JP2023113386A - Workpiece holding device and hobbing machine - Google Patents

Abstract

To improve processing accuracy by reducing influence of inclination of a core grid in a pull-in operation given to the processing accuracy.SOLUTION: A workpiece holding device 23 according to the present disclosure comprises: a core pushing device 25 which has a core grid 87, a pusher 91 that is attached to the core grid 87 and a float mechanism 85 that holds the core grid 87 in a tiltable manner; a main spindle device 23 which has a contact metal 63 on which a workpiece W is seated, an insertion hole 73 to which the core grid 87 is inserted and a pull-in device 45 that pulls in the core grid 87 inserted to the insertion hole 73 to the depth side of the insertion hole 73; and a movement device which moves the core pushing device 25 in a direction in parallel to the spindle of the main spindle device 23. The movement device moves the core pushing device 25 in a direction approaching the main spindle device 23. The pull-in device 45 pulls in the core grid 87 to make the workpiece W held between the pusher 91 and the contact metal 63. The float mechanism 85 allows tilting of the core grid 87 to the direction in parallel to the spindle in the pull-in operation by the pull-in device 45 to hold it.SELECTED DRAWING: Figure 8

Description

The present disclosure relates to a work clamping device that clamps a work between a core pressing device and a spindle device.

2. Description of the Related Art Conventionally, various proposals have been made for work holding devices for holding a work to be processed. For example, Patent Literature 1 below describes a work clamping device in which a work seated on a reference abutment of a rotary table is clamped by a abutment provided on a support. The work clamping device of Patent Document 1 moves the support in the axial direction to bring it closer to the rotary table, and inserts the rod attached to the support into the insertion hole provided in the slider of the rotary table. The work clamping device inserts and opens the collet provided around the rod into the work to center the work, and pulls in the slider with a power chuck to separate the contact and the reference contact attached to the rod. clamps the workpiece from the axial direction.

Japanese Utility Model Laid-Open No. 59-017137

In the work clamping device of the type described above, it is necessary to set the clamping force according to the processing load in order to maintain the processing accuracy when performing gear cutting on the work using a hob. For example, if the retraction force of the power chuck is strengthened in accordance with high-load machining, the tilt of the rod when retracted increases, and there is a risk that the center of rotation of the rod will deviate from the center of rotation of the turntable during machining. Specifically, the inclination of the rod occurs when the rod is pulled in due to the machining accuracy of the reference abutment, the end face of the work in contact with the abutment, the assembly accuracy of each member with respect to the center of rotation, and the like. As a result, the center of rotation of the rod may shift, which may reduce the machining accuracy.

The present disclosure has been made in view of the above problems, and aims to provide a workpiece clamping device and a hobbing machine that can reduce the influence of the inclination of the mandrel in the pulling operation on the machining accuracy and improve the machining accuracy. aim.

In order to solve the above problems, the present specification provides a core pressing device having a core bar, a pusher attached to the core bar, and a float mechanism that holds the core bar so that it can tilt; a spindle device having a contact metal that allows the metal core to be inserted, an insertion hole into which the metal core is inserted, and a retracting device that retracts the metal core inserted into the insertion hole to the inner side of the insertion hole; a moving device that moves the core pushing device in a parallel direction, the moving device moving the core pushing device in a direction approaching the main shaft device, the retracting device retracting the core metal, and the Disclosed is a work clamping device, wherein the work is clamped between a pusher and the abutment, and the float mechanism allows and holds the mandrel to tilt in a direction parallel to the main axis during the retraction operation of the retraction device. do.
The contents of the present disclosure are extremely effective not only when implemented as a work clamping device, but also when implemented as a hobbing machine equipped with a work clamping device.

According to the work clamping device and the hobbing machine of the present disclosure, the core pressing device tiltably holds the core bar and the pusher by means of the float mechanism. When the mandrel is pulled in by the retracting device in response to holding of the work, a force for holding the work is applied to the pusher and the abutment. For example, when the retracting force of the retracting device is increased in order to cope with a high load during processing, the core metal and the pusher are tilted with respect to the main body of the core pressing device by the float mechanism. Therefore, since the core pressing device does not tilt as a whole, it is possible to prevent the center of rotation from deviating relative to the main shaft of the main spindle device during the machining operation. As a result, it is possible to improve the processing accuracy.

The perspective view of the hob module concerning a present Example. A block diagram of a hob module. Sectional drawing of a core pushing device and a spindle device. FIG. 8 is a cross-sectional view cut along the II line shown in FIG. 7; Sectional drawing of a core pushing apparatus. Sectional view of the core pressing device and the spindle device at the work centering position. FIG. 4 is a cross-sectional view of the core pressing device and the spindle device when the hydraulic cylinder for core pressing is operated; FIG. 4 is a cross-sectional view of the core pressing device and the spindle device when the hydraulic cylinder for the spindle is operated;

A hob module, which is an embodiment embodying the hobbing machine of the present disclosure, will be described below with reference to the drawings. FIG. 1 shows a perspective view of the hob module 10 of this embodiment. FIG. 1 shows a state in which an exterior cover (not shown) of the hob module 10 is removed. FIG. 2 shows a block diagram of the hob module 10. As shown in FIG. In the following description, as shown in FIG. 1, the direction along the main shaft 11 of the main shaft device 23 is the Z-axis direction, and the direction perpendicular to the Z-axis direction, which is the longitudinal direction of the device, is the X-axis direction. A direction perpendicular to the axial direction and the Z-axis direction will be referred to as the Y-axis direction (horizontal direction). The X-axis direction and the Y-axis direction are directions parallel to the installation surface of the hob module 10, for example.

The hob module 10 is installed, for example, as one of a plurality of modules arranged in the Y-axis direction. A system that includes a plurality of modules including the hob module 10 (hereinafter referred to as a machine tool system) executes machining of a workpiece by, for example, a plurality of modules arranged in the Y-axis direction. The machine tool system includes a workpiece transfer robot 15 that moves in the Y-axis direction along a slide rail 13 provided on the front surface of each module. The workpiece transfer robot 15 is a multi-joint robot that transfers a workpiece to each module including the hob module 10, moves in the Y-axis direction, and transfers the workpiece from the module in the previous process to the module in the subsequent process. transport.

