JPH0329098Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a grinding wheel correction device for a grinding machine.

(Prior Art) In general, grinding machines are equipped with a grinding wheel correction device (hereinafter referred to as a dresser) equipped with a correction tool having a diamond tool because it is necessary to appropriately correct the shape of the grinding wheel used to grind the workpiece. ing. However, since the shape of the grindstone determines the machining accuracy of the workpiece, a high degree of precision is required to correct the shape. On the other hand, since the shape of the grindstone is a crowned shape or the like, in order to correct the grindstone, it is necessary to move the correction tool of the dresser back and forth by a small amount in a direction perpendicular to the direction of the rotation axis of the grindstone.

Conventionally known means for advancing and retracting the correction tool include those that move the correction tool forward and backward using a ball screw screwed by a motor, or as described in Japanese Patent Application Laid-Open No. 59-61467, the movement of the correction tool is moved forward and backward using a magnetostrictive element. There was one that made use of displacement.

(Problems to be solved by the invention) In the former case, not only does the mechanism become complicated, but also the back-cracking of the ball screw when the correction tool shifts from forward operation to backward operation (i.e., the thread in the screw gap sliding)
In the latter case, a magnetic generator is required, which complicates the structure, and there is a risk that chips may be attracted by the magnetism.

This invention was made in view of the above points,
The object of this invention is to enable highly accurate shape correction to be performed using an extremely simple-structured device.

(Means for Solving the Problems) In the present invention, as means for solving the above problems, the present invention includes a dresser body movably supported with respect to the grinding machine body, and a grindstone that is attached to the dresser body. In a grinding wheel correction device for a grinding machine, which includes a correction tool for correcting the shape of a grindstone supported so as to be movable in a direction perpendicular to a rotation axis, an applied voltage is provided between the correction tool and the dresser body. interposing a laminated piezoelectric element that acts to displace the correction tool through an expansion and contraction operation;
a grindstone position detector that detects the position of the grindstone in the rotation axis direction; and control that controls voltage applied to the laminated piezoelectric element in accordance with the position of the grindstone in the rotation axis direction obtained from the grindstone position detector. It is equipped with equipment.

(Function) In the present invention, the following effects can be obtained by the above means.

When attempting to correct the shape of a grindstone for processing a workpiece, the grindstone is rotated and moved in the direction of the grinding wheel's rotational axis, and the position of the grindstone in the direction of the rotational axis is detected by a grindstone position detector. , when the voltage applied to the laminated piezoelectric element is controlled by a control device in accordance with the position in the rotation axis direction of the grindstone obtained from the grindstone position detector, the laminated piezoelectric element is expanded and contracted by the applied voltage control; As the laminated piezoelectric element expands and contracts, the correction tool is moved forward and backward from a direction perpendicular to the grindstone rotation axis,
The shape of the grindstone is corrected using the correction tool. At this time, the control device controls the applied voltage so that the desired shape of the grinding wheel is obtained using a set value that is calculated in advance based on the amount of movement of the grinding wheel relative to the grinding machine body and the amount of advance and retreat of the correction tool. It acts on Note that the laminated piezoelectric element normally causes a hysteresis phenomenon in which a difference in displacement occurs when the voltage increases and when the voltage decreases, but the control device also performs correction to eliminate the hysteresis phenomenon.

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

The grinding machine of this embodiment includes a cutting table 2 and a grindstone table 3 that are movable on a grinding machine body 1 in directions orthogonal to each other.

The cutting table 2 is moved by a cutting motor 4, and a main shaft motor 5 and a main shaft 6 driven by the main shaft motor 5 are installed on the upper surface thereof. The main shaft 6 is provided with a work chuck 7 for holding a work 8, which is a workpiece.

A wheel head 9 equipped with a whetstone 10 is provided on the whetstone table 3, and the whetstone table 3 is arranged such that the whetstone 10 faces the workpiece 8 held by the main shaft 6 (that is, the whetstone 10 (in the direction of the rotational axis). Note that the grindstone 10 is rotated via a rotating shaft 11 by driving the wheel head 9.

Further, on the cutting table 2, the grinding wheel 1
A dresser 12 is provided which acts as a grindstone correction device for correcting the shape of the 0.

As shown in FIG. 2, the dresser 12 is a dresser main body 1 supported movably relative to the grinder main body 1 so as to interlock with the cutting table 2.
3, and the grindstone 1 is attached to the dresser main body 13.
The correction tool 15 is supported so as to be movable forward and backward in a direction perpendicular to the rotating shaft 11 of the rotary shaft 11.

The modification tool 15 includes a diamond tool 22 for modifying the shape of the grindstone 10, and a holder 23 for holding the diamond tool 22. They are swingably connected via leaf springs 16, 16. Reference numeral 17 is a connector for connecting the leaf spring 16 and the holder 23.

Further, a guide portion 24 is provided at the rear end of the holder 23.
The guide portion 24 is slidably inserted into the guide groove 14 formed in the dresser main body 13.

