JP2005138201A - Crankshaft processing device and processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a crankshaft processing device having favorable processing precision and processing efficiency. <P>SOLUTION: This crankshaft processing device has holding means 15, 25 arranged on end parts 51, 52 of a crankshaft 50 to hold the crankshaft 50 by decentering it so that an axis of a pin part 55 (55A, 55B) of the crankshaft 50 comes to a center of rotation and deforming means 16, 26 to forcibly give deflection to the crankshaft 50 in the opposite direction to a direction where the crankshaft 50 held by the holding means 15, 25 is deformed by receiving centrifugal force at the time of processing the pin part 55. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a crankshaft machining apparatus and a machining method.

A conventional crankshaft processing device holds a crankshaft eccentrically and grinds the pin portion in a state of being rotationally driven about the axis of the pin portion (see, for example, Patent Document 1).
JP-A-5-329756

  However, the crankshaft machining apparatus described in Patent Document 1 has a problem in productivity, that is, machining efficiency. For example, when rotating the crankshaft at a low speed, the crankshaft is balanced by a counterweight integrated with the chuck, so that the pin portion can be processed with high accuracy.

  On the other hand, when the crankshaft is rotated at a high speed, it is affected by the centrifugal force, so the crankshaft is bent, the parallel processing part of the pin part and the work surface of the grinding wheel are broken, and the roundness of the pin part after grinding and The cylindricity may be deteriorated.

  The present invention has been made to solve the above-described problems associated with the prior art, and an object thereof is to provide a crankshaft machining apparatus and a machining method having good machining accuracy and machining efficiency.

In order to achieve the above object, the invention described in claim 1
A holding means that is disposed at an end of the crankshaft and that holds the crankshaft eccentrically so that a central axis of a pin portion of the crankshaft is a rotation center;
When processing the pin portion, forcibly imparting deflection to the crankshaft in a direction opposite to the direction in which the crankshaft held by the holding means is deformed by receiving a centrifugal force. And a crankshaft machining apparatus characterized by comprising:

In order to achieve the above object, the invention according to claim 7 provides:
The crankshaft is rotated around the center axis of the pin portion of the crankshaft,
A crankshaft machining method characterized by forcibly imparting deflection to the crankshaft in a direction opposite to a direction in which the crankshaft receives a centrifugal force and deforming, and machining the pin portion. It is.

  The present invention configured as described above has the following effects.

  According to the first aspect of the present invention, when the centrifugal force due to the rotation acts on the crankshaft, the machining site is bent by bending the crankshaft in a direction opposite to the direction in which the centrifugal force is deformed. It is possible to make the outer peripheral surface of the pin portion parallel to the processing tool.

  Therefore, even when the crankshaft is rotated at a high speed and is processed with high efficiency, the processing tool can be brought into uniform contact with the processing portion, and the roundness and cylindricity of the pin portion can be ensured. That is, it is possible to provide a crankshaft machining apparatus having good machining accuracy and machining efficiency.

  According to the invention described in claim 7, when the centrifugal force due to the rotation acts on the crankshaft, the crankshaft is forcibly bent in a direction opposite to the direction in which the centrifugal force is deformed. The outer peripheral surface of the pin part which is a processing part is parallel to the processing tool.

  Therefore, even when the crankshaft is rotated at a high speed and processed with high efficiency, the processing tool uniformly contacts the processing site, so that the roundness and cylindricity of the pin portion are ensured. That is, a crankshaft machining method having good machining accuracy and machining efficiency can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a side view for explaining a crankshaft machining apparatus according to an embodiment of the present invention, FIG. 2 is a side view for explaining centrifugal force due to rotation acting on the crankshaft, and FIG. It is a side view for demonstrating the bending forcibly given to a shaft.

  The crankshaft machining apparatus according to the embodiment of the present invention, for example, holds a crankshaft 50 for a four-cylinder internal combustion engine and rotationally drives it, and a pin portion 55 (55A, 55B) of the crankshaft 50. ), A displacement detection device 40 for detecting the amount of displacement of the pin portion 55 of the crankshaft 50, and a control device (not shown) for controlling each portion 10, 30, 40. Have

  The holding unit 10 includes spindle heads 11 and 21, spindles 13 and 23, work drivers 14 and 24, chucks 15 and 25, and actuators 16 and 26.

