JPS63191559A - Swivel device for grinding machine - Google Patents

Abstract

PURPOSE:To set a cut-in angle of a grinding wheel quickly and accurately by obtaining the gradient angle of a grinding wheel based on a signal from a means for detecting the amount of deflection of the wheel spindle, thereby controlling the swivel angle of a wheel base via a piezoelectric element according to the obtained gradient angle. CONSTITUTION:A grinding process is performed by sliding a headstock 2 and a grinding wheel table 3 according to a preset control program so that an inner circumferential surface to be ground of a workpiece 5 is ground with a peripheral surface of a grinding wheel 11. At the same time, a changeover switch 23 is switched so that the deflection amount of a wheel spindle 9 is obtained at an operation section 18 based on a signal from a deflection amount detection means 17, a control signal for correcting the gradient condition of the wheel 11 is given to swivel control sections 19 and 20, the voltage applied to a piezoelectric element 14 is increased and the voltage applied to a piezoelectric element 15 is decreased to make the wheel spindle stock 10 swivel about a swivel pivot 9, and that the swivel angle is fine-controlled. After finishing the grinding process, the switch 23 is returned to the side of the gradient angle detection means 22 so that the wheel 10 becomes parallel with a spindle 6. In this way, the cut-in angle of the wheel can be controlled to an optimum condition quickly and accurately.

Description

Detailed Description of the Invention (Industrial Application Field) This invention provides a grinding machine equipped with a grinding wheel for grinding an object to be ground, in which the cutting angle of the grinding wheel is adjusted according to the amount of deflection of the grinding wheel shaft that occurs during grinding. This invention relates to a swivel device for a grinding machine.

(Prior art) The grinding wheel shaft of a grinding machine with a grinding wheel attached to its tip is usually supported on a grinding wheel head in a cantilevered state, so the grinding wheel shaft tends to be bent due to the grinding resistance that acts during grinding. If grinding is continued while ignoring the deflection, there is a problem that the grinding surface will be machined into a tapered shape and the finishing accuracy will deteriorate. In order to prevent the occurrence of the above-mentioned grinding defects, conventionally, for example,
As shown in Japanese Patent Application No. 2551, the cutting angle of the grindstone is adjusted by swinging the headstock on which the work to be ground is mounted or the above-mentioned grindstone head using a swivel drive means consisting of a screw feed mechanism. .

However, in conventional devices configured to oscillately displace a grinding wheel head or the like using a swivel drive means consisting of the screw feeding mechanism described above, an electric motor is used as the drive source.
There is a problem in that it is difficult to finely adjust the screw feed group, and the rocking displacement speed cannot be increased to such a large extent that quick and accurate control cannot be performed.

(Object of the Invention) The present invention was made to solve the above-mentioned problems, and has a simple structure that quickly and accurately oscillates the grindstone head around the swivel fulcrum to adjust the cutting angle of the grindstone. To provide a swivel device for a grinding machine that can be properly adjusted.

(Structure of the Invention) This invention provides a grindstone table supported swingably about a swivel fulcrum on a grindstone table, a grindstone shaft rotatably supported on the grindstone table, and a grindstone shaft from the swivel fulcrum. a piezoelectric element installed on a grinding wheel table at a position shifted in the axial direction of the grinding wheel table and disposed so that its tip abuts on the grinding wheel head, a detection means for detecting the deflection base of the grinding wheel shaft, and this detection means. and control means for determining the inclination angle of the grindstone based on the detection signal output from the grinding wheel and outputting a swivel control signal to the piezoelectric element to extend or contract the piezoelectric element in accordance with the inclination angle of the grindstone.

According to the above configuration, the amount of expansion and contraction of the piezoelectric element is set based on the swivel control signal output from the control means in accordance with the deflection angle of the grinding wheel shaft, and the inclination angle of the grinding wheel is adjusted to an appropriate state accordingly. The grindstone head is oscillated about the swivel fulcrum so that

(Example) FIG. 1 shows an example of a grinding machine equipped with a swivel device according to the present invention, and this grinding machine includes a base 1, a headstock 2 and a grindstone table 3 installed on the base 1, It is equipped with a crowning dresser 4.

On the headstock 2, there are provided a main spindle 6 having an object to be ground 5 attached to its tip, and a main spindle drive motor 7 for rotationally driving the main spindle 6. The headstock 2 is slidably displaced on the base 1 in a direction perpendicular to the axial direction of the spindle 6 by driving a screw feed mechanism (not shown) provided on the lower surface by a cutting motor 8. It is composed of

On the above-mentioned whetstone table 3, a whetstone stand 10 is placed at a swivel fulcrum 9.
It is supported so that it can swing freely around the center.

