JP3786327B2 - Touch probe support mechanism on the grinding wheel head - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a touch probe capable of selectively turning a touch probe used for accurately grasping a distance between a truing tool and a grindstone to a grinding point position and a retreat position that does not interfere with grinding work in a grinding machine. It is related with the support mechanism.
[0002]
[Prior art]
Conventionally, a touch probe in a grinding machine is mainly provided for positioning a workpiece. For example, as disclosed in Japanese Utility Model Publication Nos. 4-17325 and 7-111885, this kind of contact detector support mechanism is provided. The arm with the contact detector attached to the tip is supported on the grinding wheel base so that it can turn around an axis parallel to the workpiece rotation axis, and the arm is moved in a plane that crosses the workpiece rotation axis by linear motion or a rotary cylinder. The probe can be selectively positioned at a downward retracted position where the probe of the contact detector is retracted to the front side of the wheel head and a detection position protruding laterally in front of the wheel head.
[0003]
[Problems to be solved by the invention]
However, in these probe support mechanisms, even when the detector is positioned at either the retracted position or the detection position, the detector and its probe are in the approach position of the grindstone, and the workpiece is being ground by this grindstone. It is easily exposed to grinding dust and coolant and contaminated.
[0004]
In addition, the operating point of the detection signal output from the detector when the probe of the detector is displaced in contact with the object to be detected and the grindstone base (that is, the grinding surface of the grindstone) are set in a predetermined relative position in advance. However, if the detector breaks down and is replaced with another detector, this relative positional relationship is lost, and it is necessary to reset the relative position between the operating point of this new detector and the grinding wheel base. This resetting operation dominates the positional relationship between the grindstone platform and the workpiece whose relative position is NC-controlled, and therefore must be performed with sufficient care and is a laborious operation.
[0005]
Further, since the pivot axis of the arm is provided at the front part of the grindstone platform and is deviated from the rotation axis of the grindstone shaft toward the workpiece, thermal deformation of the portion of the grindstone table corresponding to this deviation amount becomes a detection error. In other words, the NC control amount of the grinding wheel base is normally instructed to the NC program from the viewpoint of positioning the grinding wheel rotation axis with respect to the work, so the relative position of the grinding wheel base and the work in the forward direction. Is detected at a position deviated from the rotation axis of the grindstone shaft, there is a problem that a machining error is generated by the amount of the deviation.
[0006]
The present invention has been made in view of the above-described problems, and is not contaminated by grinding dust or coolant during a grinding operation, and is easy to set up and has a high position measurement accuracy. It is an object to provide a touch probe support mechanism in a table.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, the touch probe support mechanism in the wheel head of the numerically controlled grinding machine of the present invention is:
A swivel arm support mechanism is mounted on the upper surface of the grindstone table, the swivel arm is supported by the swivel arm support mechanism in a turnable manner, and a touch probe that outputs an electrical signal is provided at the tip of the swivel arm,
The turning axis of the turning arm is an axis extending perpendicularly to the surface including the grinding point of the grinding wheel on the rotation axis of the grindstone and extending across the rotation axis of the grinding stone, and the turning arm is formed of a low thermal expansion material. ,
The swivel arm is selectively position data Tchipurobu detection position to advance to the vicinity of the grinding point of the grinding wheel, in a retracted position approaching from the detection position to the side of the wheel head retracted in a direction away from the grinding wheel It is characterized by being possible.
[0008]
Further, the touch probe support mechanism in the wheel head of the numerically controlled grinding machine of the present invention is characterized in that the reference surface member that contacts the touch probe positioned at the retracted position is fixed to the side surface of the wheel head.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Touch probe support mechanism in the wheel head of the numerically controlled grinding machine of the present invention,
A swivel arm support mechanism is mounted on the upper surface of the grindstone table, the swivel arm is supported by the swivel arm support mechanism in a turnable manner, and a touch probe that outputs an electrical signal is provided at the tip of the swivel arm,
The swivel arm has a swivel axis that extends perpendicularly to the surface including the grinding point of the grindstone on the rotation axis of the grindstone and that extends across the rotation axis of the grindstone, and the swivel arm is a low thermal expansion material such as Invar. Formed with
The swivel arm is selectively position data Tchipurobu detection position to advance to the vicinity of the grinding point of the grinding wheel, in a retracted position approaching from the detection position to the side of the wheel head retracted in a direction away from the grinding wheel Since it is possible, it is not contaminated by grinding debris or coolant during grinding, the influence of thermal deformation of the wheel head can be reduced, and high accuracy can be maintained.
[0011]
The touch probe support mechanism in the wheel head of the numerically controlled grinding machine of the present invention is a new touch by fixing a reference surface member having a reference surface contacting the touch probe positioned at the retracted position to the side surface of the wheel head. Adjustment of the probe is simplified when the probe is set, and the operation of the contact detector can be checked in a normal case.
