Precise gear grinding clamp with double pressing mechanisms

Abstract

The utility model discloses a precise gear grinding clamp with double pressing mechanisms. The precise gear grinding clamp comprises a tool mandrel, a linkage mechanism, pressing parts and a connecting part. The linkage mechanism comprises a taper elastic expansion sleeve arranged in an inner hole of the workpiece and an expansion sleeve nut movably connected with the taper elastic expansion sleeve. An inner hole of the taper elastic expansion sleeve is in taper fit with the peripheral surface of the tool mandrel; the expansion sleeve nut is connected to the tool mandrel in a threaded mode, and axial thrust or axial tension is generated on the taper elastic expansion sleeve by rotating the expansion sleeve nut. The pressing part is installed on the tool mandrel, the workpiece is pressed on the flange structure of the tool mandrel, and pressing of the end face of the workpiece is achieved. The connecting part is used for connecting the tool mandrel and the equipment spindle to guarantee synchronous movement of the workpiece and the equipment spindle. The positioning precision and the machining precision of gear grinding are improved, machining errors are reduced, and the workpiece dismounting difficulty is lowered, so that the precision of a workpiece is improved, the service life of a tool is prolonged, and precise machining of a gear in the gear grinding process is achieved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to mechanical manufacturing equipment technical field relates to a precision gear grinding fixture with double pressing mechanism. BACKGROUND

[0002] Gear as the core component of transmission mechanism, its precision and quality have very intuitive influence to the performance and life of whole transmission system, and gear grinding as the key process of gear processing, directly decides whether the precision and performance of gear can meet the requirements, in order to improve the machining precision and surface quality of gear grinding, we require that workpiece and fixture are precisely matched, and are fixed in position, and the current fixture still has the following problems:

[0003] (1) the traditional expansion sleeve type fixture only presses elastic expansion sleeve, only positions workpiece without pressing, and workpiece will move during gear grinding, which greatly influences gear grinding precision, especially pitch;

[0004] (2) the positioning surface of traditional fixture is small, and the tooth profile ground is poor;

[0005] (3) the traditional fixture needs to be disassembled by dismounting nut, which is troublesome and can wear workpiece end face. SUMMARY

[0006] The utility model discloses a main purpose is to design a precision gear grinding fixture with double pressing mechanism, utilizes the high precision control characteristic of double pressing mechanism to guarantee the stability of workpiece during processing, utilizes the taper property of taper elastic expansion sleeve, elastic property to improve the matching precision of gear grinding fixture, utilizes the positioning precision and repeat positioning precision of expansion sleeve and taper mandrel cooperation to improve the positioning precision of fixture, utilizes the linkage characteristic of elastic expansion sleeve and expansion sleeve nut to improve the dismounting efficiency of processing process, realizes the gapless cooperation of fixture and workpiece, high-precision positioning, finally reaches the purpose of stable positioning, precision machining, quick dismounting.

[0007] The utility model discloses the following technical scheme realizes:

[0008] A precision gear grinding fixture with double pressing mechanism, including frock mandrel, linkage mechanism, pressing part and connecting part, frock mandrel is a stepped shaft, linkage mechanism includes taper elastic expansion sleeve arranged in the inner hole of workpiece and expansion sleeve nut movably connected with the taper elastic expansion sleeve, the inner hole of taper elastic expansion sleeve is matched with the outer surface of frock mandrel through taper, expansion sleeve nut is connected on the frock mandrel through screw thread, generates an axial thrust or axial tension to taper elastic expansion sleeve by rotating expansion sleeve nut, pressing part is installed on the frock mandrel, and workpiece is pressed on the flange structure of frock mandrel, realizes the pressing of workpiece end face, connecting part is used to connect frock mandrel and equipment main shaft, and ensures that workpiece and equipment main shaft move synchronously.

[0009] In some embodiments, the outer circumferential surface of the tapered elastic expansion sleeve is provided with a plurality of uniform and interlaced long grooves along the entire circumference, and the long grooves are filled with rubber material.