  The spindle heads 11 and 21 are arranged so that their axis lines coincide with each other with the crankshaft 50 interposed therebetween, and have bearings 12 and 22 for rotatably supporting the spindles 13 and 23.

  The main shafts 13 and 23 are each driven to rotate by a motor (not shown). One of the main shafts 13 is movable in the axial direction.

  The work drivers 14 and 24 are attached to the opposed end surfaces of the main shafts 13 and 23 and are used to decenter the crankshaft 50 so that the central axis of the pin portion 55 of the crankshaft 50 is the center of rotation.

  The chucks 15 and 25 are attached to the work drivers 14 and 24 and grip the end portions 51 and 52 of the crankshaft 50. That is, the chucks 15 and 25 are disposed at the end portions 51 and 52 of the crankshaft 50, and the crankshaft 50 is eccentrically held so that the central axis of the pin portion 55 of the crankshaft 50 is the center of rotation. Functions as a holding means.

  The chuck 15 is movable in the axial direction by driving the main shaft 13 in the axial direction. Therefore, when the chuck 15 is moved in the axial direction and the distance between the chucks 15 and 25 is changed (reduced) in response to the change in the distance between the main shafts caused by the deflection of the crankshaft 50, the chucks 15 and 25 with respect to the crankshaft 50 are changed. It is possible to prevent a decrease in the holding force.

  That is, the main shaft 13 functions as a moving means for moving the chuck 15 in the axial direction. It is possible to drive the other 23 of the main shaft in the axial direction and move the other 25 of the chuck in the axial direction. In this case, the other 23 of the main shaft functions as a moving means. Further, both the main shafts 13 and 23 can be configured to be driven in the axial direction.

  The actuators 16 and 26 are disposed at the rear ends of the chucks 15 and 25, and can be tilted by being displaced, forcing the crankshaft 50 to bend. Function as a deformation means.

  That is, as shown in FIG. 2, when the crankshaft 50 is rotated at a high speed, the crankshaft 50 is deformed by receiving a centrifugal force. However, as shown in FIG. 3, the actuators 16 and 26 forcibly impart deflection to the crankshaft 50 in a direction opposite to the direction in which the crankshaft 50 deforms due to centrifugal force. It is possible.

  Therefore, for example, when a centrifugal force due to rotation is applied during grinding by grinding using a processing tool, the crankshaft 50 is deflected in a direction opposite to the direction of deformation due to the centrifugal force. Thus, it is possible to make the outer peripheral surface that is the processing portion of the pin portion 55 parallel to the processing tool.

  Therefore, even when the crankshaft 50 is rotated at a high speed and processed with high efficiency, the processing tool can be brought into uniform contact with the processing site, and the roundness and cylindricity of the pin portion 55 can be ensured. .

  For example, when the crankshaft 50 having low rigidity is applied, if the deflection is simply applied, a displacement in the radial direction (center misalignment) may occur, and the processing accuracy may be reduced. The work drivers 14 and 24 are movable in the radial direction (vertical direction in the drawing) to eliminate misalignment, and are aligned for matching the center of the pin portion 55 and the rotation center of the crankshaft 50. Functions as a means.

  In other words, the work drivers 14 and 24 change the positions of the chucks 15 and 25 so that the center position of the pin portion 55 is set in the direction in which the center of the pin portion 55 to be machined and the rotation center of the crankshaft 50 coincide with each other. It is possible to adjust in the radial direction. Therefore, even when the crankshaft 50 having low rigidity is rotated at a high speed, the roundness and cylindricity of the pin portion 55 can be reliably ensured.

  The processing device 30 positions the grinding wheel 31 as a processing tool for grinding, a coolant supply unit (not shown) for discharging coolant to the processing part of the pin portion 55, and the grinding wheel 31 at the processing part. Positioning means (not shown).

  The grinding wheel 31 is not particularly limited, and the kind of abrasive grains, the grain size, the kind of binder, and the average grain diameter of the abrasive grains can be appropriately selected. For example, high-precision processing is possible and the finished surface is good. And vitrified type which is excellent in durability.

  Since the grinding wheel 31 can be brought into uniform contact with the processing site based on the displacement of the actuators 16 and 26, uneven wear can be suppressed and the life of the wheel can be extended.

