JPH018291Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention relates to a grinding device that grinds a workpiece while intermittently measuring the dimensions of the workpiece being processed by a rotating and reciprocating grindstone. be.

(Prior Art) As shown in FIG. 1, this type of device grinds a workpiece M by rotationally driving a grindstone 1 through a grindstone shaft 3 supported on a wheel head 2. Generally, in the above-mentioned grinding process, The feed speed of the cutting feed device with respect to the grindstone 1 is divided into three stages. For example, when obtaining the grinding amount curve l shown in Fig. 2, the first step is grinding at a high speed of cut along the rough cut characteristic a, and then the second step is a slightly slower cutting speed along the finishing depth of cut characteristic b. At the final stage, grinding (spark out) is performed only by the restoring force of the deflection applied to the grinding wheel shaft 3 (FIG. 1) along the sizing processing characteristic c. Conventionally, as disclosed in Japanese Unexamined Patent Publication No. 17197/1983, the cutting depth of the grindstone is
It is known that rough grinding is performed at the left and right traverse ends, and fine grinding is performed at the right traverse end. On the other hand, during the grinding, the dimensions of the workpiece M are intermittently measured by a measuring device at intervals of T.

By the way, when making the above cut, the workpiece M in Fig. 1
As a result of pressing the wheel against the grinding wheel 1 in the radial direction, a deflection d is generated on the grinding wheel shaft 3, so conventionally, a certain amount of deflection d is generated at the point of changing the cutting speed, for example, at the point of transition from the rough cutting stage to the finishing cutting stage _G2 . The finishing cut is made after the above-mentioned deflection d is eliminated by performing a cutting retreat S.

However, in the case of intermittent measurement as described above, the cutting completion point may be reached during no measurement, and the predetermined grinding amount may have already been exceeded at the time of the next measurement. In other words, if the timing of retraction from rough cutting to pre-cutting is delayed, the grinding wheel spindle 3
The deflection d increases. Therefore, if the amount of cutting back is constant, the deflection d of the grindstone shaft 3 will vary even after the cutting back is retreated, leading to variations in the inclination of the workpiece grinding surface M _a .

(Purpose of the invention) This invention was made in view of the above circumstances,
It is an object of the present invention to provide a grinding device that can efficiently perform high-precision grinding by preventing over-grinding due to a delay in switching the cutting speed due to intermittent dimension measurements.

(Structure of the invention) This invention is a grinding device that changes the cutting speed by intermittently measuring the dimensions to be machined with a rotating and reciprocating grindstone, and the cutting speed of the cutting feed device is controlled by the cutting speed. When the cutting speed change control point is reached and the rough cutting speed is changed to the finishing cutting speed, the number of reciprocations by the reciprocating drive device of the grindstone head is reduced, for example, the number of reciprocations during rough cutting is changed to This is done to reduce over-grinding due to a delay in switching the cutting speed.

In other words, the structural features of the present invention include a reciprocating drive device for the grinding wheel head that reciprocates the grinding wheel head supporting the grinding wheel shaft in the axial direction of the grinding wheel shaft; A cutting feed device that moves forward, a dimension measuring device that moves reciprocally in conjunction with the grindstone head and measures the dimensions of the workpiece intermittently, and set values and dimension measurements at the cutting speed change control point that changes the cutting speed. A feed speed changing device that compares the measured value with the measured value of the cutter and sends a signal to the cutting feed device to change the cutting feed speed when the measured value reaches the set value, and a grinding wheel for rough cutting and finishing cutting. It has a reciprocating number setting device, and when the depth of cut of the cutting feed device reaches the cutting speed change control point and the rough cutting speed is changed to the finishing cutting speed, the reciprocating number setting device for rough cutting The grinding wheel reciprocating number adjusting device selects an output to the reciprocating number setting device during cutting to reduce the reciprocating number of the reciprocating drive device of the grindstone head.

(Example) An example of this invention will be described below with reference to the drawings.

