A support structure for a multi-step machining tool for a cylinder camshaft bore

Abstract

The utility model discloses a kind of for the supporting structure of cylinder camshaft hole multi-grade processing cutter, it is characterized by, including several connected tubular bushings, the outer circumference of the tubular bushing is equipped with several keys grooves arranged along tubular bushing axial direction, support piece is equipped in the keys groove, elastic member is equipped between the support piece and the bottom of keys groove, when the elastic member free stretch, support piece top surface is higher than the outer surface of tubular bushing;The inner ring of the tubular bushing is equipped with bearing.The utility model forms integral bushing group structure by rigid pin shaft series connection multiple tubular bushings, and the bearing of inner ring is combined to realize the dynamic and static separation of tool rotation and supporting system;Simultaneously, the elastic member in keys groove and support piece combination self-adapting fit hole wall, both strengthen integral anti-rotation, and compensate hole diameter error to maintain the stability of long tool.

Description

Technical Field

[0001] This utility model relates to the field of camshaft multi-stage machining technology, and in particular to a support structure for a tool used in multi-stage machining of cylinder camshaft holes. Background Technology

[0002] In the multi-stage machining of cylinder block camshaft bores, long cutting tools are often used. These tools rely on support bushings embedded in the machined bore to provide radial support. However, existing support structures lack an effective anti-rotation mechanism, causing the bushings to easily rotate with the tool under cutting forces or vibrations. This not only accelerates frictional wear between the support and the bore wall and shortens component life, but also significantly affects machining dimensional accuracy due to accumulated frictional heat. Secondly, rotational motion weakens the bushing's stable support capability for the tool, potentially leading to chatter or tool deviation during machining, posing a risk of support failure. Furthermore, a single bushing structure cannot achieve stable rigid support. Therefore, there is an urgent need for a support structure for multi-stage machining tools in cylinder block camshaft bores that can ensure effective support within the bore during tool machining while transferring anti-rotation constraints to the entire bushing string, thereby improving machining stability. Utility Model Content

[0003] The purpose of this invention is to provide a support structure for multi-stage machining tools for cylinder camshaft holes.

[0004] The innovation of this utility model lies in the use of a rigid pin to connect multiple cylindrical bushings to form an integral bushing assembly structure, which, combined with the bearing in the inner ring, achieves dynamic and static separation between the tool rotation and the support system; at the same time, the combination of elastic elements and support elements in the keyway adaptively fits the hole wall, which not only strengthens the overall anti-rotation but also compensates for hole diameter errors to maintain the stability of long tools.

[0005] To achieve the aforementioned utility model objectives, the technical solution of this utility model is as follows: A support structure for a multi-stage machining tool for a cylinder camshaft hole, characterized in that it includes several connected cylindrical bushings, each cylindrical bushing having several keyways arranged axially along its outer circumference, a support member within each keyway, and an elastic member between the support member and the bottom of the keyway. When the elastic member extends freely, the top surface of the support member is higher than the outer surface of the cylindrical bushing; a bearing is provided in the inner ring of each cylindrical bushing. Multiple cylindrical bushings are connected in series by rigid pins to form an integral bushing assembly structure, and the bearing in the inner ring achieves dynamic and static separation between the tool rotation and the support system. Simultaneously, the combination of the elastic member and the support member within the keyway adaptively conforms to the hole wall, strengthening overall anti-rotation and compensating for hole diameter errors to maintain the stability of long tools. The use of several connected cylindrical bushings provides a wider range of applications compared to a single cylindrical bushing structure.

[0006] Furthermore, the cylindrical bushings are connected to each other via pins. Adding pins to connect adjacent cylindrical bushings allows multiple bushings to form a rigid, series-connected structure, achieving coordinated anti-rotation of the multi-position support structure and avoiding the risk of chain-like rotation.

