High-speed high-power diesel engine camshaft end hole processing tool and method

Abstract

This invention discloses a tooling and method for machining the end hole of a high-speed, high-power diesel engine camshaft, belonging to the field of machining technology. The tooling includes two V-shaped positioning blocks with V-grooves in the middle; a transition chuck body is hexagonal prism-shaped, with two symmetrical inclined surfaces at its lower part abutting against the two inclined surfaces of the V-grooves, and a pair of symmetrical threaded holes on its upper two inclined surfaces, the threaded holes communicating with an inner circular hole in the middle of the transition chuck; a locking bolt is threaded into the threaded holes; a hinged post and a threaded post are fixedly connected to the upper two sides of the V-shaped positioning blocks respectively; one end of a pressure plate is hinged to the top of the hinged post, and the other end has a sleeve hole for fitting onto the threaded post, the top of the threaded post being threaded with a nut. This invention integrates the transition chuck with the camshaft into a single shaft component. After machining one end of the camshaft pin hole, flipping the integrated shaft component ensures positioning accuracy while reducing disassembly and assembly, thus improving work efficiency.

Description

Technical Field

[0001] This invention belongs to the field of machining technology, specifically a tooling and method for machining the end hole of a high-speed, high-power diesel engine camshaft. Background Technology

[0002] The camshaft is a crucial internal component of an engine. While generally short, some large diesel engines have camshafts that can reach 2-3 meters in length. Machining such long, slender shafts is expensive. Disassembling and machining the extra-long camshaft before reassembling reduces machining difficulty and cost, but requires high precision during assembly. For example, a certain type of diesel engine camshaft is assembled from two sections: a long camshaft and a short camshaft. The long and short camshafts are positioned using locating pin holes during assembly. Figure 4 , 5 As shown, the long camshaft has two locating pin holes, φ8 and φ6, at each end. The angular vector error of these two locating pin holes must be less than ±0.08° to ensure that the assembled cam angle meets the drawing requirements. Machining the pin holes at both ends of the camshaft typically uses V-block positioning on a horizontal machining center. However, if the clamping device is released directly after machining one end of the pin hole, the camshaft needs to be repositioned, and it is difficult to guarantee positioning accuracy. How to machine the pin holes at both ends of a long camshaft using an existing horizontal machining center while ensuring positioning accuracy after reversal has become a challenging problem. Summary of the Invention

[0003] To overcome the shortcomings of the prior art, the present invention provides a tooling and method for machining the end hole of a high-speed, high-power diesel engine camshaft. The purpose is to design and manufacture a transition chuck and connect it to the camshaft to form an integral shaft. After machining the pin hole of one end of the camshaft, the integral shaft is flipped over. This can ensure positioning accuracy while reducing disassembly and assembly, and improving work efficiency.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a high-speed, high-power diesel engine camshaft end hole machining fixture, comprising two V-shaped positioning blocks; a V-shaped groove is provided in the middle of the top of the V-shaped positioning block; and a transition chuck, the body of which is hexagonal prism-shaped, with two symmetrical inclined surfaces at its lower part abutting against the two inclined surfaces of the V-shaped groove, and a pair of symmetrical threaded holes provided on the two inclined surfaces at its upper part, the threaded holes communicating with the inner circular hole opened in the middle of the transition chuck; the inner circular holes of the two transition chucks are fitted onto both ends of the camshaft, and locking bolts are threadedly connected to the threaded holes, for fixing the camshaft and the transition chuck into an integral shaft when the locking bolts are tightened; a hinge post and a threaded post are respectively fixedly connected to the upper two sides of the V-shaped positioning block; one end of the pressure plate is hinged to the top of the hinge post, and the other end of the pressure plate is provided with a sleeve hole for fitting onto the threaded post, the top of the threaded post is threadedly connected to a nut, for pressing the lower end of the pressure plate against the top plane of the transition chuck when the nut is tightened.

[0005] As a further optimization, a worktable is also included, on which the two V-shaped positioning blocks are fixedly connected.

[0006] As a further optimization, the V-shaped positioning block is provided with a connection hole for detachable installation onto the worktable via bolts.

[0007] As a further optimization, the included angle between the two inclined surfaces of the V-groove is 90°.

[0008] As a further optimization, the nut is a wing nut.

[0009] The present invention also provides a method for machining the end hole of a high-speed, high-power diesel engine camshaft, which utilizes the aforementioned high-speed, high-power diesel engine camshaft end hole machining fixture and includes the following steps.

[0010] S1: Fit the transition chucks onto both ends of the camshaft, and then tighten the locking bolts to form an integral shaft, so that the top and bottom planes of the two transition chucks are parallel to the horizontal plane;

[0011] S2: Place the integral shaft flat on the upper end of a pair of V-shaped positioning blocks, so that the two symmetrical inclined surfaces at the lower part of the transition chuck abut against the two inclined surfaces of the V-shaped groove at the upper end of the V-shaped positioning block, and keep the top and bottom planes of the transition chuck horizontal.

