Crankshaft machining tool based on follow-up grinding machine tool

Abstract

The invention discloses a crankshaft machining tool based on a follow-up grinding machine tool. A centering rod is elastically supported on the upper portion of the machining tool. A self-positioning heart-shaped clamping head is clamped to the centering rod in the radial direction, and the other end of the self-positioning heart-shaped clamping head is arranged outside the crank shaft in a circumferential limiting and sleeving mode so that circumferential rotating force of the main shaft driving head can be transmitted to the crank shaft. According to the tool, the crankshaft is fixed on the main shaft driving head through circumferential rotation of the self-positioning heart-shaped clamping head, relative rotation of the crankshaft and the main shaft driving head in the machining process is avoided, namely idling of the crankshaft is avoided, and it is always guaranteed that the basic plane of the main shaft driving head and the alignment plane of the top of the counterweight block are coplanar; and the phase angle precision in the rotation process of the crankshaft and the main shaft driving head is ensured, so that the batch machining precision of the crankshaft is ensured while the machining efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of tooling fixtures, and specifically to a crankshaft machining tooling based on a follow-up grinding machine tool. Background Art

[0002] At present, with the continuous increase in the demand for robots, the continuous development of robot technology, and the continuous increase in the accuracy requirements for reducers used in robots. The traditional equipment for machining crankshafts is an "ordinary cylindrical grinder + eccentric fixture", and its machining method is to position and clamp with the involute spline of the crankshaft, and perform machining by aligning the high points of the two crankshafts. Such a machining method has poor rigidity, poor workpiece consistency, poor versatility, serious waste of grinding wheels, complex tooling, inaccurate phase difference between the two eccentric wheels, and low production efficiency. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. For this reason, an object of the present invention is to provide a crankshaft machining tooling based on a follow-up grinding machine tool. This tooling can machine crankshafts of different models by replacing the self-aligning lathe dog, and has good versatility. At the same time, for batch-produced crankshafts, batch machining can be achieved by aligning the high points and phase angles of the two crankshafts at one time, improving the workpiece consistency and production efficiency, greatly increasing the qualified rate of products, thereby reducing the assembly error of the RV reducer, ensuring the manufacturing accuracy, and meeting the high-precision requirements of the robot RV reducer. By setting the positioning point of the self-aligning lathe dog inside the tooling, the interference between the grinding wheel and the tooling is reduced, the effective machining diameter of the grinding wheel becomes larger, the grinding wheel is saved, and the cost is reduced.

[0004] For this reason, the present invention provides a crankshaft machining tooling based on a follow-up grinding machine tool. One end of the crankshaft positioned by this machining tooling is axially tightened by a front center coaxially fixed on the spindle drive head, and the other end of the crankshaft is axially tightened by a rear center on the machine tool. The lower part of the machining tooling is fixed on the axial end face of the spindle drive head, the middle part of the machining tooling is coaxially sleeved outside the front center, and the upper part of the machining tooling is elastically supported with a centering rod; a self-aligning lathe dog is radially clamped on the centering rod, and the other end of the self-aligning lathe dog is circumferentially limited and sleeved outside the crankshaft to transmit the circumferential rotational force of the spindle drive head to the crankshaft.

[0005] Preferably, the machining tooling includes crescent-shaped cushion blocks, elastic ring pieces and centering blocks. There are multiple crescent-shaped cushion blocks axially stacked and fixed on the axial end face of the spindle drive head, and elastic ring pieces are clamped and fixed between the multiple crescent-shaped cushion blocks; there are multiple elastic ring pieces arranged at intervals, and the centering blocks are fixedly connected between the elastic ring pieces; the centering rod is fixedly inserted in the radial direction of the centering block relative to the front center.

