of the tap extension rod (1) when machining a threaded section in a bolt hole. The upper end of the tap extension rod (1) is connected to a tapping shank of the drilling machine, and the lower end of the tap extension rod (1) is adaptively connected to the upper end of the tap (3). The positioning sleeve (2) is adapted to the position of the upper end opening of the light hole (4). The tap (3) passing through the positioning sleeve (2) is driven by the tapping shank to coaxially machine a threaded hole along the bottom of the light hole (4) under the anti-deflection guiding action of the positioning sleeve (2) on the tap extension rod (1).

2. The auxiliary tool for improving the verticality of bolt holes in a marine diesel engine according to claim 1, characterized in that: The positioning sleeve (2) is a T-shaped sleeve, the small diameter section at the lower end of the positioning sleeve (2) is adapted to the upper end of the light hole (4), and the step surface formed by the large diameter section and the small diameter section of the positioning sleeve (2) contacts and positions the plane on the fuselage at the opening position of the light hole (4).

3. The auxiliary tool for improving the verticality of bolt holes in a marine diesel engine according to claim 2, characterized in that: A plurality of shallow grooves (5) are evenly distributed on the circumference of the inner hole wall of the positioning sleeve (2) and are parallel to the axial direction thereof and used for guiding cutting fluid or cutting oil.

4. The auxiliary tool for improving the verticality of bolt holes in a marine diesel engine according to claim 3, characterized in that: The positioning sleeve (2) is a two-petal spliced structure, and a plurality of V-shaped shallow grooves (5) are evenly distributed on the circumference of the inner hole wall of the positioning sleeve (2).

5. The auxiliary tool for improving the verticality of bolt holes in a marine diesel engine according to claim 1, characterized in that: The positioning sleeve (2) is made of high-quality carbon structural steel after quenching and tempering.

6. The auxiliary tool for improving the verticality of bolt holes in a marine diesel engine according to claim 1, characterized in that: The tap extension rod (1) is made of 42CrMo steel through heat treatment, and the heat treatment hardness of the tap extension rod (1) is 40-45HRC.

7. The auxiliary tool for improving the verticality of bolt holes in a marine diesel engine according to any one of claims 1 to 6, characterized in that: The tap extension rod (1) comprises a connecting guide section (1-1) at the lower end, a stepped connecting section (1-3) at the upper end, and an extension section (1-2) integrally connected to the connecting guide section (1-1) and the stepped connecting section (1-3); a square hole adapted to be connected to a square column at the upper end of the tap (3) is formed on the lower end surface of the connecting guide section (1-1); a top screw threadedly connected to the connecting guide section (1-1) through a countersunk screw hole presses against a ring groove at the upper end of the tap (3); and the square column at the upper end of the stepped connecting section (1-3) is adapted to be connected to a bed tapping tool handle.

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