JP4551783B2 - Crankshaft processing equipment - Google Patents

Description

  The present invention generally relates to a crankshaft processing apparatus, and more particularly to an apparatus for processing an eccentric portion (for example, a pin journal) while rotating the crankshaft around its main journal.

  As an apparatus for processing an eccentric portion (for example, a pin journal) while rotating a crankshaft around its main journal, an apparatus described in Patent Document 1 is known. FIG. 1 shows the configuration of the conventional tool driving apparatus.

  As shown in FIG. 1, the cutting edge of the tool 31 rotates eccentrically in synchronization with the eccentric rotational movement of the eccentric portion (for example, pin journal) 2 when the crankshaft 1 rotates about the central axis C of the main journal. The eccentric part 2 is processed while moving along the locus of movement. In this conventional apparatus, a tool table 32 on which a tool 31 is mounted is attached to the two drive main shafts 33a and 33b at a position shifted by a predetermined eccentricity E from their rotation center B. The two drive main shafts 33a and 33b rotate in synchronization with the rotation of the crankshaft 1, whereby the tool table 31 performs a parallel movement along the locus of the eccentric rotation of the eccentric portion 2 of the crankshaft 1. As described in paragraph 0032 and FIG. 4 of Patent Document 1, the two drive main shafts 33a and 33b are coupled to a common drive motor 38a via a gear system, and the common drive motor 38a. It is driven by the rotational force applied through the gear system. The crankshaft 1 is also rotated by a rotational force applied from another drive motor via a gear system.

JP 2003-225803 A

  The conventional apparatus has a problem in that the cross-sectional shape of the processed portion of the crankshaft is not a perfect circle, but is slightly elliptical. The cause is that backlash occurs in the gear system coupled to the crankshaft 1 or the gear system coupled to the drive main shafts 33a and 33b while the crankshaft 1 and the drive main shafts 33a and 33b make one rotation. It is believed that there is. Specifically, in FIG. 1, when the cutting edge of the tool 31 is positioned on a straight line A passing through the center points of the two drive spindles 33a and 33b (when the illustrated rotation angles θ are 90 degrees and 270 degrees). Therefore, it is estimated that no backlash occurs. On the other hand, when the cutting edge of the tool 31 comes close to a position that is most deviated from the straight line A (the rotation angle θ shown in the figure is 0 degree and 180 degrees), backlash occurs, and the cutting edge of the tool 31 It is presumed that the distance between the centers D of the eccentric parts 2 slightly opens from the specified value. As a result, the roundness of the processed portion is reduced.

  Accordingly, an object of the present invention is to provide an apparatus for machining an eccentric portion of a crankshaft while rotating the crankshaft around its main journal and moving the cutting edge of the tool along the eccentric rotational movement locus of the eccentric portion. In the mechanism for transmitting power to the tool or the crankshaft, the roundness of the processed product is increased by preventing backlash of the gear.

  A crankshaft machining apparatus according to the present invention includes a work drive device that supports a crankshaft and rotates the main journal around the tool, a tool for machining an eccentric portion of the crankshaft, and the eccentricity in synchronization with rotation of the crankshaft. A tool driving device that moves the tool along an eccentric rotational movement locus of the part. The tool driving device has at least one tool driving main shaft and a tool fixed thereto, and is attached to the at least one tool driving main shaft so as to be eccentrically rotatable. The eccentric rotation motion is caused by rotation of the tool driving main shaft. A tool table that performs a translational movement corresponding to the locus; and at least one tool drive motor that is directly connected to the at least one tool drive motor and directly rotates the tool drive motor.

  According to this crankshaft machining apparatus, in the tool driving apparatus, at least one tool driving main shaft is directly connected to the tool driving motor and thereby directly rotated. Due to the rotation of the tool driving spindle, the tool base moves, and the tool is moved along the eccentric rotational movement locus of the eccentric portion of the crankshaft. During the machining process, since the rotational power continues to be applied directly from the tool drive motor to the tool drive spindle without going through the gear system, the problem of backlash in the gear system no longer exists. As a result, the eccentric portion can be processed with a higher roundness than before.