[0012] S3: Cover the pressure plate, tighten the nut to clamp and fix the integral shaft, and then start the horizontal machining center to start machining the pin hole at one end of the camshaft until the pin hole is machined.

[0013] S4: Loosen the nut, flip open the pressure plate, lift the integral shaft and rotate it 180°, then repeat steps S2-S3 to complete the pin hole machining at the other end of the camshaft;

[0014] S5: Loosen the nut, flip the pressure plate, remove the integral shaft, then loosen the locking bolt, remove the transition chuck, and obtain the machined camshaft;

[0015] The advantages of this invention are that it connects the camshaft to the camshaft as an integral shaft by means of a transition chuck. After machining the pin hole at one end of the camshaft, the integral shaft is flipped over, which can ensure positioning accuracy while reducing disassembly and assembly and improving work efficiency. The angular vector error of the holes at both ends of the camshaft machined according to this invention can be less than ±0.08°. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the integrated shaft component according to an embodiment of the present invention.

[0017] Figure 2This is a schematic diagram of the structure of the integral shaft clamped onto the V-shaped positioning block according to an embodiment of the present invention.

[0018] Figure 3 This is a schematic diagram of the structure of the present invention during machining using a horizontal machining center.

[0019] Figure 4 This is a schematic diagram of the camshaft structure according to an embodiment of the present invention.

[0020] Figure 5 for Figure 4 Enlarged views of the K and F directions (i.e., the two end faces of the camshaft).

[0021] The technical features in the figure correspond to the reference numerals as follows: 1. Transition chuck; 2. Locking bolt; 3. Camshaft; 4. Pressure plate; 5. Integrated shaft; 6. Front V-shaped positioning block; 7. Worktable; 8. Rear V-shaped positioning block; 10. Horizontal machining center. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some preferred embodiments of the present invention, and not all embodiments. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0023] Example; please refer to Figure 1-5 This invention provides a tooling for machining the end hole of a high-speed, high-power diesel engine camshaft, comprising two V-shaped positioning blocks; each V-shaped positioning block has a V-shaped groove in the middle of its top end; it also includes a transition chuck 1, which is hexagonal prism in shape, with two symmetrical inclined surfaces at its lower part abutting against the two inclined surfaces of the V-shaped groove, and a pair of symmetrical threaded holes on its upper two inclined surfaces, the threaded holes communicating with an inner circular hole in the middle of the transition chuck 1; a locking bolt 2 is threadedly connected to the threaded hole, used to tighten the locking bolt 2 after the inner circular holes of the two transition chucks 1 are fitted onto the two ends of the camshaft 3, thereby fixing the camshaft 3 and the transition chuck 1 into an integral shaft 5; a hinge post and a threaded post are respectively fixedly connected to the upper two sides of the V-shaped positioning block; one end of a pressure plate 4 is hinged to the top end of the hinge post, and the other end has a sleeve hole for fitting onto the threaded post, the top end of the threaded post is threadedly connected to a nut, used to press the lower end of the pressure plate 4 against the top plane of the transition chuck 1 when the nut is tightened.

[0024] In use, a self-made transition chuck 1 is made. The transition chuck 1 consists of a transition chuck 1 body and a locking bolt 2. The transition chuck 1 body is in the shape of an inner circle and an outer hexagon. The angle between the inclined surface of the transition chuck 1 body and the inclined surface of the V-shaped positioning block is 90°. During processing, two transition chucks 1 and two V-shaped positioning blocks are used, namely the front V-shaped positioning block 6 and the rear V-shaped positioning block 8, which are respectively installed at the front and rear ends of the worktable 7. Then, the transition chucks 1 are installed at the front and rear ends of the camshaft 3. The transition chucks 1 and the camshaft 3 are connected as one piece (hereinafter referred to as: integrated shaft 5) with the locking bolt 2. The front and rear transition chucks 1 are installed in the same way as the camshaft 3. By manually aligning the machine tool, ensure that the height of the V-shaped locating blocks at both ends is consistent and that the center lines of the two V-shaped locating blocks are parallel to the tool spindle. Then, place the integrated shaft 5 on the two V-shaped locating blocks on the machine tool and fix the integrated shaft 5 on the V-shaped locating blocks using the pressure plate 4. This completes the positioning and clamping work before machining the camshaft 3. Afterward, the horizontal machining center 10 can be started to complete the machining of the pin hole at one end of the camshaft 3. Once the pin hole at one end is machined, the pressure plate 4 can be released. Turn the integrated shaft 5 around and then lock the pressure plate 4 again to complete the machining of the pin hole at the other end of the camshaft 3.

[0025] In other words, the method of use, namely a method for machining the end hole of a high-speed, high-power diesel engine camshaft, includes the following steps.

