Three-groove tooth aligning and hobbing clamp

Abstract

The utility model relates to a three-groove tooth aligning and hobbing clamp which comprises a clamp body, a pressing sleeve and an expansion sleeve hydraulic tensioning device, the top end of the clamp body is of a frustum structure, a circle of step is arranged on the outer side of the top end of the clamp body, and a backer is installed on the step; the expansion sleeve hydraulic tensioning device comprises a connecting rod, a pull rod and an expansion sleeve, the connecting rod is fixed in the clamp body, one end of the pull rod is fixed on the connecting rod, and the other end of the pull rod is connected with the expansion sleeve. The three-groove tooth aligning and hobbing clamp is reasonable in design, simple, practical, high in positioning accuracy and stable and reliable in clamping.

Description

Technical Field

[0001] This utility model relates to a three-groove toothed hobbing fixture. Background Technology

[0002] The high-pressure gear inside the planetary reducer mechanism of the mid-engine bicycle has 19 teeth on the outer side and three small grooves in the inner hole. Due to the thin wall, the teeth are intentionally deflected by 5 degrees to increase strength. This improves the strength of this area under stress and prevents cracking at the bottom of the grooves. The product is made of 20CrMnTi material with a module of 1.775. It is manufactured using a hot hobbing and hot grinding process. Because the product has very high requirements for tooth angle tolerance, the tooth angle must be maintained at ±0.3 degrees before hot grinding. Therefore, a special positioning structure needs to be designed. Utility Model Content

[0003] The purpose of this utility model is to overcome the above-mentioned deficiencies in the prior art and to provide a three-slot tooth hobbing fixture that is reasonably designed, simple and practical, highly accurate in positioning, and stable and reliable in clamping.

[0004] The technical solution adopted by this utility model to solve the above problems is: a three-groove toothed hobbing fixture, including a fixture body, a pressure sleeve and a hydraulic tensioning device for the expansion sleeve. The top of the fixture body is a frustum structure, and a step is provided on the outer side of the top of the fixture body, with a backing installed on the step. The hydraulic tensioning device for the expansion sleeve includes a connecting rod, a pull rod and an expansion sleeve. The connecting rod is fixed inside the fixture body, one end of the pull rod is fixed on the connecting rod, and the other end of the pull rod is connected to the expansion sleeve.

[0005] The backing of this utility model is provided with three positioning pins, which are distributed at the top of the backing.

[0006] This utility model uses three positioning pins on the back of the workpiece and the positioning groove to achieve end face positioning, which has high positioning accuracy and reduces circumferential sway; it uses a hydraulic tensioning device to clamp the inner hole of the workpiece, which has reliable clamping and good stability; the outer end face of the workpiece is clamped by a pressure cap to achieve axial positioning of the workpiece and meet the positioning accuracy requirements.

[0007] Compared with the prior art, this utility model has the following advantages and effects: 1. The fixture has a simple structure, is easy to install, requires less skill from operators, effectively improves production efficiency, and saves costs. 2. It has high positioning accuracy, reliable clamping, high machining precision, and good stability. Attached Figure Description

[0008] Figure 1 This is a structural schematic diagram of an embodiment of the present utility model.

[0009] Figure 2 This is a schematic diagram of the support structure in an embodiment of the present utility model.

[0010] Figure 3This is a schematic diagram of the three-dimensional structure of the support wall in an embodiment of the present utility model.

[0011] In the diagram: 1. Clamp body; 2. Conical frustum; 3. Step; 4. Pressure sleeve; 5. Backing; 6. Positioning pin; 7. Expanding sleeve hydraulic tensioning device; 8. Connecting rod; 9. Pull rod; 10. Expanding sleeve; 11. Workpiece; 12. Hob. Detailed Implementation

[0012] The present invention will be further described in detail below with reference to the accompanying drawings and through embodiments. The following embodiments are explanations of the present invention, but the present invention is not limited to the following embodiments.

[0013] See Figure 1-3 The 3-groove tooth hobbing fixture in this embodiment includes a fixture body 1, a pressure sleeve 4, and a hydraulic tensioning device 7 for the expansion sleeve. The top of the fixture body 1 is a frustum 2 structure, and a step 3 is provided on the outer side of the top of the fixture body 1. A backing 5 is installed on the step 3. The hydraulic tensioning device 7 for the expansion sleeve includes a connecting rod 8, a pull rod 9, and an expansion sleeve 10. The connecting rod 8 is fixed inside the fixture body 1, one end of the pull rod 9 is fixed to the connecting rod 8, and the other end of the pull rod 9 is connected to the expansion sleeve 10.

[0014] In this embodiment, the support 5 is provided with three positioning pins 6, which are distributed on the top of the support 5 and cooperate with the positioning groove on the workpiece 11.

[0015] In the processing of this embodiment, the operator positions the positioning groove on the positioning end face of the workpiece 11 in conjunction with the three positioning pins 6 on the backrest 5, places the inner hole of the workpiece 11 on the expansion sleeve 10, and the connecting rod 8 of the expansion sleeve hydraulic tensioning device 7 drives the pull rod 9 to make linear reciprocating motion to expand the expansion sleeve 10, thereby clamping it to the workpiece 11. The pressure cover 4 is pressed down to axially position the workpiece 11, and then the hob 12 is used to process the workpiece 11.

[0016] In this embodiment, the three positioning pins 6 of the backing 5 and the positioning groove of the workpiece 11 are used to achieve end face positioning, which has high positioning accuracy and reduces circumferential sway; the expansion sleeve hydraulic tensioning device 7 is used to clamp the inner hole of the workpiece 11, which has reliable clamping and good stability; the outer end face of the workpiece 11 is pressed by the pressure cap 4 to achieve axial positioning of the workpiece 11 and meet the positioning accuracy requirements.

[0017] Furthermore, it should be noted that all equivalent or simple variations made based on the structure, features, and principles of this utility model patent are included within the scope of protection of this utility model patent.

Claims

1. A 3-groove pinion hobbing fixture, characterized by: It includes a clamping body, a pressure sleeve, and a hydraulic tensioning device for the expansion sleeve. The top of the clamping body is a frustum-shaped structure, and a ring of steps is provided on the outer side of the top of the clamping body. A backing is installed on the steps. The expansion sleeve hydraulic tensioning device includes a connecting rod, a pull rod, and an expansion sleeve. The connecting rod is fixed inside the clamping body, one end of the pull rod is fixed to the connecting rod, and the other end of the pull rod is connected to the expansion sleeve.

2. The 3-groove counter gear hobbing fixture of claim 1, wherein: The backrest is equipped with three positioning pins, which are located at the top of the backrest.

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