NC rolling mill

Abstract

The invention provides an NC rolling machine capable of realizing miniaturization in an NC rolling machine for rough machining and finish machining of a workpiece. An NC rolling mill (100) is provided with: a pair of first gear plates (104a, 104b) for rough machining; a pair of second gear plates (105a, 105b) for finish machining, which are arranged adjacent to the first gear plates in parallel; and rack drive mechanisms (106a, 106b) for moving one of the first gear plate and the second gear plate and the other of the first gear plate and the second gear plate in parallel and opposite directions. And a numerical control unit (148) that controls the mechanisms including the rack drive mechanism, supports the workpiece between the first gear plates, performs rough machining on the workpiece by means of the first gear plates, and performs rough machining on the workpiece by means of the second gear plates, and performs rough machining on the workpiece by means of the second gear plates. The workpiece after rough machining is displaced between the second gear plates, and finish machining is performed on the workpiece by using the second gear plates.

Description

Technical Field

[0001] The present invention relates to an NC rolling mill for rolling the shape of gears on a workpiece. Background Art

[0002] As a rolling mill, there is known a structure in which a pair of rolling serration plates (also called forming racks) are pressed against the outer peripheral surface of a shaft-like member such as a shaft (workpiece) and rolled while being rotated, and the tooth shape on the surface of the serration plate is transferred to the workpiece.

[0003] For example, a rolling serration plate is described in Patent Document 1. The rolling serration plate has: a first serration plate member for rough machining, which has cutting teeth; a second serration plate member for finish machining, which has finish machining teeth; and a plate. In addition, the first serration plate member and the second serration plate member are detachably fixed above the plate by fastening members in a state of being arranged in a row.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Patent No. 6268995 Summary of the Invention

[0007] Problems to be Solved by the Invention

[0008] However, for the rolling serration plate of Patent Document 1, when the diameter of the workpiece increases, the number of teeth required increases, so the overall length of the serration plate composed of the first serration plate member and the second serration plate member becomes longer. Therefore, the rolling mill using this rolling serration plate becomes larger in size and the cost increases. In addition, in a vertical rolling mill, due to the increase in size, the installation positions of the workpiece and the serration plate are raised, and the workability also decreases.

[0009] In view of such problems, an object of the present invention is to provide an NC rolling mill that can be miniaturized in an NC rolling mill for rough machining and finish machining of a workpiece.

[0010] Means for Solving the Problems

[0011] In order to solve the above problems, a representative structure of the NC rolling machine of the present invention is that it rolls a gear shape on a workpiece, and is characterized in that the NC rolling machine includes: a pair of first hobbing plates for rough machining, the pair of first hobbing plates facing each other; a pair of second hobbing plates for finish machining, the pair of second hobbing plates being arranged adjacent to and in parallel with the pair of first hobbing plates, and the pair of second hobbing plates facing each other; two rack drive mechanisms that move one first hobbing plate and the second hobbing plate and the other first hobbing plate and the second hobbing plate in the parallel direction and in opposite directions; a workpiece rotation mechanism that rotates the workpiece between the pair of first hobbing plates and the pair of second hobbing plates; a headstock drive mechanism and a tailstock drive mechanism that support both ends of the workpiece in a rotatable manner and displace the workpiece; and a numerical control unit that controls the operations of the rack drive mechanism, the workpiece rotation mechanism, the headstock drive mechanism, and the tailstock drive mechanism. The numerical control unit controls the headstock drive mechanism and the tailstock drive mechanism to support the workpiece between the pair of first hobbing plates. The numerical control unit controls the workpiece rotation mechanism and the rack drive mechanism to rough-machine the workpiece using the pair of first hobbing plates. The numerical control unit controls the headstock drive mechanism and the tailstock drive mechanism to displace the rough-machined workpiece between the pair of second hobbing plates. The numerical control unit controls the workpiece rotation mechanism and the rack drive mechanism to finish-machine the workpiece using the pair of second hobbing plates.

[0012] Preferably, the pair of first hobbing plates and the pair of second hobbing plates have retracting teeth formed at positions where the workpiece is displaced.