As shown in FIGS. 1 and 2, the hob module 10 includes a base 21, a spindle device 23, a core pushing device 25, a core pushing moving device 27, a hob 29, a hob driving device 31, a control panel 33, an operating panel 35, a control A device 37 and the like are provided. The hob module 10 is, for example, a modularized hobbing machine, and performs gear cutting on a work with a hob 29 . The base 21 has a substantially rectangular parallelepiped shape that is long in the X-axis direction and has a predetermined thickness in the Z-axis direction. The slide rail 13 described above is provided on the front surface of the base 21 . A bed 39 is provided on the base 21 . The bed 39 is slidable in the X-axis direction with respect to the base 21 by a plurality of wheels 38 . Each device such as the spindle device 23, the core pressing device 25, the core pressing moving device 27, the hob 29, the hob driving device 31, the control panel 33, the operation panel 35, the control device 37, etc. is provided on the base 21, and the base 21 It is possible to slide together with

The main shaft device 23 extends along the main shaft 11 and has a support 63 (see FIG. 3) on which the workpiece W (see FIG. 3) is seated. The spindle device 23 includes a spindle motor 41 and an encoder 43.
etc. The main shaft device 23 rotates the work W around the main shaft 11 by controlling the rotation of the main shaft motor 41 under the control of the control device 37 . The encoder 43 outputs information on the rotational position of the spindle motor 41 to the control device 37 . Thereby, the control device 37 can control the rotation speed, acceleration, etc. of the spindle device 23 .

The core pressing device 25 is supported by a core pressing moving device 27 at a position above the spindle device 23 . The core pushing device 25 moves in the Z-axis direction along the main shaft 11 based on the driving of the core pushing moving device 27 . The core pushing device 25 holds the work W (see FIG. 3) between itself and the spindle device 23 and rotates around the spindle 11 . Details of the spindle device 23, the core pressing device 25, and the core pressing moving device 27 will be described later.

The hob 29 is, for example, a cutting tool having a cylindrical shape whose axial direction is the Y-axis direction, and which has a blade portion for performing gear cutting on the outer periphery. The hob driving device 31 includes a hob motor 31A (see FIG. 2) that rotates the hob 29 around a B-axis 51 parallel to the Y-axis direction. The hob driving device 31 also includes an X-axis slide mechanism 31B that changes the position of the hob 29 in the X-axis direction, and a Z-axis slide mechanism 31C that changes the position of the hob 29 in the Z-axis direction. The control device 37 controls, for example, the hob drive device 31 to change the rotation speed and position of the hob 29, and the rotating hob 29 is moved to the work W clamped by the spindle device 23 and the core pushing device 25. Execute gear cutting by applying.

The control panel 33 is provided behind the hob module 10 and is provided with a breaker or the like for switching power supply from the power supply to each device of the hob module 10 . The operation panel 35 is a user interface, and is provided, for example, on the front surface of an exterior cover (not shown) of the hob module 10, and includes a touch panel, operation switches, and the like.

The control device 37 is a processing device including a CPU 53 and mainly composed of a computer. The control device 37 is electrically connected to each device (the spindle motor 41, the hob motor 31A, etc.) of the hob module 10 via a drive circuit 55, and is capable of controlling the operation of each device. The drive circuit 55 is, for example, an amplifier circuit or the like that controls power supply to the spindle motor 41 or the like. The control device 37 also includes a storage device 57 . The storage device 57 includes, for example, RAM, ROM, flash memory, hard disk, and the like. The storage device 57 stores various control data D1.

The control data D1 includes, for example, a program for controlling the operation of the spindle device 23, the tailstock moving device 27, and the hob driving device 31, the type of work W to be produced, the position of the hob 29 with respect to the work W during work, and other data. It is The program referred to here is, for example, a sequence control program (ladder circuit), an NC program, or the like. Further, the control data D1 stores a control program for controlling the gripping operation of the workpiece W by the main shaft device 23 and the core pushing moving device 27, which will be described later. The control device 37 controls the operation of each device by causing the CPU 53 to execute the program of the control data D1. In the following description, the fact that the control device 37 executes the program of the control data D1 to control each device may be simply referred to as the device name. For example, "the control device 37 controls the spindle motor 41 of the spindle device 23" means "the control device 37 executes the program of the control data D1 by the CPU 53 and controls the spindle motor 41 via the drive circuit 55." means "to do".

The control device 37 performs gear cutting on the workpiece W by controlling each device with the above configuration. For example, when the workpiece W is set on the abutment 63 (see FIG. 3) of the spindle device 23 by the workpiece transfer robot 15, the control device 37 controls the core pressing moving device 27 to lower the core pressing device 25. , the spindle device 23 and the core pressing device 25 hold the workpiece W. The control device 37 controls the spindle motor 41 to rotate the work W, and the hob driving device 31 causes the hob 29 to rotate and apply the hob 29 to the work W to perform machining. When the machining is completed, the control device 37 controls the core pressing moving device 27 to raise the core pressing device 25 . The workpiece conveying robot 15 receives the workpiece W after machining from the spindle device 23 and conveys the workpiece W to a module or the like in a post-process. Thereby, desired machining can be performed on the workpiece W by a plurality of modules.

(Regarding Spindle Device 23 and Core Pushing Device 25)
Next, details of the spindle device 23 and the core pressing device 25 will be described. FIG. 3 shows a cross-sectional view of the core pushing device 25 and the spindle device 23 taken along a plane parallel to the Y-axis direction and the Z-axis direction. As shown in FIG. 3 , the spindle device 23 has a device main body 61 and a contact 63 fixed to the upper surface of the device main body 61 . The main shaft device 23 rotates the contact 63 and the workpiece W seated on the contact 63 about the main shaft 11 based on the rotation of the main shaft motor 41 provided in the device main body 61 . In the following description, the side closer to the main shaft 11 is called the inner side, and the side farther from the main shaft 11 is called the outer side in the direction orthogonal to the main shaft 11 .