A whetstone shaft 12 having a whetstone 11 attached to its tip end is rotatably supported on the whetstone head 10, and the whetstone shaft 12 is configured to be driven by a drive motor (not shown).

The grindstone table 3 is slidably displaced on the base 1 in the axial direction of the grindstone shaft 12 by a screw feeding mechanism (not shown) provided on the lower surface being driven by the grindstone table drive motor 13. It is composed of Further, the crowning dresser 4 dresses the circumferential surface of the grindstone 11 into a shape corresponding to the grinding surface of the object 5 to be ground.

Further, the swivel fulcrum 9 is placed on the grindstone table 3.
A pair of piezoelectric elements 1 whose tips come into contact with the sides of the grindstone head 1o at a position shifted rearward in the axial direction of the grindstone shaft 12.
4.15 is installed.

This piezoelectric element 14, 15 is an actuator formed by a large number of piezoelectric ceramic discs electrically connected in parallel, and has a voltage that corresponds to a swivel control signal output from the control means 16 shown in FIG. is applied, the grinding wheel head 10 expands and contracts, centering on the swivel fulcrum 9.
It is designed to swing and displace quickly and accurately. The control means 16 receives a detection signal output from a non-contact type deflection amount detection means 17 which is installed upright on the grindstone table 3 and measures the amount of deflection of the grindstone shaft 12 by measuring the distance between it and the grindstone shaft 12. a calculation section 18 that calculates the inclination angle of the grindstone 10 according to the calculation section 18; and a swivel control section 19.
A voltage control section 21 outputs an 1lIII control signal to control the voltage value applied to the voltage element 20, and control for extending one of the voltage elements 14 and 15 and contracting the other from the voltage control section 21 during grinding. By outputting a signal and causing the grindstone 10 to generate a moment about the swivel fulcrum 9, the grindstone 10 is oscillated in a direction that corrects the inclination of the grindstone 11.

Further, on the grindstone table 3, there is a contact type inclination angle detection means 22 that measures the inclination angle of the grindstone head 10 by coming into contact with the side part of the whetstone head 10 at a position where the tip detection part is close to the piezoelectric element 14. The detection signal of the inclination angle detection means 22 is inputted to the calculation section 18 of the control means 16 via the changeover switch 23.

In the grinding machine configured as described above, when grinding the workpiece 5 mounted on the main spindle 6 using the grindstone 11,
First, the arithmetic unit 18 determines whether or not the grindstone head 10 is in a parallel state with the main shaft 6 in accordance with the detection signal output from the inclination angle detection means 22, and it is determined that both members are not in a parallel state. Then, the piezoelectric element 14 is connected to the voltage controller 21 so that the grindstone head 10 is in the parallel state.
The installation angle of the grindstone head 10 is corrected by outputting a control signal to the swivel control units 19 and 20 of the grindstone head 15.

Then, by slidingly displacing the headstock 2 and the grindstone table 3 based on a preset control program, the peripheral surface of the grindstone 11 is brought into contact with the grinding surface of the workpiece 5 to perform the grinding process, and the above-mentioned switching is performed. switch 23
is switched to the deflection amount detection means 17 side, and the amount of deflection of the grindstone shaft 10 is determined in the calculating section 18 according to the detection signal output from the deflection amount detection means 17.

That is, as shown in FIG. 3, when the grindstone shaft 12 is bent in response to the grinding resistance that is exerted when the grindstone 11 comes into contact with the object to be ground 5, the axis a of the grindstone shaft 120 is
is inclined with respect to the center axis of the grinding wheel head 10, and the distance between the detection portion of the deflection l detection means 17 and the corresponding circumferential surface of the grinding wheel shaft 12 changes. Then, the amount of deflection of the grindstone shaft 12 is calculated.

Next, a control signal for correcting the inclination state of the grinding wheel 11 based on the calculated value of the deflection is outputted from the voltage control section 21 to the swivel control section 19.20 of the piezoelectric element 14.15,
As shown in FIG. 4, by increasing the voltage applied to one piezoelectric element 14 to make it expand, and decreasing the voltage applied to the other piezoelectric element 15 to make it smaller. , the axis a of the grinding wheel shaft 12 and the center line C of the object to be ground 5 are set parallel, and the grinding surface of the object to be ground 5 and the grinding wheel 1 are set parallel to each other.
A predetermined grinding process is performed while finely adjusting the swivel angle of the whetstone head 10 so that the swivel angle of the whetstone head 10 is in surface contact with the circumferential surface of the whetstone head 10 in an appropriate state.

When the above-mentioned grinding process is completed, the above-mentioned grindstone table 3
After returning to the initial position, the changeover switch 23 is switched to the inclination angle detection means 22 side, and the grindstone head 10 becomes parallel to the main shaft 6 in accordance with the detection signal output from the inclination angle detection means 22. to control its swivel angle.

