CN204673341U - Not rounded Internal periphery many curved surfaces quick centring fixture - Google Patents

Abstract

The utility model discloses a non-circular inner contour multi-curved surface fast centering fixture, which is used for centering a workpiece with a non-circular inner contour multi-curved surface. The fixture includes a mandrel arranged on a machine tool, and The mandrel is a regular polygonal prism structure, the diameter φJmin of the minimum inscribed circle of the mandrel is less than the minimum inscribed circle diameter φGmin of the non-circular inner contour multi-curved surface on the workpiece, and the maximum circumscribed circle diameter φJmax of the mandrel is is smaller than the maximum circumscribed circle diameter φGmax of the non-circular inner contour multi-curved surface on the workpiece, and the minimum inscribed circle diameter φGmin of the non-circular inner contour multi-curved surface on the workpiece is smaller than the maximum circumscribed circle diameter φJmax of the mandrel. The fixture can accurately locate the symmetrical centerline of the multi-curved surface of the non-circular inner contour in the processed workpiece, thereby ensuring the processing accuracy of the workpiece.

Description

Non-circular inner contour multi-curved surface quick centering fixture

technical field

The utility model relates to a fixture, in particular to a fast centering fixture with non-circular inner contour and multi-curved surfaces.

Background technique

In the field of mechanical engineering, due to the requirements of the workpiece process or working principle, in addition to a large number of parts whose forming surfaces are circles or planes, a considerable part will be made into a center or axially symmetrical inner contour multi-curved surface. Due to the multi-curved contour The design reference point (surface) of the curved surface cannot be determined with the reference working point (surface) of the clamping of the processing machine tool, so an auxiliary fixture must be designed.

The processing of the inner rotor and outer rotor parts in the rotor oil pump is a typical case. Figure 1 is a schematic structural diagram of a conventional oil pump, where 11 indicates the oil pump body, 12 indicates the outer rotor, 3 indicates the inner rotor, and 4 indicates the oil pump Cover, 5 represents the sealing ring, 6 represents the bearing, 7 represents the oil pump shaft, 8 represents the key, 9 represents the transmission pulley, and 10 represents the locking nut. Wherein, the outer rotor 12 has a central shaft hole in the shape of a non-circular inner contour polycurved surface (it specifically includes five external tooth curved surfaces 5a, as shown in FIG. 4 ), and the non-circular inner contour polycurved surface on the outer rotor is an axisymmetric structure. The inner rotor 3 has an outer wall surface in the shape of a non-circular outer contour multi-curved surface (it specifically includes four outer tooth curved surfaces 3a, as shown in Figure 4), and the non-circular outer contour multi-curved surface of the inner rotor is also a centrosymmetric structure, while the inner rotor 3 is provided with a central shaft hole, that is, the pump shaft hole 3b of the inner rotor. Wherein, the number of teeth Zinner of the inner rotor is ≥ 4, and the number of teeth Zouter of the outer rotor is Zinner+1, as shown in Fig. 2 .

When the oil pump works, the oil pump shaft drives the inner rotor to rotate, and the inner rotor drives the outer rotor to rotate in the same direction. Since the contours of the working surfaces of the inner and outer rotors are a pair of conjugate curves, it can be ensured that the two rotors do not interfere or disengage when they mesh with each other. The contact points between the inner and outer rotors divide the inner cavity of the outer rotor into four working chambers. When a working chamber turns over the oil inlet, the volume increases to generate a vacuum, and the oil is sucked into the working chamber through the oil inlet. When the working chamber turns over the oil suction port, the volume decreases, the oil pressure rises, and the machine oil is pressed out through the oil outlet.

The inner and outer rotors rotate in the same direction when they work. In Figure 2, the pump shaft hole 3b of the inner rotor 3 and the outer tooth surface 3a of the inner rotor have coaxiality requirements, and the centerline of the inner rotor and the end surface of the inner rotor have perpendicularity requirements. The inner tooth curved surface 12a of the outer rotor and the circular outer wall surface 12b of the outer rotor have coaxiality requirements, and the center line of the outer rotor and the end surface of the outer rotor have perpendicularity requirements.

The rotors rotate in the pump and slide against each other, so the requirements for the wear resistance and precision roughness of the rotors are required. At present, the rotors are manufactured by powder metallurgy. Due to the large size deformation of powder metallurgy in the process of forming and sintering, it is necessary to The processing meets the requirements of dimensional accuracy and roughness.

Utility model content

The purpose of the utility model is: to solve the above problems, provide a non-circular inner contour multi-curved surface fast centering fixture to accurately locate the symmetrical center line of the non-circular inner contour multi-curved surface in the workpiece to ensure the machining accuracy of the workpiece.