[0013]
【Example】
Next, an embodiment of the present invention will be described with reference to FIGS.
The present invention is mainly applied to a numerically controlled grinder, and the cylindrical grinder will be described. A work table 2 slidably guided in the Z-axis direction is provided on a sliding guide surface formed on the upper surface of the bed 1, and a headstock 3 and a tailstock (not shown) are placed on the work table 2. The work W is rotatably supported between the center 4 of the head stock 3 and the center of the tailstock. The work table 2 can be controlled and moved in the Z-axis direction with respect to the bed 1 by numerical control or the like by a known method. On one bed 1, a grinding wheel base 6 is placed on a sliding guide surface 5 in the X-axis direction perpendicular to the moving direction of the work table 2, and the grinding wheel base 6 has a CBN grinding wheel 7 fixed to one end. A bearing 8 is rotatably supported and is driven to rotate by a grindstone drive motor 9. The grindstone bed 6 can be controlled and moved in the X-axis direction with respect to the bed 1 by a numerical control or the like using a known feed screw 10 and nut 11.
[0014]
A swivel arm support mechanism 20 is provided on the upper surface of the grindstone table 6, and the swivel arm support mechanism 20 extends perpendicularly to the rotation axis of the grindstone shaft 8 and the surface including the grinding point P and extends across the rotation axis. A pivot 21 is provided, and a pivot arm 24 is pivotally supported by the pivot 21. A rotary cylinder 25 is fixed to the upper part of the pivot 21 of the swivel arm 24, and a dog 26 for operating a limit switch 29 for restricting the rotation angle is provided at the upper end of the rotary cylinder 25. The swivel arm 24 has a front portion bent vertically downward to form an L shape, and supports a contact detector 23 having a touch probe 22 at the tip at the lower end thereof. The tip of the touch probe 22 forms a spherical contact portion, and the spherical tip is substantially aligned with the grinding point P of the CBN grindstone 7 and is disposed on a line connecting the central axis of the grindstone 7 and the center line of the workpiece W. The swivel arm 24 can be swung and positioned between a detection position where the swivel arm 24 is perpendicular to the Z-axis and a retracted position where the touch probe 22 approaches the side surface of the grindstone table 6. The swivel arm 24 is made of a low thermal expansion material such as Invar, thereby preventing the length of the touch probe 22 and the pivot 21 from changing due to thermal expansion.
[0015]
A reference surface member 27 is fixed to a side surface of the grindstone table 6 facing the work table 2, and a reference surface member 27 is fixed on the spherical surface of the touch probe 22 at the retracted position. The reference surface 28 is at the retracted position. It is formed to be perpendicular to a line connecting the tip of a touch probe 22 and the pivot 21 of the swing arm 24. The reference surface member 27 is configured so that a predetermined electrical signal is output from the detector 23 when the touch probe 22 comes into contact with the reference surface member 27. When the contact detector 23 fails and is replaced with a new one. The set distance between the tip spherical portion of the touch probe 22 and the grinding wheel axis position can be easily reproduced to the set distance before the failure. Further, prior to turning the touch probe 22 to the detection position, it also has a function of checking the operation of the contact detector 23. The contact detector 23 is of a type that outputs an analog or digital electric signal, but may be a type that outputs a simple on / off signal.
[0016]
On the other hand, the spindle head 3 is provided with a truing device 31 for sharpening a grindstone on the side surface facing the grinding wheel pedestal 6, and the truing device 31 can rotate a tool shaft supporting a rotary truing tool 32 at the tip. And is configured to be rotationally driven by a motor 33 provided at the other end.
Further, a transfer pin 34 is fixed to the side surface of the headstock 3 near the workpiece W of the truing tool 32 by a holder 35, and the tip of the transfer pin 34 is made to substantially coincide with the outer diameter surface of the truing tool 32. .
Reference numeral 40 denotes a grindstone guard provided on the grindstone base 6 so as to cover the grindstone.
[0017]
Next, the operation of the embodiment of the present invention will be described.
The contact detector 23 with the touch probe 22 of the present invention is used to detect the tip position of a truing tool in order to calculate the grindstone diameter prior to the truing operation of the grindstone as an example of the usage pattern.
First, the work table 2 is moved to align the transfer pin 34 with the grindstone 7, the grindstone base 6 is advanced by the feed screw 10, and the transfer pin 34 is ground by a predetermined minute amount with the grindstone 7. Whether or not the grinding has been performed is confirmed by an AE sensor (not shown), the grinding wheel base 6 is stopped at that position, and the position is stored.
[0018]
Next, the rotary cylinder 25 of the turning arm support mechanism 20 is operated, the turning arm is turned to the detection position by the action of the dog 26 and the limit switch 29, the work table 2 is moved in the Z direction, and the transfer pin 34 is detected in contact. The grinding wheel base 6 is moved forward until a predetermined electrical output is obtained from the contact detector 23, the grinding wheel base 6 is stopped, and its position is stored.