[0006] Preferably, the self-aligning dog clutch is of an L-shaped structure. One end of the self-aligning dog clutch is provided with a V-shaped groove for radially clamping the centering rod, and the other end of the self-aligning dog clutch is integrally provided with a spline sleeve that is circumferentially limited and sleeved outside the crankshaft. A threaded hole is radially provided on the spline sleeve, and a bolt threadedly connected in the threaded hole radially presses against the crankshaft to fix the self-aligning dog clutch on the crankshaft.

[0007] Preferably, a plurality of screws are axially penetrated and fixed on the upper part of the elastic ring piece. The middle part of the screw penetrates and fixes the centering block, and the other end of the screw is threadedly connected to the fastening back plate. Axial clamping force is provided by the screw and the fastening back plate to axially clamp the centering block between a plurality of elastic ring pieces.

[0008] Preferably, a semi-circular steel sheet is bolted and connected to an axial end surface at the lower part of the elastic ring piece. The bolts on the semi-circular steel sheet sequentially penetrate a plurality of crescent-shaped pads and the elastic ring piece and are threadedly connected to the axial end surface of the main shaft driving head.

[0009] Preferably, a basic alignment plane is radially provided on the circumferential outer wall of the main shaft driving head; a centering rod is radially inserted in the middle of the top plane of the centering block, and the top plane of the centering block is flush with the basic alignment plane.

[0010] The advantages of the present invention compared with the prior art are as follows:

[0011] (1) In the present invention, the workpiece is positioned by the front and rear double center points of the grinding machine, which has good versatility, low cost, good rigidity, high repeat positioning accuracy, and is convenient for loading and unloading the workpiece, etc.

[0012] (2) In the present invention, the perpendicularity between the alignment plane on the centering block and the centering rod is less than or equal to 0.002. When the workpiece is installed, the phase angle consistency between the spline and the eccentric circle is good, the versatility is good, which is beneficial to improving the assembly accuracy, and further improving the product accuracy; the good phase angle consistency between the spline and the eccentric circle can reserve a smaller finishing allowance, improving the working efficiency.

[0013] (3) In the present invention, the elastic ring piece has a simple structure, is easy to manufacture, the elastic clamping force is adjustable, is applicable to different workpieces of various sizes, has low cost, and has good versatility.

[0014] (4) In the present invention, the V-shaped groove of the self-aligning dog clutch cooperates with the centering rod on the centering block to achieve rapid replacement, self-centering, self-alignment, etc. of the workpiece; the elastic ring piece axially applies an axial force to it, making the connection between the two firm and ensuring the positional relationship between the part and the tooling, ensuring the repeat positioning accuracy of the part clamping, making the workpiece alignment convenient and simple, and batch processing can be realized with one alignment; through design, the self-aligning dog clutch reduces the radial dimension, so that the available size of the grinding wheel is increased by half, reducing the frequency of grinding wheel replacement and saving costs.

[0015] The present invention is applicable to the small - batch or large - batch machining of various precision outer circles and eccentric circles. It has a wide application range and high efficiency. The present invention can machine crankshafts of different models by replacing the self - positioning lathe dog, with good versatility. At the same time, for workpieces in mass production, multiple machining can be achieved through one alignment, improving production efficiency and increasing the qualified rate and product quality of the products. The present invention also has the characteristics of simple processing tooling structure, low cost, strong versatility, high product consistency and qualified rate, and has a very broad application prospect in this field. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0017] Figure 1 is an exploded perspective view of the three - dimensional structure of the present invention;

[0018] Figure 2 is a partial cross - sectional view of the three - dimensional structure of the present invention;

[0019] Figure 3 is a schematic diagram of the three - dimensional structure of the self - positioning lathe dog in the present invention;

[0020] Figure 4 is a schematic diagram of the three - dimensional structure of the elastic ring piece in the present invention;

[0021] Figure 5 is a schematic diagram of the three - dimensional structure of the centering rod in the present invention;

[0022] Figure 6 is a schematic diagram of the three - dimensional structure of the counterweight in the present invention;

[0023] In the figure: 1 - main shaft drive head; 2 - fastening back plate; 3 - elastic ring piece; 4 - centering rod; 5 - centering block; 7 - screw; 8 - self - positioning lathe dog; 9 - crankshaft; 10 - rear center; 11 - semi - circular steel sheet; 12 - crescent - shaped spacer; 13 - front center; 14 - V - shaped groove; 15 - spline sleeve; 16 - threaded hole. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] The following will describe in detail the embodiments of the present application. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present application and should not be construed as a limitation of the present application.