  In a preferred embodiment, not only in the tool driving device but also in the work driving device, the work supporting device that grips the crankshaft is directly connected to the work driving motor and directly driven to rotate without a gear system. . Therefore, the work drive device is also freed from the problem of backlash in the gear system, and as a result, the eccentric portion can be processed with a higher roundness.

  In a preferred embodiment, the tool driving device includes a plurality of tool driving spindles arranged in parallel. The tool table is attached to the plurality of tool drive main shafts so as to be eccentric and rotatable, and the tool drive main shaft performs a parallel movement corresponding to the eccentric rotational movement locus by the rotation of the tool drive main shafts. A plurality of tool drive spindles are directly connected to a plurality of tool drive motors, respectively, and are directly rotated. In this way, the plurality of tool drive spindles are directly driven by the tool drive motor, respectively, so that the problem of backlash is solved satisfactorily.

  On the other hand, in another preferred embodiment, only at least one of the above-described plurality of tool drive spindles is directly connected to the tool drive motor, and the other tool drive spindle is, for example, a tool It is indirectly coupled to the tool drive motor through a power transmission mechanism such as a gear system that connects the drive main shafts. In this way, if at least one of the plurality of tool drive spindles is directly driven, the other tool drive spindle can be driven back by the tool drive device even if it is indirectly driven through a gear system or the like. Rush can be improved. In this case, as the directly driven tool driving spindle, a spindle arranged at a position closest to the tool 31 among a plurality of tool driving spindles can be selected.

  In one preferred embodiment, in addition to the above-described configuration, an eccentric amount adjusting device for adjusting the eccentric amount of the tool base with respect to the plurality of tool driving main shafts is further provided. The eccentricity adjusting device has an eccentricity adjusting mechanism provided on each of the plurality of tool driving main shafts. A common adjustment motor is coupled to the eccentricity adjustment mechanisms of the plurality of tool drive spindles, and the eccentricity adjustment mechanisms are operated simultaneously to adjust the eccentricity to the same value. It has become. According to this eccentricity adjusting device, the eccentricity in the plurality of tool drive spindles can be set to the same value at the same time by a common adjustment motor, so that the adjustment work is easy.

  ADVANTAGE OF THE INVENTION According to this invention, the problem of the gear backlash in the mechanism which transmits motive power to a tool or a crankshaft is improved, and the roundness of the eccentric part of the crankshaft after a process increases.

  FIG. 2 is a perspective view showing an overall exterior configuration of the crankshaft machining apparatus according to the first embodiment of the present invention.

  As shown in FIG. 2, the left and right ends of the front surface on the bed 60 support both ends of the crankshaft 1 (hereinafter referred to as a workpiece) to be processed, and the workpiece is rotated by the workpiece driving motors 23 and 23. Two work drive devices 20, 20 are provided. Work supporting devices 21 having chuck three claws 21b and 21b and chucks 21a and 21a for gripping and supporting both ends of the main journal of the work 1 are provided on the surfaces of the work driving devices 20 and 20 facing each other. 21 are provided. The two workpiece driving devices 20 and 20 are movable along a rail 25 provided on the bed 60 in the horizontal direction shown in the drawing in order to adjust the distance between the workpiece supporting devices 21 and 21 to the length of the workpiece 1. is there.

  Further, an auxiliary supporter 24 is provided at a position between the work support devices 21 and 21 on the bed 60, and the auxiliary supporter 24 includes an auxiliary supporter body 24a and an auxiliary supporter claw 24b. The auxiliary supporter main body 24 a is movable on the rail 25 and is disposed corresponding to the position of the main journal 3 in the vicinity of the center portion of the work 1. The auxiliary supporter claw 24 is provided on the upper part of the auxiliary supporter main body 24a, and supports the main journal 3 near the center of the workpiece 1 at a fixed position by a centripetal clamp (not shown).

