JP2005034974A - Inner face machining method and device for hollow work - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make an inner face machining of hollow work performable with high accuracy. <P>SOLUTION: A cutter 13 is arranged in a differential case 11, and held from both sides by a pair of cutter drivers 15, 17 inserted in the inside from a side opposed to each other of an outer part of the differential case 11 through through-holes 11c, 11d. In this state, one inner face 11b of the differential case 11 is machined by rotating the cutter 13 while pressing the cutter 13 by one cutter driver 15, and the other inner face 11a of the differential case 11 is machined by rotating the cutter 13 while pressing the cutter 13 by the other cutter driver 17. Both cutter drivers 15, 17 apply a prescribed compression stress to the cutter 13 when the cutter 13 is held. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a hollow workpiece inner surface machining method and machining apparatus.

  As a hollow work, for example, a differential case in which a differential gear mechanism in an automobile is accommodated has an inner surface on which the back surface of the pinion and side gears constituting the Kia mechanism slides. By processing this sliding surface with high accuracy, the clearance between the inner surface of the differential case and the rear surface of the gear is reduced, and vibration and noise are reduced.

  FIG. 11 shows an inner surface processing apparatus for processing inner surfaces 1a and 1b on which the back surface of a pinion (not shown) of the differential case 1 slides. When processing the inner surfaces 1a and 1b of the differential case, a cutter 3 is disposed in the differential case 1, and the cutter 3 is held by a pair of cutter drivers 5 and 7 inserted into the differential case 1 from both the left and right sides in FIG. In this holding state, one cutter driver 5 (7) is rotated while pressing the cutter 3 toward the inner surface 1b (1a) on the other side.

In this case, it is conceivable to use, for example, a ball screw mechanism as a feed mechanism for moving both the cutter drivers 5 and 7 close to and away from the cutter 3. There is one.
Japanese Patent Laid-Open No. 11-77472

  In the apparatus for processing the inner surface of the hollow workpiece using the pair of cutter drivers described above, when pressing one cutter driver toward the cutter, the other cutter driver is released by the amount of pressing, and both cutters are released. The drivers provided individually in the driver are synchronized with each other. For this reason, there is a problem that the holding of the cutter becomes unstable and high-precision machining becomes difficult.

  Also, when the contact position of the cutter with the workpiece after use changes, or when the contact position of the cutter with the workpiece changes due to the difference in the type (size) of the workpiece, Position adjustment becomes complicated, resulting in a decrease in workability, and high-precision machining is difficult.

  In view of the above, an object of the present invention is to enable high-precision machining of the inner surface of a hollow workpiece.

  In order to achieve the above-mentioned object, the present invention is arranged such that a cutter is disposed in a hollow workpiece, and the cutter is held from both sides by a pair of cutter drivers that are inserted through through holes from opposite sides outside the hollow workpiece. An inner surface processing method for a hollow workpiece in which one of the opposing inner surfaces of the hollow workpiece is rotated by pressing the cutter with one of the pair of cutter drivers, and the cutter is held. In this case, the inner cutter of the hollow workpiece is such that both cutter drivers apply a predetermined compressive stress to the cutter.

  According to this invention, both cutter drivers are held in a state where a predetermined compressive stress is applied to the cutter, and the inner surface of the hollow workpiece is processed in this held state, so that the cutter can be held stably and high Accurate machining can be performed. Also, even if the cutter contact position changes due to wear or the like, the cutter driver moves in the direction of pressing the cutter by applying compressive stress, so the change in the cutter contact position with respect to the workpiece is absorbed. Complicated position adjustment of the cutter driver is unnecessary, so that workability can be prevented from being lowered and high-precision processing can be performed.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a front view showing an entire configuration of an inner surface machining apparatus for a hollow workpiece according to a first embodiment of the present invention. As the hollow work, here, a differential case 11 in which a differential gear mechanism in an automobile is accommodated is used, as described in the prior art.

  In this differential case 11, a cutter 13 is accommodated as shown in an enlarged view in FIG. The cutter 13 has a pair of cutter drivers 15 and 17 arranged so as to face each other with the tips of the cutter drivers 15 and 17 inserted into the holding holes 13a and 13b and held from both sides. The inner surfaces 11a and 11b facing each other are processed.