[0025] In the description of the present application, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0026] The following further elaborates on the present invention with reference to the accompanying drawings.

[0027] A crankshaft machining tooling based on a follow-up grinding machine tool according to the present invention. One end of the crankshaft 9 positioned by the machining tooling is axially tightened by a front center 13 coaxially fixed on a main shaft drive head 1, and the other end of the crankshaft is axially tightened by a rear center 10 on the machine tool. The lower part of the machining tooling is fixed on the axial end face of the main shaft drive head. The middle part of the machining tooling is coaxially sleeved outside the front center, and a centering rod 4 is elastically supported on the upper part of the machining tooling; a self-aligning dog clutch 8 is radially clamped on the centering rod, and the other end of the self-aligning dog clutch is circumferentially limited and sleeved outside the crankshaft to transmit the circumferential rotational force of the main shaft drive head to the crankshaft.

[0028] Preferably, the machining tooling includes crescent-shaped pads 12, elastic ring pieces 3, and centering blocks 5. A plurality of crescent-shaped pads are axially stacked and fixed on the axial end face of the main shaft drive head, and elastic ring pieces are clamped and fixed between the plurality of crescent-shaped pads; a plurality of elastic ring pieces are spaced apart, and centering blocks are fixedly connected between the elastic ring pieces; the centering rod is fixedly inserted in the radial direction of the centering block relative to the front center.

[0029] Preferably, the self-aligning dog clutch is of an L-shaped structure. One end of the self-aligning dog clutch is provided with a V-shaped groove 14 for radially clamping the centering rod, and a spline sleeve 15 for circumferentially limiting and sleeving outside the crankshaft is integrally formed at the other end of the self-aligning dog clutch; a threaded hole 16 is radially opened on the spline sleeve, and a bolt threadedly connected in the threaded hole radially tightens the crankshaft to fix the self-aligning dog clutch on the crankshaft.

[0030] Preferably, a plurality of screws 7 are axially penetrated and fixed on the upper part of the elastic ring piece. The middle part of the screw penetrates and fixes the centering block, and the other end of the screw is threadedly connected to a fastening back plate 2. Axial clamping force is provided by the screw and the fastening back plate to axially clamp the centering block between the plurality of elastic ring pieces.

[0031] Preferably, a semi-circular steel sheet 11 is bolted and connected to an axial end face at the lower part of the elastic ring piece. The bolts on the semi-circular steel sheet sequentially penetrate the plurality of crescent-shaped pads and the elastic ring pieces and are threadedly connected to the axial end face of the main shaft drive head.

[0032] Preferably, a basic alignment plane is radially provided on the circumferential outer wall of the main shaft drive head; a centering rod is radially inserted in the middle of the top plane of the centering block, and the top plane of the centering block is flush with the basic alignment plane.

[0033] In order to more clearly illustrate the specific implementation manners of the present invention, an embodiment is provided below:

[0034] A crankshaft processing tooling based on a follow-up grinding machine tool of the present invention mainly includes a centering block, a centering rod, an elastic ring piece, a self-aligning lathe dog, a crescent-shaped spacer, a semi-circular steel sheet, and a fastening back plate. The combined structure of this tooling is Figure 1 and Figure 2 shown as follows.

