JP4159790B2 - Rack shaft processing equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for performing processing with a lathe on the basis of the processing position of the rack on a rod-shaped workpiece (referred to as “rack shaft” in this specification) in which a rack is processed at one place on a peripheral surface. .
[0002]
[Prior art]
An apparatus for providing a hob cutter for gear cutting on a tool post of a lathe and machining a gear on a work gripped by a main spindle of a lathe is known. In this type of apparatus, the hob, which is a relatively large tool, and its driving device must be mounted on the tool post, so that the mechanical structure becomes complicated and the apparatus becomes large. In addition, when rack processing is performed with this type of equipment, a mechanism for rotating and fixing the rotation axis of the hob cutter close to 90 degrees and a Y-axis feed mechanism for the tool post equipped with the hob cutter are required, resulting in a mechanical structure. As it becomes more complex and expensive, there is a limit to processing accuracy and processing capability.
[0003]
Therefore, when machining an axial rack on a bar, it is common to perform necessary machining with a lathe and then rack machining with a gear cutter.
[0004]
[Problems to be solved by the invention]
When machining a rack on a workpiece that has been pre-machined with a lathe, it is necessary to machine the rack on the basis of the lathe's machining surface, so a jig for accurately positioning and fixing the workpiece to the gear cutting machine is used. There is a hassle that it is necessary to prepare each of the workpieces having different dimensions.
[0005]
In view of this, an object of the present invention is to provide a versatile apparatus that makes it possible to perform post-processing on a lathe on a lathe using a work that has been processed as a rack by pre-processing.
[0006]
[Means for Solving the Problems]
A rack shaft machining apparatus according to the present invention, that is, a machining apparatus for a shaft workpiece 35 having a rack 36, and a lathe of a hollow spindle having a chuck 5 at its tip, and a lathe that grips the rear end of the workpiece and passes through the hollow hole of the spindle. A workpiece feeding device 1 for feeding the workpiece into the machining area, and a workpiece rotating device 3 and a phase adjusting device 2 arranged between the workpiece feeding device and the lathe. A friction body 18 that rotates the friction body 18 around the axis, an electric motor 27 that rotates the friction body when a workpiece is supplied, and stops by a detection signal of the detector 16 below, and an advance / retreat device 28 for the friction body 18. The phase matching device includes a phase matching piece 12 that is elastically pressed against the peripheral surface of a work that is rotationally driven by the work rotating device, and an advance / retreat device 15 for the phase matching piece. And a detector 16 for detecting a predetermined advancing end of the serial phasing piece, the chuck 5 of the lathe is provided with a gripping claws 30 forming the rack teeth 33a on the grip end.
[0007]
In order to perform accurate machining based on the axis of the workpiece, an outer peripheral gripping portion 30a for gripping the outer peripheral surface of the workpiece is provided along with the rack tooth profile 33a at the gripping end of the gripping claw 30. The rack tooth profile 33a at this time has a shape that leaves a gap of an allowable dimensional difference with the tooth surface of the work rack 36 when the outer peripheral gripping portion 30a comes into contact with the outer peripheral surface of the work.
[0008]
When the rack 36 processes the workpiece 35 processed on the tip side in the workpiece feeding direction, the workpiece rotating device 3 is arranged on the workpiece feeding device 1 side, and the phase matching device 2 is arranged on the lathe side. When the rack is arranged on the rear end side in the workpiece feeding direction, the arrangement of the workpiece rotating device 3 and the phase matching device 2 is reversed. In order to facilitate this setup change, it is preferable that the work rotating device 3 and the phase aligning device 2 are provided on the same machine base frame 37 so that they can be attached and detached by a simple operation with fixing means having the same structure. The friction body 18 of the work rotating device is, for example, a friction roller or a friction belt.