  The cutter drivers 15 and 17 are inserted into the differential case 11 through pinion shaft holes 11c and 11d as through holes into which pinion shafts that support the pinions are inserted. The cutter 13 is inserted into the inside of the rough hole 11 e provided in the differential case 11 in a state where the annular support groove 13 c is suspended and supported by the lower end support portion 19 a of the tool suspension mechanism 19. The lower end support portion 19a of the tool suspension mechanism 19 is formed in an annular shape and includes a bearing (not shown) on the inner surface thereof, and supports the cutter 13 in a rotatable manner.

  The cutter drivers 15 and 17 are rotated via spindle heads 23 and 24 by driving motors 21 and 22, respectively. Ball guide nuts 25 and 27 are provided below the spindle heads 23 and 24, and screw rods 29 and 31 are respectively screwed into the ball guide nuts 25 and 27 to constitute a ball screw mechanism. That is, the rotation of the screw rods 29 and 31 causes the spindle heads 23 and 24 to move toward and away from the differential case 11, and as a result, the cutter drivers 15 and 17 approach the differential case 11. Move in the direction of separation.

  As for each screw rod 29 and 31, the inner end part on the mutually opposing side is the rotation support parts 35 and 37 on the base frame 33, and the outer end part on the opposite side is the rotation support parts 39 and 41, respectively. It is rotatably supported.

  On the other hand, drive shafts 43 and 45 extending in parallel with the screw rods 29 and 31 are respectively installed below the screw rods 29 and 31 described above. The drive shaft 43 constitutes a first rotation axis, and the drive shaft 45 constitutes a second rotation axis.

  Among these, the outer end of the drive shaft 43 serving as the first rotating shaft is connected to a feed motor 47 as drive means. The feed motor 47 is attached to the base frame 33 via a motor mounting bracket 49.

  The opposite inner end sides of the drive shafts 43 and 45 are supported by the rotation support portions 51 and 52 on the support base 50 provided at the central portion on the base frame 33, and the opposite outer end sides are supported by the drive shafts 43 and 45. The rotation supports 57 and 59 on the bases 53 and 55 are rotatably supported, respectively.

  A power transmission unit 61 incorporating a gear or the like is installed on the support base 53 inside the rotation support unit 57 described above, and the driving force of the feed motor 47 is transmitted to the screw rod 29 via the power transmission unit 61. To do. On the other hand, a power transmission unit 63 incorporating a gear or the like is installed on the support base 55 inside the rotation support unit 59, and the driving force of the feed motor 47 is applied to the screw rod 31 via the power transmission unit 63. introduce.

  In addition, a brake unit 67 that restricts the rotation of the screw rod 31 is provided at the outer end portion of the screw rod 31 in a state of being installed on the support base 65 on the base frame 33. That is, the brake unit 67 constitutes a restricting means that restricts the movement of the cutter driver 17 by restricting the rotation of the screw rod 31.

  The drive shaft 43, the power transmission unit 61, the drive shaft 45, and the power transmission unit 63 described above constitute a power transmission mechanism.

  Further, on the support base 50 between the drive shafts 43 and 45, a clutch unit 69 is installed as a power connection / disconnection mechanism for connecting and disconnecting the drive shafts 43 and 45 to each other.

  Further, a differential case which is a hollow work is provided between the block 71 on which the rotation support portions 35 and 39 are installed on the base frame 33 and the block 73 on which the rotation support portions 37 and 41 are installed. A transport device 75 for transporting 11 in a direction perpendicular to the paper surface in FIG.

  Further, on the base frame 33 located on both sides of the conveying device 75, a pair of support posts 77, 79 indicated by a two-dot chain line is installed, and a support member spanned between the upper ends of the support posts 77, 79. The tool suspension mechanism 19 that supports the cutter 13 is provided at 81. The tool suspending mechanism 19 is moved up and down by the drive unit 82 on the support member 81 and is movable with respect to the support member 81 along the moving direction of the cutter driver 15, 17.

  Next, the operation procedure of the inner surface machining apparatus for a hollow workpiece according to the first embodiment will be described with reference to FIGS.

  (1) FIG. 2 shows an in-situ standby state in which each cutter drive 15, 17 is in a symmetrical position with a predetermined distance L about the differential case 11. In this state, it is possible to carry in / out the differential case 11 with respect to the machining position shown in FIG. 2 and to insert (lower) / return (up) the cutter 13 into the differential case 11.

  Note that the differential case 11 in FIG. 2 is supported by, for example, a support arm that extends upward from the transfer device 75.