The technical scheme of the utility model is: a non-circular inner contour multi-curved surface fast centering fixture, which is used for centering the workpiece with non-circular inner contour multi-curved surface, the fixture includes a core set on the machine tool rod, and the mandrel is a regular polygonal prism structure, the diameter φJmin of the minimum inscribed circle of the mandrel is smaller than the minimum inscribed circle diameter φGmin of the non-circular inner contour multi-curved surface on the workpiece, and the maximum circumscribed diameter of the mandrel is The circle diameter φJmax is smaller than the maximum circumscribed circle diameter φGmax of the non-circular inner contour multi-curved surface on the workpiece, and the minimum inscribed circle diameter φGmin of the non-circular inner contour multi-curved surface on the workpiece is smaller than the maximum circumscribed circle diameter φJmax of the mandrel.

On the basis of the above-mentioned technical solutions, the utility model also includes the following preferred solutions:

The workpiece is the outer rotor of the rotor type oil pump.

The mandrel is a regular pentagonal prism structure.

The mandrel is rotatably arranged on the machine tool.

The utility model has the advantages of:

1. The fast centering fixture of the utility model can guarantee to process parts that meet the requirements based on the multi-curve of the non-circular inner contour.

2. The fast centering fixture of the utility model has a regular polygonal prism structure, and the fixture itself has high dimensional accuracy and is easy and simple to process.

3. The fast centering fixture of the utility model is convenient and quick to clamp workpieces, and has high production efficiency.

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the accompanying drawings that need to be used in the description of the embodiments. The accompanying drawings in the following description are only some embodiments of the present invention. As far as the skilled person is concerned, other drawings can also be obtained based on these drawings on the premise of not paying creative work.

Fig. 1 is a structural schematic diagram of a rotor type oil pump;

Fig. 2 is a schematic cross-sectional structure diagram of the inner and outer rotors in the rotor oil pump;

Fig. 3 is a demonstration diagram of the use method of the non-circular inner contour multi-curved surface rapid centering fixture in the embodiment of the present invention;

Fig. 4 is a size comparison diagram of the non-circular inner contour multi-curved surface rapid centering fixture and the workpiece to be processed in the embodiment of the utility model.

Among them: 1-workpiece, 1a-non-circular inner contour multi-curved surface on the workpiece, 1b-circular outer wall surface of the workpiece, 2-mandrel, 3-inner rotor, 3a-outer tooth surface of the inner rotor, 3b-inner rotor Pump shaft hole, 4-oil pump cover, 5-sealing ring, 6-bearing, 7-oil pump shaft, 8-key, 9-drive pulley, 10-lock nut, 11-oil pump body, 12-outer Rotor, 12a-the internal tooth curved surface of the outer rotor, 12b-the circular outer wall surface of the outer rotor.

Detailed ways

The above solution will be further described below in conjunction with specific embodiments. It should be understood that this embodiment is used to illustrate the utility model and not limit the scope of the utility model. The implementation conditions used in the examples can be further adjusted according to the conditions of specific manufacturers, and the implementation conditions not indicated are usually the conditions in routine experiments.

Figure 3 and Figure 4 show a specific embodiment of the non-circular inner contour multi-curved surface fast centering fixture of the present invention, which is used for the workpiece 1 with non-circular inner contour multi-curved surface Centering processing, the non-circular inner contour multi-curved surface 1a on the workpiece is an axisymmetric structure, which has a central axis as the center of symmetry, and the fixture is specifically used to process the non-circular inner contour multi-curved surface 1a on the workpiece 1 The circular outer wall surface of the coaxial line. This example takes the outer rotor of the oil pump described in the background art as an example for specific description, that is, the workpiece 1 described in this example is the same part as the outer rotor of the oil pump described in the background art.

The fast centering fixture of this embodiment includes a mandrel 2 arranged on the machine tool, and the mandrel 2 is a regular polygonal prism structure, and the diameter φJmin of the smallest inscribed circle of the mandrel 2 is smaller than the workpiece 1 ( This example is specifically the minimum inscribed circle diameter φGmin of the non-circular inner contour multi-curved surface 1a on the outer rotor of the oil pump, and the maximum circumscribed circle diameter φJmax of the mandrel 2 is smaller than that of the non-circular inner contour multi-curved surface 1a on the workpiece 1. The maximum circumscribed circle diameter φGmax, the minimum inscribed circle diameter φGmin of the non-circular inner contour multi-curved surface 1a on the workpiece 1 is smaller than the maximum circumscribed circle diameter φJmax of the mandrel 2 . Figure 4.

