JPS5914463A - Grindstone wheel feed controller for grinder - Google Patents

Abstract

PURPOSE:To improve the final working accuracy by interrupting temporal feeding at the specific time in the grinding stage then detecting flexure from the width of member to be grinded through springback function and advancing grinding. CONSTITUTION:Upon start of grinding of member to be cut, a grindstone wheel 2 is fed by a servo motor 32 and when the dimension of said member to be measured by a pair of contactors 40 and a differential transformer 42 reaches to the referential level for a comparison circuit 54, a signal AS1 is produced to stop a motor 32 while simultaneously a dimension signal is stored in a sample-hold circuit 56 and during said interval grinding is performed through springback function of said member to input the dimension signal from a delay circuit 60 after predetermined time to the sample-hold circuit 58, while after elapsing predetermined time the flexure is obtained by a subtraction circuit 64 and an aiythmetic unit 68 to provide the corresponding feed signal from a processor 70 to the motor 32. Said feed speed is decelerated at the point SP2 while the flexure is obtained again at the point SP3 to command the retreat direction feed speed. Consequently the final working accuracy can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a grinding machine that improves grinding accuracy by limiting the deflection of the work piece during grinding within a certain range, and controls the optimum grinding speed. ) Closed to the wheel feed control I device.

What is the feed control device for the grinding wheel in a conventional grinding machine? t
11 There was a method C that controlled the feed interval of the grinding head so that the cutting force was always constant. When the grinding resistance is constant, the amount of deflection of the workpiece changes depending on the rigidity of the workpiece. If the rigidity is low, it will deflect a lot. If the amount of deflection is large, it will cause chatter, resulting in poor finished dimensional accuracy and reduced roundness. Therefore, it was necessary to change the setting value of the cutting force depending on the stiffness of the material to be stiffened. Determining this setting required many experiments and efforts.

Therefore, when setting grinding conditions, the grinding speed is generally slowed down to reduce the amount of deflection in consideration of safety, which results in long machining times and a poor machining rate.

On the other hand, as a wheel feed control device to improve this drawback, whereas the above-mentioned device kept the grinding resistance constant,
A device is known that controls the feed of a grinding wheel so that the amount of deflection during ω1 cutting of a workpiece is always constant. This device calculates the machining allowance (X-W) at that time from the relationship between the outer diameter of the workpiece I\1 method (X) and the final finished outer diameter dimension of the workpiece material <W) during grinding. Then, using the finishing position as a reference, find the feed m (Y) of the wheelhead, and from the relationship between the machining allowance (X-W) and the feed amount (Y), calculate the deflection of the workpiece m27 = (X
-W>-2Y was calculated. And this l
[Feed m so that the deflection ff1 (27) is always constant
It was intended to control <y>.

However, this method does not measure the position of the secondary surface of the grinding wheel, but rather the feed position of the wheel head to which the grinding wheel is fixed, so the position of the grinding surface is not necessarily accurate. It wasn't something that could be measured. That is, the radius of the grinding wheel decreases during grinding, and the grinding table also undergoes thermal deformation, causing a slight change in the position of the grinding wheel on the grinding table. depth of cut and
Since there is an error in the amount of separation of the grinding wheel, the position of the grinding surface of the grinding wheel cannot always be measured by the position of the grinding wheel table.

Therefore, the amount of deflection of the workpiece measured using Method C includes errors, and accurate feed control of the wheel cannot be performed.

The present invention has been made in order to improve such drawbacks of the conventional technology, and is based on data measured during grinding by means for detecting the outer diameter of the workpiece, and calculates the deflection during grinding. By squeezing out the amount, the amount of deflection can be measured with high precision, and then the amount of deflection can be measured accurately. I! The cutting speed is controlled according to the amount of deflection.