[0026] S1: The transition chucks 1 are fitted onto both ends of the camshaft, and the locking bolts 2 are tightened to form an integral shaft 5, so that the top and bottom planes of the two transition chucks 1 are parallel to the horizontal plane.

[0027] S2: Place the integral shaft 5 flat on the upper end of the pair of V-shaped positioning blocks, so that the two symmetrical inclined surfaces at the lower part of the transition chuck 1 abut against the two inclined surfaces of the V-shaped groove at the upper end of the V-shaped positioning block, and keep the top and bottom planes of the transition chuck 1 horizontal.

[0028] S3: Cover the pressure plate 4, tighten the nut to clamp and fix the integral shaft 5, and then start the horizontal machining center to start machining the pin hole at one end of the camshaft 3 until the pin hole is machined.

[0029] S4: Loosen the nut, flip open the pressure plate 4, lift the integral shaft 5 and rotate it 180°, then repeat steps S2-S3 to complete the pin hole machining on the other end of the camshaft 3.

[0030] S5: Loosen the nut, flip the pressure plate 4, remove the integral shaft 5, then loosen the locking bolt 2, remove the transition chuck 1, and obtain the machined camshaft 3.

[0031] Preferably, the V-shaped positioning block is provided with a connecting hole for detachable installation onto the worktable 7 via bolts, making the V-shaped positioning block detachable for easy maintenance and replacement. Preferably, the nut is a wing nut for quick assembly and disassembly, improving work efficiency.

[0032] The advantage of this device is that it connects the camshaft 3 to the transition chuck 1 to form an integral shaft 5. After machining the pin hole of one end of the camshaft 3, the integral shaft 5 is flipped over, which can ensure positioning accuracy while reducing disassembly and assembly and improving work efficiency. The angular vector error of the holes at both ends of the camshaft machined according to this invention can be less than ±0.08°.

[0033] The parts of this invention not described in detail are prior art; for those skilled in the art, the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. The scope of this invention is defined by the appended claims and their equivalents.

Claims

1. A tooling for machining the end hole of a high-speed, high-power diesel engine camshaft, comprising two V-shaped positioning blocks; wherein a V-shaped groove is provided in the middle of the top of each V-shaped positioning block; characterized in that: It also includes a transition chuck (1), the body of which is a hexagonal prism shape, with two symmetrical inclined surfaces at the bottom abutting against the two inclined surfaces of the V-groove, and a pair of symmetrical threaded holes on the two inclined surfaces at the top. The threaded holes are connected to the inner circular hole in the middle of the transition chuck (1). The inner circular holes of the two transition chucks (1) are fitted onto the two ends of the camshaft (3), and the locking bolts (2) are threaded into the threaded holes. When the locking bolts (2) are tightened, the camshaft (3) and the transition chuck (1) are fixed together as an integral shaft (5). The upper sides of the V-shaped positioning block are respectively fixedly connected to the hinge column and the threaded column; one end of the pressure plate (4) is hinged to the top of the hinge column, and the other end is provided with a sleeve hole for fitting onto the threaded column. The top of the threaded column is threaded with a nut, so that when the nut is tightened, the lower end of the pressure plate (4) presses against the top plane of the transition chuck (1). The V-shaped positioning block is provided with a connecting hole for detachable installation onto the workbench (7) by bolts; The following steps are included when using it; S1: Fit the transition chucks (1) onto both ends of the camshaft (3), and then tighten the locking bolts (2) to form an integral shaft (5), so that the top and bottom planes of the two transition chucks (1) are parallel to the horizontal plane; S2: Place the integral shaft (5) flat on the V-groove of a pair of V-shaped positioning blocks, so that the two symmetrical inclined surfaces of the lower part of the transition chuck (1) abut against the two inclined surfaces of the V-groove at the upper end of the V-shaped positioning block, and keep the top and bottom planes of the transition chuck (1) horizontal. S3: Cover the pressure plate (4), tighten the nut to clamp and fix the integral shaft (5), and then start the horizontal machining center to process the pin hole at one end of the camshaft (3) until the pin hole is processed; S4: Loosen the nut, flip open the pressure plate (4), lift the integral shaft (5) and rotate it 180°, then repeat steps S2-S3 to complete the pin hole processing at the other end of the camshaft (3); S5: Loosen the nut, flip open the pressure plate (4), remove the integral shaft (5), then loosen the locking bolt (2), remove the transition chuck (1), and obtain the camshaft (3) after processing.

2. The tooling for machining the end hole of the camshaft of a high-speed, high-power diesel engine according to claim 1, characterized in that: The angle between the two inclined surfaces of the V-groove is 90 degrees.

3. The tooling for machining the end hole of the camshaft of a high-speed, high-power diesel engine according to claim 1, characterized in that: The nut is a wing nut.

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