[0013] Preferably, the NC rolling machine includes two OPD adjustment mechanisms that move the pair of first hobbing plates and the pair of second hobbing plates relative to each other in the approaching and separating direction orthogonal to the parallel direction. The numerical control unit controls the operation of the OPD adjustment mechanism after the rough machining of the workpiece by the pair of first hobbing plates to widen the intervals of the pair of first hobbing plates and the pair of second hobbing plates. The numerical control unit controls the headstock drive mechanism and the tailstock drive mechanism to displace the workpiece between the pair of second hobbing plates. The numerical control unit controls the operation of the OPD adjustment mechanism to narrow the intervals of the pair of first hobbing plates and the pair of second hobbing plates, thereby clamping the workpiece using the pair of second hobbing plates.

[0014] Effects of the Invention

[0015] According to the present invention, it is possible to provide an NC rolling machine that can be miniaturized in an NC rolling machine for rough machining and finish machining of a workpiece. Description of the Drawings

[0016] Figure 1 It is a perspective view showing an outline of the structure of the NC rolling machine according to the embodiment of the present invention.

[0017] Figure 2 is a diagram showing Figure 1 the main parts of the NC rolling mill.

[0018] Figure 3 is Figure 1 the functional block diagram of the NC rolling mill.

[0019] Figure 4 is a diagram showing Figure 2 the first and second gear hobbing plates.

[0020] Figure 5 is a diagram showing Figure 1 the flow chart of the operation of the NC rolling mill.

[0021] Figure 6 is a diagram showing the situation of rough machining of the workpiece.

[0022] Figure 7 is a diagram showing the situation of fine machining of the workpiece by shifting the workpiece after rough machining.

[0023] Explanation of reference numerals

[0024] 100, NC rolling mill; 102, workpiece; 104a, 104b, first gear hobbing plate; 105a, 105b, second gear hobbing plate; 106a, 106b, rack driving mechanism; 108a, 108b, OPD adjusting mechanism; 110, workpiece rotating mechanism; 112, headstock driving mechanism; 114, tailstock driving mechanism; 116a, 116b, main body; 118a, 118b, 126a, 126b, ball screw; 120a, 120b, 128a, 128b, 138, 141, servo motor; 122a, 122b, moving block; 124a, 124b, table; 130a, 130b, wedge mechanism, 132a, 132b, wedge; 134a, 134b, stopper; 136a, 136b, teeth of the first gear hobbing plate; 137a, 137b, teeth of the second gear hobbing plate; 140, tailstock; 142, control device; 144, input device; 146, servo motor for each axis; 148, numerical control unit; 150, servo control unit; 152, storage unit; 154, machining program; 156, workpiece measuring unit; 158, PMC ladder diagram; 160, machine control unit; 162, various machines; 164a, 164b, lower end portions of the teeth of the first gear hobbing plate; 165a, 165b, lower end portions of the teeth of the second gear hobbing plate; 166a, 166b, upper end portions of the teeth of the first gear hobbing plate; 167a, 167b, upper end portions of the teeth of the second gear hobbing plate; 168a, 168b, retracting teeth of the first gear hobbing plate; 169a, 169b, retracting teeth of the second gear hobbing plate. Detailed Embodiments

[0025] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the appended drawings. The dimensions, materials, other specific numerical values, etc. shown in this embodiment are merely examples for facilitating understanding of the invention, and do not limit the present invention except in the case of special instructions. In addition, in this specification and the drawings, elements having substantially the same function and structure are denoted by the same reference numerals, and repeated descriptions are omitted. Further, illustrations of elements not directly related to the present invention are omitted.

[0026] Figure 1 is a perspective view showing a schematic structure of an NC rolling mill 100 according to an embodiment of the present invention.

[0027] Figure 2 is showing Figure 1 a main part of the NC rolling mill 100. The NC rolling mill 100 is a machine tool for rolling a workpiece (workpiece 102) shown in Figure 2 . The workpiece 102 is, for example, a shaft-like member such as a shaft.

[0028] The NC rolling mill 100 includes Figure 2 a pair of first gear hobbing plates 104a and 104b and a pair of second gear hobbing plates 105a and 105b shown in. The first gear hobbing plates 104a and 104b are gear hobbing plates for rough machining that face each other. The second gear hobbing plates 105a and 105b are gear hobbing plates for finish machining that are arranged adjacent to and parallel with the first gear hobbing plates 104a and 104b (see Figure 6 and Figure 7 ) and face each other.