[0007] Furthermore, a washer is provided between the cylindrical bushing and the connected cylindrical bushing, and the pin passes through the washer and connects to the two cylindrical bushings. By providing a washer between adjacent cylindrical bushings and connecting them with a pin, a controllable gap is formed between adjacent bushings, which can adapt to the differences in hole spacing at different gear positions, while maintaining the overall anti-rotation force transmission efficiency of the pin.

[0008] Furthermore, a sealing ring is provided between the gasket and the adjacent cylindrical bushing. This sealing ring between the gasket and the cylindrical bushing prevents coolant and debris from entering the connection interface of the cylindrical bushing, thus preventing foreign matter from entering the pin mating surface and causing jamming, and ensuring the long-term reliability of the overall anti-rotation chain.

[0009] Furthermore, the bearing is a needle roller bearing. Needle roller bearings are used to adapt to the combined working conditions of long tool sag due to gravity and cutting vibration, while simultaneously reducing rotational torque loss.

[0010] Furthermore, the keyway is a T-slot, and the support member is a T-shaped support bar. The design of the T-slot and the T-shaped support bar, when pushed by the elastic element, prevents the support bar from dislodging due to processing vibration, ensuring the continuity and stability of the radial support.

[0011] Furthermore, the support member has a slope at at least one end. By adding a slope to the end of the support member, the cylindrical bushing can be guided to compress and retract when it enters the machined hole, which greatly reduces the installation resistance and prevents the edge of the support bar from scratching the precision surface of the hole wall.

[0012] Furthermore, the cylindrical bushings are sequentially connected to form a bushing assembly structure. Each bushing assembly structure has grooves at both ends, and thrust bearings are respectively installed in the grooves to prevent axial movement of the bushing assembly structure during machining. The addition of thrust bearing structures at both ends of the bushing assembly allows the axial cutting force of the tool to be absorbed by the thrust bearings, preventing axial movement of the bushing assembly structure within the hole and maintaining the positioning accuracy and system rigidity of the multi-stage support.

[0013] Furthermore, a sealing ring is provided between the thrust bearing and the bushing assembly. This sealing ring prevents coolant from seeping into the bearing raceway, ensuring the long-term operational reliability of the entire assembly.

[0014] The beneficial effects of this utility model are: by connecting multiple cylindrical bushings in series with rigid pins to form an integral bushing assembly structure, and combining the bearing in the inner ring to achieve dynamic and static separation of the tool rotation and the support system; at the same time, by using the combination of elastic elements and support elements in the keyway to adaptively fit the hole wall, it not only strengthens the overall anti-rotation, but also compensates for hole diameter errors to maintain the stability of long tools; and by using several connected cylindrical bushings, the application range is wider than that of a single cylindrical bushing structure. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0016] Figure 2 This is a schematic diagram of the structure of a single cylindrical bushing of this utility model.

[0017] Figure 3 This is a cross-sectional schematic diagram of the cylindrical bushing of this utility model.

[0018] Figure 4 This is a partial structural schematic diagram of the present invention. Detailed Implementation

[0019] The technical solutions in the embodiments of this utility model will now be clearly and completely described with reference to the accompanying drawings.

[0020] Example: such as Figure 1 , 2 As shown in Figures 3 and 4, a support structure for a multi-stage machining tool for a cylinder camshaft bore includes several connected cylindrical bushings 1. Each cylindrical bushing 1 has several keyways 2 arranged axially along its outer circumference. A support member 3 is provided within each keyway 2. An elastic member 4 is provided between the support member 3 and the bottom of the keyway 2. When the elastic member 4 is freely extended, the top surface of the support member 3 is higher than the outer surface of the cylindrical bushing 1. A bearing 5 is provided on the inner ring of each cylindrical bushing 1. Each cylindrical bushing 1 is connected to another cylindrical bushing 1 by a pin 6. A washer 7 is provided between each cylindrical bushing 1 and another cylindrical bushing 1. The pin 6 passes through the washer 7 and connects to both ends of the cylindrical bushing 1. A sealing ring 8 is provided between the washer 7 and an adjacent cylindrical bushing 1. The bearing 5 is a needle roller bearing. The keyway 2 is a T-slot, and the support member 3 is a T-shaped support bar. At least one end of the support member 3 has a slope. Cylindrical bushings 1 are connected in sequence to form bushing assembly structure 9. Both ends of bushing assembly structure 9 are provided with grooves 10, and thrust bearings 11 are respectively provided in the two grooves 10 to prevent axial movement of bushing assembly structure 9 during processing. A sealing ring 12 is provided between the thrust bearing 11 and the bushing assembly structure.