[0035] (1) Centering block

[0036] Figure 6 As shown in the schematic diagram of the centering block, the centering block is used to align the relative position relationship between the tooling and the workpiece, that is, the phase angle between the spline and the eccentric circle of the workpiece; wherein the alignment plane is perpendicular to the pin hole, and the perpendicularity is less than or equal to 0.002; the centering block is installed between two elastic ring pieces through two holes on it.

[0037] (2) Centering rod

[0038] Figure 5 As shown in the schematic diagram of the centering rod, the centering rod is used to drive the self-aligning lathe dog to rotate, and its positioning and transmission functions are equivalent to those of a shift lever. The centering rod is a tapered core rod and is installed in the pin hole on the centering block.

[0039] (3) Elastic ring piece

[0040] Figure 4 As shown in the schematic diagram of the elastic ring piece, the elastic ring piece is used to provide rotational movement and axial pressure Fz for the self-aligning lathe dog. During operation, the elastic ring piece generates axial pressure by relying on its own deformation. There are two elastic ring pieces, and they are used together. They are connected to the main shaft headstock through three holes below with two crescent-shaped spacers and a semi-circular steel sheet; the two holes above are connected to the fastening back plate and the centering block together, transmitting the rotational movement of the main shaft headstock to the centering rod, and then to the self-aligning lathe dog through the centering rod, thereby driving the workpiece to move.

[0041] (4) Self-aligning lathe dog

[0042] Figure 3 As shown in the schematic diagram of the self-aligning lathe dog, the self-aligning lathe dog is used to determine the circumferential position relationship between the tooling and the workpiece, and transmit the rotational movement of the headstock to the workpiece to drive the workpiece to rotate together; the internal spline of the self-aligning lathe dog is in mating connection with the external spline of the workpiece, and the V-shaped groove on the lathe dog is in contact and mating with the centering rod on the centering block, and is pressed tightly by the axial pressure provided by two elastic ring pieces, playing a role in ensuring circumferential and axial positioning.

[0043] The working principle of the present invention is:

[0044] (1) Install the spindle drive head and the front center on the grinder headstock, and the rear center on the tailstock of the machine tool. Adjust the positions of the front and rear centers so that the center hole of the workpiece fits firmly with the two centers, and lock the front and rear centers.

[0045] (2) Press the semicircular steel sheet of the crescent block and the two elastic ring sheets together. Figure 1 The fixture structure is intended to be mounted on the spindle drive head frame by screws.

[0046] (3) Similarly, tighten the back plate, centering rod, and centering block. Figure 1 Or 2 the tooling structure is intended to be mounted on two elastic ring pieces by screws.

[0047] (4) Install the self-locating heart-shaped chuck and the workpiece through the spline on the workpiece, and fix the heart-shaped chuck with a fastening screw to prevent axial movement between it and the workpiece; it is emphasized again that the positioning point of the heart-shaped chuck must be aligned with the positioning point of the spline to ensure the phase angle position error between the heart-shaped chuck and the eccentric circle.

[0048] (5) The V-groove on the self-locating heart-shaped clamp is brought into contact with the centering rod on the centering block to ensure that the deformation of the elastic ring can provide sufficient axial clamping force.

[0049] (6) Use a lever micrometer to align the center block and the front side. The error should be less than or equal to 0.002. At this time, the highest point of the eccentric circle of the workpiece is the grinding wheel tool setting point. Operate the machine tool to set this point as the C-axis zero point, and the tool setting and installation steps before workpiece processing are completed.

[0050] (7) If you need to replace the workpiece of the same drawing, you only need to remove the heart-shaped chuck and the workpiece and replace the new workpiece. There is no need to repeat the previous alignment operation process, and the workpiece can be quickly replaced.

[0051] (8) If you need to replace a workpiece with a different drawing size, you only need to remake a new heart-shaped chuck and adjust the front and rear center positions to achieve quick replacement of the workpiece, saving a lot of time and improving processing efficiency.