[0029] As Figure 1 shown, the NC rolling mill 100 is an example of a vertical rolling mill. The NC rolling mill 100 includes two rack drive mechanisms 106a and 106b, two OPD (Overpin Diameter) adjustment mechanisms 108a and 108b, a workpiece rotation mechanism 110, a headstock drive mechanism 112, and a tailstock drive mechanism 114, and each of these drive mechanisms is controlled numerically. Therefore, Figure 1 the NC rolling mill 100 shown in is a 7-axis rolling mill. In addition, one of the headstock drive mechanism 112 and the tailstock drive mechanism 114 may not be NC controlled but a hydraulic or pneumatic cylinder, and in this case, it becomes a 6-axis NC control.

[0030] As Figure 2As shown, the rack drive mechanisms 106a and 106b face each other. In addition, the workpiece 102 is located between the rack drive mechanisms 106a and 106b. Moreover, OPD adjustment mechanisms 108a and 108b that face each other with the workpiece 102 interposed therebetween are disposed between the rack drive mechanisms 106a and 106b and the workpiece 102.

[0031] As Figure 2 shown, the rack drive mechanisms 106a and 106b each have a pair of ball screws 118a and 118b disposed inside a pair of columnar bodies 116a and 116b. A pair of moving blocks 122a and 122b are movably mounted on the ball screws 118a and 118b.

[0032] Servo motors 120a and 120b are driven by being supplied with power, and rotate the ball screws 118a and 118b as independent shafts, respectively. As a result, the rack drive mechanisms 106a and 106b rotate the ball screws 118a and 118b by driving the servo motors 120a and 120b, so that the moving blocks 122a and 122b can move toward each other in parallel and in opposite directions. The downward direction of the X-axis, which is the moving axis of the servo motor 120a, is positive, and the upward direction of the Y-axis, which is the moving axis of the servo motor 120b, is positive.

[0033] The OPD adjustment mechanisms 108a and 108b have Figure 2 a pair of tables 124a and 124b as shown. The tables 124a and 124b are fixed to the moving blocks 122a and 122b of the rack drive members 106a and 106b. Moreover, the OPD adjustment mechanisms 108a and 108b have a pair of ball screws 126a and 126b, a pair of servo motors 128a and 128b (U-axis, V-axis), and a pair of wedge mechanisms 130a and 130b.

[0034] The wedge mechanisms 130a and 130b each include a wedge 132a and 132b and a stopper 134a and 134b, and these members are combined with each other in such a way as to produce a wedge action (orthogonal transformation in the moving direction). For example, as Figure 1 shown, the first gear hobbing plate 104a and the second gear hobbing plate 105a are fixed to the stopper 134a and are arranged adjacent to each other in parallel. In addition, the first gear hobbing plate 104b and the second gear hobbing plate 105b are fixed to the stopper 134b and are arranged adjacent to each other in parallel.

[0035] In this way, the first gear hobbing plate 104a and the second gear hobbing plate 105a are fixed to the table 124a by means of the wedge mechanism 130a. The first gear hobbing plate 104b and the second gear hobbing plate 105b are fixed to the table 124b by means of the wedge mechanism 130b.

[0036] Wedges 132a and 132b are connected to ball screws 126a and 126b. Therefore, when servo motors 128a and 128b rotate ball screws 126a and 126b as independent axes respectively, wedges 132a and 132b can move in the vertical direction as shown by arrows A and B. Thereby, stoppers 134a and 134b can move in the horizontal direction as shown by arrows C and D.

[0037] Thereby, OPD adjustment mechanisms 108a and 108b can move the first gear plates 104a and the second gear plates 105a fixed to stopper 134a and the first gear plates 104b and the second gear plates 105b fixed to stopper 134b in the approaching and separating directions. The approaching and separating directions refer to the directions in which the first gear plates 104a and 104b and the second gear plates 105a and 105b approach and separate while maintaining a relative state, and are directions orthogonal to the above parallel directions of the rack drive mechanisms 106a and 106b. Therefore, OPD adjustment mechanisms 108a and 108b can change the distance between the first gear plates 104a and 104b and the distance between the second gear plates 105a and 105b.

[0038] In addition, the first gear plates 104a and 104b have a plurality of teeth 136a and 136b on the surfaces facing the workpiece 102. Moreover, the second gear plates 105a and 105b have a plurality of teeth 137a and 137b on the surfaces facing the workpiece 102.