That is, the present invention includes a means for detecting the outer diameter usage of a workpiece, and a means for detecting an IC signal detected by the detecting means and outputting a predetermined control signal that can arbitrarily vary the feed speed of the grinding wheel. A wheel feed control device comprising a control means, and a single drive means for manually inputting a control signal from the control means and sending the grindstone at an IC speed in accordance with the signal. One means is to reduce the feed of the wheel width to a predetermined slow speed including stopping for a predetermined time at a specific time during grinding, at least when grinding a workpiece for the first time, and to detect The amount of decrease in the outer diameter dimension of the workpiece within the predetermined time is determined by the measurement signal of , the deflection of the workpiece is calculated from the amount of decrease, and the above-mentioned after -C and A is calculated according to the deflection. It consists of a grinding wheel feed control device for a grinding machine, which is characterized by transmitting a signal to control the feed speed of the grinding wheel.

Next, the present invention will be explained in detail.

FIG. 1 shows a principle diagram of how the deflection of a workpiece is measured by the apparatus of the present invention. Toishi Mon is the center axis 0
It rotates around axis 3 and grinds by contacting the workpiece 10. If there is no deflection in the workpiece, the workpiece will be centered at axis 0.
1 and has an outer diameter such as 16 cylinders 12. However, due to the Ttll cutting force from the grinding wheel, the workpiece material 1
0 is deflected into a shape like a cylinder 14 centered on the 02 axis.

1 = lateral suspension can be expressed as the distance δ between the axes 01.02. If the feed of the grinding wheel is stopped at d:ff with this amount of deflection δ occurring, the workpiece material will exert an elastic force so that the o2 axis overlaps the Q1 axis due to the springback action proportional to the amount of deflection. arise. For this reason, even if the feed rate of the wheel width is zero, the surface of the workpiece is ground and ideally the surface of the workpiece is ground to avoid contacting the grinding wheel with its own ω1 cutting force. , 02 are positioned so as to overlap with the 01 axis, and are ground into the shape of a circle n16 having a cylindrical radius r1.

So, when I stopped feeding the wheel width and it rusted, I used J3.
Measure the radius ``2'' of the workpiece, measure the radius r1 of the workpiece that has reached a steady state after a while after stopping feeding, find the difference (r2-rl), and further calculate the radius of the workpiece per revolution of the workpiece. The value obtained by subtracting the cutting depth of the wheel 7t3△ (r 2-r 1-△
) is equal to the deflection ratio δ mentioned above. Therefore, the amount of deflection δ can be measured using such a principle.

The device of the present invention applies the above principle. That is, first, during the first stage of grinding 83, the grinding wheel is sent out at a constant speed, and the feeding is stopped at a specific time! - Deflection is measured by measuring the amount of change in the outer diameter of the workpiece over a predetermined period of time.

In other words, the feed-out speed of the wheel is calculated so that the deflection during subsequent grinding is within a certain deflection amount limit. After calculating the flexural suspension (A), grinding is carried out with precision (d) while controlling the feed wheel speed using the speed described above. In this case, it is preferable to stop the feed of the grinding wheel, but in cases such as when the rigidity of the workpiece is large, it is also possible to reduce the feed speed to a very low speed at which the amount of strain can be ignored.

Hereinafter, the present invention will be further described in detail based on specific examples.

FIG. 2 is a block diagram showing the specific configuration of this embodiment.

The control device of the present invention mainly consists of a means for detecting the outer diameter of the workpiece, an f-stage control, and a means for driving the grinding wheel. The outer diameter detection means of the workpiece is provided on the outer surface of the workpiece 10.
It consists of a pair of contacts r40 that are in point contact and an actuation transformer 42 or other position detector that changes the amount of displacement 11A electrically. The electric signal L) is proportional to the outer diameter detected by the pair of contacts 40 and the control means 5
Manually connect to the 0 input terminal. The control means 50 has a predetermined configuration as described above, and the output horn signal is as follows.
It is output to a drive circuit 74 that drives the delivery of the grinding wheel. The drive circuit 74 has three servo circuits directly connected to one part,
A servo motor is connected to drive the motor in response to a control signal. The servo motor 32 rotates the feed screw 26 which is tied to the shaft of the first novo motor, and rotates the feed screw 2.
Send out the hoop l-2/l that meshes with 6. nut 24
Since it is fixed to the wheel stand 22, the wheel width receives the rotational force of the feed screw 26 and moves linearly toward or away from the workpiece. The grinding wheel head 22 is slidably mounted on the intermediate base 30.

