A kind of easily deformed stator cavity chain wheel inner hole machining inner support tensioning tool

Abstract

The utility model belongs to lathe hole tooling technical field, concretely relates to an easy deforming stator cavity sprocket hole processing inner support tension tool. Equipment connecting plate is arranged in the area of being under inspection, and the limiting tool is fixedly arranged on the equipment connecting plate, and the positioning tool is arranged on the equipment connecting plate, and the positioning tool is movably arranged in the space formed by the equipment connecting plate and the limiting tool, and the pull rod is arranged at the bottom center position of the equipment connecting plate, and the pull rod is vertically arranged on the equipment connecting plate, and the pull rod is slidably connected with the equipment connecting plate, and the positioning tool is consistent with the movement direction of the pull rod, and the pressing plate is fixedly connected with the positioning tool at the bottom center position of the positioning tool, and the tension pressing plate is vertically arranged on the pressing plate. Only need to carry out accurate calibration to the limiting circle once, can satisfy the requirement of batch production, greatly simplifies the debugging process of clamp, reduces the dependence on the experience of operating personnel, is favorable for quick change of production and improves production efficiency.

Description

Technical Field

[0001] This utility model belongs to the technical field of lathe internal hole tooling, specifically relating to an internal support and tensioning tooling for machining the internal hole of an easily deformable stator cavity sprocket. Background Technology

[0002] In the manufacturing process of VVT (Variable Valve Timing) stator sprockets, the product structure has evolved from a scraper-type to a scraperless type. With structural improvements, the coaxiality accuracy requirements between the large and small inner diameters of the scraperless sprocket have significantly increased, becoming more stringent than those with scrapers. Currently, the machining of the inner hole of this part mainly employs two positioning methods: one uses the gear tooth tip circle as the clamping datum, and the other uses an internal support method to position the large-diameter area of ​​the stator cavity. However, due to machining errors between the tooth tip circle and the stator cavity, and the relatively thin wall thickness of the part, traditional clamping methods are prone to deformation due to clamping force. Furthermore, the accumulation of errors is further aggravated when switching between different datums, resulting in the final machined inner hole coaxiality failing to meet the dimensional and geometric tolerance requirements specified in the drawings, leading to a persistently high product defect rate.

[0003] In existing machining techniques, relying on the tooth tip circle for positioning easily introduces positional errors. Furthermore, when using an internally supported stator cavity with a large diameter, insufficient part rigidity and clamping stress make deformation difficult to control, thus affecting coaxiality accuracy. Therefore, a new clamping scheme that can balance positioning accuracy and deformation control is urgently needed to ensure consistency between the machining datum and the inspection datum, and to effectively suppress the deformation of the part under stress during machining. Utility Model Content

[0004] This utility model aims to at least solve one of the technical problems existing in the prior art. Therefore, one aspect of this utility model is to provide an internal support and tensioning fixture for machining the inner hole of a easily deformable stator cavity sprocket. The internal support and tensioning fixture includes a device connecting plate, a positioning fixture, and a limiting fixture. The device connecting plate is disposed in the inspection area. The limiting fixture is fixedly disposed on the device connecting plate. The positioning fixture is disposed on the device connecting plate and within the limiting fixture, and is movably disposed within the space formed by the device connecting plate and the limiting fixture. The device connecting plate includes a pull rod, which is disposed at the bottom center of the device connecting plate and is vertically disposed on the device connecting plate. The pull rod is slidably connected to the device connecting plate. The positioning fixture moves in the same direction as the pull rod. The positioning fixture includes a pressure plate and a tensioning pressure plate. The pressure plate is disposed at the bottom center of the positioning fixture and is fixedly connected to the positioning fixture. The tensioning pressure plate is vertically disposed on the pressure plate.

[0005] Preferably, the equipment connecting plate includes a spring groove and a spring return device. The spring groove is located above the equipment connecting plate and corresponds to the position below the positioning fixture. One end of the spring return device is fixedly installed in the spring groove and is movably connected to the positioning fixture.

[0006] Preferably, the number of spring grooves and rebound devices is the same, and at least three rebound devices are provided.

[0007] Preferably, the rebound device is a nitrogen spring.

[0008] Preferably, the tensioning plate 22 is L-shaped.

[0009] Preferably, the inner diameter of the limiting fixture is the upper limit dimension of the major diameter of the product to be measured, and the reference dimension of the positioning fixture is 0.05mm smaller than the lower limit dimension of the product.

[0010] Preferably, the limiting fixture includes positioning posts, and the equipment connecting plate is fixedly connected to the limiting fixture through the positioning posts, and at least two sets of positioning posts are provided.

[0011] Preferably, the positioning fixture further includes an expansion rod, one end of which is connected to a tapered rod, and the other end of which is fixedly connected to a pressure plate.