A main shaft hydraulic cylinder 45 that functions as a drive source for the retraction device of this embodiment is provided in the device main body 61 . A shaft 65 is connected to the output rod of the main shaft hydraulic cylinder 45 . The shaft 65 advances and retreats along the main shaft 11 in the Z-axis direction in response to driving of the main shaft hydraulic cylinder 45 . A pair of tops 67 are provided at the upper end of the shaft 65 . A pair of tops 67 are attached to the upper end of the shaft 65 by pins 69 . The pair of tops 67 are arranged so as to face each other in a direction orthogonal to the main shaft 11, and are movable toward each other. A pair of tops 67 are arranged so that the convex portions face each other. The pair of tops 67 move in the Z-axis direction together with the shaft 65 based on the movement of the shaft 65 , that is, the drive of the main shaft hydraulic cylinder 45 . The pair of pieces 67 are biased upward by elastic members 71 provided on the outer circumference of the shaft 65 when, for example, the main shaft hydraulic cylinder 45 is not supplied with hydraulic oil and is not driven, and is positioned at the position shown in FIG. hereinafter referred to as the initial position). The elastic member 71 is, for example, a compression spring. The pair of tops 67 is pulled downward from the initial position shown in FIG. Accordingly, the main shaft hydraulic cylinder 45, shaft 65 and top 67 function as the retraction device of the present disclosure.

An insertion hole 73 for inserting a core metal 87 of a core pressing device 25, which will be described later, is provided at the center of the upper portion of the device main body 61 and the center of the contact metal 63. As shown in FIG. The insertion hole 73 is a hole formed along the main shaft 11 . A shaft hole 65A is formed in the center of the shaft 65. As shown in FIG. The shaft hole 65A is formed along the main shaft 11 and has an opening on the upper surface of the shaft 65. As shown in FIG. The bottom of the insertion hole 73 communicates with the opening of the shaft hole 65A. The insertion hole 73 widens outward in a direction perpendicular to the main shaft 11 at a portion that is the initial position of the top 67, and a recess for accommodating the top 67 is formed. Further, the hole diameter of the insertion hole 73 is shorter below the initial position of the top 67 . Therefore, when the pair of tops 67 are pulled inward, that is, downward, in the insertion hole 73 by driving the main shaft hydraulic cylinder 45, they are guided by the inner wall of the insertion hole 73 and move inward toward each other. The pair of tops 67 sandwich the engaging portion 87G (see FIG. 5) at the tip of the cored bar 87 with their convex portions from both sides in the direction orthogonal to the main shaft 11, and draw the cored bar 87 downward.

FIG. 4 shows a cross section taken along line II shown in FIG. 7, which will be described later. As shown in FIGS. 3 and 4, the metal member 63 is a metal member that is arranged around the insertion hole 73 and has an annular shape in plan view (viewed in the Z-axis direction). The center of the abutment 63 is arranged on the main shaft 11 . A groove 63A opening upward is formed in the contact metal 63. As shown in FIG. The groove 63A has an inner diameter that increases from bottom to top, and has an annular shape centered on the main shaft 11 in a plan view. The contact metal 63 is fixed to the upper end portion of the device main body portion 61 by a bolt 75 inserted into the bottom portion 63B of the groove 63A. It should be noted that the abutment 63 is changed according to the type of the work W. As shown in FIG. Therefore, the shape of the workpiece W and the contact metal 63 shown in FIG. 3 is an example.

A collet 77 is provided at the upper end of the insertion hole 73 and at a position corresponding to the center upper portion of the contact metal 63 . The collet 77 is provided with, for example, a plurality of slits along the direction parallel to the Z-axis direction. The collet 77 is pressed downward by an abutting member 109 (see FIG. 5) of the core pressing device 25, which will be described later, to be pushed open (spread) outward. When the collet 77 is opened, the work W seated on the contact metal 63 is positioned (centered) so that the center of the work W is on the spindle 11, and the work W is clamped. A collet elastic member 79 and a collet pusher 81 are provided at a position below the collet 77 which is a portion inserted into the contact metal 63 in the upper portion of the device main body 61 . The collet elastic member 79 is, for example, a compression spring, and upwardly urges the collet pusher 81 provided thereon. When the collet 77 is not pushed downward by the core pushing device 25 , the collet pusher 81 pushes the collet 77 upward by the force of the collet elastic member 79 to close the collet 77 . The collet 77 is in an unclamped state in which the workpiece W is released from being held in the closed state.

The work W is, for example, an annular member, and is placed on the contact metal 63 by the work transfer robot 15 (see FIG. 1). The workpiece W is placed, for example, on a portion of the contact metal 63 where the groove 63A is not formed, and is placed with a portion thereof inserted into the groove 63A. The outer shape of the work W is, for example, ten and several centimeters.

FIG. 5 shows an enlarged view of the core pushing device 25. As shown in FIG. As shown in FIGS. 3 and 5 , the core pressing device 25 includes a device main body 83 , a rotating body 84 , a float mechanism 85 , a metal core 87 , a pusher mounting member 89 and a pusher 91 . The device main body 83 moves in the Z-axis direction along the main shaft 11 based on the drive of the core pressing moving device 27 . The tail pressing moving device 27 includes a servomotor 93 and a tail pressing hydraulic cylinder 95 as a drive source for moving the device main body 83 (see FIG. 2). As shown in FIG. 1, the core pressing moving device 27 has a pair of Z-axis guide rails 27A extending in a direction parallel to the Z-axis direction, and a Z-axis slide 27B slidable relative to the Z-axis guide rails 27A. I have. A pair of Z-axis guide rails 27A are arranged in a direction parallel to the Z-axis direction with a predetermined gap between them in the X-axis direction, and hold the Z-axis slide 27B slidably in the Z-axis direction. A device body portion 83 of the core pressing device 25 is attached to the Z-axis slide 27B. The core pressing moving device 27, for example, transmits the rotational output of the servomotor 93 to the Z-axis slide 27B via a transmission mechanism (ball screw or the like), and moves the Z-axis slide 27B, that is, the core pressing device 25 in the Z-axis direction. move.