On the grinding wheel stand 22, there is a wheel Φ2 which can be freely rotated. On the other hand, the intermediate base 30 is
8 is fixed on the upper surface. Further, an actuating transformer 42 constituting a part of the outer diameter detecting means for the workpiece is fixed to a support base 46 which is connected to and covers the table 44 fixed to one end surface of the bed 28. The pair of contacts 40 are supported in a manner that allows them to be displaced in the radial direction of the workpiece 10.

Next, the control means 50 according to the gist of the present invention will be described.

The control means 50 has an amplifier 52 that inputs and amplifies the signal from the outer diameter measuring means. The amplifier 52 amplifies the measurement signal and outputs it to the comparison circuit 5/l connected thereto. The comparator circuit 54 has a predetermined reference setting value set in advance, and when the measurement signal reaches this predetermined reference setting value, it outputs a position signal to that effect to the processing device 70. On the other hand, the position signal amount horn of the comparison circuit 54 is inputted to a delay circuit 60 and gated to a ripple bold circuit 56. , the single-node pull-hold circuit 56 is designed to manually input the measurement signal as well. Similarly, the 4 non-pull hold circuit 58 inputs the measurement signal and outputs the output signal of the delay circuit 60. The measured signal is input to the fraud circuit 64 by the Linsol hold circuit J 61 L58, and its output is digitally listened to via the △D converter 66. and manually input it to the arithmetic circuit 68. On the other hand, the arithmetic circuit 68 receives the time signal (α1+α2) through the delay circuit 62. Then, the arithmetic circuit 68 calculates the deflection using a predetermined method in synchronization with the time signal, and outputs the value to the processing device 70. The processing device 70 calculates a predetermined tl based on the information, sends out the wheel and sends one command pulse to the deviation counter 72. The deviation counter 72 manually reduces the number of pulses by feeding back the output signal from the rotational M detector 34 coupled to the axis of the ribo motor 32.
The value of the deviation 7J counter 72 is proportional to the amount by which the grinding wheel should be fed, and the grinding wheel is fed until the value becomes zero.

Based on the value of the deviation counter 72, the drive circuit 74 sends out an output signal that rotates the servo motor at a predetermined speed to a predetermined position. The drive circuit 74 is configured to control the speed signal detected from the speed detector 36 directly connected to the shaft of the 1-no-vo motor 32 at a constant speed to avoid the no-drive motor 32.

The above is the specific configuration C of the embodiment of the device of the present invention.

Next, the operation of the apparatus of the present invention will be described based on such a configuration.

FIG. 3 is a Noikl diagram when the grinding wheel is sent out using the control device of the present invention. In the figure, point 1] 0 indicates a case where there is a space between the grinding surface of the grinding wheel and the workpiece, and the positional relationship is such that the workpiece is not yet ground. From point 10, advance the grinding wheel a predetermined distance l1lltl) to reach 1]1. 1)1
Immediately after that, the grinding surface of the grinding wheel comes into contact with the workpiece and begins grinding. From Pl, the workpiece is then ground at a constant feed rate -(P2 is reached.

Here, P2 is the position when the measurement signal measured by the differential transformer 42 reaches a predetermined value, that is, ΔS1. When the position signal (ΔS1 signal) is sent from the comparator 54 to the processing device 70, the processing device 70 acts to stop the feeding of the grinding width. Then, the period during which the transmission is stopped is the time from 1]2 to the 13th point - 11.

During this time, the workpiece is being ground for this predetermined time due to springback, as described in the deflection measurement principle above. Therefore, the V-emblem bold circuit 56 first performs a ripple hold on the value of the outer diameter r2 of the workpiece when the value [2] is reached.

