Motor shell inner hole machining clamp and inner hole machining method

Abstract

The invention discloses a motor shell inner hole machining clamp and an inner hole machining method. The clamp comprises a clamp base, a hydraulic cylinder, a hydraulic station and a rotary oil distributor. The hydraulic cylinders are symmetrically distributed on the periphery of the upper surface of the clamp base, and clamping heads are installed at the top ends of the hydraulic cylinders respectively. The hydraulic station is connected with an oil path pipeline of the hydraulic cylinder through the rotary oil distributor; the machining method comprises the steps of clamping the motor shell, roughly machining the inner hole and finely machining the inner hole. Through the design of the clamp, the hydraulic station is used for driving the multiple hydraulic cylinders to synchronously press the motor shell, the clamping force is stable and controllable, vibration is eliminated, the machining efficiency is improved by more than 56%, meanwhile, the machining precision is improved, the roundness tolerance of an obtained inner hole is stably controlled within 0.07 mm, and the yield is improved to more than 98%.

Description

Technical Field

[0001] The present invention relates to the technical field of machining and manufacturing, and particularly relates to a fixture for machining the inner hole of a motor housing and a method for machining the inner hole. Background Art

[0002] In the field of machining and manufacturing, the machining of the inner hole of a motor housing usually adopts traditional manual clamping processes, such as using mechanical screws or manual fixtures to fix the workpiece.

[0003] In the actual production process, most of these machining methods have the following defects: Manual clamping requires repeated adjustment of the fixture position and clamping force, which is time-consuming. And during the machining process, it is necessary to frequently replace the cutting tool or adjust the parameters, resulting in low overall production efficiency, with the original output being only 83 pieces / 10 hours; The operator needs to manually operate the fixture and the cutting tool throughout the process, consuming a large amount of physical strength, and it is easy to cause operation errors due to fatigue, especially in mass production; It is difficult to uniformly control the clamping force of manual clamping, and during the machining process, it is easy for the roundness of the workpiece to exceed the tolerance due to vibration or displacement, exceeding 0.07 mm; In addition, due to insufficient machining accuracy, the inner hole after machining usually requires subsequent shaping processes to correct the shape tolerance, increasing the production cycle and cost.

[0004] The above problems seriously restrict the production efficiency and product quality of machining the inner hole of the motor housing. Summary of the Invention

[0005] The present invention provides a fixture for machining the inner hole of a motor housing and a method for machining the inner hole, which can solve the above-mentioned deficiencies existing in the existing machining of the inner hole of the motor housing.

[0006] To solve the above technical problems, the present invention provides a fixture for machining the inner hole of a motor housing, which includes a fixture base, a hydraulic cylinder, a hydraulic station, and a rotary oil distributor; wherein, the hydraulic cylinders are evenly distributed around the upper surface of the fixture base, and clamping heads are respectively installed at their tops; the hydraulic station is connected to the oil pipeline of the hydraulic cylinders through the rotary oil distributor.

[0007] In a preferred embodiment of the present invention, the clamping head includes a pressing plate and an auxiliary retractable rod; one end of the pressing plate is rotatably connected to the end of the power output shaft of the hydraulic cylinder; one end of the pressing plate is rotatably connected to the end of the power output shaft of the hydraulic cylinder; the auxiliary retractable rod is vertically installed inside the top of the hydraulic cylinder, and the other end thereof is rotatably connected to the pressing plate; when the power output shaft of the hydraulic cylinder extends, it drives the pressing plate to rotate towards the center of the fixture base to press the motor housing; when the power output shaft of the hydraulic cylinder contracts, it pulls the pressing plate to rotate in the reverse direction to unlock the motor housing from under the pressing plate and take it out.

[0008] In a preferred embodiment of the present invention, a support block is further installed at the bottom end of the hydraulic cylinder for adjusting the axial height of the hydraulic cylinder.

[0009] In a preferred embodiment of the present invention, the number of the hydraulic cylinders is more than 3.