[0009]
The rack shaft to be processed is supplied to the arrangement area of the workpiece rotating device 3 and the phase matching device 2 by the chute, loader or workpiece feeding device 1 before being fed into the lathe. When supply of the workpiece is detected by an operation signal of a sensor or loader provided at the receiving position, the friction body 18 and the phase matching piece 12 of the phase matching device advance toward the workpiece circumferential surface. Then, when the friction body 18 is driven to rotate and the work rotates so that the rack 36 is in a phase opposite to the phasing piece 12, the phasing piece that is in contact with the peripheral surface of the work is placed in the tooth groove of the work rack 36. The phase around the axis of the workpiece 35 is defined by being inserted or in contact with the tooth tip surface of the rack. When the phase of the workpiece is defined, the phase matching piece reaches the advancing end, so that the detector 16 generates a detection output and the rotation of the friction body 18 stops.
[0010]
In this state, the workpiece feeding device 1 grips the rear end of the workpiece 35, and after the friction body 18 and the phase matching piece of the phase matching device are retracted, the workpiece feeding device 1 moves forward and passes through the hollow hole of the main shaft. Into the lathe machining area. The workpiece feeding position in the axial direction may be determined by positioning the workpiece stopper 7 mounted on the turret 6 of the lathe on the spindle axis so that the tip of the workpiece to be fed comes into contact with the workpiece stopper.
[0011]
When the workpiece is fed to a predetermined axial position, the lathe chuck 5 is closed. A rack tooth 33a is formed at the gripping end of the gripping claw 30 facing the work rack 36, which meshes with the work rack 36, and finally determines the axial position of the work and the phase around the shaft. Stipulate.
[0012]
When only the rack tooth profile 33 a is formed at the grip end of the grip claw 30, the accuracy of the axis of the work gripped by the chuck 5 is defined by the processing accuracy of the rack 36. Since the accuracy of the rack is lower than the processing accuracy of the outer periphery of the workpiece, when it is desired to more accurately define the position of the axis of the workpiece, the outer peripheral gripping portion 30a together with the rack tooth profile 33a is provided at the tip of the gripping claw 30 provided with the rack tooth profile 33a. Is formed so that the workpiece is finally gripped by the outer periphery gripping portion 30a.
[0013]
In this case, a gap is generated between the gripped work rack and the gripping claw rack tooth profile 33a. However, the phase around the axis of the fed work is determined by the outer peripheral gripping part 30a. Immediately before gripping, the rack 36 and the rack tooth profile 33a of the gripping claw are corrected within the allowable dimension difference. This allowable dimensional difference is determined by the processing accuracy between the rack tooth profile 33a of the gripping claw 30 and the outer periphery gripping portion 30a.
[0014]
After gripping the shaft workpiece with the lathe chuck 5 in the above procedure and then machining the workpiece 35 with a turning tool or rotating tool mounted on the lathe tool post, accurate machining of the relative positional relationship with the rack 36 is possible. It can be performed.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram schematically showing the overall configuration, in which 1 is a workpiece feeding device, 2 is a phase matching device, 3 is a workpiece rotating device, 4 is a hollow spindle of a lathe, 5 is a chuck mounted on the spindle 4, Reference numeral 6 denotes a lathe turret, and reference numeral 7 denotes a work stopper attached to a tool mounting station of the turret 6.
[0016]
The workpiece feeding apparatus 1 includes a carrier 9 guided by a guide 8 in the axial direction (the main axis direction of the lathe), and a linear reciprocating drive mechanism such as a chain, a ball screw, and an air cylinder (not shown) is connected to the carrier. ing. The collet chuck 10 that grips the rear end of the workpiece is attached to the tip of a support bar 41 that extends from the carrier 9 toward the lathe. Although the intermediate portion is omitted in the figure, the length of the support bar is such that the collet chuck 10 reaches the rear end of the main spindle 4 of the lathe when the carrier 9 comes close to the work rotating device 3. is there.