On the other hand, the 1-no-pull-hold circuit 58 performs a rippling-hold on the outer diameter value r1 of the workpiece of JJG at the instant of the delay period α1, which is slightly longer than 1, after reaching P2. The two outputs of the non-pull voltage circuits 56 and 58 are outputted to the extraction circuit 64, where the l stiff product δr is calculated as 81n by the arithmetic expression
be done. The value [Y, while the grinding wheel stopped feeding
), the workpiece is ground by (σ1) due to its own springback action.

Then, after converting the analog quantity representing this deflection δr into a digital quantity by Δ1, the arithmetic circuit 66
I will appear on 8th. The arithmetic circuit 68 calculates the detected deflection δ
Determine the ratio of r to a standard amount of deflection δS, and multiply it by a proportionality constant K to obtain the deflection rate. This deflection rate is output to the processing device 70. Then, in accordance with the deflection rate C, the feed-out speed of the grinding wheel is determined so that the amount of deflection falls within a certain limit range. Predetermined time L
After 1 elapse, that is, at the 13th point, the wheel width is fed out according to the speed. As a result, the speed of the grinding wheel is U
It will be sent up to 4 points at the speed of FM. 24 points are the cases where the above-mentioned differentials 1 to lance detect and the I value is AS2, and this is a preset value. The area after the 14th point is a fine grinding area where smoother grinding is performed. When the control means detects that the fine grinding region has been entered, the comparison circuit 54 sends the ΔS2 signal to the processing device 70.
Send to. The processing device 70 detects this signal and calculates a fine grinding speed according to the deflection rate, and the time point is when the calculated outer diameter measurement value of the workpiece detected by fine grinding reaches ΔS3. When this point is reached, the comparison circuit 55/l is
3 signals are sent to the processing circuit 70, and the processing circuit 70 detects the signals and controls the feeding of the grinding wheel for a predetermined period (King 2).
Stop covering. This waiting period is a period of time to recover the slight deflection caused by 41] during fine grinding. And 2 days have passed! ,,: After reaching P6 point, Yu fast-forwards the grinding wheel to avoid going backwards and reaches 1) P7 point.

In this way, the -cycle grinding process is completed.

Next, the operation of the processing device 70 will be explained.

FIG. 1 shows the operation of the processing device 70.
Guaru. In step 102, a speed setting is made to feed the grinding wheel to a predetermined position. Then, in step 104, a pulse train having a predetermined number of pulses and a pulse period is generated according to the position and speed set in the previous step 102. In the next step 106, idle cutting feed is performed in the previous step 10/I. , the first rough grinding feed rate (FR) is set after the grinding wheel is about to contact the workpiece.In the next step 108,
J3 is in the previous step 106, and C according to the set speed.
1. Process the feeding of the grinding wheel in units of 1. Next step 1
At step 10'c, when the outer diameter usage data of the workpiece reaches a predetermined value, the AS1 signal is input from the comparator circuit 54, but if that signal is input manually, the process moves to the next step 112.
If the signal is not yet input, step 108
Return to and repeat the process of feeding the grindstone. Step 112
At (the grinding progresses to the predetermined position /υ), stop the feed of the wheel width for -1-1 seconds. Then,
In the next step 114, since the deflection rate of the stiffened material has been calculated during the stop period as described above, that data is input. In the next step 116, a speed inversely proportional to the deflection rate is set to a second coarse grinding feed rate (F M
). In step 118, the grinding wheel is fed per unit according to the speed set in step 116. In the next step 120, A
If the S2 signal is manually input, the feed is stopped and the process proceeds to step 122. If the signal AS2 has not been inputted yet, the process returns to step 118, and the grinding wheel is sent out one unit at a time, and one error is recorded. In step 122, J'3 is shown in FIG. 3 in the preprocessing. Since up to 4 points (l, I) have been processed, in step 122, the polishing feed rate 11Jj (F=
F) Set and cover. Note that FFR is a reference fine grinding feed rate. - Next, in step 124, feed control is similarly performed unit by unit according to the speed. Step 12
At step 6, ΔS3 (predetermined 1 if No. 5 is manually operated) 5-point grinding becomes advance/v, so at step 128, the feed is stopped for 2 seconds. On the other hand, ΔS3 If the signal is not input, the 25th point has not yet been reached, so the process returns to step 124 and performs feed control one unit at a time. The action grinds only a very small width.