  The displacement detection device 40 includes a first laser displacement meter 41 and a second laser displacement meter 42 which are detection means spaced apart from the pin portion 55 and arranged along the central axis of the pin portion 55.

  The first laser displacement meter 41 and the second laser displacement meter 42 are set to detect displacement amounts at both ends of the processed portion of the pin portion 55, and detect the displacement amount and inclination of the pin portion 55 of the crankshaft 50. Is possible.

  Therefore, even if the shape of the crankshaft 50 to be machined varies, an appropriate deflection can be imparted to the crankshaft 50 based on the amount of displacement of the pin portion 55, and good machining is possible. It is possible to ensure the accuracy (roundness and cylindricity of the pin portion) with certainty.

  In addition, the displacement detection apparatus 40 is not limited to having a plurality of detection means, and the configuration can be simplified by having a single detection means. Further, the detection means is not limited to the laser type, and other appropriate methods can be applied.

  The control device manages, for example, forcible application of deflection to the crankshaft, and outputs signals from the first laser displacement meter 41 and the second laser displacement meter 42, that is, detected displacement amount data of the pin portion 55. And the movement of the main shaft 13 in the axial direction, the displacement amount of the actuators 16 and 26 (the inclination amount of the chucks 15 and 25), and the vertical movement of the work drivers 14 and 24 are controlled. .

  As described above, the embodiment of the present invention can provide a crankshaft machining apparatus having good machining accuracy and machining efficiency.

  Next, a crankshaft machining method according to an embodiment of the present invention will be described.

  4 to 6 are graphs for explaining output signals of the first laser displacement meter and the second laser displacement meter. FIG. 4 is a diagram showing a case where the crankshaft is rotated at a low speed, and FIG. FIG. 6 shows the state after the inclination of the crankshaft pin is eliminated.

  The pin part to be processed has a complete cylindrical shape (both roundness and cylindricity are 0 μm), and the distance from the crank journal (holding center) located at the end of the crankshaft to the center of the pin part is It is assumed that the median value shown in the figure (1/2 stroke median value) is obtained. Further, the first laser displacement meter 41 and the second laser displacement meter 42 constantly monitor the displacement amount of the pin portion 55A while the crankshaft 50 is rotating.

First, the main shafts 13 and 23 are rotated at a low speed not affected by the centrifugal force, for example, 100 min ⁻¹ or less. The control device stores output signals (see FIG. 4) from the first laser displacement meter 41 and the second laser displacement meter 42 during low-speed rotation.

Thereafter, the main shafts 13 and 23 are raised to the number of rotations during processing, for example, 300 min ⁻¹ or more, and the main shafts 13 and 23 are rotated at a high speed. Since the crankshaft 50 bends under the action of centrifugal force (see FIG. 2), the first laser displacement meter 41 and the second laser displacement meter 42 generate output signals having the waveforms shown in FIG.

  Next, by driving and displacing the actuators 16 and 26, the chucks 15 and 25 are tilted, and the crankshaft 50 is forcibly bent.

  At this time, the control device controls the displacement amounts of the actuators 16 and 26 so that the output signals of the first laser displacement meter 41 and the second laser displacement meter 42 coincide (see FIG. 6). Thereby, the inclination of the pin portion 55A of the crankshaft 50 is eliminated, and the positional relationship between the processed portion of the pin portion 55A and the grinding wheel 31 becomes parallel.

  Thereafter, the control device drives the work drivers 14 and 24 so that the output signals of the first laser displacement meter 41 and the second laser displacement meter 42 substantially coincide with those at the time of low speed rotation (see FIG. 4). Move up and down. Thereby, the positions of the chucks 15 and 25 are changed, and the center position of the pin portion 55A is adjusted in the radial direction, so that the center of the pin portion 55A and the rotation center of the crankshaft 50 coincide with each other, and misalignment occurs. It will be resolved.

  And coolant is discharged from the coolant supply part of the processing apparatus 30, and the pin part 55A is processed by grinding of the grinding wheel 31.

