A fixture for machining deep hole of crankshaft

Abstract

The application provides a crankshaft deep hole machining clamp, which comprises a shaft end support and a limiting support, a plurality of concave guide supports and a plurality of convex guide supports are arranged between the shaft end support and the limiting support, a center support is arranged at the front part, the middle part and the rear part of the crankshaft to be machined; the concave guide support comprises a U-shaped base, a guide cover is detachably arranged on the base, and a first guide structure is arranged at the lower part of the guide cover; the convex guide support comprises a base, a supporting part is arranged on the base, and a second guide structure is arranged at the upper part of the supporting part; the center support comprises a fixing base and a pressing plate, and a V-shaped clamping groove is arranged at the upper part of the fixing base. The concave guide support, the convex guide support and the center support are used for guiding and supporting the drilling of the crank oil hole, so that the machining precision of the main oil passage hole is ensured; under the action of the fixing and thrusting devices of the shaft end support and the limiting support, the crankshaft axial movement phenomenon in the drilling process is avoided, and the machining precision and efficiency are improved.

Description

Technical Field

[0001] This invention belongs to the field of crankshaft machining technology, and in particular relates to a fixture for machining deep holes in crankshafts. Background Technology

[0002] The crankshaft, a key component of a diesel engine, is often referred to as its heart. The dimensional and geometrical tolerances of each part of the crankshaft are extremely high. Because the main oil passage hole intersects with straight and oblique oil holes, running through the entire crankshaft's main journal and crankshaft, current fixtures lack guiding and axial limiting devices. They only support and clamp the journals at both ends and the middle journal. This still presents problems during drilling the main oil passage hole. Due to the high hardness of the crankshaft and the poor rigidity of the cutting tool, tool dips during continuous drilling of the intermittent crankshaft, causing the drilled hole to be positioned too low. This ultimately leads to a decrease in the machining accuracy of the main oil passage hole, or even exceeding tolerances. Furthermore, during drilling the main oil passage hole, the crankshaft is subjected to axial force from the cutting tool, which can easily cause insufficient clamping force of the support block, leading to problems such as tool breakage and chipping. Therefore, it is necessary to improve the existing fixtures. Summary of the Invention

[0003] In view of this, the present invention aims to overcome the deficiencies in the prior art and proposes a fixture for machining deep holes in crankshafts.

[0004] To achieve the above objectives, the technical solution created by this invention is implemented as follows:

[0005] A fixture for machining deep holes in a crankshaft includes a shaft end support and a limiting support, with several concave guide supports and several convex guide supports between them. The top of the limiting support is coaxial with the axis of the crankshaft being machined. A central support is provided at the front, middle, and rear of the crankshaft being machined. The concave guide support includes a U-shaped base, on which a guide cover is detachably installed. A first guide structure is provided at the lower part of the guide cover. The convex guide support includes a base, on which a support part is provided. A second guide structure is provided at the upper part of the support part. A third guide structure is provided at the top of the shaft end support. Guide sleeves are installed on the first, second, and third guide structures. The central support includes a fixed seat and a pressure plate detachably installed at the top of the fixed seat. A V-shaped groove is provided at the upper part of the fixed seat.

[0006] Furthermore, the shaft end bracket, the limiting bracket, the central bracket, and the guide bracket are all installed in the T-slot of the machine tool worktable.

[0007] Furthermore, the shaft end bracket, the limiting bracket, the central bracket, and the guide bracket are all installed in the T-slot of the machine tool worktable using quick-release bolts.

[0008] Furthermore, the top head on the limiting bracket is arranged horizontally, and the limiting bracket is provided with an adjustment mechanism for adjusting the position of the top head.

[0009] Furthermore, the adjustment mechanism includes a horizontally arranged clamping bolt, which is screwed onto the limiting bracket, and the top head is installed at the end of the clamping bolt.

[0010] Furthermore, each of the guide sleeves is equipped with a bushing.

[0011] Furthermore, reinforcing ribs are provided between the support portion and the base.

[0012] Furthermore, the shaft end support includes a shaft end seat and a shaft end frame, with reinforcing ribs provided between the shaft end seat and the shaft end frame.