[0039] Rack drive mechanisms 106a and 106b move the first gear plates 104a and 104b and the second gear plates 105a and 105b in the parallel directions and in opposite directions to each other, and reciprocate them. Thereby, rack drive mechanisms 106a and 106b can roll the workpiece 102 while pressing the teeth 136a and 136b of the first gear plates 104a and 104b against the outer peripheral surface of the workpiece 102 to perform rough machining on the workpiece 102, which will be described in detail later. In addition, Figure 2 shows a state before the workpiece 102 is supported between the first gear plates 104a and 104b and the teeth 136a and 136b of the first gear plates 104a and 104b are pressed against the outer peripheral surface of the workpiece 102.

[0040] Moreover, rack drive mechanisms 106a and 106b can roll the workpiece 102 while pressing the teeth 137a and 137 of the second gear plates 105a and 105b against the outer peripheral surface of the rough-machined workpiece 102 to perform finish machining on the workpiece 102 (described later).

[0041] Figure 1The workpiece rotation mechanism 110 shown has a servo motor (not shown), and the servo motor synchronizes the rotation of the workpiece 102 along the C axis, which is the rotation direction around the Z axis in the figure, with the vertical movement of the first hobbing plates 104a and 104b and the second hobbing plates 105a and 105b by means of the rack drive mechanisms 106a and 106b.

[0042] The headstock drive mechanism 112 has a headstock (not shown) and a servo motor 138, and the headstock is supported so as to be movable along the Z-axis direction. The headstock drive mechanism 112 drives the headstock to move along the Z-axis direction, that is, the axial direction of the workpiece 102, and further supports the workpiece 102 in a rotatable manner.

[0043] The tailstock drive mechanism 114 has a tailstock 140 and a servo motor 141, and the tailstock 140 is supported so as to be movable along the W-axis direction in the figure. The tailstock 140 is arranged opposite to the headstock, and is moved along the axial direction of the workpiece 102 by means of the servo motor 141 and abuts against the workpiece 102. Thus, the headstock drive mechanism 112 and the tailstock drive mechanism 114 support both ends of the workpiece 102 in a rotatable manner and displace the workpiece 102 in the axial direction.

[0044] Figure 3 is Figure 1 a functional block diagram of the NC hobbing machine 100. The NC hobbing machine 100 includes a control device 142 and an input device 144. The control device 142 controls the operation of the NC hobbing machine 100.

[0045] The input device 144 inputs values obtained by measuring the shape of the workpiece 102 and various values set according to the processing specifications of the workpiece 102. As an example, the input device 144 sets the OPD target value (OPD target value W) of the workpiece 102, measures the position of the OPD of the workpiece 102 (OPD measurement position A) according to the processing specifications, and inputs the OPD measurement value P measured at the OPD measurement position A. Then, the input device 144 inputs the OPD measurement value P, the OPD target value W, and the OPD measurement position A to the control device 142.

[0046] The control device 142 includes a numerical control unit 148, a servo control unit 150, a storage unit 152, a machining program 154, a workpiece measurement unit 156, a PMC (Programmable Machine Controller) ladder diagram 158, and a machine control unit 160.

[0047] The numerical control unit 148 can perform multi-axis synchronous control. While constantly monitoring the load torque of each axis servo motor 146, it calculates the control amount of each axis servo motor 146 and inputs this control amount to the servo control unit 150, thereby controlling the operations of the rack drive mechanisms 106a, 106b, the OPD adjustment mechanisms 108a, 108b, and the workpiece rotation mechanism 110, and performing rolling processing on the workpiece 102 using the first gear hobbing plates 104a, 104b and the second gear hobbing plates 105a, 105b. The servo control unit 150 outputs the control amount output from the numerical control unit 148 as a drive signal to each axis servo motor 146.

[0048] The storage unit 152 stores the shape (number of teeth: even or odd) of the specification of the workpiece 102 and the rolling processing conditions (rolling speed, etc.). Moreover, the workpiece measurement unit 156 writes the OPD measurement value P, the OPD target value W, and the OPD measurement position A from the input device 144 into the storage unit 152. The machining program 154 is a program for the machining process during the rolling operation, and for example, an NC program can be exemplified.

[0049] The PMC ladder diagram 158 is built into the PC (Programmable Controller) of the control device 142 which is a CNC (Computer Numerical Control), and executes the sequential control of the machine tool. In addition, the PMC ladder diagram 158 exchanges signals with various machines 162 such as external devices that cannot directly exchange signals with the numerical control unit 148 using the sequential program made by the ladder diagram language, or uses the internal I / O to hand over signals of predetermined content with the numerical control unit 148. The machine control unit 160 controls various machines 162 based on the signals output from the PMC ladder diagram 158.