  (2) In the state shown in FIG. 2, the clutch unit 69 is connected and the drive shafts 43 and 45 are connected to each other, and the brake unit 67 is opened and the rotation restriction of the screw rod 31 is released.

  In this state, as shown in FIG. 3, the tool suspension mechanism 19 is lowered and the cutter 13 is inserted into the differential case 11. At this time, the cutter 13 is in a neutral (center) position in the differential case 11. Thereafter, when the feed motor 47 is driven, the drive shafts 43 and 45 connected to each other by the clutch unit 69 rotate as a unit, and the screw rods 29 are connected via the power transmission units 61 and 63 along with this rotation. , 31 rotate in the same direction.

  As both screw rods 29 and 31 rotate in the same direction, the cutter drivers 15 and 17 move together while maintaining a predetermined distance L so that the cutter driver 17 approaches the differential case 11. By this movement, the cutter driver 17 is inserted into the differential case 11, and the tip thereof enters the holding hole 13 b of the cutter 13.

  (3) In the state of FIG. 3, the clutch unit 69 is disconnected to disconnect the drive shafts 43 and 45 from each other, and the rotation of the screw rod 31 is restricted by the brake unit 67. In this state, the feed motor 47 is driven in the opposite direction to rotate the screw rod 29 in the opposite direction, thereby moving the cutter driver 15 toward the differential case 11 as shown in FIG. The tip is inserted into the differential case 11 and the tip is inserted into the holding hole 13 a of the cutter 13.

  Further, from this state, the cutter driver 15 is advanced by driving the feed motor 47, and the cutter 13 is pressed toward the cutter driver 17. At this time, since the movement of the cutter driver 17 is restricted by the brake unit 67, a predetermined compressive stress (4900N) is applied to the cutter 13 between the two cutter drivers 15 and 17. Thereafter, the driving of the feed motor 47 is stopped while the compressive stress is applied to the cutter 13.

  (4) Next, in the state of FIG. 4, the clutch unit 69 is brought into the connected state, and the brake unit 67 is released to release the movement restriction of the cutter driver 17. At this time, the compressive stress is still applied to the cutter 13.

  In this state, both the cutter drivers 15 and 17 are rotated together with the cutter 13 through the spindle heads 23 and 24 by driving the motors 21 and 22, and the feed motor is driven so that the cutter driver 15 presses the cutter 13 in this rotated state. 47 is driven. Due to the movement of the cutter driver 15 accompanying the processing in the pressing direction, the cutter driver 17 also moves in the same direction as the cutter driver 15, whereby the inner surface 11 b of the differential case 11 is processed.

  Note that the tool suspension mechanism 19 also moves in the same direction in synchronization with the movement of the cutter 13 accompanying the above-described processing.

  (5) FIG. 6 shows a state in which the inner surface 11a of the differential case 11 on the cutter driver 15 side is processed. The operation at this time is only symmetrical with respect to the processing of the inner surface 11b in FIG.

  (6) FIG. 7 shows a state in which the processing of the inner surfaces 11a and 11b of the differential case 11 is completed. Here, from the state shown in FIG. 6, by driving the feed motor 47, the cutter driver 15 moves forward and the cutter driver 17 moves backward so that the cutter 13 is in the neutral position shown in FIG. 15 and 17 are moved together.

  Thereafter, the rotation of both cutter drivers 15 and 17 is stopped, and the rotation of the cutter 13 is stopped.

  (7) Next, the rotation of the screw rod 31 by the brake unit 67 is restricted, and the clutch unit 69 is brought into a disconnected state. In this state, when the feed motor 47 is driven in the direction in which the cutter driver 15 moves backward, only the drive shaft 43 rotates, and the screw rod 29 connected to the drive shaft 43 rotates. As shown in FIG. With the driver 17 stopped, the cutter driver 15 moves backward, and the cutter drivers 15 and 17 are in the same state as in FIG.

  (8) In the state of FIG. 8, the clutch unit 69 is brought into the connected state, and the rotation restriction of the screw rod 31 by the brake unit 67 is released. In this state, by driving the feed motor 47 in the opposite direction to the above (7), the cutter drivers 15 and 17 are moved together in the direction in which the cutter driver 17 is separated from the differential case 11.