  Two tool drive devices 30 and 30 on the left and right sides are installed behind the two work support devices 21 and 21. These two tool driving devices 30 and 30 are arranged in a direction parallel to the rotation center axis of the workpiece 1 (Z-axis direction) and in a horizontal direction perpendicular to the Z-axis direction (X-axis direction which is the front-rear direction in the drawing). Each is mounted on a bed 60 so as to be movable. On the surfaces of the tool driving devices 30 and 30 facing each other in the Z-axis direction, rectangular plate-shaped tool tables 32 and 32 extending in the X-axis direction are provided, respectively. The tool bases 32 and 32 have portions protruding from the front surfaces of the tool driving devices 30 and 30 toward the workpiece 1, and an eccentric portion of the workpiece 1, typically, is located at an end portion of the protruding portion closest to the workpiece 1. Tools 31 and 31 for cutting the pin journal are fixed to each. The tools 31 and 31 can be attached to and detached from the tool tables 32 and 32. The exterior structure on the side where the tool tables 32 and 32 of the tool driving devices 30 and 30 are provided is the same as that of the conventional device shown in FIG. By adjusting the positions of the tool driving devices 30 and 30 in the Z-axis direction and the X-axis direction, the cutting edges of the tools 31 and 31 are aligned with the machining target portion of the eccentric portion (pin journal) of the workpiece 1. Two places of the work 1 can be processed simultaneously by the two tools 31 and 31.

  The two tool driving devices 30 and 30 have the same basic configuration except that the arrangement of the components is symmetrical to each other. Therefore, in the following, one of the tool driving devices 30 is taken as an example, and the configuration will be described in more detail.

  As shown in FIG. 1 already described, during the machining process, the workpiece 1 is rotated around the central axis C of the main journal 3 by the workpiece support devices 21 and 21 described above, and the eccentric portion 2 to be machined. The (pin journal 2a) performs an eccentric rotational motion in a state where the central axis D is separated from the rotational central axis C by the eccentric amount E. On the other hand, each tool driving device 30 includes two tool driving main shafts 33a and 33b each having a central axis B parallel to the rotation center axis C of the workpiece 1, and a tool base 32 is attached to the tool driving main shafts 33a and 33b. It has been. The tool base 32 is rotatable about the central axes B and B of the eccentric pins 34a and 34b with respect to the tool driving main shafts 33a and 33b via the eccentric pins 34a and 34b provided on the tool driving main shafts 33a and 33b. Is attached. The amount of eccentricity of the eccentric pins 34a, 34b with respect to the tool drive main shafts 33a, 33b is equal to the amount of eccentricity E of the eccentric portion 2 (pin journal) of the workpiece 1 with respect to the main journal 3. By the initial setting before starting machining, both the rotation angle θ of the tool drive spindles 33a and 33b and the rotation angle θ of the work 1 are set to zero, and the height h of the cutting edge of the tool 31 is the center of the pin journal 2 Set to the height of axis D. During the subsequent machining process, the two tool drive main shafts 33 a and 33 b are rotated by the same rotation amount in synchronization with the rotation of the workpiece 1. As a result, the cutting edge of the tool 31 on the tool table 32 performs a motion corresponding to the eccentric rotational motion of the pin journal 2 of the workpiece 1 to cut the outer periphery of the pin journal 2a into a circle centering on the central axis D. . As can be seen from FIG. 2, the outer diameter dimension of the pin journal 2 after processing is determined by the approach distance of the cutting edge of the tool 31 to the workpiece 1 in the X-axis direction. That is, the distance between the center axis D of the pin journal 2 and the cutting edge of the tool 31 is the radius of the outer diameter of the pin journal 2.

  FIG. 3 is a plan view of the tool driving device 30. 4 is a cross-sectional view of the tool driving device 30 taken along line VV in FIG. Hereinafter, the structure of the tool driving device 30 will be described in more detail with reference to FIGS.