The core pressing moving device 27 is provided with an encoder 97 that outputs information on the rotational position of the servomotor 93 . The control device 37 can move the Z-axis slide 27B to any position in the Z-axis direction based on the rotational position information output from the encoder 97 . Note that the device for detecting the position of the Z-axis slide 27B is not limited to the encoder 97, and may be another device such as a linear scale. Further, the core pushing hydraulic cylinder 95 downwardly urges a rotating body 84 of a later-described tailing device 25 and downwardly urges a core bar 87 via the rotating body 84 . The core pressing hydraulic cylinder 95 urges the rotating body 84 and the core metal 87 downward along the Z-axis direction under the control of the control device 37 .

The rotating body 84 is rotatably attached to the device main body 83 via, for example, a bearing member 99 (ball bearing or the like), and rotates about the Z-axis direction. A float mechanism 85 is attached below the rotating body 84 . The float mechanism 85 has a support member 86 and a threaded member 88 . The support member 86 is fixed to the rotating body 84 by, for example, bolts 101 and rotates together with the rotating body 84 . The support member 86 is, for example, a metal member having a substantially circular shape when viewed from the Z-axis direction. A recess 86A is formed in the central portion of the support member 86 . The recess 86A is formed by recessing the support member 86 upward from below. A convex portion 87C of a metal core 87, which will be described later, is inserted into the concave portion 86A. The recess 86A is, for example, a substantially conical groove, and the center 86B of the bottom is arranged on the main shaft 11 (see FIG. 5). A tapered surface 86C is formed on the inner peripheral surface of the recess 86A. The tapered surface 86C is inclined at a predetermined angle, and is inclined upward from the outside toward the inside in the direction orthogonal to the main shaft 11 .

The core bar 87 has a base portion 87A and a rod portion 87B. The base portion 87A is, for example, a substantially disc-shaped member having a predetermined thickness in the Z-axis direction. The core bar 87 is tiltably held by the float mechanism 85 . A convex portion 87C is formed on the upper surface of the cored bar 87 . The convex portion 87C protrudes upward from the upper surface of the central portion of the base portion 87A. The convex portion 87C has, for example, a substantially circular shape when viewed from the Z-axis direction. The upper surface of the convex portion 87C is formed, for example, by a spherical surface 87D curved with a constant curvature (see the enlarged view of FIG. 5) and bulges upward. The supporting member 86 has the spherical surface 87D of the convex portion 87C inserted into the concave portion 86A, and supports the core metal 87 in a state where the tapered surface 86C is in contact with the spherical surface 87D. The center of the spherical surface 87D (apex of the convex portion 87C) 87E is arranged on the main shaft 11 in a state in which the core bar 87 is not tilted (see the enlarged view of FIG. 5). In other words, when the core metal 87 is not tilted, the spherical surface 87D has a circular shape centered on the main shaft 11 when viewed from the Z-axis direction, and the center 87E coincides with the center 86B of the recess 86A. (overlapping).

A through hole 87F is formed in the base portion 87A outside the protrusion 87C. The through hole 87F is formed through the base portion 87A along a direction parallel to the Z-axis direction. A threaded member 88 of the float mechanism 85 is inserted into the through hole 87F. The screwing member 88 is, for example, a bolt, and has a tip portion 88A screwed to the support member 86 and a head portion 88B housed in the through hole 87F. The threaded member 88 is not limited to a bolt, and may be another threaded member such as a screw.

The threaded member 88 is fixed in the through-hole 87F with a gap 105 provided between the head 88B in the Z-axis direction and the bottom of the through-hole 87F accommodating the head 88B. In other words, the core bar 87 is in a state in which the head portion 88B of the threaded member 88 is brought into contact with the bottom portion of the through hole 87F, that is, the state in which the threaded member 88 is slightly loosened from the normal tightened state. ing. For example, when the male thread provided at the tip portion 88A of the screwing member 88 is tightened against the female thread of the support member 86, a gap 105 is formed between the head portion 88B and the through hole 87F. , the shape and size of the portion of the through hole 87F that accommodates the head portion 88B are adjusted. The core metal 87 is tiltable with respect to the main shaft 11 within a predetermined angle range by contacting the spherical surface 87D with the tapered surface 86C and being held by the through hole 87F with the gap 105. As shown in FIG. In other words, the cored bar 87 is held in such a state that it rattles slightly with respect to the support member 86 . The tiltable angle of the core metal 87 with respect to the main shaft 11 is, for example, about 0.1 to 0.2 degrees.

The rod portion 87B is a substantially cylindrical member and extends downward from the lower surface of the center of the base portion 87A. When no external force is applied, the core bar 87 assumes the postures shown in FIGS. is placed in In this posture, the axial direction of the rod portion 87B is along the main shaft 11. As shown in FIG. That is, the rod portion 87B extends along the main shaft 11 from the base portion 87A when the cored bar 87 is not tilted.

An engaging portion 87G is formed at the tip of the rod portion 87B. The engaging portion 87G is formed at a position slightly returned from the tip of the rod portion 87B toward the base portion 87A (base end), and has a cylindrical shape with a smaller diameter than the other portions. For this reason, the rod portion 87B has an inwardly recessed portion formed on its outer periphery at the portion where the engaging portion 87G is formed. The engaging portion 87G is engaged with a pair of tops 67 of the spindle device 23 and pulled downward by the hydraulic cylinder 45 for the spindle.