[0010] In some embodiments, the inner circumferential surface of the tapered elastic expansion sleeve is provided with a tapered surface with a 6° taper, the wall thickness of the tapered elastic expansion sleeve is 7mm-12mm, and the expansion and contraction amount is 0.05mm-0.1mm.

[0011] In some embodiments, the narrow opening of the inner circumferential surface of the tapered elastic expansion sleeve is provided with a ring of flange structure;

[0012] The expansion sleeve nut is divided into two parts, namely a nut and an annular connector with a T-shaped cross section; the nut is used for threaded connection with the tool mandrel; the annular connector is fixed to the axial end surface of the nut in a coaxial manner with the nut, and the flange structure of the tapered elastic expansion sleeve is matched with the annular groove of the annular connector, so that the expansion sleeve nut can rotate on the tapered elastic expansion sleeve.

[0013] In some embodiments, the pressing component comprises:

[0014] The pressing disc is sleeved on the tool mandrel and is attached to the workpiece;

[0015] The pressing nut is installed on the tool mandrel in a threaded manner, and rotating the pressing nut presses the pressing disc and further presses the workpiece.

[0016] In some embodiments, the pressing disc is a cylindrical structure, the bottom surface of which is provided with a central hole, the tool mandrel is arranged in the central hole, and the linkage mechanism is located in the accommodating space of the pressing disc.

[0017] In some embodiments, the connecting component is a yoke, two prongs of the yoke are connected to the main shaft of the equipment, and the inner hole of the yoke is tightly matched with the tool mandrel.

[0018] In some embodiments, each of the two axial end surfaces of the tool mandrel is provided with a coaxially arranged central hole, and the taper of the central hole is the same as the taper of the lathe center.

[0019] In some embodiments, the tool mandrel, the tapered elastic expansion sleeve, the expansion sleeve nut, the pressing component, and the connecting component are coaxially assembled together.

[0020] The utility model has the advantages of:

[0021] The utility model provides a kind of can utilize the close cooperation of taper to realize workpiece locking and can be conveniently disassembled gear grinding fixture, improve the positioning accuracy and machining accuracy of gear grinding, reduce processing error, reduce workpiece disassembly difficulty, to improve the precision and tool service life of workpiece, realize the precision machining of gear in gear grinding process. Attached Figure Description

[0022] The accompanying drawings, as part of this utility model, are used to provide a further understanding of the present utility model. The illustrative embodiments and descriptions of the present utility model are used to explain the present utility model, but do not constitute an undue limitation of the present utility model. Obviously, the drawings described below are merely some embodiments; those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0023] In the attached diagram:

[0024] Figure 1 This is a schematic diagram illustrating the application of the precision gear grinding fixture with a double clamping mechanism of this utility model.

[0025] Figure 2 This is a schematic diagram of the linkage mechanism of this utility model;

[0026] Figure 3 This is a schematic diagram of the tapered elastic expansion sleeve of this utility model.

[0027] Attached diagram labels: 1-Shift fork, 2-Tooling mandrel, 3-Tapered elastic expansion sleeve, 4-Expansion sleeve nut, 5-Pressure plate, 6-Pressure nut.

[0028] It should be noted that these accompanying drawings and textual descriptions are not intended to limit the scope of the present invention in any way, but rather to illustrate the concept of the present invention to those skilled in the art by referring to specific embodiments. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate this utility model, but are not intended to limit the scope of this utility model.

[0030] In the description of this utility model, it should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0031] In the description of the utility model, it needs to explain, unless another explicit provision and limitation, the term '' install '' '' connect '' '' connection '' should do the broad sense understanding, for example, can be fixed connection, also can be detachable connection, or integrally connected, can be mechanical connection, also can be electrical connection, can be directly connected, also can be indirectly connected through the intermediate medium, for the ordinary skill in the art, the specific meaning of the above-mentioned term in the utility model can be understood according to specific circumstances.