  As shown in FIGS. 2 to 4, the tool driving device 30 includes two spindle driving motors 70 a and 70 b for rotationally driving the tool driving spindles 33 a and 33 b, and these spindle driving motors 70 a and 70 b are tool driving. The main body base 30 a of the device 30 is fixed or built in. Both of these two spindle driving motors 70a and 70b are, for example, low speed and high torque servo motors. The output shafts of the two main shaft drive motors 70a and 70b are directly connected to the tool drive main shafts 33a and 33b without interposing a gear system, as well shown in FIG. That is, for example, in this embodiment, the output shafts of the spindle driving motors 70a and 70b are the tool driving spindles 33a and 33b themselves. Therefore, the rotational force output from the spindle drive motors 70a and 70b is directly applied to the tool drive spindles 33a and 33b without using a gear system. Each of the spindle driving motors 70a and 70b is a motor of a type suitable for directly driving the tool driving spindles 33a and 33b, for example, a low speed (for example, 300 to 800 rpm) high torque servo motor.

  Although not shown in detail, the output shafts of the work drive motors 23 and 23 and the chucks 21a and 21a are also located between the gear systems in the two work drive devices 20 and 20 shown in FIG. It is connected directly without going through. Work support devices 21 and 21 having the above are respectively provided. The work drive motors 23 are also motors of a type suitable for directly driving the work 1, for example, a low speed (for example, 300 to 800 rpm) high torque servo motor.

  With the above-described configuration, the problem of backlash of the gear system that occurs in the conventional apparatus in the machining process does not occur, and as a result, the pin journal 2 can be machined with high roundness.

  As well shown in FIG. 4, the tool driving main shafts 33 a and 33 b are rotatably supported on the main body base 30 a of the tool driving device 30 via a bearing 36. The eccentric pins 34a and 34b described above are attached to the respective distal end portions of the tool drive main shafts 33a and 33b via the slidable joints 52 and 52, respectively. The eccentric pins 34a and 34b have central axes F and F arranged in parallel to the central axes B and B of the tool driving main shafts 33a and 33b and at positions shifted by an eccentric amount E therefrom. The above-described tool table 32 is attached to the two eccentric pins 34a and 34b so as to be rotatable around the central axes F and F of the eccentric pins 34a and 34b via the eccentric pin bearings 35a and 35b.

  As shown in FIGS. 2 to 4, the tool driving device 30 further processes the eccentric amount E (that is, the eccentric amount E of the movement locus of the tool 31) with respect to the tool driving main shafts 33 a and 33 b of the eccentric pins 34 a and 34 b. The pin journal 2 is provided with an eccentricity adjusting device 50 for variably adjusting the pin journal 2 accordingly. As shown in FIG. 4, the eccentricity adjusting device 50 includes adjustment rods 51e and 51e that are inserted through the central portions of the tool drive main shafts 33a and 33b, respectively, and rotate together with the tool drive main shafts 33a and 33b. The adjustment rods 51e and 51e can move forward and backward in the direction of the rotation center axis B of the tool drive main shafts 33a and 33b. The leading ends of the adjustment rods 51e, 51e have an oblique cut surface, and are inserted into the holes formed in the above-described slider joints 52, 52. The holes of the slidable joints 52 and 52 also have an oblique cut surface, which abuts the slidable on the oblique cut surfaces at the tips of the adjustment rods 51e and 51e, respectively. The adjusting rods 51e, 51e are fixed in the rotational direction to the slidable joints 52, 52 by a wedge 51i so that the slidable joints 52, 52 are rotated together when they are rotated. The slidable joints 52 and 52 are slidable in parallel to the eccentric direction of the eccentric pins 34a and 34b with respect to the tool driving main shafts 33a and 33b. When the slidable rod 51e is moved forward or backward, the slidable block 52 slides parallel to the eccentric direction, so that the eccentric amount E is variably adjusted.