The pusher mounting member 89 is mounted below the base portion 87A and around the base end portion of the rod portion 87B. The pusher mounting member 89 is fixed to the base portion 87A by bolts 107 and tilts together with the cored bar 87 . A contact member 109 is provided at the central portion of the pusher mounting member 89 . The contact member 109 is, for example, a substantially cylindrical member that covers the outer periphery of the rod portion 87B and has a bottom portion downward. A bottom portion of the contact member 109 is formed with, for example, a hole 109B into which the rod portion 87B is inserted, and an annular collet convex portion 109A surrounding the hole 109B. The collet convex portion 109A is formed at a position close to the rod portion 87B and protrudes downward. An elastic member 111 is provided inside the contact member 109 . The elastic member 111 is, for example, a compression spring, and is provided on the outer circumference of the rod portion 87B. The elastic member 111 is compressed as the contact member 109 (collet projection 109A) is pushed upward, and urges the contact member 109 downward with elastic force. The core pushing device 25 pushes open the collet 77 of the spindle device 23 by the collet protrusion 109A.

The pusher mounting member 89 holds the pusher 91 with respect to the cored bar 87 . The pusher 91 is attached below the pusher attachment member 89 . The pusher 91 is, for example, an annular metal member (see FIG. 4), and is fixed to the pusher mounting member 89 by a screwing member (bolt or the like) 113 . Therefore, the pusher 91 can tilt with respect to the support member 86 together with the pusher mounting member 89 and the cored bar 87 . A contact surface 91A that contacts the work W is formed on the lower surface of the pusher 91 . The pusher 91 holds the workpiece W between the contact surface 91A and the contact 63. As shown in FIG.

(Pinching operation of workpiece W)
Next, the clamping operation of the workpiece W by the core pressing device 25 and the spindle device 23 will be described. For example, the machine tool system controls the workpiece transfer robot 15 to transfer the workpiece W from the previous process module to the hob module 10 when the machining of the workpiece W by the previous process module is completed. The work conveying robot 15 moves to the front of the hob module 10 and sets the work on the contact metal 63 of the spindle device 23 . The control device 37 of the hob module 10 moves the core pressing device 25 upward and extracts the rod portion 87B of the core metal 87 from the insertion hole 73 of the spindle device 23 before the work conveying robot 15 sets the work W. move to position. In this state, the work conveying robot 15 inserts the hole of the work W into the collet 77 of the spindle device 23 and places the work W on the contact metal 63 .

The control device 37 supplies air from the main shaft device 23 through a pipe 63C (see FIG. 3) provided in the abutment 63, for example, and the work W is set on the abutment 63 based on the air pressure (leakage amount). It is determined whether or not the seat is seated. When the control device 37 confirms that the work conveying robot 15 has retreated and detects that the work W has been set, the core pushing device 25 starts to descend. The control device 37 drives the servo motor 93 of the core pressing moving device 27 to lower the Z-axis slide 27B and lower the core pressing device 25 . As shown in FIG. 3 , the control device 37 inserts the tip of the rod portion 87B of the cored bar 87 into the insertion hole 73 of the spindle device 23 . In the state of FIG. 3, the hydraulic cylinder 95 for tail pressing is in a state in which hydraulic oil is not supplied, for example, and the output rod is pulled up to the upper end position. Further, the main shaft hydraulic cylinder 45 is, for example, in a state in which hydraulic oil is not supplied, and no pulling force is applied to the shaft 65 via the output rod. 65) is pulled up to the upper end position. In addition, the collet 77 is pushed upward by the collet elastic member 79 to be in an unclamped state (closed state).

The control device 37 continues to lower the core pushing device 25 even after the tip of the rod portion 87B is inserted into the insertion hole 73, and lowers the core pushing device 25 to the position shown in FIG. Then, the lowering of the core pressing device 25 is temporarily stopped. At the work centering position, the collet projection 109A of the contact member 109 comes into contact with the collet 77 from above, and the elastic force of the elastic member 111 pushes the collet 77 open (see the enlarged view of FIG. 6). As described above, the pusher mounting member 89 of this embodiment has the elastic member 111 and the abutting member 109 that is urged downward by the elastic member 111 when it comes into contact with the collet 77 and pushes the collet 77 open. . As a result, when the contact member 109 is brought into contact with the collet 77, the elastic member 111 is compressed and deformed in the Z-axis direction, and the elastic force pushes the collet protrusion 109A downward, thereby opening the collet 77. The work W can be appropriately positioned (centered) by the collet 77 .

On the other hand, the pusher 91 is arranged at a position slightly above the upper surface of the work W with a gap 115 between the contact surface 91A and the work W in the Z-axis direction (enlarged view of FIG. 6). reference). In other words, the control device 37 feedback-controls the servomotor 93 based on the position information of the encoder 97 so that the collet convex portion 109A contacts the collet 77 and the contact surface 91A does not contact the workpiece W. The descent of the pushing device 25 is stopped. Here, when the work W and the pusher 91 come into contact with each other, the work W is subjected to a frictional force between the pusher 91 and the abutment 63 and a nipping force between the pusher 91 and the abutment 63 . Therefore, movement of the workpiece W is restricted. Therefore, if the pusher 91 is brought into contact with the work W when the collet 77 is opened and the work W is clamped and centered at a predetermined position, the collet 77 will not open properly and the work W will be arranged at a desired position and orientation. Can not.

Therefore, in the control device 37 of the present disclosure, when the collet 77 is opened and clamped, the pusher 91 is kept out of contact with the workpiece W (see FIG. 6). The control device 37 of this embodiment controls the servomotor 93 of the core pressing moving device 27 to separate the contact surface 91A of the work W seated on the contact metal 63 and the pusher 91, and the contact member 109 is moved to the collet. The core pressing device 25 is stopped at the position where the collet 77 is pushed open by contacting the collet 77 . This prevents the movement of the work W from being hindered by the pusher 91 and allows the work W to follow the collet 77 and assume a desired position and posture. The desired position or posture here means, for example, a state where the center of the work W is on the spindle 11 and the plane of the work W is substantially parallel to the X-axis direction and the Y-axis direction (centered state).