[0013] Compared with existing technologies, the present invention has the following advantages:

[0014] This invention features a rationally designed structure. It uses concave guide brackets, convex guide brackets, and a central bracket to guide and support the drilling of each crank oil hole, ensuring the machining accuracy of the main oil passage hole. Under the fixation of the shaft end bracket and the limit bracket, as well as the thrust-resistant device, the workpiece is prevented from axial movement of the crankshaft during drilling, thus improving machining accuracy and efficiency. At the same time, by changing the guide sleeve, it can adapt to the machining of crankshafts with different main oil passage hole diameters, which can reduce the cost of fixture manufacturing and lower the cost of scientific research and production. Attached Figure Description

[0015] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0016] Figure 1 A schematic diagram illustrating the application of this invention;

[0017] Figure 2 A three-dimensional structural diagram illustrating the application of this invention;

[0018] Figure 3 This is a schematic diagram of the concave guide bracket in this invention.

[0019] Figure 4 This is a schematic diagram of the convex guide bracket in this invention.

[0020] Figure 5 This is a schematic diagram of the shaft end bracket in this invention.

[0021] Figure 6 This is a schematic diagram of the central support in this invention.

[0022] Figure 7 This is a schematic diagram of the limiting bracket in this invention. Detailed Implementation

[0023] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0024] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0025] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0026] The invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0027] A jig for machining deep holes in crankshafts, such as Figures 1 to 7As shown, the crankshaft includes a shaft end bracket 1 and a limiting bracket 2, with several concave guide brackets 3 and several convex guide brackets 4 between them. The top 5 of the limiting bracket is coaxial with the axis of the crankshaft being machined 6. A central bracket 7 is provided at the front, middle, and rear of the crankshaft being machined. The concave guide bracket includes a U-shaped base 8, on which a guide cover 9 is detachably installed. A first guide structure 10 is provided below the guide cover. The convex guide bracket includes a base 11, on which a support part 12 is provided. A second guide structure 13 is provided above the support part. A third guide structure 14 is provided at the top of the shaft end bracket. Guide sleeves 15 are installed on the first, second, and third guide structures. Preferably, a bushing is installed inside each of the guide sleeves. The central bracket includes a fixed seat 16 and a pressure plate 17 detachably installed at the top of the fixed seat. A V-shaped groove 18 is provided on the upper part of the fixed seat. In an optional embodiment, the guide cover of the concave guide bracket is fixed to the base by bolts, and the pressure plate of the central bracket is fixed to the fixed seat by bolts.

[0028] The shaft end bracket, limiting bracket, central bracket, and guide bracket are all installed in the T-slot of the machine tool worktable. For example, the shaft end bracket, limiting bracket, central bracket, and guide bracket are all installed in the T-slot of the machine tool worktable using quick-release bolts. The mandrel on the limiting bracket is horizontally arranged, and an adjustment mechanism 19 for adjusting the position of the mandrel is provided on the limiting bracket. For example, the adjustment mechanism includes a horizontally arranged clamping bolt, which is screwed onto the limiting bracket, and the mandrel is installed at the end of the clamping bolt.

[0029] The supporting part is provided with reinforcing ribs between itself and the base. The shaft end bracket includes a shaft end seat and a shaft end frame, with reinforcing ribs between the shaft end seat and the shaft end frame. In an optional embodiment, an adjusting shim 20 is provided between the guide cover and the base, and the height of the guide cover can be adjusted by adding or removing the adjusting shim. Two adjusting blocks 21 are symmetrically provided in the V-shaped groove, and the two adjusting blocks are detachably installed on the side wall of the V-shaped groove. By replacing the adjusting blocks, the central bracket can be stably fitted with the workpiece to form an effective support.

[0030] When using this fixture for production, first, match a suitable guide sleeve according to the diameter of the main oil passage hole. Then, select the appropriate number of concave and convex guide supports according to the structural dimensions of the crankshaft being machined to avoid interference between the crank and the guide supports. Use positioning keys to sequentially clamp the shaft end support, center support, concave guide support, and convex guide support onto the T-slot of the machine tool worktable 22. Finally, fix the limit support to the worktable with quick-release bolts to ensure that the axis of the mandrel is coaxial with the axis of the crankshaft being machined.