FIG. 3 shows an example of a grinding device according to this invention. In the figure, 1 is a grinding wheel for grinding a workpiece M, 2 is a wheel head that supports a grinding wheel shaft 3, and 4 is a grinding wheel head that supports the wheel head 2, which moves in the axial direction of the grinding wheel shaft 3 (in the direction of the arrow X). possible. Reference numeral 5 denotes a measuring device for intermittently measuring the machining dimensions of the workpiece M, and is provided with a driven rod 7 driven by a driving rod 6 fixed to the grindstone head 4. 8 is a return spring.

Reference numeral 9 denotes a cutting feed device that feeds the workpiece M relative to the grinding wheel 1; 10a to 10c are cutting speed setting devices that respectively set rapid feed, rough cutting, and finishing cutting speed; 11 is a feed motor; Yes, measuring device 5
A work head table 12 consisting of a workpiece M, etc.
It is what drives the. Reference numeral 13 denotes a position setting device for setting the cutting start position and the like for the workpiece M.

14a, 14b, and 14c are switching point setters 15 for respectively setting switching points G ₂ , G ₁ , and G ₀ (FIG. 4A) for switching the cutting feed rate by the cutting feed device 9;
is a comparator. This comparator 15 is the measuring device 5
The measurement signal from the switching point setters 14a to 14c is compared with the setting signal from the switching point setters 14a to 14c, and when the measurement signal exceeds the setting signal, a switching signal is sent to the cutting feed device 9 via the sequence circuit 16. Ori,
The switching point setters 14a, 14b, and 14c, the comparator 15, and the sequence circuit 16 constitute a feed rate changing device 17.

18 is a cam receiving member provided on the grindstone head 4;
19 is an eccentric cam driven by the motor 20;
This eccentric cam 19 rolls into contact with the cam receiving member 18 and drives the grindstone head 4 in the X direction. The eccentric cam 19, the motor 20, and the like constitute a reciprocating drive device 21 for the grindstone head 4.

Reference numeral 22 denotes a grindstone reciprocation frequency adjustment device that controls the reciprocating drive device 21 so that the number of reciprocations of the grindstone head 4 is reduced when the cutting speed is changed by the cutting feed device 9. This device 22 includes, for example, a motor rotation speed control device 23 that controls the rotation speed of the motor 20 according to an input voltage, and a reciprocation number setting device 2 for rough cutting that outputs a voltage for setting the number of reciprocations during rough cutting.
4. A reciprocating number setter 25 for finishing cut which outputs a voltage for setting the number of reciprocating times during finishing cut, a power supply 26 and a reciprocating number switching signal from the sequence device 16, which outputs a voltage for setting the number of reciprocating times from the setting devices 24 and 25. It consists of a selection switching circuit 27 that selects the output. Selection circuit 2
7 has a normally closed relay contact 271 and a normally open relay contact 272, for example.

Next, the operation of the above configuration will be explained.

After the cutting start position P (Fig. 4A) of the grinding wheel 1 by the cutting feed device 9 is set by the position setting device 13, the grinding wheel 1 on the wheel head 2 is driven and placed on the workpiece M. Grinding begins. On the other hand, when the grindstone head 4 is reciprocated in the direction of arrow X by the rotation of the eccentric cam 19 by the motor 20, the inner diameter of the workpiece M is intermittently measured by the measuring device 5. That is, in conjunction with the separation of the grindstone 1 from the workpiece M, the measuring device 5 advances toward the workpiece M side. As described above, the depth of cut into the workpiece M is made in accordance with the rough depth of cut, finish depth of cut, and spark-out characteristics a, b, and c shown in FIG. 4A.

Assume that the workpiece M is currently being ground with a rough depth of cut. The output of the reciprocating number setting device 24 during rough cutting is transmitted to the motor rotation speed control device 2 through the relay contact 271.
3 as input eia (Fig. 5), this device 23 drives the grinding wheel head drive motor 4.
rotates at, for example, 1000 cpM as shown in FIG. 4B. That is, the above-mentioned grindstone 1 is
It reciprocates at a frequency corresponding to 1000 cpM, and the dimensions are measured by the measuring device 5 at this period, and the measured values are compared by the successive comparator 15.