Next, the control device 37 drives the tail pushing hydraulic cylinder 95 of the tail pushing moving device 27 while the servomotor 93 is stopped at the workpiece centering position shown in FIG. The core pressing device 25 and the spindle device 23 are in the state shown in FIG. The control device 37 , for example, supplies hydraulic oil to the tail pushing hydraulic cylinder 95 and urges the tail pushing device 25 downward by the tail pushing hydraulic cylinder 95 with a predetermined hydraulic pressure. In the state of FIG. 7, the control device 37 does not drive the main shaft hydraulic cylinder 45 and maintains the state in which the pulling force is not applied to the shaft 65 . The pusher 91 is urged downward according to the force applied from the hydraulic cylinder 95 for core pressing to bring the contact surface 91A into contact with the work W. As shown in FIG. The gap 115 in FIG. 6 described above is eliminated. The work W is sandwiched between the pusher 91 and the abutment 63 in the Z-axis direction. Since the pusher 91 is tiltably held by the float mechanism 85 via the pusher mounting member 89, the pusher 91 tilts when a reaction force is applied from the work W. As shown in FIG. The pusher 91 presses the work W while tilting following the position and posture of the work W positioned by the collet 77 . In other words, the pusher 91 is tilted by the float mechanism 85, so that it is possible to apply a clamping force to the work W arranged at a desired position and orientation without changing the position and orientation of the work W.

Next, the control device 37 drives the main shaft hydraulic cylinder 45 of the main shaft device 23 to lower the top 67 and retract the core bar 87 . As shown in FIG. 7, the hydraulic cylinder 9 for core pressing
5 is driven, the engaging portion 87G of the cored bar 87 is arranged between the pair of tops 67. As shown in FIG. As shown in FIG. 8, the control device 37 drives the main shaft hydraulic cylinder 45 to move the shaft 65 downward. For example, the control device 37 keeps the spindle motor 41 stopped at the workpiece centering position shown in FIG. Also, the main shaft hydraulic cylinder 45 is driven. That is, the control device 37 maintains the state of the spindle motor 41 and the tail pressing hydraulic cylinder 95 before driving the spindle hydraulic cylinder 45 and drives the spindle hydraulic cylinder 45 . The pair of tops 67 moves downward as the shaft 65 descends, and moves inward toward each other by following the insertion hole 73 . The pair of tops 67 descends while sandwiching the engaging portion 87G, thereby pulling the cored bar 87 downward, that is, pulling it into the insertion hole 73 to the far side.

Here, for example, when the load generated during gear cutting is high, it is difficult to firmly fix the work W only by the clamping force of the collet 77 and the pressing force of the hydraulic cylinder 95 for core pressing, and the position of the work W shifts. There is a risk that the machining accuracy will deteriorate due to the Therefore, the mandrel 87 is pulled in by a stronger force of the main shaft hydraulic cylinder 45, and the work W is clamped from both sides in the axial direction by the pusher 91 and the abutment 63. As shown in FIG. For example, the output of the main spindle hydraulic cylinder 45 is several tons, which is larger than the output of the tail pressing hydraulic cylinder 95 . However, if the output (pull-in force) of the main spindle hydraulic cylinder 45 is increased in accordance with the increase in the gear cutting load, the core metal 87 may be tilted. Specifically, depending on the machining accuracy of the upper surface and the lower surface of the work W, an inclination occurs between the work W and the contact 63 and between the work W and the pusher 91 due to the drawing operation. Alternatively, depending on the assembly error of each member involved in clamping the workpiece W, such as the contact metal 63, the pusher mounting member 89, the pusher 91, and the core metal 87, with respect to the main shaft 11, that is, the center of rotation, the member may tilt during the retraction operation. do. If the position and attitude of the core metal 87 were fixed with respect to the support member 86 , the inclination of the core metal 87 would be the inclination of the support member 86 and the rotating body 84 , and thus the entire core pushing device 25 . As a result, the center of rotation of the core pressing device 25 shifts, resulting in a decrease in machining accuracy.

Therefore, the core pressing device 25 of the present embodiment holds the core bar 87 tiltably by the float mechanism 85 . As a result, for example, in the example shown in FIG. 8, when the cored bar 87 is retracted, the cored bar 87, the pusher mounting member 89 attached to the cored bar 87, and the pusher 91 move slightly to the left with respect to the main shaft 11. only tilted. In this way, tilting of the core metal 87 caused by the pusher 91 is absorbed by the float mechanism 85, so that tilting of the core pushing device 25 as a whole with respect to the main shaft 11 can be eliminated. As a result, it is possible to secure a sufficient clamping force for the work W while reducing the displacement of the center of rotation of the core pushing device 25, so that the machining accuracy of the work W can be improved.

Here, as described above, as shown in FIG. 5, the support member 86 of the float mechanism 85 has a concave portion 86A having a tapered surface 86C. 87 is supported. The threaded member 88 of the float mechanism 85 is inserted into the through hole 87F of the core metal 87, and the tip portion 88A is screwed into the support member 86. In the screwed state, the head portion 88B and the head portion of the through hole 87F are connected. It is arranged with a gap 105 between it and the bottom of the portion that accommodates 88B. As a result, the core metal 87 is held so as to be slightly freely movable with respect to the threaded member 88 without being completely tightened and fixed by the threaded member 88 . By bringing the spherical surface 87D of the cored bar 87 into contact with the tapered surface 86C of the support member 86, the cored bar 87 can be smoothly tilted.

Further, the support member 86 has a recess 86A into which the projection 87C of the core metal 87 is inserted. The core metal 87 is supported by bringing the surface 86C into contact with the spherical surface 87D. A center 86B of the recess 86A is arranged on the main shaft 11 of the main shaft device 23 (see FIG. 5). According to this, by aligning the center 86B of the concave portion 86A with the position of the main shaft 11 and inserting the convex portion 87C into the concave portion 86A, the core metal 87 can be tilted about the main shaft 11. FIG.

