JPH0141473B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a grinding wheel head feeding device for a grinding machine, and more particularly to a grinding wheel head feeding device that can improve the efficiency of grinding a stepped roll having stepped portions of different diameters.

For example, when grinding steps A and B of a stepped roll-shaped workpiece W as shown in FIG. It is being done. However, since there are nearly infinite differences in the shapes and dimensions of the workpieces W, it is uneconomical to use a full-form grindstone except in the case of mass production of one type of workpiece. Therefore, in a normal grinding machine, the grinding wheel 1 is sent in the direction of the arrow a in Fig. 1 to perform a plunge cut on the A or B portion, and then the grinding wheel is traversed in the direction of the arrow b and the remaining portion is plunge cut. .

Therefore, in recent years, a grindstone head feeding device has been proposed and put into practical use, which stores the steps of the cutting feed operation of the grindstone 1 and automatically performs the process.

An example of the operation of this conventional automatic grindstone head feeding device will be described, for example, in the case where part A of a workpiece W having two step parts A and B having different diameters as shown in FIG. 1 is ground. First, when the start button is pressed, the grindstone head is driven by a hydraulic device or the like while holding the rotating grindstone and is rapidly sent toward the workpiece W (so-called rapid feed). When the grindstone approaches the workpiece W, the forward end of the grindstone head drives a limit switch, and the rapid feed changes to cutting feed by a pulse motor. Next, in accordance with a pre-programmed procedure, for example, after giving a cutting feed divided into three stages, a dwell operation is performed to stop the feed of the grinding wheel, a finish feed and a spark out after the finish dwell, and then the above-mentioned rapid feed mechanism is given a reverse direction. Perform a quick return operation to return to the standby position shown in the first diagram.

When subsequently grinding part B of the workpiece W,
After returning the grindstone 1 to the standby position, move the grindstone forward by a distance corresponding to the sum of the amount of dressing of the grindstone after grinding part A and the amount of step between parts A and B of the workpiece W to reach the reference position. Only after you fix it,
It is not possible to provide the grinding feed for the plunge cut in part B. The correction work for correcting the reference position is time consuming and troublesome, and causes a decline in the improvement of work efficiency.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a grinding wheel head feeding device for a grinding machine that can easily correct the standby position of the grinding wheel according to the dressing amount and step amount of the grinding wheel to improve work efficiency when grinding stepped portions of different diameters of a workpiece. is to provide.

Embodiments of the present invention will be described below with reference to FIG.

In FIG. 2, reference numeral 2 denotes a drive shaft, which is supported by a ball bearing so that it can rotate freely, and which is connected via an idle gear (not shown) that meshes with a pinion 3 formed at one end of the drive shaft. ,
For example, it is gear-coupled to a feed shaft (not shown) for feeding the grindstone head, such as a precision feed screw.

At least one (for example, three) support arms 4 are provided at the other end of the drive shaft 2 so as to be perpendicular to the axis. 5 is pivoted so that it can rotate.

Furthermore, first and second sun gears 6 and 7 are rotatably supported on the drive shaft 2 via ball bearings, respectively. These sun gears 6,7
are arranged in the diametrical direction of the planetary gear 5, and are provided on both sides of the support arm 4 and the planetary gear 5 so that the differential gear device 10 can be constructed by meshing with the planetary gear 5, respectively. It's a gear.

The first sun gear 6 is coaxially and directly connected to the rotary encoder 8 via an encoder input shaft 8a, and the first spur gear 9, first idle gear 11, pinion 3 and It is connected to a grindstone feed pulse motor 13 via a first connection shaft 12 .

On the other hand, the second sun gear 7 includes a second spur gear 14 and a second idle gear 1 coaxially formed integrally therewith.
5, a correction pulse motor 18 via the third idle gear 16, pinion 3 and second connecting shaft 17.
is connected to.

In addition, the rotary encoder 8, the grindstone feed pulse motor 13, and the correction pulse motor 18
are each connected to a control circuit (not shown). This control circuit controls the programmed cutting feed after the rapid feed of the grinding wheelhead.
In addition to having a control circuit, for example, in order to set the diameters of parts A and B (see Fig. 1) of the stepped roll,
For example, at least two dimension input devices such as thumbwheel switches, a subtracter for calculating the difference between the two diameters set by the dimension input devices, and the differential gear 1
Taking into account gear ratios such as 0, A and B of stepped rolls
It is enough to move the grindstone head by the height difference δ (Fig. 1).
It includes a calculation circuit that calculates the number of pulses to be supplied to the grindstone feed pulse motor 13.