Referring to Fig. 3 and Fig. 4 again, the using method of this fast centering fixture of the present embodiment is introduced as follows: During practical application, at first the workpiece 1 to be processed (at this time the circular outer wall surface 1b of the workpiece 1 is still (unformed) is set outside the mandrel 2. When the circular outer wall surface 1b of the workpiece 1 is turned by the lathe, the workpiece 1 and the mandrel 2 will rotate relative to each other, so that the workpiece 1 and the mandrel 2 are locked and positioned in one direction along the circumferential direction. Clamping, at this moment the center line of symmetry of non-circular inner contour multi-curved surface 1a on the workpiece 1 will coincide with the central axis of the regular pentagonal prism mandrel 2 (automatic centering), so we use the central axis of the mandrel 2 (because of the core Rod 2 is a regular pentagonal prism structure, so the position of its central axis is easy to determine) as the center to process the circular outer wall surface 1b of the workpiece 1, which becomes very simple and convenient, and can ensure the center of the circular outer wall surface 1b of the workpiece The axis is precisely coincident with the central axis of the non-circular inner contour multi-curved surface 1a on the workpiece (automatic centering). This has the following advantages: 1) When machining the circular outer wall surface 1b of the workpiece, the coaxiality between the outer wall surface and the inner contour curved surface can be guaranteed; 2) When machining one side end surface of the workpiece, the perpendicularity between the end surface of the workpiece and the central axis can be guaranteed . And after the processing is finished, the workpiece 1 can be taken off by reversely rotating the mandrel 2, which is very convenient. Use the machined end face of the outer rotor as a reference and then grind out the other end face to ensure the parallelism between the two.

Of course, in actual application, it is also possible to process other structures coaxially distributed with the non-circular inner contour multi-curved surface 1a of the workpiece on the workpiece 1, such as circular grooves coaxially distributed with the inner contour curved surface, and are not limited to The circular outer wall surface mentioned in this embodiment.

We can also rotate the mandrel 2 on the machine tool. When the workpiece 1 to be processed is set on the mandrel 2, the operator can rotate the mandrel 2 so that the workpiece 1 and the mandrel 2 are clamped in the circumferential direction, and the process is completed. Pre-positioning of the workpiece and mandrel, followed by subsequent machining of the circular outer wall and end faces.

Since the workpiece 1 to be processed in this example is an outer rotor with five inner tooth curved surfaces, the mandrel 2 correspondingly adopts a regular pentagonal prism structure. If the workpiece 1 to be processed has other structural forms, the number of edges of the mandrel 2 should be adjusted accordingly, such as a regular hexagonal prism, a regular heptagonal prism, and the like.

Said in the present embodiment " mandrel 2 is regular polygonal prism structure ", does not mean that all bar sections of mandrel 2 must all be regular polygonal prism shape, as long as the mating section of mandrel 2 and workpiece 1 to be processed is regular A polygonal prism shape will suffice.

Certainly, the above-mentioned embodiments are only for illustrating the technical conception and characteristics of the present utility model, and its purpose is to allow people to understand the content of the utility model and implement it accordingly, and not to limit the protection scope of the utility model. All equivalent transformations or modifications made according to the spirit of the main technical solutions of the utility model shall fall within the protection scope of the utility model.

Claims (4)

1. A non-circular inner contour multi-curved surface fast centering fixture is used for centering a workpiece (1) with a non-circular inner contour multi-curved surface. It is characterized in that: the fixture includes a set on the machine tool core rod (2), and the core rod (2) is a regular polygonal prism structure, the diameter of the smallest inscribed circle of the core rod (2) smaller than the minimum inscribed circle diameter of a non-circular inner contour polysurface (1a) on said workpiece (1) The maximum circumscribed circle diameter of the mandrel (2) smaller than the maximum circumscribed circle diameter of the non-circular inner contour polysurface (1a) on said workpiece (1) The minimum inscribed circle diameter of the non-circular inner contour multi-curved surface (1a) on the workpiece (1) Less than the maximum circumscribed circle diameter of the mandrel (2) 2. The non-circular inner contour multi-curved surface rapid centering fixture according to claim 1, characterized in that: the workpiece (1) is an outer rotor of a rotor type oil pump. 3. The non-circular internal contour multi-curved surface rapid centering fixture according to claim 1, characterized in that: the mandrel (2) is a regular pentagonal prism structure. 4. The non-circular inner contour multi-curved surface rapid centering fixture according to claim 1, characterized in that: the mandrel (2) is rotatably set on the machine tool.