Further, after the contact member 109 pushes the collet 77 open (FIG. 6), the control device 37 controls the core pressing hydraulic cylinder 95 to urge the core pressing device 25 downward toward the spindle device 23. The pusher 91 is brought into contact with the work W and the work W is sandwiched between the pusher 91 and the abutment 63 (FIG. 7). After the control device 37 controls the core pressing hydraulic cylinder 95 to clamp the workpiece W, the main shaft hydraulic cylinder 45 is driven to pull the core metal 87 into the insertion hole 73 . According to this, first, after the contact member 109 opens the collet 77 and clamps the work W, the pusher 91 and the work W are brought into contact with each other by the hydraulic cylinder 95 for core pressing. After that, the spindle hydraulic cylinder 45 is pulled with a stronger force. By filling the gap 105 between the pusher 91 and the work W before retracting with the main shaft hydraulic cylinder 45, collision between the work W and the pusher 91 due to the retraction of the main shaft hydraulic cylinder 45 can be avoided. Also, after the position of the workpiece W is temporarily determined by the collet 77 and the core pressing hydraulic cylinder 95, which have a weaker restricting force than the spindle hydraulic cylinder 45, positioning is performed by the strong force of the spindle hydraulic cylinder 45. , the workpiece W can be accurately positioned at a desired centering position.

7, the control device 37 controls the core pushing hydraulic cylinder 95 to urge the core pushing device 25 with a predetermined hydraulic pressure to sandwich the work W between the pusher 91 and the abutment 63. As shown in FIG. 8, the control device 37 executes the retraction by the main shaft hydraulic cylinder 45 while maintaining the hydraulic pressure of the tail pressing hydraulic cylinder 95 at the predetermined hydraulic pressure described above. By keeping the pressing force of the tail pressing hydraulic cylinder 95 constant when the spindle hydraulic cylinder 45 is retracted, it is possible to suppress the positional deviation of the work W during retraction.

Then, as shown in FIG. 8, the control device 37 drives the hob driving device 31 to move the hob 29 in a state in which the work W is sandwiched between the main shaft device 23 and the tail pushing device 25 by driving the hydraulic cylinder 45 for the main shaft. Gear cutting is performed on the workpiece W by rotating it. As a result, machining can be performed while suppressing deviation of the center of rotation of the core pressing device 25 with respect to the main shaft 11, so machining accuracy can be improved.

Incidentally, the hob module 10 is an example of a hobbing machine. The spindle device 23 and the core pressing device 25 are examples of a work clamping device. The core pressing moving device 27 is an example of a moving device and a workpiece clamping device. The main shaft hydraulic cylinder 45, the shaft 65, and the top 67 are an example of a retraction device. The servomotor 93 is an example of a motor. The core pressing hydraulic cylinder 95 is an example of a fluid pressure cylinder. The spherical surface 87D is an example of a curved surface.

As described above, the present embodiment described above has the following effects.
The float mechanism 85 of the hob module 10 , which is one aspect of the present application, allows and holds the core metal 87 with respect to the main shaft 11 during the retraction operation by the main shaft hydraulic cylinder 45 . With this structure, the float mechanism 85 absorbs the inclination of the core metal 87, and the deviation of the center of rotation of the core pushing device 25 (rotating body 84) from the main shaft 11 can be eliminated or minimized. As a result, the influence of the inclination of the cored bar 87 during the pull-in operation on the accuracy during subsequent machining can be reduced, and the machining accuracy can be improved.

In addition, the contents of the present disclosure are not limited to the above embodiments, and can be implemented in various modes with various modifications and improvements based on the knowledge of those skilled in the art.
For example, in the above embodiments, the hobbing machine of the present disclosure employs the hob module 10, which is a module incorporated in a machine tool system, but the present invention is not limited to this. The hobbing machine of the present disclosure may be a single unit. Further, the hobbing machine may be a device in which the work W is arranged manually by the user without being equipped with the work conveying robot 15 or the like. Further, the hobbing machine is not limited to the NC processing device, and may be configured without the control device 37 . In this case, the hobbing machine may be a device that drives the main shaft hydraulic cylinder 45, the servomotor 93, and the tail pressing hydraulic cylinder 95 by a predetermined amount of movement according to the user's button operation.
Further, the device for transferring the work to the hobbing machine is not limited to the articulated robot such as the work transfer robot 15, and may be, for example, a gantry type loader.
Further, the direction of the main shaft 11 of the main shaft device 23 is not limited to the vertical direction of the device, and may be the horizontal direction. That is, the hobbing machine of the present disclosure may be a horizontal hobbing machine.

The configurations of the spindle device 23 and core pressing device 25 in the above embodiment are examples. For example, the spindle device 23 does not have to include the collet 77 . Also, the core pressing device 25 does not have to include the pusher mounting member 89 . Further, the output of the tail pressing hydraulic cylinder 95 may be the same as or larger than the output of the main shaft hydraulic cylinder 45 .
Also, the configuration of the float mechanism 85 described above is an example. For example, in the above embodiments, the spherical surface 87D curved with a constant curvature is used as the curved surface of the present disclosure, but the present invention is not limited to this. The curved surface may be a curved surface with an elliptical cross section, or a surface that is curved multiple times. Also, contrary to the relationship described above, the metal core 87 may be formed with a concave portion and the support member 86 may be formed with a convex portion and brought into contact with each other. Further, the float mechanism 85 may have a configuration in which the core metal 87 is tiltably held by an elastic member such as a spring. The support member 86 has, for example, a hole into which the tip of the projection 87C of the core metal 87 is inserted, and a tapered surface 86C surrounding the hole. It may be configured to be supported by the tapered surface 86C.
Also, the center 86B of the recess 86A does not need to be arranged on the main shaft 11 of the main shaft device 23.
The motor of the present disclosure is not limited to the servomotor 93, and may be another motor such as a stepping motor.