[0031] Adjust each guide bracket to the appropriate position according to the crankshaft crank spacing, loosen the center bracket nut, remove the center bracket pressure plate, loosen the concave guide bracket nut, and remove the guide cover.

[0032] Hoist the crankshaft to be machined to the support position, tighten the quick-release bolts and nuts of the shaft end bracket, center bracket, concave guide bracket, and convex guide bracket, close the center bracket pressure plate, tighten the nut, close the guide cover of the concave guide bracket, tighten the nut, adjust the limit bracket nut so that the mandrel presses against the crankshaft end face, and start drilling the main oil passage hole.

[0033] After drilling is completed, loosen the nuts on the concave guide bracket, remove the guide cover, loosen the nuts on the center bracket, remove the center bracket pressure plate, loosen the limit bracket nuts, replace the crankshaft to be machined, and proceed with the machining of the next workpiece.

[0034] This invention features a rationally designed structure. It uses concave guide brackets, convex guide brackets, and a central bracket to guide and support the drilling of each crank oil hole, ensuring the machining accuracy of the main oil passage hole. Under the fixation of the shaft end bracket and the limit bracket, as well as the thrust-resistant device, the workpiece is prevented from axial movement of the crankshaft during drilling, thus improving machining accuracy and efficiency. At the same time, by changing the guide sleeve, it can adapt to the machining of crankshafts with different main oil passage hole diameters, which can reduce the cost of fixture manufacturing and lower the cost of scientific research and production.

[0035] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A fixture for machining deep holes in crankshafts, characterized in that: The system includes a shaft end bracket and a limiting bracket, with several concave guide brackets and several convex guide brackets between them. The top of the limiting bracket is coaxial with the axis of the crankshaft being machined. A central bracket is provided at the front, middle, and rear of the crankshaft being machined. The concave guide bracket includes a U-shaped base with a detachable guide cover. A first guide structure is provided below the guide cover. The convex guide bracket includes a base with a support portion. A second guide structure is provided above the support portion. A third guide structure is provided at the top of the shaft end bracket. Guide sleeves are installed on the first, second, and third guide structures. The central bracket includes a fixed seat and a pressure plate detachably mounted on the top of the fixed seat. A V-shaped groove is provided on the upper part of the fixed seat. The top of the limiting bracket is horizontally arranged. The limiting bracket is equipped with an adjustment mechanism for adjusting the position of the mandrel. The adjustment mechanism includes a horizontally arranged clamping bolt, which is screwed onto the limiting bracket, and the mandrel is installed at the end of the clamping bolt. An adjustment shim is provided between the guide cover and the base. The height of the guide cover is adjusted by adding or removing the adjustment shim. Two adjustment blocks are symmetrically arranged in the V-shaped groove. The two adjustment blocks are detachably installed on the side wall of the V-shaped groove. By replacing the adjustment blocks, the center bracket and the workpiece can form an effective support. The shaft end bracket, the limiting bracket, the center bracket, and the guide bracket are all installed in the T-slot of the machine tool worktable. When using this fixture for production, a suitable guide sleeve is matched according to the diameter of the main oil passage hole. By changing the guide sleeve, it can adapt to the machining of crankshafts with different main oil passage hole diameters.

2. The jig for machining deep holes in a crankshaft according to claim 1, characterized in that: The shaft end bracket, limit bracket, center bracket, and guide bracket are all installed in the T-slot of the machine tool worktable using quick-release bolts.

3. The jig for machining deep holes in a crankshaft according to claim 1, characterized in that: Each of the guide sleeves is fitted with a bushing.

4. The jig for machining deep holes in a crankshaft according to claim 1, characterized in that: The support portion is provided with reinforcing ribs between itself and the base.

5. A jig for machining deep holes in a crankshaft according to claim 1, characterized in that: The shaft end support includes a shaft end seat and a shaft end frame, with reinforcing ribs provided between the shaft end seat and the shaft end frame.

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