[0032] As Figure 1 The utility model discloses a precision gear grinding fixture with double pressing mechanism, including tool mandrel 2, linkage mechanism, pressing part and connecting part, tool mandrel 2 is a stepped shaft, linkage mechanism includes the taper elastic expansion sleeve 3 arranged in the inner hole of workpiece and the expansion sleeve nut 4 with taper elastic expansion sleeve 3 swing joint, the inner hole of taper elastic expansion sleeve 3 is with the outer periphery of tool mandrel 2 through taper cooperation, expansion sleeve nut 4 is screwed on tool mandrel 2, and an axial thrust or axial tension is generated to taper elastic expansion sleeve 3 by rotating expansion sleeve nut 4, pressing part is installed on tool mandrel 2, and workpiece is pressed on the flange structure of tool mandrel 2, realizes the pressing of workpiece end face, and connecting part is used to connect tool mandrel 2 and equipment main shaft, and ensures that workpiece and equipment main shaft move synchronously.

[0033] The specific structure of the taper elastic expansion sleeve and the expansion sleeve nut is further described below.

[0034] As Figure 3 The outer circumferential surface of the taper elastic expansion sleeve 3 is provided with a plurality of uniform and mutually intersecting elongated grooves along the entire circumference, and the elongated grooves are filled with rubber material.

[0035] It should be noted that the taper elastic expansion sleeve is made of 65Mn material, which is quenched and tempered, quenched and ground to ensure the elasticity and repeat positioning accuracy of the expansion sleeve. The outer circumferential surface is provided with six uniform and mutually intersecting elongated grooves along the entire circumference, and the elongated grooves are filled with rubber material to prevent abrasive particles from entering the mating surface. The inner surface of the taper elastic expansion sleeve is provided with a tapered surface with a 6° taper, and the coincidence degree of the tapered portion and the mandrel is greater than 90%, so that the expansion sleeve can be tightened without external force after the expansion sleeve nut is tightened, ensuring the positioning accuracy. In order to fully exert the taper and elastic properties of the taper elastic expansion sleeve, the wall thickness of the expansion sleeve is designed to be 7mm~12mm, and the expansion and contraction amount is 0.05mm~0.1mm. The repeat positioning accuracy of the expansion sleeve is less than 0.002 mm, and the positioning accuracy of the taper elastic expansion sleeve remains unchanged after 150,000 times of processing.

[0036] As Figure 2As shown, the expansion sleeve nut 4 is mounted on the tapered elastic expansion sleeve 3, and the expansion sleeve nut 4 is used to rotate and press or disassemble the tapered elastic expansion sleeve 3, so as to realize the close cooperation and rapid disassembly of the tapered elastic expansion sleeve 3 and the inner ring of the workpiece, and ensure the positioning accuracy of the gear. A flange structure is arranged on the narrow opening of the inner circumferential surface of the tapered elastic expansion sleeve 3; the expansion sleeve nut 4 is divided into two parts, which are a nut and a T-shaped annular connector; the nut is used for threaded connection with the tool mandrel 2; the annular connector is coaxially fixed to the axial end surface of the nut, and the flange structure of the tapered elastic expansion sleeve 3 is matched with the annular groove of the annular connector, so that the expansion sleeve nut 4 can rotate on the tapered elastic expansion sleeve 3.

[0037] It should be noted that the linkage mechanism is a mechanism for riveting the expansion sleeve nut and the tapered elastic expansion sleeve together, and driving the tapered elastic expansion sleeve to move by rotating the expansion sleeve nut. The tapered elastic expansion sleeve and the expansion sleeve nut are in interference fit, and the expansion sleeve nut is buckled into the tapered elastic expansion sleeve during the manufacture of the tapered elastic expansion sleeve by using a special process. A gap of 0.6mm is provided at the matching position. If the gap is too small, the tapered elastic expansion sleeve will be rotated during the rotation of the expansion sleeve nut, which will affect the positioning accuracy of the tapered elastic expansion sleeve. If the interference amount is too large, the force generated during the rotation of the nut cannot be transmitted to the tapered elastic expansion sleeve, which will affect the cooperation area between the outer circle of the tapered elastic expansion sleeve and the inner hole of the workpiece.