Further, in the above embodiment, the axial direction of the rod portion 87B of the cored bar 87 is the direction along the main shaft 11 when the workpiece W is not clamped, but the present invention is not limited to this. For example, the axial direction of the rod portion 87B and the main shaft 11 may be shifted in the X-axis direction or the Y-axis direction.
Moreover, although the direction in which the core pressing device 25 is moved is the direction along the main shaft 11, it is not limited to this. The direction in which the core pressing device 25 is moved may be a direction forming a predetermined angle with the main shaft 11 and a direction approaching the main shaft device 23 . Alternatively, the direction in which the core pressing device 25 is moved may be parallel to the main shaft 11 and deviated from the main shaft 11 in the X-axis direction and the Y-axis direction.
Further, in the above embodiment, a hydraulic cylinder is adopted as the fluid pressure cylinder of the present disclosure, but the invention is not limited to this. The fluid pressure cylinder of the present disclosure may be a cylinder using other fluids such as an air cylinder. Further, the drive source for pushing the mandrel 87 by the core pushing moving device 27 and the drive source for the main shaft device 23 to pull in the mandrel 87 are not limited to hydraulic cylinders, and other drive sources such as actuators may be used.
In the above embodiment, the control device 37 drives the hydraulic cylinder 95 for core pressing (FIG. 7) and then drives the hydraulic cylinder 45 for the spindle (FIG. 8), but it is not limited to this. The control device 37 may drive the tail pressing hydraulic cylinder 95 and the spindle hydraulic cylinder 45 at the same time, or may drive the spindle hydraulic cylinder 45 prior to the tail pressing hydraulic cylinder 95 .
In addition, the control device 37 maintains the hydraulic pressure of the tail pressing hydraulic cylinder 95 at a predetermined hydraulic pressure in the retraction operation in which the spindle hydraulic cylinder 45 is driven. You can push it in. Similarly, the control device 37 stops the servomotor 93 in the retraction operation in which the main spindle hydraulic cylinder 45 is driven.
Further, the control device 37 may change the rotation position of the servomotor 93 in the pushing operation of the hydraulic cylinder 95 for core pressing.

10 hob module (hobbing machine), 23 spindle device (work clamping device), 25 tail pushing device, 27 tail pushing movement device (moving device, work clamping device), 29 hob, 37 control device, 45 hydraulic cylinder for main shaft (retraction device), 63 catch, 65 shaft (retraction device), 67 top (retraction device), 73 insertion hole, 77 collet, 85 float mechanism, 86 support member, 86A concave portion, 87 core metal, 87A base portion, 87B rod portion, 87C convex portion, 87D tapered surface, 87E through hole, 88 threaded member, 88A tip portion, 88B head portion, 89 pusher mounting member, 91 pusher, 93 servo motor (motor), 95 core pressing hydraulic cylinder (fluid pressure cylinder ), 105 gap, 109 contact member, 111 elastic member, W work.

Claims (8)

a core pressing device having a core bar, a pusher attached to the core bar, and a float mechanism that holds the core bar so that it can tilt;
a spindle device having an abutment for seating a work, an insertion hole for inserting the core metal, and a retracting device for retracting the core metal inserted into the insertion hole to the inner side of the insertion hole;
a moving device that moves the core pressing device in a direction parallel to the main shaft of the main shaft device;
with
The moving device
moving the core pressing device in a direction approaching the spindle device;
The retraction device is
pulling in the core bar to sandwich the workpiece between the pusher and the abutment bar;
The float mechanism is
A workpiece clamping device that holds the core bar while permitting tilting of the cored bar in a direction parallel to the main axis during a retraction operation by the retraction device. The core metal has
A curved surface is formed,
The float mechanism is
a support member having a tapered surface inclined at a predetermined angle and supporting the cored bar by bringing the tapered surface into contact with the curved surface of the cored bar;
A screwing member that is inserted into a through hole provided in the core metal, has a tip portion screwed to the support member, and is arranged with a gap between the head and the core metal in the screwed state. and,
The workpiece clamping device according to claim 1, comprising: The core bar is
Having a convex portion formed with the curved surface,
The support member is
The tapered surface is provided on the inner peripheral surface of the recess, and the tapered surface is brought into contact with the curved surface in a state in which the protrusion is inserted into the recess, so that the core metal is moved. support,
The center of the recess is
3. The workpiece clamping device according to claim 2, arranged on the spindle of said spindle device. The spindle device is
a collet that is provided on the outer periphery of the insertion hole and holds the work by opening and releases the work by closing;
The core bar is
a base held by the float mechanism;
a rod extending in one direction from the base;
has
The core pressing device
a pusher mounting member attached to the base side of the rod portion and holding the pusher with respect to the core bar;
The pusher mounting member is
an elastic member;
an abutting member that is biased by the elastic member when in contact with the collet and pushes the collet open;
The workpiece clamping device according to any one of claims 1 to 3, comprising: further comprising a control device that controls the retraction device and the movement device,
The moving device
having a motor,
The control device is
By controlling the motor, the core pushing device is stopped at a position where the work seated on the abutment is separated from the pusher and the abutment member comes into contact with the collet and pushes the collet open. 5. The workpiece clamping device according to claim 4. The moving device
having a hydraulic cylinder,
The control device is
After the collet is pushed open by the abutting member, the fluid pressure cylinder is controlled to urge the core pushing device in a direction approaching the main shaft device to bring the pusher into contact with the work, thereby causing the pusher and the Sandwiching the workpiece between the metals,
6. The apparatus according to claim 5, wherein after the work is sandwiched between the pusher and the abutment by controlling the fluid pressure cylinder, the retraction device is driven to retract the cored bar into the insertion hole. Work clamping device. The control device is
controlling the fluid pressure cylinder to bias the core pressing device with a predetermined fluid pressure to sandwich the work between the pusher and the abutment;
7. The workpiece clamping device according to claim 6, wherein in the retracting operation by said retracting device, retraction is performed while maintaining the fluid pressure of said fluid pressure cylinder at said predetermined fluid pressure. a workpiece clamping device according to any one of claims 1 to 7;
a hob that has a blade on its outer periphery and that rotates and applies the blade to the workpiece sandwiched by the workpiece sandwiching device in a state in which the core pushing device is retracted by the retracting device;
A hobbing machine.

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