[0050] Figure 4 It is a diagram showing Figure 2 the first gear hobbing plate 104a and the second gear hobbing plate 105a. The teeth 136a of the first gear hobbing plate 104a for rough machining are provided with an inclination such that the tooth height gradually increases from the lower end portion 164a towards the vicinity of the upper end portion 166a as shown in the attached drawing, and a retraction tooth 168a with a lower tooth height is formed near the upper end portion 166a.

[0051] The teeth 137a of the second gear hobbing plate 105a for finish machining are hardly provided with an inclination. Therefore, the teeth 137a of the second gear hobbing plate 105a are formed such that the tooth height is substantially equal from the lower end portion 165a to the vicinity of the upper end portion 167a as shown in the attached drawing, and a retraction tooth 169a with a lower tooth height is formed near the upper end portion 167a.

[0052] In addition, as Figure 6 andFigure 7 As shown, the teeth 136b of the first gear hobbing plate 104b on the opposite side are provided with an inclination such that the tooth height gradually increases from the upper end portion 166b toward the lower end portion 164b, and a retracting tooth 168b with a relatively low tooth height is formed near the lower end portion 164b. In addition, the teeth 137b of the second gear hobbing plate 105b on the opposite side are almost not provided with an inclination. Therefore, the teeth 137b of the second gear hobbing plate 105b are formed such that the tooth height is substantially equal from the upper end portion 167b to the vicinity of the lower end portion 165b, and a retracting tooth 169b with a relatively low tooth height is formed near the lower end portion 165b.

[0053] Figure 5 It shows Figure 1 a flowchart of the operation of the NC rolling mill 100. Figure 6 It is a view showing a case where rough machining is performed on the workpiece 102. Figure 7 It is a view showing a case where the workpiece 102 after rough machining is displaced and finish machining is performed on the workpiece 102.

[0054] Here, as Figure 6 and Figure 7 shown, the NC rolling mill 100 divides the gear hobbing plates into those for rough machining (the first gear hobbing plates 104a and 104b) and those for finish machining (the second gear hobbing plates 105a and 105b). Therefore, in the NC rolling mill 100, the overall length of the gear hobbing plates (longitudinally in the Figure 1 structure) can be shortened (to approximately half), and thus miniaturization can be achieved.

[0055] The operation in the case of performing rough machining and finish machining on the workpiece 102 using such an NC rolling mill 100 will be described. First, in the NC rolling mill 100, the numerical control unit 148 controls the headstock drive mechanism 112 and the tailstock drive mechanism 114 (refer to Figure 1 ), and as Figure 2 and Figure 6 (a) shown, the workpiece 102 is supported between the first gear hobbing plates 104a and 104b (step S100). In addition, in Figure 6 (a), the workpiece 102, which is a round bar before rolling, is shown.

[0056] In addition, in step S100, the numerical control unit 148 controls the OPD adjustment mechanisms 108a and 108b to reduce the distances between the first gear hobbing plates 104a and 104b and between the second gear hobbing plates 105a and 105b, so as to press the teeth 136a and 136b of the first gear hobbing plates 104a and 104b against the outer peripheral surface of the workpiece 102.

[0057] Next, the numerical control unit 148 controls the workpiece rotation mechanism 110 and the rack drive mechanisms 106a and 106b, as Figure 6As shown in (b), the workpiece 102 is rough-processed by forward rolling (Japanese: forward rolling) using the first rolling tooth plates 104a and 104b (step S102). Figure 6 As shown by the arrows in (b), the rack drive mechanisms 106a and 106b respectively move the first tooth plate 104a and the second tooth plate 105a downward, and move the first tooth plate 104b and the second tooth plate 105b upward. In this way, the rack drive mechanisms 106a and 106b press the teeth 136a and 136b of the first tooth plates 104a and 104b against the outer peripheral surface of the workpiece 102 while rolling the workpiece 102, transferring the tooth shape on the surface of the tooth plates to the workpiece 102, thereby enabling rough processing of the workpiece 102. In addition, Figure 6 (b) shows the workpiece 102 after rough machining.