[0021] The working principle of this utility model is as follows: First, multiple cylindrical bushings are connected into an integral bushing assembly structure through rigid pins and washers. When the first cylindrical bushing is inserted into the machined hole, its T-shaped support bar, under the action of the elastic element, presses against the hole wall to generate static friction, preventing the bushing from rotating. This anti-rotation constraint is synchronously transmitted to all subsequent cylindrical bushings through the series pins, forming a cooperative anti-rotation chain. Second, the rotation and support systems are separated: the tool rotation rod passes through the bushing assembly structure and only rotates with the inner ring of the needle roller bearing in the inner ring of the cylindrical bushing, while the bushing assembly structure as a whole remains stationary. The support member is limited by the T-slot to prevent it from coming out, and its end slope guides the bushing assembly structure smoothly into and out of the hole. The elastic element continuously compensates for the hole diameter tolerance, maintaining the radial rigidity of the tool against gravity deformation. Finally, the thrust bearings at both ends of the bushing assembly structure absorb the axial cutting force of the tool, preventing the bushing assembly structure from moving. The sealing rings at the washer interface and the thrust bearing prevent coolant and debris from entering, protecting the pin connection surface and the bearing raceway, ensuring the long-term reliability of the overall anti-rotation chain.

[0022] In summary, the described embodiments are merely some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.

Claims

1. A support structure for a multi-stage machining tool for a cylinder camshaft hole, characterized in that, It includes several connected cylindrical bushings, and the outer circumference of the cylindrical bushings is provided with several keyways arranged along the axial direction of the cylindrical bushings. A support member is provided in the keyway, and an elastic member is provided between the support member and the bottom of the keyway. When the elastic member is freely extended, the top surface of the support member is higher than the outer surface of the cylindrical bushings; a bearing is provided in the inner ring of the cylindrical bushings.

2. The support structure for multi-stage machining tools of cylinder camshaft holes according to claim 1, characterized in that, The cylindrical bushings are connected to each other by a pin.

3. The support structure for multi-stage machining tools of cylinder camshaft holes according to claim 2, characterized in that, A washer is provided between the cylindrical bushing and the connected cylindrical bushing, and the pin passes through the washer and connects to the two cylindrical bushings at both ends.

4. The support structure for multi-stage machining tools of cylinder camshaft holes according to claim 3, characterized in that, A sealing ring is provided between the gasket and the adjacent cylindrical bushing.

5. The support structure for multi-stage machining tools of cylinder camshaft holes according to claim 1, characterized in that, The bearing is a needle roller bearing.

6. The support structure for multi-stage machining tools of cylinder camshaft holes according to claim 1, characterized in that, The keyway is a T-shaped groove, and the support member is a T-shaped support bar.

7. The support structure for multi-stage machining tools of cylinder camshaft holes according to claim 1, characterized in that, The support member has a slope at at least one end.

8. The support structure for multi-stage machining tools of cylinder camshaft holes according to claim 1, characterized in that, The cylindrical bushings are connected in sequence to form a bushing assembly structure. The bushing assembly structure has grooves at both ends, and thrust bearings are respectively installed in the two grooves to prevent axial movement of the bushing assembly structure during processing.

9. The support structure for multi-stage machining tools of cylinder camshaft holes according to claim 8, characterized in that, A sealing ring is provided between the thrust bearing and the bushing assembly.

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