Furthermore, the dresser main body 13 and the correction tool 1
5 (i.e., between the guide portion 24 and the guide groove 1
4), there are a number of piezoelectric elements 19, 1
A laminated piezoelectric element 18 configured by laminating 9 is interposed. The laminated piezoelectric element 18 expands and contracts in response to applied voltage, and acts to move the correction tool 15 forward and backward by the expansion and contraction action.

With the above configuration, in this dresser 12, the correction tool 15 moves forward and backward toward the grindstone 10 according to the voltage applied to the laminated piezoelectric element 18 (in other words, the amount of expansion and contraction of the laminated piezoelectric element 18). This is what we are learning to do.

The voltage applied to the laminated piezoelectric element 18 is controlled by a control device 21 that receives a signal from a grindstone position detector 20 that detects the position of the grindstone 10 in the rotation axis direction (in other words, the position of the grindstone table 3). be done. As the grindstone position detector 20, a linear scale that emits a pulse signal for each unit movement amount of the grindstone table 3 is adopted.

Note that the whetstone 10 has a crowning shape.
In this case, it is necessary to expand and contract the laminated piezoelectric element 18 in response to the forward motion of the grinding wheel 10 in the direction of the rotation axis, and move the correction tool 15 forward and backward by the expansion and contraction. Since a so-called hysteresis phenomenon occurs, in which a difference occurs in the amount of displacement depending on the voltage drop and the voltage drop, it is necessary to correct this phenomenon. This hysteresis correction is performed by determining the degree of voltage drop when the correction tool 15 moves backward (in other words, when the applied voltage drops) rather than the voltage rise when the correction tool 15 moves forward (in other words, when the applied voltage increases). This is done by controlling the voltage by the control device 21 so that the voltage is increased.

In addition to the methods described above, methods for performing this hysteresis correction include a method in which the dresser 12 is moved in advance and the deviation from the calculated value is corrected, and a method in which the movement position of the correction tool 15 is detected on the dresser 12 side as well. It is also possible to adopt a method in which a scale is provided to perform feedback control, a method in which the piezoelectric elements 19, 19, .

Next, the operation of the illustrated grinding wheel correction device will be explained.

When trying to modify the shape of the grinding wheel 10 for processing a workpiece, the grinding machine body 1 is rotated while the grinding wheel 10 is being rotated.
A control device 2 detects the position of the grinding wheel 10 in the direction of the rotation axis by a linear scale 20, and receives a pulse signal from the linear scale 20.
1 controls the voltage applied to the laminated piezoelectric element 18 in accordance with the position of the grinding wheel 10 in the rotation axis direction, the applied voltage control causes the laminated voltage element 18 to expand and contract in accordance with the shape of the grinding wheel 10, As the laminated piezoelectric element 18 expands and contracts, the correction tool 15 is moved forward and backward in a direction perpendicular to the grindstone rotating shaft 11 in accordance with the shape of the grindstone,
The shape of the grindstone 10 is corrected by the diamond tool 22 of the correction tool 15. In other words, by using extremely simple control means such as controlling the voltage applied to the laminated piezoelectric element 18, it is possible to modify the shape of the grinding wheel 10 to have an arbitrary profile with a very small amount and with high precision.

It goes without saying that the present invention is not limited to the embodiments described above, and that the design can be modified as appropriate without departing from the gist of the invention.

(Effects of the Invention) As described above, according to the present invention, between the dresser body and the repair tool supported so as to be freely extendable and retractable in the direction orthogonal to the rotation axis of the grindstone relative to the dresser body, A control device that receives a signal from a grindstone position detector that detects the position of the grindstone in the rotational axis direction, and includes a laminated piezoelectric element that acts to displace the correction tool by an expansion and contraction operation corresponding to an applied voltage. Therefore, since the voltage applied to the laminated piezoelectric element is controlled in accordance with the position of the grinding wheel in the rotational axis direction, the voltage applied to the laminated piezoelectric element is controlled by an extremely simple control means. This allows the correction tool to be displaced by a minute amount, and has the practical effect of making it possible to extremely easily correct the shape of a grindstone having an arbitrary profile with high precision.

[Brief explanation of drawings]

FIG. 1 is a plan view schematically showing a grinding machine according to an embodiment of the present invention, and FIG. 2 is a longitudinal sectional side view of a grinding wheel correction device in the grinding machine of FIG. 1... Grinding machine body, 10... Grinding wheel, 11... Rotating shaft, 13... Dresser body, 15... Correction tool, 18... Laminated piezoelectric element, 20... Grinding wheel position detector (linear scale), 21...control device.

Claims (1)

[Scope of utility model registration request] a dresser body supported movably relative to the grinding machine body; a correction tool for modifying the shape of the grindstone supported so as to be movable forward and backward relative to the dresser body in a direction perpendicular to the rotation axis of the grindstone; interposed between the correction tool and the dresser main body,
a laminated piezoelectric element that acts to displace the correction tool by an expansion/contraction action corresponding to an applied voltage; a grindstone position detector that detects the position of the grindstone in the rotation axis direction; A grinding wheel correction device for a grinding machine, comprising: a control device that controls voltage applied to the laminated piezoelectric element in accordance with the position of the grinding wheel in the rotational axis direction.