[0058] Next, the numerical control unit 148 controls the main shaft box drive mechanism 112 and the tail shaft drive mechanism 114 so that Figure 6 The workpiece 102 after rough machining between the first rolling tooth plates 104a and 104b shown in (b) is as shown in FIG. Figure 7 As shown by the arrow in (a), the second tooth plates 105a and 105b are shifted (step S104).

[0059] Here, Figure 6 The workpiece 102 after rough machining shown in (b) is located at the retreat tooth 168a (refer to Figure 4 ) and the retreat tooth 168b, the retreat tooth 168a is formed near the upper end 166a of the first tooth plate 104a, and the retreat tooth 168b is formed near the lower end 164b of the first tooth plate 104b. As described above, the tooth heights of the retreat teeth 168a of the first tooth plate 104a and the retreat teeth 168b of the first tooth plate 104b are reduced. Therefore, in Figure 6 A gap is generated between the workpiece 102 after rough machining shown in (b) and the first tooth rolling plates 104a and 104b.

[0060] Moreover, if Figure 7 As shown in (a), the rough-machined workpiece 102 shifted between the second tooth plates 105a and 105b in step S104 is located between the backing teeth 169a and 169b, and the backing teeth 169a are formed near the upper end 167a of the second tooth plate 105a, and the backing teeth 169b are formed near the lower end 165b of the second tooth plate 105b. As described above, the tooth heights of the backing teeth 169a of the second tooth plate 105a and the backing teeth 169b of the second tooth plate 105b become lower. Therefore, in Figure 7 A gap is generated between the roughly machined workpiece 102 after displacement shown in (a) and the second tooth plates 105a and 105b.

[0061] In this way, the retracted teeth 168a, 168b of the first tooth-rolling plates 104a, 104b and the retracted teeth 169a, 169b of the second tooth-rolling plates 105a, 105b are formed at positions that displace the workpiece 102. As a result, when the workpiece 102 is displaced in step S104, the workpiece 102 does not collide with the first tooth-rolling plates 104a, 104b and the second tooth-rolling plates 105a, 105b and is cut. Therefore, lateral cutting when the workpiece 102 is displaced can be prevented.

[0062] Here, the first toothed plates 104a, 104b for rough machining and the second toothed plates 105a, 105b for fine machining are installed in a phase-matched manner. In addition, in step S104, a gap is generated between the workpiece 102 after rough machining and the first toothed plates 104a, 104b, and the workpiece 102 is displaced in a state where the meshing between the retracted teeth 168a, 168b of the first toothed plates 104a, 104b and the teeth of the workpiece 102 remains (for example, the retracted teeth 168a, 168b and the teeth of the workpiece 102 are slightly separated to a degree that they do not disengage). As a result, when the workpiece 102 after rough machining is displaced between the second toothed plates 105a, 105b, no phase shift occurs, and therefore, phase matching is not required.

[0063] Next, the numerical control unit 148 controls the workpiece rotating mechanism 110 and the rack drive mechanisms 106a and 106b, as shown in FIG. Figure 7 As shown in (b), the workpiece 102 is finished by back rolling (Japanese: 复転造) using the second rolling tooth plates 105a and 105b (step S106). Figure 7 As shown by the arrows in (b), the rack drive mechanisms 106a and 106b respectively move the first tooth plate 104a and the second tooth plate 105a upward, and move the first tooth plate 104b and the second tooth plate 105b downward. In this way, the rack drive mechanisms 106a and 106b press the teeth 137a and 137b of the second tooth plates 105a and 105b against the outer peripheral surface of the workpiece 102 while rolling the workpiece 102, transferring the tooth shape on the surface of the tooth plate to the workpiece 102, thereby enabling the workpiece 102 to be finished. In addition, Figure 7 (b) shows the workpiece 102 after finishing.

[0064] As described above, according to the NC rolling machine 100 , it is possible to achieve downsizing and perform rough machining and finish machining on the workpiece 102 .

[0065] In addition, in the NC rolling machine 100, by forming the retracting teeth 168a and 168b of the first gear hobbing plates 104a and 104b and the retracting teeth 169a and 169b of the second gear hobbing plates 105a and 105b at positions where the workpiece 102 is displaced, lateral cutting during the displacement of the workpiece 102 is prevented, but it is not limited thereto.