Then, when the 16th point is reached, fast forwarding and backward processing is performed in step 130. In step 130, the retract position and speed for fast forward retract processing are set. 43 to the next step 132, step 1, . 30′C・
Generates a pulse according to the set retreat distance and speed. In this way, one grinding and two presses are completed.

In the second grinding, if the workpiece material C is the same type, grinding may be performed at an appropriate speed from the beginning of C1 based on the amount of deflection measured in the first grinding.

In the embodiments described above, part of the control means 50 is processed by an analog circuit, and part of it is processed by an f-digital circuit or a microprocessor. However, in the process of this embodiment, when the outer diameter measurement lens 1 is used, this analog signal is converted into a digital signal. Il! It can also be constructed by using a ΔD converter, a series of digital digital converter systems that manually operate the converter, and an output interface that sends signals to the C drive circuit in accordance with the processed data.

In summary, the present invention temporarily stops the grinding at any specified time in the grinding stage, or decelerates the grinding speed to a very low speed, during which time the material is ground due to the springback action of the rigid material. Detects the amount of deflection of the rigid material from the width. Then, using this actually measured amount of deflection, subsequent grinding is performed at a speed such that the amount of deflection falls within an appropriate range.

Therefore, according to the device of the present invention, the deflection of the rigid material is directly determined from the outer diameter measurement of the work material. ,: Measurement of wami-hang is extremely accurate. In addition, as described below, this control device controls the feed of the grinding wheel so that the amount of deflection is within a certain range. It is done. Furthermore, since the measurement accuracy of the amount of deflection is high, the final machining accuracy is also high, and the grinding speed is increased in order to deliver the grinding wheel to the maximum speed C within the allowable limit of deflection.

[Brief explanation of the drawing]

7 Figure 1 G: i This invention is an explanatory diagram showing the principle of measuring the amount of deflection of a rigid material measured by the device. FIG. 2 is a specific configuration diagram of a control device showing an integrated embodiment of the device of the present invention. FIG. 3 is a cycle diagram showing the feed control of the grinding wheel by the control device used in the same embodiment. FIG. 4 is a flowchart showing the processing of the processing device used in the same embodiment. 2... Grinding wheel 10... Work material 5/I.
... Comparison circuit 56.58 ... Length pull bold circuit 64 ... Subtraction circuit 70 ... Processing device 72 ... Deviation counter 74 ... Drive circuit 32 ... Serbo motor patent applicant Toyoda Machine Tools Co., Ltd. Agent Co., Ltd. Patent Attorney Hiroshi Okawa Patent Attorney Shuu Fujitani Patent Attorney Akio Maruyama Figure 2 424o10 2 7/22 ○ 24 3032346
14 8 6: 70, , 72174 1 5! L 裡茡 set I S spear 1 ■ 1 sawa υ′・ 1 1
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. C +5254 60. ,. ---, AMP J:l: Comparison circuit ■ So-called Ei cX2 - to (: circuit 1 1 window r two islands

Claims (1)

[Claims] A means for detecting the outer diameter of a rigid material is inputted with a signal detected from the detecting means and outputs a predetermined control signal for arbitrarily varying the feed speed of the grinding wheel. A grinding wheel feeding control device comprising: a control means for outputting an output; and a single drive means for manually feeding a grinding wheel at a speed according to the signal by manually inputting a control signal from the controlling means, The control means is configured to reduce the feed of the wheel to a predetermined slow speed including stopping for a predetermined time at a specific time during grinding at least during the first grinding of the workpiece, and to reduce the feed of the wheel to a predetermined slow speed including stopping, and to The amount of decrease in the outer diameter of the rigid material within the predetermined time is calculated based on the measurement signal from the first method, the deflection of the rigid material is calculated from the amount of decrease, and the subsequent This device is characterized by sending out a signal to control the feed speed of the wheel wheel.