[0010] In a preferred embodiment of the present invention, the fixture base further has a positioning disk and a transition disk, and the positioning disk and the transition disk are respectively installed at the centers of the top surface and the bottom surface of the fixture base.

[0011] To solve the above technical problems, the present invention also provides a method for machining the inner hole of a motor shell. Using the above fixture, the method includes the following steps:

[0012] (1) Clamping the motor shell: Place the motor shell to be machined on the fixture base between the hydraulic cylinders, and drive the clamping heads of the hydraulic cylinders to clamp the top end of the motor shell through the hydraulic station and the rotary oil distributor.

[0013] (2) Rough machining of the inner hole: Select a special turning tool bar, and use the rough machining cutting edge to roughly machine the inner hole in the motor shell.

[0014] (3) Finish machining of the inner hole: Use the finish machining cutting edge to finish machine the inner hole so that the roundness tolerance of the inner hole is less than or equal to 0.07 mm.

[0015] In a preferred embodiment of the present invention, the special turning tool bar has a stepped tool head structure, the front end of the tool head is a rough machining cutting edge, and the rear end is a finish machining cutting edge.

[0016] In a preferred embodiment of the present invention, the cutting angle of the rough machining cutting edge is 15 - 20°; the cutting angle of the finish machining cutting edge is 5 - 8°.

[0017] In a preferred embodiment of the present invention, in step (2), the cutting depth of the rough machining is 2 - 3 mm, and the feed rate is 0.2 - 0.5 mm / r.

[0018] In a preferred embodiment of the present invention, in step (3), the cutting depth of the finish machining is 0.5 - 0.8 mm, and the feed rate is 0.1 - 0.2 mm / r.

[0019] The beneficial effects of the present invention are as follows: For a fixture for machining the inner hole of a motor shell and a method for machining the inner hole of the present invention, through the design of the fixture, a hydraulic station is used to drive a plurality of hydraulic cylinders to synchronously press the motor shell, the clamping force is stable and controllable, vibration is eliminated, the machining efficiency is increased by more than 56%, and at the same time, the machining accuracy is improved. The roundness tolerance of the obtained inner hole is stably controlled within 0.07 mm, and the qualified product rate is increased to more than 98%. Description of the Drawings

[0020] Figure 1 is a schematic perspective view of a preferred embodiment of a fixture for machining the inner hole of a motor shell of the present invention;

[0021] Figure 2 is a schematic structural diagram of the shown special turning tool bar;

[0022] The markings of each component in the attached drawings are as follows:

[0023] 10. Fixture base, 20. Hydraulic cylinder, 30. Hydraulic station, 40. Rotary oil distributor, 50. Motor housing, 60. Turning tool bar, 11. Transition plate, 12. Positioning plate, 13. Support block, 21. Pressure plate, 22. Auxiliary retraction rod, 61. Front cutting edge, 62. Rear cutting edge. Detailed implementation manners

[0024] The following elaborates on the preferred embodiments of the present invention in conjunction with the attached drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0025] Please refer to Figure 1 and 2 , the embodiments of the present invention include:

[0026] Embodiment 1

[0027] The present invention discloses a fixture for machining the inner hole of a motor housing. The fixture includes a fixture base 10, a hydraulic cylinder 20, a hydraulic station 30, and a rotary oil distributor 40. The oil outlet pipeline of the hydraulic station 30 is connected to the rotary oil distributor 40, and the oil outlet pipelines of the rotary oil distributor 40 are respectively connected to the oil pipelines of each hydraulic cylinder 20 to drive the hydraulic cylinders to uniformly press the motor housing, realizing unified and stable control of the clamping force, thereby facilitating the improvement of the inner hole machining accuracy and machining uniformity.

[0028] Among them, the fixture base 10 is of a disc structure, a circular transition plate 11 is installed in the middle of its bottom surface, and a positioning plate 12 is installed in the middle of its top surface. The positioning plate 12 is used to support the workpiece, that is, the motor housing 50 to be machined.