At this time, since the crankshaft 50 is forcibly bent in a direction opposite to the direction in which it is deformed by receiving centrifugal force, the outer peripheral surface, which is the processed portion of the pin portion 55A, is parallel to the grinding wheel 31. It is. Therefore, even if the rotational speed at the time of processing is 300 min ⁻¹ or higher, the grinding wheel 31 is uniformly in contact with the processing site, so that the roundness and cylindricity of the pin portion are ensured.

  In addition, since the deflection for uniformly bringing the grinding wheel 31 into contact with the processing site is controlled based on the amount of displacement of the pin portion, even if there is a variation in the shape of the crankshaft 50 to be processed, good processing is possible. Accuracy (roundness and cylindricity of the pin part) is reliably ensured.

  Then, after finishing the processing of the pin portion 55A, the grinding wheel 31 is moved to the position of the pin portion 55B that is the next processing object, positioned, and the pin portion 55B is processed. At this time, it is also preferable to execute again the above adjustment for eliminating the tilt and misalignment based on the output signals of the first laser displacement meter 41 and the second laser displacement meter 42.

  As described above, the embodiment of the present invention can provide a crankshaft machining method having good machining accuracy and machining efficiency.

  In response to the change in the distance between the main shafts caused by the deflection of the crankshaft 50, the chuck 15 is moved in the axial direction, the distance between the chucks 15 and 25 is changed, and the holding force of the holding means exerted on the crankshaft. It is also preferable to prevent the decrease of the above.

It is a side view for demonstrating the crankshaft processing apparatus which concerns on embodiment of this invention. It is a side view for demonstrating the centrifugal force by the rotation which acts on a crankshaft. It is a side view for demonstrating the bending forcibly provided to a crankshaft. It is a graph for demonstrating the output signal of a 1st laser displacement meter and a 2nd laser displacement meter, and has shown at the time of low-speed rotation of a crankshaft. It is a graph for demonstrating the output signal of a 1st laser displacement meter and a 2nd laser displacement meter, and has shown at the time of high-speed rotation of a crankshaft. It is a graph for demonstrating the output signal of a 1st laser displacement meter and a 2nd laser displacement meter, and has shown after inclination cancellation in the pin part of a crankshaft.

Explanation of symbols

10. ・ Holding part,
11, 21, ... spindle head,
12, 22 ... Bearings
13, 23 ... Spindle,
14, 24 ... Work driver,
15, 25 .. Chuck (holding means),
16, 26 .. Actuator (deformation means),
23 .. Spindle,
30. ・ Processing equipment,
31. ・ Grinding wheel,
40. ・ Displacement detector,
41..Laser displacement meter,
42 .. Laser displacement meter,
50 ・ ・ Crankshaft,
51, 52 .. end,
55, 55A, 55B .. Pin part.

Claims (9)

A holding means that is disposed at an end of the crankshaft and that holds the crankshaft eccentrically so that a central axis of a pin portion of the crankshaft is a rotation center;
When processing the pin portion, forcibly imparting deflection to the crankshaft in a direction opposite to the direction in which the crankshaft held by the holding means is deformed by receiving a centrifugal force. A crankshaft machining apparatus, comprising:   The crankshaft machining apparatus according to claim 1, further comprising a moving means for moving at least one of the holding means in the axial direction.   The crankshaft machining apparatus according to claim 1, further comprising a detecting unit for detecting a displacement amount of the pin portion.   4. The crankshaft machining apparatus according to claim 3, wherein a plurality of the detection means are disposed apart from the pin portion and along a central axis of the pin portion. 5.   The crankshaft machining apparatus according to any one of claims 1 to 4, further comprising an aligning means for causing the center of the pin portion and the rotation center of the crankshaft to coincide with each other.   The crankshaft processing apparatus according to any one of claims 1 to 5, wherein the processing is grinding processing and includes a processing tool made of a grinding wheel. The crankshaft is rotated around the center axis of the pin portion of the crankshaft,
A crankshaft machining method characterized by forcibly imparting deflection to the crankshaft in a direction opposite to a direction in which the crankshaft receives a centrifugal force and deforming, and machining the pin portion. .   8. The crankshaft machining method according to claim 7, wherein a deflection that is compulsorily applied to the crankshaft is controlled based on detecting a displacement amount of a pin portion of the crankshaft.   The crankshaft machining method according to claim 7 or 8, wherein the machining is grinding using a grinding wheel as a machining tool.

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