[0012] The beneficial effects of this utility model are as follows: Effective deformation control and guaranteed coaxiality accuracy: The downward movement of the pull rod first drives the positioning fixture to expand radially until it contacts the inner hole of the precisely calibrated limit plate. This "hard limit" mechanism ensures that the elastic deformation of the workpiece during clamping is strictly limited within the preset size range. By calibrating the limit circle of the limit plate once during assembly, it is possible to stably guarantee that the small inner diameter and the large inner diameter of the product after processing have extremely high coaxiality in batch processing, thus eliminating the problem of coaxiality deviation from the source of the process.

[0013] Automatic sequential action, reliable clamping: This design realizes an automated sequential action of "expansion first, then compression". After the positioning fixture expands to its limit, it moves down as a whole and uses the L-shaped pressure plate at the top to finally press the end face of the product. This process ensures that the workpiece is axially locked only after radial positioning is completed, avoiding positioning deviation or loosening caused by improper clamping sequence, and making clamping more stable and reliable.

[0014] Simplify the setup process and improve efficiency: Since the coaxiality accuracy is mainly guaranteed by the locating circle size of the locating plate, only one precise calibration of the locating circle is required during equipment assembly and debugging to meet the requirements of mass production. This greatly simplifies the fixture debugging process, reduces reliance on operator experience, facilitates rapid production changeover, and improves production efficiency.

[0015] Additional aspects and advantages of this invention will become apparent from the description which follows, or may be learned by practice of this invention. Attached Figure Description

[0016] The accompanying drawings, which are included to provide a further understanding of the present invention and form part of this application, illustrate exemplary embodiments of the present invention and, together with the description thereof, serve to explain the present invention and do not constitute an undue limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the internal support and tensioning fixture structure for machining the inner hole of the easily deformable stator cavity sprocket of this utility model; Figure 2 This is a schematic diagram of the connecting plate structure of the device of this utility model; Figure 3 This is a schematic diagram of the positioning tooling structure of this utility model; Figure 4 This is a schematic diagram of the limiting tooling structure of this utility model; Figure 5 This is a schematic diagram of the tie rod structure of this utility model; Figure 6 This is a schematic diagram of the expansion core tie rod structure of this utility model; Figure 7 This is a schematic diagram of the workpiece structure of this utility model; Figure 8 This is a schematic diagram of the use of the internal support and tensioning fixture for machining the inner hole of the easily deformable stator cavity sprocket according to this utility model; The correspondence between the reference numerals and component names in the figure is as follows: 1 is the equipment connection plate, 11 is the tie rod, 12 is the spring groove, 13 is the spring return device, 2 is the positioning fixture, 21 is the pressure plate, 22 is the tensioning pressure plate, 23 is the expansion core tie rod, 3 is the limit fixture, 31 is the positioning column, and 4 is the workpiece. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0018] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" 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 can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0019] The utility model of the internal support and tensioning fixture for machining the inner hole of the easily deformable stator cavity sprocket includes a connecting plate 1, a tie rod 11, a spring groove 12, a spring rebound device 13, a positioning fixture 2, a pressure plate 21, a tensioning pressure plate 22, an expansion tie rod 23, a limiting fixture 3, and a positioning column 31.

[0020] The equipment connecting plate 1 is set in the inspection area. The limiting fixture 3 is fixedly set on the equipment connecting plate 1 by the positioning column 31. At least two sets of positioning columns 31 are provided. The positioning fixture 2 is movably set in the space formed by the equipment connecting plate 1 and the limiting fixture 3. The pull rod 11 is set at the bottom center of the equipment connecting plate 1. The pull rod 11 is vertically set on the equipment connecting plate 1 and is slidably connected to the equipment connecting plate 1. One end of the expansion core pull rod 23 is taperedly connected to the pull rod 11, and the other end of the expansion core pull rod 23 is fixedly connected to the pressure plate 21. The positioning fixture 2 moves in the same direction as the pull rod 11. The pressure plate 21 is set at the bottom center of the positioning fixture 2 and is fixedly connected to the positioning fixture 2. The tensioning pressure plate 22 is vertically set on the pressure plate 21. The inner diameter of the limiting fixture 3 is the upper limit dimension of the major diameter of the product to be tested. The reference dimension of the positioning fixture 2 is 0.05mm smaller than the lower limit dimension of the product.

[0021] The spring groove 12 is located above the equipment connecting plate 1, and the position of the spring groove 12 corresponds to the position below the positioning fixture 2. One end of the spring rebound device 13 is fixedly installed in the spring groove 12, and the other end of the spring rebound device 13 is movably connected to the positioning fixture 2. The number of spring grooves 12 and spring rebound devices 13 is the same, and at least three spring rebound devices 13 are provided.

[0022] Installation of the tooling: First, secure the entire tooling mechanism to the rotating spindle of the CNC lathe using bolts through the equipment connection plate 1, ensuring a firm connection.

[0023] Place the workpiece: Place the workpiece 4 to be processed on the positioning fixture 2 initially, manually rotate the workpiece to align it with the fixture, and ensure that the L-shaped tensioning plate 22 at the upper end of the positioning fixture can be accurately pressed onto the end face of the workpiece.