The amount of deflection of the grinding wheel shaft 12 that occurs in response to the grinding resistance is detected by the deflection amount detection means 17, and a control signal corresponding to this amount of deflection is sent from the voltage control section 21 of the control means 16 to the piezoelectric element 14.15. Since the output is output to the swivel controllers 19 and 20, the cutting angle of the grindstone 11 can be appropriately controlled in accordance with the deflection. That is, the grinding resistance slightly changes depending on the cutting speed of the grinding wheel 11 into the workpiece 5, the surface roughness and outer diameter of the grinding wheel 11, and the amount of deflection of the grinding wheel shaft 12 changes accordingly. If the swivel angle of the grindstone head 10 cannot be finely adjusted in accordance with the
7, and the swivel angle of the grindstone head 10 is sequentially controlled to an appropriate state by the actuator made of the piezoelectric element that can quickly and accurately adjust the swivel angle of the grindstone head 10. The occurrence of the above-mentioned grinding defects can be reliably prevented.

Further, in the above embodiment, a pair of piezoelectric elements 14.15 are arranged on the grindstone table 3, and the tips of both piezoelectric elements 14.15 are brought into contact with both sides of the grindstone table 10, respectively. Therefore, there is an advantage that the whetstone head 10 can be restrained from both sides and its swivel angle can be stably maintained.

Further, the piezoelectric element 14.15 has hysteresis between when it is expanded and when it is compressed, and even if the same voltage is applied to both piezoelectric elements 14.15, the amount of expansion will not necessarily be the same depending on the state. However, in the above embodiment, an inclination angle detection means 22 for detecting the inclination angle of the grindstone head 10 is provided, and the inclination angle detection means 22 outputs an inclination angle. Since the installation angle of the grinding wheel head 10 is corrected in accordance with the detection signal, the grinding wheel head 10 is
can be prevented from becoming tilted.

FIG. 5 shows an embodiment in which the swivel device according to the present invention is used during crowning dressing work, in which the control means 1
A control signal is outputted from the voltage control section 21 to the swivel control sections 19 and 20 of the piezoelectric elements 14 and 15 in accordance with the output signal of the crowning shape setting section 24 provided in the grinding wheel head 10, and the inclination angle of the grinding wheel head 10 is adjusted to an angle. By controlling the inclination angles of the whetstone head 10 and the whetstone 11 in accordance with the slide displacement state of the whetstone head 10 while detecting with the detection means 22,
It is configured to dress the peripheral surface of the grindstone 11 into a predetermined shape.

In this way, in the angle detection means 22, the grindstone head 10
While detecting the inclination angle of
Since it was configured to output a control signal that
It is determined whether the inclination angle of the grinding wheel 11 is at an appropriate angle corresponding to the crowning force r according to the detection signal, and if it is determined that this angle is not in an appropriate state, the swivel angle is quickly adjusted. Moreover, there is an advantage that crowning processing can be performed while making accurate corrections.

(Effects of the Invention) As explained above, the present invention detects the detection signal output from the detection means for detecting the amount of deflection of the grinding wheel shaft, determines the inclination angle of the grinding wheel, and expands and contracts the piezoelectric element accordingly. Since the control signal is output to control the swivel angle of the grindstone head, it is possible to quickly and accurately control the cutting angle of the grindstone according to the deflection of the grindstone shaft that occurs during grinding.

[Brief explanation of the drawing]

Fig. 1 is an overall plan view showing an example of a grinding machine equipped with a swivel device of the present invention, Fig. 2 is a plan view showing main parts of an embodiment of the present invention, and Figs. 3 and 4 are respectively in accordance with the present invention. FIG. 5 is a plan view showing another embodiment of the present invention. 3... Grindstone table, 9... Swivel fulcrum, 10...
...Whetstone head, 11...Whetstone, 12...Wheelstone shaft, 14
．． 15... Piezoelectric element, 16... Control means, 17.2
2...Detection means. Patent applicant Mazda Co., Ltd. Representative Patent attorney Etsushi Kotani
Patent Attorney Chief 1) Masayuki Patent Attorney Kiwao Itaya Figure 3 Figure 4

Claims (1)

[Claims] 1. A whetstone head supported swingably around a swivel fulcrum on a whetstone table, a whetstone shaft rotatably supported on the whetstone table, and a position offset from the swivel fulcrum in the axial direction of the whetstone shaft. a piezoelectric element installed on a grindstone table and disposed such that its tip abuts on the grindstone head, and a detection means for detecting the amount of deflection of the grindstone shaft;
The present invention is characterized by comprising a control means for determining the inclination angle of the grindstone based on the detection signal outputted from the detection means and outputting a swivel amount control signal to the piezoelectric element to extend or contract the piezoelectric element in accordance with the inclination angle. Grinding machine swivel device.