[0029] In this embodiment, the number of the hydraulic cylinders 20 is 4, which are symmetrically distributed around the upper surface of the fixture base 10 and are used to press the workpiece. Specifically, a support block 13 is also installed at the bottom end of the hydraulic cylinder 20 and the upper surface of the fixture base 10 to adjust the axial height of the hydraulic cylinder 20 to meet the requirements of motor housings 50 of different heights.

[0030] A clamping head for clamping and fixing the motor housing 50 is installed at the top end of each hydraulic cylinder 20.

[0031] Specifically, the clamping head includes a pressure plate 21 and an auxiliary contraction rod 22. Among them, one end of the pressure plate 21 is rotationally connected to the end of the power output shaft of the hydraulic cylinder 20 by screws, and the other end is a free end. The auxiliary contraction rod 22 is vertically installed inside the top of the hydraulic cylinder 20, that is, on the side close to the motor housing 50, and the other end is rotationally connected to the pressure plate 21 by screws. When the power output shaft of the hydraulic cylinder 20 extends, it drives the pressure plate 21 to rotate towards the center of the fixture base 10, so that the front end of the pressure plate 21 presses against the top of the motor housing 50; when the power output shaft of the hydraulic cylinder 20 contracts, it pulls the pressure plate 21 to rotate in the opposite direction, unlocking the motor housing 50 from under the pressure plate 21, and enabling it to be taken out of the fixture.

[0032] Embodiment 2

[0033] The present invention discloses a method for machining the inner hole of a motor housing. Using the fixture in Embodiment 1, the specific steps are as follows:

[0034] (1) Clamping the motor housing: Place the motor housing 50 to be machined vertically on the positioning disk 12 on the fixture base 10. Start the hydraulic station 30 to convey hydraulic oil with a certain pressure to the rotary oil distributor 40, drive the power output shaft of the hydraulic cylinder 20 to extend, and drive the pressure plate 21 in the clamping head to rotate towards the center of the fixture base 10 until the top of the motor housing 50 is tightly pressed. The pressing pressure is 8 - 10 MPa, and in this example, it is 10 MPa.

[0035] (2) Rough machining of the inner hole: Select a special turning tool bar. The front end of the cutting head of the special turning tool bar is a rough machining cutting edge with a cutting angle of 15°, and the rear end is a finish machining cutting edge with a cutting angle of 3°. This special turning tool bar adopts an integrated cutting head, reducing the tool change time and improving the machining efficiency.

[0036] Use the rough machining cutting edge to roughly machine the inner hole in the motor housing 50; the cutting depth of the rough machining is 2 mm, and the feed rate is 0.2 mm / r.

[0037] (3) Finish machining of the inner hole: Use the finish machining cutting edge to further finish machine the inner hole machined in step (2). The cutting depth of the finish machining is 0.5 mm, and the feed rate is 0.1 mm / r, so that the roundness tolerance of the finished inner hole is less than or equal to 0.05 mm, and the qualified product rate is 98.5%.

[0038] After the machining is completed, through the action of the hydraulic station 30 and the rotary oil distributor 40, the power output shafts of the four hydraulic cylinders 20 contract simultaneously, enabling the clamping head to release the motor housing, take out the motor housing, and complete the machining process of the inner hole of one motor housing. Replace the next motor housing to be machined and repeat the above steps.

[0039] Specifically, the inner hole includes a side lifting ring screw bottom hole (with a diameter of φ8.5×21.5 mm), a side lifting ring screw hole (with a diameter of M10×20 mm), a nameplate hole (a nameplate hole with a diameter of φ2.5 +0.05 / 0 and a depth of 8 +1 / 0 mm), and a processing wiring hole (M6×14 mm, 4-M5×12 mm, 1-M6×11 mm, with a thread of 4-Φ6.2×2 mm counterbore).

[0040] The output of machining the inner hole of the motor housing by the above preparation method is 130 pieces / 10H. Among them, the qualified product rate is over 98.5%. Compared with the prior art of 80 pieces / 10H, the processing efficiency is increased by 56%.

[0041] The inner hole of the machined motor housing is smooth and regular, and no shaping treatment is required, and the comprehensive cost is reduced by more than 20%.