  As shown in FIGS. 3 and 4, the rear ends of the adjusting rods 51e and 51e are respectively connected to a common slidable support block 51j attached on the main body base 30a of the tool driving device 30 via bearings 51g and 51g. And is rotatably supported. The positions of the adjustment rods 51e, 51e in the direction of the central axis B with respect to the slidable support block 51j are unchanged. The slidable support block 51j is attached to the main body base 30a via a slide 51f, and is slidable in the direction of the central axis B of the adjustment rods 51e and 51e on the main body base 30a. Therefore, when the slidable support block 51j moves in the direction of the central axis B, the adjustment rods 51e and 51e also move in the direction of the central axis B, thereby moving the slidable joints 52 and 52 in the eccentric direction. Become.

  Further, a nut 51d is fixed to the slidable support block 51j, and a rotating bolt 51c is screwed into the nut 51d. The rotating bolt 51c is rotatably supported by a fixed support block 51k fixed on the main body base 30a via a bearing 51h, and is also an eccentricity adjustment motor fixed to the fixed support block 51k via a coupling 51b. 51a is coupled to the output shaft. By rotating the rotating bolt 51c by the eccentric amount adjusting motor 51a, the slidable support block 51j moves, and the two adjusting rods 51e and 51e are simultaneously moved forward or backward by the same amount. Thereby, the two eccentric pins 34a and 34b described above are simultaneously advanced or retracted by the same amount, and the eccentric amount E of the two eccentric pins 34a and 34b is simultaneously adjusted by the same amount.

  According to the embodiment described above, the pin journal 2 can be processed with high roundness. In addition, it is easy to adjust the amount of eccentricity E of the motion trajectory of the tool 31.

  Next, a second embodiment of the present invention will be described.

  FIG. 5 is a plan view of the tool driving device 30 of the crankshaft machining apparatus according to the second embodiment. FIG. 6 is a cross-sectional view taken along the line VV of FIG. 5 of the tool driving device 30 in the second embodiment.

  The second embodiment is different from the first embodiment described above in the mechanism for rotationally driving the tool drive main shafts 33a and 33b of the tool drive device 30, and the structure of the other parts is the first embodiment. It is the same. This difference will be described below.

  As shown in FIGS. 5 and 6, one spindle driving motor 70 a is fixed or built in the main body base 30 a of the tool driving device 30. Then, the output shaft of this one spindle drive motor 70a does not interpose a gear system, and one of the two tool drive spindles 33a, 33b, for example, a tool drive spindle on the side close to the tool 31 (hereinafter referred to as a tool drive spindle) , Referred to as a first tool driving main shaft). For example, in this embodiment, the output shaft of the spindle drive motor 70a is the first tool drive spindle 33a itself.

  On the other hand, a drive motor is not directly coupled to a tool drive spindle 33b far from the tool 31 (hereinafter referred to as a second tool drive spindle) 33b. Instead, the first tool drive spindle 33a is connected via a gear system 72. Is bound to. The gear system 72 includes a first gear 72a externally fitted to and fixed to the first tool drive main shaft 33a, a second gear 72a externally fitted to and fixed to the second tool drive main shaft 33b, and a first gear. A third gear disposed between the second gear 72a and the second gear 72a. When the main shaft driving motor 70a rotates, the rotational power is directly applied to the first tool driving main shaft 33a to rotate it, and is also transmitted to the second tool driving main shaft 3 through the gear system 72 to rotate it. The main shaft driving motor 70a is a motor of a type suitable for driving the tool driving main shafts 33a and 33b, for example, a low speed (for example, 300 to 800 rpm) high torque servo motor.