[0017]
Details of the phase matching device 2 are shown in FIG. 3, and details of the workpiece rotating device 3 are shown in FIG. The phasing device 2 includes a pedestal 11 elongated in the axial direction of a shallow V-shaped cross-section for receiving a workpiece to be supplied, and a phasing piece 12 positioned on the upper side facing the cradle (see FIGS. 1 and 2). 3). The cradle 11 is supported by two guides 38 of the cylinder 13 so as to move up and down, and moves up after receiving a workpiece falling from a shooter (not shown) at the lowered position. This upward movement position is determined by a stopper bolt 14 above the cylinder 13. At the upward movement position of the cradle 11, the axis of the workpiece becomes a height that coincides with the axis of the main spindle 4 of the lathe. The phase matching piece 12 is fixed to the tip of a downward rod of the air cylinder 15, and a tooth shape is formed on the lower surface thereof. The tooth shape of the phase matching piece is a shape that meshes with a rack 36 formed on the workpiece. The phase matching piece 12 descends and comes into contact with the peripheral surface of the workpiece, and reaches the lowest descending position when engaged with the workpiece rack. The position of the lowest end is detected by the detector 16.
[0018]
The work rotating device 3 includes four lower rollers 18 that are arranged two by two at a predetermined distance in the axial direction, and four upper rollers 17 that face the lower rollers (see FIG. 1 and FIG. 1). 2). The lower roller 18 and the upper roller 17 are pivotally attached to the tip end portions of roller brackets 20 and 21 that are guided by two guide shafts 19 erected on the machine frame 37 so as to be movable up and down. The upper and lower roller brackets 20, 21 are connected by a pantograph mechanism in which three links 22, 23, 24 are connected in a Z shape. The center of the center link 23 is pivotally supported by a bracket 26 fixed to the guide shaft 19 by a fulcrum pin 25. Therefore, when the lower roller bracket 21 is moved up and down by a cylinder 28 installed below the machine base frame 37, The roller bracket 20 moves up and down symmetrically, and moves close to and away from the upper roller 17 and the lower roller 18. The fulcrum pin 25 is provided at the same height as the center of the main spindle 4 of the lathe. Therefore, when the upper and lower rollers 17 and 18 are moved in the proximity direction, the axis of the work gripped by the upper and lower rollers is the center of the main spindle of the lathe. become. An electric motor 27 is provided at the end of the lower roller bracket 21 opposite to the roller, and the two on the back side of the lower roller are rotationally driven via a belt 29. That is, two lower rollers 18 on the back side of the eight rollers that grip the workpiece serve as a friction wheel (friction body) that rotationally drives the workpiece. When the rollers 17 and 18 approach, the deformation allowance of the elastic friction material on the peripheral surface of the roller with the work of the elastic roller is erected on the lower roller bracket 21 and comes into contact with the upper surface of the shaft 39 penetrating the bracket 26 and the upper roller bracket 20. It is adjusted with the screw 40.
[0019]
The gripping portions of the three gripping claws 30, 31, 32 of the lathe chuck 5 are processed into an arc shape in accordance with the outer periphery of the workpiece. Of the three gripping claws, one of the gripping ends 30 is provided with a notch, and a block 33 having a rack tooth shape formed on the lower surface is fixed with bolts 34 (see FIGS. 4 and 5). The rack tooth profile 33a formed on the gripping end of the gripping claw 30 by this block is between the tooth surface of the workpiece rack when the arcuate surface (outer gripping portion) 30a of the gripping end abuts on the outer periphery of the workpiece. It is formed in a positional relationship that leaves a gap of an allowable dimensional difference.