[0038] The use process is as follows: first, the tapered elastic expansion sleeve and the expansion sleeve nut connecting body are installed in the inner hole of the workpiece, the expansion sleeve nut is rotated to make the tapered surface of the tapered elastic expansion sleeve cooperate with the tapered surface of the tool mandrel, and a radial expansion force is generated during the slow expansion process of the tapered elastic expansion sleeve, so as to realize the positioning and compression of the inner hole of the workpiece. Then, the pressure plate is installed on the workpiece, the compression nut is rotated to compress the pressure plate, and then the workpiece is attached to the positioning surface of the mandrel, so as to realize the positioning and compression of the end surface of the workpiece, and finally ensure the complete positioning of the workpiece.

[0039] The specific structure of the compression component is further described as follows.

[0040] As shown in Figure 1 The compression component includes a pressure plate 5 and a compression nut 6; the pressure plate 5 is sleeved on the tool mandrel 2 and attached to the workpiece; and the compression nut 6 is installed on the tool mandrel 2 in a threaded manner, and the compression nut 6 is rotated to compress the pressure plate 5 and then compress the workpiece.

[0041] It should be noted that the pressure plate is pressed on the workpiece, the positioning surface of the tool and the workpiece is increased through linear contact, and the gear grinding precision is improved. The pressure plate is a cylindrical structure, a center hole is arranged on the bottom surface, the tool mandrel is arranged in the center hole, and the linkage mechanism is arranged in the accommodating space of the pressure plate. The compression nut is installed at the top end of the tool mandrel, the workpiece is compressed by compressing the pressure plate, and the clamp is firmly clamped. The pressure plate, the compression nut and the expansion sleeve nut are made of medium carbon alloy 40Cr, and after quenching and tempering, quenching and tempering, certain toughness, plasticity and wear resistance are obtained.

[0042] The specific structure of the connecting component is further described below.

[0043] As shown in Figure 1 , the connecting component is a fork 1, two prongs of the fork 1 are connected with the equipment main shaft, and the inner hole of the fork 1 is tightly matched with the tool mandrel 2.

[0044] It should be noted that the fork is connected with the outer circle of the tool mandrel and the main shaft of the machine tool, so that the workpiece and the main shaft of the machine tool move synchronously, the machine tool center and the center hole of the workpiece are tightly matched, the coaxiality requirement of the workpiece is ensured, and the gear grinding processing of the workpiece is realized.

[0045] The specific structure of the tool mandrel is further described below.

[0046] As shown in Figure 1 , the tool mandrel is a transition positioning shaft for connecting the machine tool and the machined workpiece through the positioning inner hole / outer circle or center hole, realizing accurate positioning between the machined part and the machine tool, and ensuring the gear grinding precision. The tool mandrel is made of GCr15 alloy steel, which is quenched and tempered, and is ground to ensure the rigidity and precision durability of the mandrel; the center hole of the two end faces of the tool mandrel has a roughness Ra0.8μm, and the coaxiality is less than 0.003mm; the taper of the headstock and tailstock center is the same as the taper of the center hole of the mandrel, and the fitting degree is greater than 90%; the coaxiality of the headstock and tailstock center hole is less than 0.002mm; the diameter of the tailstock center cannot be greater than the diameter of the gear tooth root circle of the machined workpiece.