As is clear from FIG. 2, the grinding wheel head feeding device for a grinding machine according to an embodiment of the present invention configured as described above stops the correction pulse motor 18 while maintaining a constant holding torque. , second
When the grindstone feed pulse motor 13 is operated with the sun gear 7 fixed, its rotational force is transmitted to the first sun gear 7 through the gear train described above, and drives the planetary gear 5 that meshes with it while rotating. It is converted into a torque that causes it to revolve around axis 2. That is, the grindstone head is driven by rotating the drive shaft 2 and a feedshaft (not shown) connected thereto for feeding the grindstone head. Since the rotation of the first sun gear 7 rotates the encoder 8, this movement of the grinding wheel head is fed back to the control circuit in the form of an output signal of the rotary encoder 8. If the correction pulse motor 18 is stopped in this manner, programmed grindstone head cutting feed control can be performed in the same way as in the conventional grindstone feed device. In this case, the rotational speed of the drive shaft 2 is half that of the first sun gear.

On the other hand, when the grinding wheelhead feed pulse motor 13 is stopped and the correction pulse motor 18 is operated, the second
As is clear from the figure, the differential gear device 10 operates symmetrically to the above, and can drive the grindstone head by rotating only the drive shaft 2 while the rotary encoder 8 remains stopped.

Therefore, when grinding a stepped roll, the correction pulse motor 18 is stopped according to the procedure programmed in advance in the control circuit, and the grinding of section A in FIG. 1 is fed back to the control circuit by the rotary encoder 8. At the same time, the grindstone feed pulse motor 13 automatically feeds the cut, and after reaching the fixed size and sparking out, the grindstone head is returned to the standby position, and then the table is automatically moved so that the grindstone 1 is above section B. Then, the grindstone head feed pulse motor 13 is driven again to automatically feed the grindstone head in the direction a by an amount corresponding to the sum of the dressing correction amount and the step difference δ of both parts A and B. , B
Part B enters automatic cutting and grinding is performed on part B.
The correction pulse motor 18 is operated during grindstone correction correction, rapid forward/backward movement, correction of the grindstone head position using the feed dial, and cutting after the remaining cutting amount display becomes "0". be.

As is clear from the above description, the present invention provides a differential gear device having a planetary gear and two sun gears, in which one of the sun gears is equipped with a grinding wheel head feed pulse motor and an encoder, and the other sun gear is equipped with a correction gear. Since the pulse motors are connected and the rotational force of the two pulse motors can be transmitted independently to the drive shaft via the support arm that pivots the planetary gear, it is possible to make corrections such as dressing the grindstone. By using a correction pulse motor, continuous grinding is possible without changing the depth of cut and step feed mode.

In addition, there is no need to correct the position of the grinding wheel head every time the diameter of the grinding section changes as in conventional models. Thereafter, the grinding wheel can be brought close to the next processing step, so the correction setup time can be significantly shortened and the grinding efficiency can be improved.

[Brief explanation of drawings]

FIG. 1 is a diagram illustrating the grinding of a stepped roll, and FIG. 2 is a partially sectional plan view showing a main part of a grindstone head feeding device of a grinding machine according to an embodiment of the present invention. 2... Drive shaft, 4... Support arm, 5... Planetary gear, 6, 7... Sun gear, 8... Encoder,
10...Differential gear device, 13...Wheelhead feed pulse motor, 18...Correction pulse motor.

Claims (1)

[Claims] 1. A drive shaft connected to a grindstone feedshaft, at least one support arm that is integrally vertically installed on this drive shaft and has a planetary gear rotatably supported at its tip, and a support arm that is coaxial with the drive shaft. , and two sun gears which are pivotally supported so as to rotate independently of each other, and which are disposed along the diameter direction of the planetary gear and are meshingly engaged with the planetary gear. One of the two sun gears is connected to a grindstone feed pulse motor and an encoder that detects the rotation angle of the feedshaft to perform programmed cutting and step feed of the grindstone head, and the other sun gear is connected to a correction pulse motor. A grinding wheel head feeding device for a grinding machine, characterized in that the position of the grinding wheel head can be corrected independently of the cutting feed of the grinding wheel head programmed by the grinding wheel head feed pulse motor and the encoder.