Based on the advance position of the grinding wheel base 6 in which the transfer pin 34 is ground by a minute amount, the advance position of the grinding wheel base 6 at which a predetermined electrical output is obtained from the contact detector 23, and the distance between the pivot 21 to the touch probe 22, CBN The grindstone diameter of the grindstone 7 is calculated.
[0019]
Next, after moving the work table 2 in the Z direction again to align the touch probe 22 and the truing tool 32 whose rotation has been stopped, the grindstone platform until a predetermined electrical output is obtained from the contact detector 23. 6 is advanced, and the tip position of the truing tool 32 is detected.
When the detection ends, the rotary cylinder 25 is actuated again, the turning arm 24 is turned, and the touch probe 22 is retracted to the side surface of the grindstone bed that does not affect the processing. In this retracted position, the touch probe 22 comes into contact with the reference surface 28 of the reference surface member 27 fixed to the side surface of the grindstone.
[0020]
Based on these data, when the CBN grindstone 7 is trued by the truing tool 32 that is rotated thereafter, a predetermined minute notch can be accurately given to the grindstone 7, and the height based on the accurate grindstone diameter data can be obtained. Precision grinding work can be performed.
As mentioned above, although what was applied to the cylindrical grinder was demonstrated as an Example of this invention, it cannot be overemphasized that it can apply also to other grinders, such as a cylindrical grinder with an angle grindstone base, and a surface grinder, for example. Absent.
[0021]
【The invention's effect】
With the configuration as described above, the touch probe support mechanism in the grinding wheel base of the numerically controlled grinding machine of the present invention is a direction in which the touch probe moves away from the grinding wheel from the detection position where the touch probe advances in the vicinity of the grinding point of the grinding wheel. Therefore, it is possible to retreat to a retreat position that approaches the side surface of the grindstone table, so that it is not contaminated by grinding debris or coolant during the grinding process, failure can be reduced, and high accuracy can be maintained for a long time. At the same time, the swivel axis of the swivel arm is an axis extending perpendicularly to the surface including the grinding point of the grindstone on the rotation axis of the grindstone and extending across the rotation axis of the grindstone. Is the same as the distance between the grinding wheel axis and the grinding wheel grinding point, and in an NC control grinding machine, it is usually controlled by the position of the rotational axis of the grinding wheel. Compared to the one mounted closer to the grinding wheel grinding point than the rotation axis, there is no influence of thermal deformation of the wheel head, the influence of thermal deformation on the measurement result of the touch probe can be reduced, and the swivel arm Higher accuracy can be maintained by forming the inflatable material. Therefore, a highly accurate grinding operation can be performed .
[0022]
Further, the touch probe support mechanism in the wheel head of the numerically controlled grinding machine according to the present invention causes the contact detector to break down when the touch probe positioned at the retracted position contacts the reference surface member fixed to the side surface of the wheel head. When the touch probe is replaced with a new one, the set distance between the tip spherical portion of the touch probe and the grinding wheel axis position can be easily reproduced to the set distance before the failure, and prior to turning the touch probe to the detection position It is also possible to check the operation of the contact detector.
[Brief description of the drawings]
FIG. 1 is a plan view of a main part of a cylindrical grinder provided with a contact detector support mechanism according to an embodiment of the present invention.
FIG. 2 is a right side view of the grinding machine shown in FIG.
FIG. 3 is a front view of a grindstone table shown by cutting a part of the grinding machine shown in FIG. 1;
[Explanation of symbols]
1: Bed 2: Work table 3: Headstock 6: Grinding wheel base 7: CBN grinding wheel 20: Turning arm support mechanism 22: Touch probe 23: Contact detector 24: Turning arm 27: Reference surface member 32: Truing tool 34: Transfer Pin W: Workpiece P: Grinding point

Claims (2)

A swivel arm support mechanism is mounted on the upper surface of the grindstone table, the swivel arm is supported by the swivel arm support mechanism in a turnable manner, and a touch probe that outputs an electrical signal is provided at the tip of the swivel arm,
The turning axis of the turning arm is an axis extending perpendicularly to the surface including the grinding point of the grinding wheel on the rotation axis of the grindstone and extending across the rotation axis of the grinding stone, and the turning arm is formed of a low thermal expansion material. ,
The swivel arm is selectively position data Tchipurobu detection position to advance to the vicinity of the grinding point of the grinding wheel, in a retracted position approaching from the detection position to the side of the wheel head retracted in a direction away from the grinding wheel A touch probe support mechanism for a wheel head of a numerically controlled grinding machine, which is possible. 2. The touch probe support mechanism for a grindstone bed of a numerically controlled grinding machine according to claim 1, wherein a reference surface member that contacts the touch probe positioned at the retracted position is fixed to a side surface of the grindstone bed.

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