  According to this configuration, the second tool drive main shaft 33 b is driven by the first tool drive main shaft 33 a via the gear system 72. However, since the first tool drive main shaft 33a is directly connected to the main shaft drive motor 70a and driven directly, the problem of backlash hardly occurs. In this case, the fact that the first tool drive main shaft 33a on the side close to the tool 31 is selected as the tool drive main shaft directly connected to the main shaft drive motor 70a is also effective in suppressing the brush. As a result, the pin journal 2 can be processed with high roundness. In addition, since the two tool drive spindles 33a and 33b are driven by the common spindle drive motor 70a, it is easy to match the rotational speeds of both the tool drive spindles 33a and 33b.

  In the second embodiment, instead of the gear system 72 in which the first and second tool driving main shafts 33a and 33b are coupled, a gear system having a different configuration or another type of power transmission mechanism is used. The power of the main shaft drive motor 70a may be used for the second tool drive main shaft 33b.

  As mentioned above, although embodiment of this invention was described, this embodiment is only the illustration for description of this invention, and is not the meaning which limits the scope of the present invention only to this embodiment. The present invention can be implemented in various other modes without departing from the gist thereof.

It is a side view which shows the structure of the side by which the tool stand of the tool drive device in the conventional apparatus was attached. 1 is a perspective view showing an overall exterior configuration of a crankshaft machining apparatus according to a first embodiment of the present invention. It is a top view of the tool drive device 30 of 1st Embodiment. It is sectional drawing in alignment with the VV line | wire of FIG. 3 of the tool drive device 30 of 1st Embodiment. It is a top view of the tool drive device 30 of the crankshaft processing apparatus concerning the 2nd Embodiment of this invention. It is sectional drawing along the VV line of FIG. 5 of the tool drive device 30 of 2nd Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Crankshaft (workpiece), 2 ... Eccentric part (pin journal), 3 ... Main journal, 20 ... Work drive device, 21 ... Work support device, 21a ... Chuck, 23 ... Work drive motor, 24 ... Auxiliary supporter, 30 ... tool drive device, 30a ... main body base, 31 ... tool, 32 ... tool table, 33a, 33b ... tool drive spindle, 34a, 34b ... eccentric pin, 50 ... eccentricity adjusting device, 70a, 70b ... spindle drive motor, 72 ... Gear system

Claims (2)

A work drive device (20) that supports a crankshaft (1) and rotates it around a main journal, a tool (31) for machining an eccentric portion (2) of the crankshaft (1), and the crankshaft In a crankshaft machining apparatus comprising a tool driving device (30) that moves a tool (31) along an eccentric rotational movement locus of the eccentric portion (2) in synchronization with the rotation of (2),
The tool driving device (30) is
A plurality of tool drive spindles (33a , 33b ) arranged in parallel ;
Wherein the tool (31) is fixed, said plurality of tool drive spindle (33a, 33b) rotatably mounted eccentric to the eccentric rotated by the rotation of said plurality of tool drive spindle (33a, 33b) A tool table (32) that performs parallel movement corresponding to the movement locus;
Of the plurality of tool drive main shafts, the tool drive main shaft (33a) disposed closest to the tool is directly connected to the tool drive main shaft (33a) and directly rotated, and power is transmitted to the other tool drive main shaft (33b). A tool drive motor (70a) that indirectly couples through a mechanism and rotates it indirectly ;
An eccentric amount adjusting device (50) for adjusting an eccentric amount of the tool table (32) with respect to the plurality of tool driving main shafts (33a, 33b),
The eccentricity adjusting device (50) includes:
An eccentricity adjustment mechanism (51e, 52) provided on each of the plurality of tool drive spindles (33a, 33b);
The plurality of tool drive main shafts (33a, 33b) are coupled to the eccentricity adjustment mechanisms (51e, 52), and the plurality of eccentricity adjustment mechanisms (51e, 52) are operated simultaneously so that the eccentricity is the same. A crankshaft machining apparatus comprising a common adjustment motor (51a) for adjusting to a value . In the crankshaft processing apparatus according to claim 1,
The work drive device (20)
A workpiece support device (21) for gripping the crankshaft (1);
A crankshaft machining apparatus, comprising: a work drive motor (24) that is directly connected to and directly rotates the work support device (21).

Images