When the measured value from the measuring device 5 exceeds the set value, a cutting feed rate change signal is applied from the sequence device 16 to the cutting feed device 9 to change the cutting rate (switching point A in Fig. 4). _G2 ). When changing the cutting speed, a signal for switching the number of reciprocations of the grindstone is input from the sequence device 16 to the selection switching circuit 27, and the relay contact 271 is opened and the relay contact 272 is closed. By closing the relay contact 272, the output from the reciprocating number setter 25 during finishing cut is applied to the motor rotation speed control device 23 as input eib (Fig. 5), so that the grinding head is driven by this device 23. As shown in FIG. 4B, the motor 4 for
It will rotate at 500cpM. In other words, the grinding wheel 1 has a grinding speed of 500 cpM after entering the finishing cut.
It will reciprocate at a frequency corresponding to .

In this way, the number of reciprocating movements of the grinding wheel during rough cutting is greater than that during finishing cutting, and the measurement cycle is shortened, which prevents the depth of cut at cutting switching point _G2 from becoming excessively large. . Therefore, the inclination of the grindstone 1 when entering the finishing cutting stage is eliminated, and a proper grinding surface can be obtained.

Note that the number of reciprocations of the grindstone 1 is determined not only at the switching point from rough cutting to finishing cutting (G ₂ shown in Fig. 4A), but also at the switching point from finishing cutting to sizing processing (Fig. 4A).
It is also possible to reduce G ₁ ) shown in FIG.

(Effects of the invention) As described above, this invention allows the grinding wheel to adjust the number of reciprocations when the measured value of the workpiece reaches the set value and the cutting speed is changed from the rough cutting speed to the finishing cutting speed. Since the output is selected from the reciprocating number setting device for cutting to the reciprocating number setting device for finishing cut to control the reciprocating drive device of the grindstone head and reduce the number of reciprocations of the grinding wheel, the excess per reciprocation of the grinding wheel can be reduced. It is possible to provide a grinding device that can efficiently continue high-precision grinding by eliminating the need for a deep cut.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway side view showing the state in which grinding is being performed, Fig. 2 is a diagram showing the relationship between time and cutting feed amount in grinding applied to a conventional grinding process, and Fig. 3 4 is a block diagram showing an example of the grinding device according to this invention, FIG. 4A is a diagram showing the relationship between time and cutting feed amount applied to the device of this invention, and FIG. A characteristic diagram of the number of reciprocations of the grindstone shown in correspondence with the characteristics, and FIG. 5 is a characteristic diagram of the rotation speed control of the motor by the motor rotation speed control device. DESCRIPTION OF SYMBOLS 1... Grindstone, 3... Grindstone diagram, 4... Grindstone head, 5... Measuring instrument, 9... Cut feed device, 17... Feed speed change device, 21... Grindstone reciprocating drive device, 22... Grindstone reciprocation frequency adjustment device, M …work.

Claims (1)

[Scope of utility model registration request] In a grinding device that intermittently measures the dimensions processed by a rotating and reciprocating grindstone and changes the cutting speed, a grinding wheel head that supports a grindstone shaft is moved reciprocally in the axial direction of the grindstone shaft. A reciprocating drive device, a cutting feed device that moves the workpiece relatively close to the grindstone axis and feeds the cut, and a dimension measuring device that moves reciprocatingly in conjunction with the grindstone head and measures the dimensions of the workpiece intermittently. Then, the setting value at the cutting speed change control point that changes the cutting speed is compared with the measured value of the dimension measuring device, and when the measured value reaches the setting value, a signal is sent to the cutting feeder to change the cutting feed rate. It has a feed speed changing device that sends out the feed speed, and a setting device for the number of reciprocations of the grinding wheel during rough and finishing cuts. A grindstone reciprocation number adjustment device that selects an output from a reciprocation number setting device for rough cutting to a reciprocation number setting device for finishing cut to reduce the number of reciprocations of the reciprocating drive device of the grindstone head when the cutting speed is changed. Equipped with grinding equipment.