[0047] The working principle of the above-mentioned gear grinding fixture is that firstly, the tapered elastic expansion sleeve and the expansion sleeve nut connecting body are put into the workpiece, the inner hole of the tapered elastic expansion sleeve is matched with the outer circle of the tool core shaft through tapering, the expansion sleeve nut is rotated to extrude the tapered elastic expansion sleeve, the tapered elastic expansion sleeve is slowly expanded, the outer circle of the tapered elastic expansion sleeve is attached to the inner hole of the workpiece, the positioning and compression of the inner hole of the workpiece are realized, then the pressing plate and the outer circle of the tool core shaft are matched, the compression nut is rotated to extrude the pressing plate to move towards the workpiece, the workpiece is attached to the end face of the tool core shaft, the end face positioning and compression of the workpiece are realized, then the outer circle of the tool core shaft is connected with the main shaft of the machine tool through the shift fork, the synchronous movement of the workpiece and the main shaft of the machine tool is ensured, the center hole of the tool core shaft is tightly attached to the tailstock center, the coaxiality requirement of the workpiece is ensured, the complete positioning of the workpiece is ensured, and the workpiece is processed. When the workpiece is processed, firstly, the compression nut and the pressing plate are removed, then the expansion sleeve nut is rotated outward, in this process, the expansion sleeve nut generates an axial tension to drive the tapered elastic expansion sleeve to separate from the inner hole of the workpiece, and the tapered elastic expansion sleeve is taken out, so that the workpiece can be removed.

[0048] In summary, the precision gear grinding fixture with the double compression mechanism has the following functions and effects:

[0049] (1) The tapered elastic expansion sleeve is designed, wherein the taper design ensures the high-precision positioning and self-locking of the fixture; the design of the tapered elastic expansion sleeve can eliminate the gap between the hole and the shaft, realize repeated precise positioning, prolong the service life of the tooling, and effectively prevent the abrasive grains of the grinding wheel from entering the matching surface to affect the matching precision; the wall thickness design ensures the effectiveness and stability of the expansion sleeve; in general, the expansion sleeve can improve the positioning accuracy and repeated positioning accuracy of the fixture, and realize the gapless matching and high-precision positioning of the fixture and the workpiece.

[0050] (2) The linkage mechanism is designed, the expansion sleeve nut and the tapered elastic expansion sleeve constitute a linkage mechanism, which can realize the positioning and compression of the inner hole of the workpiece by rotating the expansion sleeve nut; when the workpiece is disassembled, the traditional expansion sleeve tooling needs to be first assembled with the disassembly nut, and then the disassembly nut is rotated to extrude the workpiece to disassemble the workpiece, which is not only complex and time-consuming, but also causes wear on the positioning surface of the workpiece, affecting the quality of the workpiece; the linkage mechanism is designed in the patent, an axial tension is generated on the elastic expansion sleeve by rotating the expansion sleeve nut, so that the expansion sleeve slowly separates from the workpiece, and the workpiece can be quickly disassembled and assembled, which saves labor time and ensures the quality of the workpiece; the expansion sleeve nut is designed as an external quadrangle, which can uniformly expand the expansion sleeve and improve the gear grinding accuracy.

[0051] (3) the design of the pressure plate, rotating the pressure nut and then press the workpiece, to achieve the workpiece end face pressure, to prevent the workpiece in the gear grinding process occurs, with the workpiece through the linear contact to reduce the contact surface, ensure that the pressure is evenly distributed, so that the contact surface can be pressed flat.

[0052] (4) the selection of the pressure nut, in work with the pressure plate supporting pressure workpiece, to achieve the workpiece and the mandrel positioning surface close, improve the positioning accuracy of the workpiece, reduce the error due to the workpiece positioning accuracy is not enough when grinding.

[0053] (5) the design of the double pressure mechanism, to achieve the workpiece hole and end face double positioning and double pressure, so that the workpiece in the machining process firmly attached, improve the gear grinding precision.

[0054] The utility model provides a kind of can utilize the close cooperation of taper to realize workpiece locking and can be conveniently disassembled gear grinding fixture, improve the positioning accuracy and machining accuracy of gear grinding, reduce processing error, reduce workpiece disassembly difficulty, to improve the precision of workpiece and tooling service life, realize the precision machining of gear in gear grinding process.

[0055] In the specification provided herein, a large number of specific details are described. However, it can be understood that the embodiments of the utility model can be practiced without these specific details. In some examples, well-known methods, structures and techniques are not shown in detail in order not to obscure the understanding of the present specification.