[0024] Clamping: Activate the hydraulic tensioning function of the CNC machine tool. The hydraulic tie rod 5 moves, driving the expansion tie rod 23 connected to it to move downward. The tapered surface at the lower end of the expansion tie rod 23 interacts with the positioning fixture 2, forcing the positioning fixture 2 to expand radially, thereby internally tightening the large diameter of the inner hole stator cavity of the workpiece.

[0025] Initial positioning: When the positioning fixture 2 expands to the point where its outer diameter contacts the upper limit dimension of the inner diameter of the limiting fixture 3, i.e. the product's major diameter, the radial expansion stops.

[0026] Final clamping: The hydraulic lever continues to pull down. When the downward pulling force exceeds the preload of the springback device 13, the entire positioning fixture 2 begins to move axially downward. The L-shaped tensioning plate 22 at its upper end then clamps the end face of the workpiece, thus achieving complete fixation of the workpiece.

[0027] Machining: After the workpiece is firmly clamped, the spindle of the CNC lathe drives the entire fixture and workpiece to rotate together, and the predetermined machining process can begin.

[0028] Workpiece removal: After machining, the CNC machine tool releases the hydraulic pressure, and the expansion rod 23 retracts upward under the action of the mechanism. Its conical surface releases the radial constraint on the positioning fixture 2. At the same time, multiple spring-loaded devices 13 (such as nitrogen springs) push the positioning fixture upward to reset, causing it to contract radially and disengage from the inner hole of the workpiece. The operator can then easily remove the machined workpiece and prepare for the next work cycle.

[0029] The above description only describes the preferred embodiments of the present utility model. However, the present utility model is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present utility model, and all such changes should be included within the protection scope of the present utility model.

Claims

1. A tooling for machining the inner hole of a easily deformable stator cavity sprocket with internal support and tensioning, characterized in that: The internal support tensioning fixture includes an equipment connecting plate (1), a positioning fixture (2), and a limiting fixture (3). The equipment connecting plate (1) is set in the inspection area. The limiting fixture (3) is fixedly set on the equipment connecting plate (1). The positioning fixture (2) is set on the equipment connecting plate (1) and is located inside the limiting fixture (3). The positioning fixture (2) is movably set in the space formed by the equipment connecting plate (1) and the limiting fixture (3). The equipment connecting plate (1) includes a pull rod (11). The pull rod (11) is set at the bottom center of the equipment connecting plate (1), and is vertically set on the equipment connecting plate (1). The pull rod (11) is slidably connected to the equipment connecting plate (1). The positioning fixture (2) moves in the same direction as the pull rod (11). The positioning fixture (2) includes a pressure plate (21) and a tensioning pressure plate (22). The pressure plate (21) is set at the bottom center of the positioning fixture (2), and is fixedly connected to the positioning fixture (2). The tensioning pressure plate (22) is vertically set on the pressure plate (21).

2. The internal support and tensioning fixture for machining the inner hole of a easily deformable stator cavity sprocket according to claim 1, characterized in that: The equipment connecting plate (1) includes a spring groove (12) and a spring rebound device (13). The spring groove (12) is located above the equipment connecting plate (1) and the position of the spring groove (12) corresponds to the position below the positioning fixture (2). One end of the spring rebound device (13) is fixedly installed in the spring groove (12) and the other end of the spring rebound device (13) is movably connected to the positioning fixture (2).

3. The internal support and tensioning fixture for machining the inner hole of a easily deformable stator cavity sprocket according to claim 2, characterized in that: The number of spring grooves (12) and spring rebound devices (13) are the same, and at least three spring rebound devices (13) are provided.

4. The internal support and tensioning fixture for machining the inner hole of a easily deformable stator cavity sprocket according to claim 2, characterized in that: The rebound device (13) is a nitrogen spring.

5. The internal support and tensioning fixture for machining the inner hole of a easily deformable stator cavity sprocket according to claim 1, characterized in that: The tensioning plate (22) is L-shaped.

6. The internal support and tensioning fixture for machining the inner hole of a easily deformable stator cavity sprocket according to claim 1, characterized in that: The inner diameter of the limiting fixture (3) is the upper limit dimension of the major diameter of the product to be measured, and the reference dimension of the positioning fixture (2) is 0.05mm smaller than the lower limit dimension of the product.

7. The internal support and tensioning fixture for machining the inner hole of a easily deformable stator cavity sprocket according to claim 1, characterized in that: The limiting fixture (3) includes a positioning column (31), and the equipment connecting plate (1) is fixedly connected to the limiting fixture (3) through the positioning column (31). At least two sets of positioning columns (31) are provided.

8. The internal support and tensioning fixture for machining the inner hole of a easily deformable stator cavity sprocket according to claim 1, characterized in that: The positioning fixture (2) also includes an expansion rod (23), one end of which is taperedly connected to the rod (11), and the other end of which is fixedly connected to the pressure plate (21).

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