  As a result of this movement, each cutter drive 15, 17 is in the in-situ standby state at the left-right symmetrical position with a predetermined distance L around the differential case 11, as in FIG. 2. Thereafter, the tool suspension mechanism 19 is raised, the cutter 13 is extracted from the differential case 11, and the differential case 11 is carried out.

  According to the first embodiment described above, both cutter drivers 15 and 17 are held in a state in which a predetermined compressive stress is applied to the cutter 13, so that the holding of the cutter 13 is stable, and the differential case 11 The inner surfaces 11a and 11b can be processed with high accuracy.

  Further, even if the contact position with respect to the inner surfaces 11a and 11b changes due to wear of the cutter 13, etc., the cutter drivers 15 and 17 move in the direction of pressing the cutter 13 against the inner surfaces 11a and 11b by applying compressive stress to the cutter 13. Therefore, the change in the contact position described above is absorbed. For this reason, the complicated position adjustment resulting from the wear of the cutter 13 of the cutter drivers 15 and 17 is not necessary, so that the workability can be prevented from being lowered and high-precision machining can be performed.

  Furthermore, since the feeding operation of both cutter drivers 15 and 17 can be performed by one feeding motor 47, the equipment cost can be reduced as compared with the case where separate feeding motors are provided for both cutter drivers 15 and 17. Can do.

  FIG. 10: is a front view which shows the whole structure of the internal surface processing apparatus of the hollow workpiece | work concerning 2nd Embodiment of this invention. In this embodiment, the power transmission mechanism (drive shafts 43 and 45 and power transmission units 61 and 63) in the first embodiment described above is eliminated, and the screw rods 29 and 31 are directly driven by the feed motor 47. is there. By eliminating the power transmission mechanism, the structure is simplified as compared with the first embodiment.

  The screw rods 29 and 31 are connected to each other by a connecting shaft 83, and the connecting shaft 83 is rotatably supported by rotation support portions 89 and 91 installed on support bases 85 and 87 on the base frame 33 at both ends. The connecting shaft 83 and the screw rod 29 are connected and fixed by a connecting portion 93, and the connecting shaft 83 and the screw rod 31 are connected by a clutch unit 69 installed on the support base 87. A brake unit 67 is installed at the outer end of the screw rod 31.

  Also in the second embodiment described above, both cutter drivers 15 and 17 are integrated with each other by connecting and blocking the screw rods 29 and 31 with the clutch unit 69 and driving the feed motor 47 in the connected state. When the feed motor 47 is driven in the cut-off state, only the cutter driver 15 is moved. Further, by operating the brake unit 67, the rotation of the screw rod 31, that is, the movement of the cutter driver 17 is restricted.

  By using such an operation, it is possible to perform the same machining operation as that of the first embodiment shown in FIGS.

  In the configuration of FIG. 10, the connecting shaft 83 can be eliminated by extending the screw rod 29 to the clutch unit 69.

  Further, in each of the above-described embodiments, the example in which the inner surfaces 11a and 11b in which the back surface of the pinion slides in the differential case 11 has been shown has been described. Can do. In this case, the cutter is changed to a corresponding one, and the cutter driver is inserted into the differential case 11 through the through hole into which the axle supporting the side gear is inserted.

It is a front view which shows the whole structure of the internal surface processing apparatus of the hollow workpiece | work concerning 1st Embodiment of this invention. It is operation | movement explanatory drawing of the inner surface processing apparatus of FIG. 1, and shows an in-situ standby state. It is operation | movement explanatory drawing of the internal surface processing apparatus of FIG. 1, and shows the state which inserted the one cutter driver in the workpiece | work. It is operation | movement explanatory drawing of the internal surface processing apparatus of FIG. 1, and shows the state which inserted both cutter drivers in the workpiece | work. It is operation | movement explanatory drawing of the inner surface processing apparatus of FIG. 1, and the state which is processing the one inner surface in a workpiece | work is shown. It is operation | movement explanatory drawing of the inner surface processing apparatus of FIG. 1, and shows the state which is processing the other inner surface in a workpiece | work. It is operation | movement explanatory drawing of the inner surface processing apparatus of FIG. 1, and shows the state which moved the cutter to the neutral position after the process. It is operation | movement explanatory drawing of the internal surface processing apparatus of FIG. 1, and shows the state which pulled out one cutter driver from the inside of a workpiece | work. It is operation | movement explanatory drawing of the internal surface processing apparatus of FIG. 1, and shows the state which pulled out both cutter drivers from the inside of a workpiece | work, and returned to the original position standby state. It is a front view which shows the whole structure of the internal surface processing apparatus of the hollow workpiece | work concerning 2nd Embodiment of this invention. It is sectional drawing of the conventional apparatus which processes the inner surface of a differential case.