[0052] The crankshaft processing tooling of the present invention is based on a follow-up grinding machine tool. The crankshaft is axially clamped and positioned by the front center and the rear center of the machine tool. The crankshaft is circumferentially rotated and fixed on the spindle drive head by a self-positioning chicken heart clamp, so as to avoid relative rotation between the crankshaft and the spindle drive head during processing, that is, to avoid idling of the crankshaft, always ensure that the base plane of the spindle drive head and the alignment plane on the top of the counterweight block are coplanar, and ensure the phase angle accuracy of the crankshaft and the spindle drive head during rotation, thereby improving the processing efficiency and ensuring the batch processing accuracy of the crankshaft.

[0053] The present invention and its embodiments have been described above. Such description is not restrictive. What is shown in the drawings is only one of the embodiments of the present invention, and the actual structure is not limited thereto. In general, if those of ordinary skill in the art are inspired by it and, without departing from the gist of the present invention, design similar structural modes and embodiments to this technical solution without creative efforts, they shall fall within the protection scope of the present invention.

Claims

1. A crankshaft processing tool based on a follow-up grinding machine tool, wherein one end of the crankshaft positioned by the processing tool is axially pressed by a front center coaxially fixed on the spindle drive head, and the other end of the crankshaft is axially pressed by a rear center on the machine tool, characterized in that: The lower part of the processing tooling is fixed on the axial end face of the spindle drive head, the middle part of the processing tooling is coaxially sleeved on the outside of the front center, and the upper part of the processing tooling is elastically supported with a centering rod; a self-positioning heart-shaped clamp is radially clamped on the centering rod, and the other end of the self-positioning heart-shaped clamp is circumferentially limited and sleeved on the outside of the crank shaft to transmit the circumferential rotational force of the spindle drive head to the crank shaft.

2. The crankshaft processing tool based on a follow-up grinding machine according to claim 1, characterized in that: The processing tooling includes a crescent pad, an elastic ring sheet and a centering block. The crescent pad is provided in plurality and is axially stacked and fixed on the axial end face of the spindle drive head, and elastic ring sheets are clamped and fixed between the plurality of crescent pads; the elastic sheet replacement interval is provided in plurality, and the elastic ring sheets are fixedly connected to the centering blocks; a centering rod is fixedly inserted on the centering block in the radial direction relative to the front top.

3. The crankshaft processing tool based on a follow-up grinding machine according to claim 1, characterized in that: The self-positioning heart-shaped clamp is an L-shaped structure, one end of which is provided with a V-shaped groove for radially clamping a centering rod, and the other end of the self-positioning heart-shaped clamp is provided with a spline sleeve with a circumferential limit sleeve arranged on the outside of the crank shaft; the spline sleeve is radially provided with a threaded hole, and the crank shaft is radially tightened by a bolt threaded in the threaded hole to fix the self-positioning heart-shaped clamp on the crank shaft.

4. The crankshaft processing tool based on a follow-up grinding machine according to claim 2 is characterized in that: A plurality of screws are axially penetrated and fixed on the upper part of the elastic ring piece, the middle part of the screw penetrates and fixes the centering block, and the other end of the screw is threadedly connected to the fastening back plate, and the screw and the fastening back plate provide axial clamping force to axially clamp the centering block between the plurality of elastic ring pieces.

5. The crankshaft processing tool based on a follow-up grinding machine according to claim 2, characterized in that: A semicircular steel sheet is fixedly connected with bolts on an axial end face of the lower part of the elastic ring sheet, and the bolts on the semicircular steel sheet penetrate multiple crescent gaskets and the elastic ring sheet in sequence and are threadedly connected with the axial end face of the main shaft driving head.

6. The crankshaft processing tool based on a follow-up grinding machine according to claim 2, characterized in that: A basic plane is radially provided on the circumferential outer wall of the spindle driving head; a centering rod is radially inserted into the middle of the top plane of the centering block, and the top plane of the centering block is flush with the basic plane.

Images