[0042] The roundness tolerance of the inner hole of the prepared motor housing is measured and calculated to be 0.055 mm.

[0043] The present invention has the following advantages:

[0044] First, through the design of the fixture, the present invention uses a hydraulic station to drive multiple hydraulic cylinders to synchronously clamp the motor housing. The clamping force is stable and controllable, vibration is eliminated, and the processing efficiency is increased by more than 56%.

[0045] Second, the present invention improves the processing accuracy. The roundness tolerance of the obtained inner hole is stably controlled within 0.07 mm, and the qualified product rate is increased to over 98%.

[0046] The above are only the embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structure or equivalent process transformation made by using the specification and drawings of the present invention, or directly or indirectly applied to other related technical fields, shall be equally included in the patent protection scope of the present invention.

Claims

1. A fixture for machining the inner hole of a motor housing, characterized in that The fixture includes a fixture base, a hydraulic cylinder, a hydraulic station, and a rotary oil distributor; wherein, the hydraulic cylinders are evenly distributed around the upper surface of the fixture base, and clamping heads are respectively installed at their tops; the hydraulic station is connected to the hydraulic cylinders through the rotary oil distributor by an oil pipeline.

2. The machining fixture for the inner hole of the motor housing according to claim 1, characterized in that The clamping head includes a pressure plate and an auxiliary retraction rod; one end of the pressure plate is rotatably connected to the end of the power output shaft of the hydraulic cylinder; the auxiliary retraction rod is vertically installed inside the top of the hydraulic cylinder, and the other end thereof is rotatably connected to the pressure plate; the power output shaft of the hydraulic cylinder extends out to drive the pressure plate to rotate towards the center of the fixture base to press the motor housing; the power output shaft of the hydraulic cylinder retracts to pull the pressure plate to rotate in the reverse direction, unlocking the motor housing from under the pressure plate and taking it out.

3. The machining fixture for the inner hole of a motor housing according to claim 2, characterized in that, A support block is further installed at the bottom end of the hydraulic cylinder for adjusting the axial height of the hydraulic cylinder.

4. A fixture for machining the inner hole of a motor housing according to claim 3, characterized in that, The number of the hydraulic cylinders is more than 3.

5. A fixture for machining the inner hole of a motor housing according to claim 4, characterized in that, The fixture base also has a positioning disk and a transition disk, and the positioning disk and the transition disk are respectively installed at the centers of the top surface and the bottom surface of the fixture base.

6. A method for machining the inner hole of a motor housing, characterized in that, Using the fixture according to any one of claims 2-5, comprises the following steps: (1) Clamping the motor housing: placing the motor housing to be machined on the fixture base between the hydraulic cylinders, and driving the clamping heads of the hydraulic cylinders to clamp the top end of the motor housing through the hydraulic station and the rotary oil distributor; (2) Rough machining of the inner hole: selecting a special turning tool bar, and using a rough machining cutting edge to roughly machine an inner hole in the motor housing; (3) Finish machining of the inner hole: using a finish machining cutting edge to finish machine the inner hole so that the roundness tolerance of the inner hole is less than or equal to 0.07 mm.

7. A method for machining the inner hole of a motor housing according to claim 6, characterized in that, The special turning tool bar has a stepped tool head structure, the front end of the tool head is a rough machining cutting edge, and the rear end is a finish machining cutting edge.

8. A method for machining the inner hole of a motor housing according to claim 7, characterized in that, The cutting angle of the rough machining cutting edge is 15-20°; the cutting angle of the finish machining cutting edge is 5-8°.

9. A method for machining the inner hole of a motor housing according to claim 6, characterized in that, In step (2), the cutting depth of the rough machining is 2-3 mm, and the feed rate is 0.2-0.5 mm / r.

10. A method for machining the inner hole of a motor housing according to claim 6, characterized in that, In step (3), the cutting depth of the finish machining is 0.5-0.8 mm, and the feed rate is 0.1-0.2 mm / r.

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