Explanation of symbols

11 Hollow work 11c, 11d Hollow work through hole 13 Cutter 15, 17 Cutter driver 25, 27 Ball guide nut (ball screw mechanism)
29,31 Screw rod (ball screw mechanism)
43 Drive shaft (first rotary shaft, power transmission mechanism)
45 Drive shaft (second rotary shaft, power transmission mechanism)
47 Feeding motor (driving means)
61, 63 Power transmission part (power transmission mechanism)
67 Brake unit (regulation means)
69 Clutch unit (power disconnection mechanism)

Claims (9)

A cutter is disposed in the hollow workpiece, and the cutter is held from both sides by a pair of cutter drivers inserted from the opposite sides of the hollow workpiece into the inside through through holes, and the cutter is held by one of the pair of cutter drivers. A hollow work inner surface machining method for machining one of the mutually facing inner faces of the hollow work by pressing while pressing the cutter, and when the cutter is held, the two cutter drivers move against the cutter. And applying a predetermined compressive stress to the inner surface of the hollow workpiece. A ball screw mechanism for moving the pair of cutter drivers in directions toward and away from each other is provided for each pair of cutter drivers, and one driving means for driving each of the ball screw mechanisms is provided. Provided with a power connection / cutoff mechanism for cutting off the power connection so that the power can be transmitted only to the ball screw mechanism, and when applying compressive stress to the cutter, the power connection cut-off mechanism is set in a cut-off state, and the operation of the drive means The forward movement of one cutter driver causes the cutter to be pressed toward the other cutter driver, and then the power connection cut-off mechanism is connected to hold the compressive stress applied to the cutter. Item 2. A method for processing an inner surface of a hollow workpiece according to Item 1. The method for machining an inner surface of a hollow workpiece according to claim 2, wherein a power transmission mechanism for transmitting the power of the driving means to the ball screw mechanism is provided, and the power connection cutoff mechanism is provided in the power transmission mechanism. 4. The method of processing an inner surface of a hollow workpiece according to claim 2, wherein when compressive stress is applied to the cutter, the movement of the other cutter driver on the side opposite to the side pressing the cutter is regulated by regulating means. . A cutter is disposed in the hollow workpiece, and the cutter is held from both sides by a pair of cutter drivers inserted from the opposite sides of the hollow workpiece into the inside through through holes, and the cutter is held by one of the pair of cutter drivers. A hollow work inner surface machining apparatus for machining one of the mutually facing inner faces of the hollow work by pressing while rotating, wherein the both cutter drivers hold the cutter against the cutter. And applying a predetermined compressive stress to the inner surface processing apparatus for a hollow workpiece. A ball screw mechanism for moving the pair of cutter drivers in directions toward and away from each other is provided for each pair of cutter drivers, and one driving means for driving each of the ball screw mechanisms is provided. A power connection / cut-off mechanism for cutting off the power connection is provided so that the power can be transmitted only to the ball screw mechanism. The power connection / cut-off mechanism is in a cut-off state when compressive stress is applied to the cutter, By moving the cutter driver forward, the cutter is pressed toward the other cutter driver, while the inner surface of the hollow workpiece is processed to be in a connected state, and the compressive stress applied to the cutter is maintained. The inner surface processing apparatus of the hollow workpiece | work of Claim 5. 7. The inner surface machining apparatus for a hollow work according to claim 6, wherein a power transmission mechanism for transmitting the power of the driving means to the ball screw mechanism is provided, and the power connection cutoff mechanism is provided in the power transmission mechanism. 8. An inner surface machining apparatus for a hollow workpiece according to claim 6, further comprising a restricting means for restricting movement of the other cutter driver on the side opposite to the pressing side of the cutter when the compressive stress is applied. . The power transmission mechanism connects a first rotating shaft that transmits power to the one cutter driver to the driving means, and transmits power to the other cutter driver on the first rotating shaft. 9. A ball screw mechanism configured to connect two rotating shafts via the power connection cutoff mechanism and receive power from the second rotating shaft, and the restriction means is provided. The hollow workpiece inner surface processing apparatus as described.

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