[0056] In addition, those skilled in the art can understand that although some embodiments described herein include certain features included in other embodiments rather than other features, combinations of features of different embodiments also mean within the protection scope of the utility model and form different embodiments. For example, in the above embodiments, those skilled in the art can use in a combined manner according to the known technical solutions and the technical problems to be solved by the present application.

[0057] The above is only the preferred embodiment of the utility model, and does not limit the utility model in any form, although the utility model has been disclosed as above with the preferred embodiment, however, it is not used to limit the utility model, any skilled person in the art can make some changes or modifications for equivalent embodiments with the above prompt technical content without departing from the technical solution range of the utility model, as long as it does not depart from the technical solution of the utility model, according to the technical essence of the utility model, any simple modification, equivalent change and modification of the above embodiment, all still belong to the range of the utility model scheme.

Claims

1. A precision gear grinding fixture with a double clamping mechanism, characterized in that, include: The tooling mandrel is a stepped shaft; The coordinating organizations include: A tapered elastic expansion sleeve is arranged in the inner hole of the workpiece, and its inner hole is tapered to the outer peripheral surface of the tooling mandrel. The expansion sleeve nut, which is movably connected to the tapered elastic expansion sleeve, is threaded onto the tooling mandrel. Rotating the expansion sleeve nut generates an axial thrust or axial tension on the tapered elastic expansion sleeve. A clamping component is installed on the tooling mandrel to clamp the workpiece onto the flange structure of the tooling mandrel, thereby clamping the end face of the workpiece. Connecting components are used to connect the tooling mandrel and the equipment spindle to ensure that the workpiece moves synchronously with the equipment spindle.

2. The precision gear grinding fixture with a double clamping mechanism according to claim 1, characterized in that: The tapered elastic expansion sleeve has multiple uniformly spaced and intersecting elongated grooves along the entire circumference on its outer circumference, and the elongated grooves are filled with rubber material.

3. A precision gear grinding fixture with a double clamping mechanism according to claim 1, characterized in that: The inner circumferential surface of the tapered elastic expansion sleeve is a tapered surface with a 6° taper. The wall thickness of the tapered elastic expansion sleeve is 7mm to 12mm, and the expansion and contraction amount is 0.05mm to 0.1mm.

4. A precision gear grinding fixture with a double clamping mechanism according to claim 1, characterized in that: The tapered elastic expansion sleeve has a flange structure at the narrow opening of its inner circumferential surface. The expansion sleeve nut is divided into two parts: Nut, used for threaded connection with the tooling mandrel; The annular connector with a T-shaped cross-section is fixed coaxially to one axial end face of the nut. The flange structure of the tapered elastic expansion sleeve cooperates with the annular groove of the annular connector, allowing the expansion sleeve nut to rotate on the tapered elastic expansion sleeve.

5. A precision gear grinding fixture with a double clamping mechanism according to claim 1, characterized in that, The clamping component includes: The pressure plate is fitted onto the workpiece after being mounted on the tooling mandrel. The clamping nut is threaded onto the tooling mandrel. Rotating the clamping nut clamps the pressure plate and thus clamps the workpiece.

6. A precision gear grinding fixture with a double clamping mechanism according to claim 5, characterized in that: The pressure plate has a cylindrical structure with a central hole on its bottom surface. The tooling mandrel passes through the central hole, and the linkage mechanism is located in the accommodating space of the pressure plate.

7. A precision gear grinding fixture with a double clamping mechanism according to claim 1, characterized in that: The connecting component is a shift fork, the two claws of which are connected to the main shaft of the equipment, and the inner hole of the shift fork is tightly fitted with the tooling mandrel.

8. A precision gear grinding fixture with a double clamping mechanism according to claim 1, characterized in that: The tooling mandrel has a coaxially arranged center hole on each of its two axial end faces, and the taper of the center hole is the same as the taper of the machine tool tip.

9. A precision gear grinding fixture with a double clamping mechanism according to claim 1, characterized in that: The tooling mandrel, tapered elastic expansion sleeve, expansion sleeve nut, clamping component, and connecting component are all assembled together in a coaxial manner.

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