[0066] As an example, after the rough machining of the workpiece 102 by the first gear hobbing plates 104a and 104b is completed, in step S104, the numerical control unit 148 first controls the operation of the OPD adjustment mechanisms 108a and 108b to increase the intervals between the first gear hobbing plates 104a and 104b and the second gear hobbing plates 105a and 105b. Then, the numerical control unit 148 controls the headstock drive mechanism 112 and the tailstock drive mechanism 114 to displace the workpiece 102 between the second gear hobbing plates 105a and 105b.

[0067] Next, the numerical control unit 148 controls the operation of the OPD adjustment mechanisms 108a and 108b again to decrease the intervals between the first gear hobbing plates 104a and 104b and the second gear hobbing plates 105a and 105b, thereby clamping the workpiece 102 by the second gear hobbing plates 105a and 105b. Thus, in step S106, finish machining based on backward rolling can be performed on the workpiece 102 by the second gear hobbing plates 105a and 105b.

[0068] In this way, when the workpiece 102 is displaced, lateral cutting in which the workpiece 102 collides with the first gear hobbing plates 104a and 104b and the second gear hobbing plates 105a and 105b and is cut can be prevented. As a result, it is not necessary to provide the retracting teeth 168a and 168b of the first gear hobbing plates 104a and 104b and the retracting teeth 169a and 169b of the second gear hobbing plates 105a and 105b, and thus the overall lengths of the first gear hobbing plates 104a and 104b and the second gear hobbing plates 105a and 105b can be further shortened.

[0069] As described above, the preferred embodiments of the present invention have been described with reference to the drawings, but it goes without saying that the present invention is not limited to this example. It is obvious that those skilled in the art can conceive of various modification examples or correction examples within the scope described in the claims, and these modification examples or correction examples naturally also belong to the technical scope of the present invention.

[0070] Industrial Applicability

[0071] The present invention can be used as an NC rolling machine for rolling the gear shape of a workpiece.

Claims

1. An NC rolling machine for rolling a workpiece into a gear shape, characterized in that: The NC rolling machine has: A pair of first tooth rolling plates for rough machining, the pair of first tooth rolling plates facing each other; A pair of second toothed plates for finishing, the pair of second toothed plates being arranged adjacent to the pair of first toothed plates in parallel, and the pair of second toothed plates being opposite to each other; Two rack drive mechanisms, the two rack drive mechanisms enable one of the first and second toothed plates to move in parallel and in opposite directions to the other of the first and second toothed plates; a workpiece rotating mechanism for rotating the workpiece between the pair of first tooth rolling plates and the pair of second tooth rolling plates; a headstock drive mechanism and a tail shaft drive mechanism, which support both ends of the workpiece in a manner that the workpiece can rotate and displace the workpiece; as well as a numerical control unit that controls the actions of the rack drive mechanism, the workpiece rotation mechanism, the headstock drive mechanism, and the tail shaft drive mechanism; The numerical control unit controls the headstock drive mechanism and the tail shaft drive mechanism to support the workpiece between the pair of first tooth rolling plates. The numerical control unit controls the workpiece rotating mechanism and the rack driving mechanism to perform rough processing on the workpiece using the pair of first tooth rolling plates. The numerical control unit controls the headstock drive mechanism and the tail shaft drive mechanism to shift the rough-machined workpiece between the pair of second tooth rolling plates. The numerical control unit controls the work rotating mechanism and the rack driving mechanism to perform finish machining on the work using the pair of second tooth rolling plates.

2. The NC rolling machine according to claim 1, characterized in that: The pair of first tooth-rolling plates and the pair of second tooth-rolling plates have retracted teeth formed at positions for displacing the workpiece.

3. The NC rolling machine according to claim 1, characterized in that: The NC rolling machine includes two OPD adjustment mechanisms, which move the pair of first tooth rolling plates and the pair of second tooth rolling plates relative to each other in a direction of approaching and moving away from each other orthogonal to the parallel direction. The numerical control unit controls the operation of the OPD adjustment mechanism to increase the interval between the pair of first gear rolling plates and the interval between the pair of second gear rolling plates after the pair of first gear rolling plates finish rough machining the workpiece. The numerical control unit controls the headstock drive mechanism and the tail shaft drive mechanism to shift the workpiece between the pair of second tooth rolling plates. The numerical control unit controls the operation of the OPD adjustment mechanism to reduce the interval between the pair of first tooth rolling plates and the interval between the pair of second tooth rolling plates, thereby clamping the workpiece by the pair of second tooth rolling plates.

Images