[0020]
As shown in FIG. 1, the work 35 of the rack shaft supplied by the apparatus of this embodiment has a rack 36 formed on the front end side in the work insertion direction (therefore, the phase matching device 2 is the work rotation device 3. And the lathe). This work is supplied one by one from the work base extending obliquely in the front-rear direction of the paper surface of FIG. When the workpiece is supplied, the cradle 11 and the lower roller 18 move upward (by the cylinder 13 and the cylinder 28), and the upper roller 17 descends in synchronization with the upward movement operation, and the rear end side ( The workpiece feeding device side) is sandwiched between eight rollers. Next, air pressure is supplied to the cylinder 15, and the phase matching piece 12 is pressed against the peripheral surface of the workpiece. Then, the electric motor 27 rotates and the friction wheel 18 rotates to rotate the workpiece 35 at a low speed. When the work rack 36 is rotated to the upward position, the teeth of the phase matching piece 12 are inserted into the tooth grooves of the rack, and the phase matching piece 12 is lowered. The descending amount of the phase matching piece 12 becomes the largest when the work rack 36 is directed upward, and the descending position is detected by the detector 16 and the electric motor is stopped. Since the tooth tip surface of the rack 36 is often lower than the outer periphery of the cylinder of the workpiece, the phase matching piece 12 can detect the lowered position even if it is a flat plate having no tooth profile on its lower surface, and phase matching can be performed.
[0021]
In this state, the carrier 9 moves forward, the collet chuck 10 grips the rear end of the work 35, and then the phasing piece 12 moves up, and the cradle 11 and the lower roller 18 move down. The upper roller 17 moves up. Thereafter, the carrier 9 advances, and the work gripped by the collet chuck 10 is fed through the hollow hole of the hollow spindle 4 until the work tip comes into contact with the work stopper 7. The final positioning of the fed work is performed by a rack tooth profile 33a formed at the grip end of the grip claw 30 when the grip claw of the chuck 5 grips the work. That is, immediately before the workpiece is gripped, the rack tooth profile 33a and the workpiece rack 36 mesh with each other, and after matching the workpiece axial position and phase, the workpiece is gripped by the outer periphery gripping portion 30a.
[0022]
【The invention's effect】
According to the present invention, a bar-shaped workpiece in which a rack is processed in advance can be gripped by a lathe spindle chuck based on the rack, and the workpiece can be easily and efficiently processed on the lathe based on the tooth surface of the rack. become able to.
[Brief description of the drawings]
FIG. 1 is an explanatory view schematically showing the overall configuration of the present invention. FIG. 2 is a cross-sectional view taken along the line AA in FIG. FIG. 4 is a view showing the phase matching device in a visual view. FIG. 4 is a cross-sectional view of the chuck of the present invention. FIG. 5 is a cross-sectional view taken along the line CC in FIG.
DESCRIPTION OF SYMBOLS 1 Work feeding apparatus 2 Phase alignment apparatus 3 Work rotating apparatus 5 Chuck
12 Phase matching piece
15 cylinders
16 detector
18 Lower roller
27 Electric motor
33a Rack tooth profile
35 Rack shaft
36 racks

Claims (2)

A machining device for a shaft work (35) having a rack (36), which is a lathe of a hollow spindle having a chuck (5) at the tip, and machining the lathe through the hollow hole of the spindle by gripping the rear end of the work A workpiece feeding device (1) for feeding the workpiece into the area, and a workpiece rotating device (3) and a phase adjusting device (2) disposed between the workpiece feeding device and the lathe, and the workpiece rotation The apparatus includes a friction body (18) that rotates the workpiece around an axis, an electric motor (27) that rotates the friction body when the workpiece is supplied, and stops the detection by a detection signal of the detector (16) below, and the friction A phase adjusting piece (12) that is elastically pressed against the peripheral surface of the work that is rotationally driven by the work rotating device, and the phase adjusting piece. Advancing / retreating device (15) and a detector (16) for detecting a predetermined advancing end of the phase matching piece And the chuck (5) of the lathe includes a gripping claw (30) having a rack tooth shape (33a) formed at the gripping end. The gripping claw (30) includes an outer peripheral gripping portion (30a) that grips the outer peripheral surface of the workpiece together with the rack tooth profile (33a) at the grip end, and the outer peripheral gripping portion of the rack tooth profile is in contact with the outer peripheral surface of the workpiece. 2. The rack shaft machining apparatus according to claim 1, wherein the rack shaft machining device is formed in a shape that sometimes leaves a gap of an allowable dimensional difference between the tooth surface of the work rack (36).

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