JP2933795B2 - Grinding equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grinding device.

[0002]

2. Description of the Related Art In a grinding machine, the temperature of a workpiece during machining is closely related to the surface properties of a grinding wheel, and can be an important judgment item for grinding abnormalities such as blinding, clogging, or missing. Conventionally, such workpiece temperature measurement has been performed by
The thermocouple is embedded in the workpiece by disassembling the workpiece or forming pores, and the thermoelectromotive force between the metals is measured and detected.

[0003]

However, the method for measuring the temperature of a workpiece as described above is effective for an experiment, but has a problem that it cannot be applied to a workpiece as a product. The present invention has been made in view of the above problems, and has as its object to provide a grinding apparatus that performs grinding while appropriately measuring a workpiece temperature.

[0004]

In order to achieve the above object, a first aspect of the present invention is to provide a method in which one end of each thermocouple wire constituting a thermocouple is separated and brought into contact with the surface of a workpiece being ground. A temperature detecting means for measuring an object temperature is provided, and grinding is performed while detecting the temperature of the workpiece by the temperature detecting means.

In a second aspect of the present invention, a temperature range in which processing quality is not deteriorated due to blinding, clogging, or dropping of the grinding wheel within a predetermined time during grinding is set as a first allowable temperature range, and the temperature detecting means is provided. A determination means is provided for determining whether the measured workpiece temperature is within the first allowable temperature range and determining whether dressing of the grinding wheel is necessary.

A third aspect of the present invention is to set a temperature at which a grinding wheel does not cause blinding, clogging or dropping within a predetermined time during grinding as a second allowable temperature upper limit, and measure a workpiece temperature measured by the temperature detecting means. Is determined to be the second allowable temperature upper limit, and the cutting speed is adjusted to a predetermined high speed value until the second allowable temperature upper limit is reached. Cutting speed adjusting means for adjusting the cutting speed to a low value.

A fourth aspect of the present invention is provided with a notch dimension adjusting means for calculating an expansion dimension of the workpiece based on the workpiece temperature measured by the temperature detecting means and adjusting the notch dimension based on the expanded dimension. Things.

According to a fifth aspect of the present invention, a pair of fingers for measuring a processing diameter of a workpiece are provided with contacts, respectively, and one end of the thermocouple wire constituting the thermocouple is sandwiched by one of the contacts. The part is attached.

[0009]

According to the first aspect of the present invention, each thermocouple wire constituting the thermocouple contacts at two separated points on the surface of the workpiece. The surface temperature of the workpiece is uniform except for the area of contact with the grinding wheel, and there is no temperature difference between the two points. Generated thermoelectromotive force. Then, the workpiece temperature is measured based on the thermoelectromotive force.

According to the second aspect of the present invention, if the temperature of the workpiece is lower than the first allowable temperature range, it is determined that the abrasive grains are in a spilled state. It is determined that it is in a jam state. Then, based on this determination, a whetstone is appropriately dressed.

According to the configuration of the third aspect of the present invention, there is no fear of dropping while the workpiece temperature is lower than the second allowable temperature upper limit. Slow down as there is a risk of clogging. Thereby, the grinding can be continued at an appropriate cutting speed according to the state of the grinding wheel determined from the temperature of the workpiece.

According to the fourth aspect of the invention, since the cut size is adjusted based on the expansion size obtained from the temperature of the workpiece, the workpiece has a desired dimensional accuracy when it contracts due to a decrease in temperature. Formed.

According to the fifth aspect of the invention, while measuring the grinding dimension of the workpiece with the contact, the temperature of the workpiece at the dimension measuring position is directly detected by the thermocouple provided close to the contact. The actual grinding condition can be more accurately determined without abnormal deformation or rapid wear of the thermocouple.

[0014]

Next, an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a schematic view of a grinding device, and 1 is a cutting table. The cutting table 1 is reciprocated in the vertical direction in FIG. A substantially cylindrical workpiece W is rotatably mounted on the cutting table 1, and a dresser 3 is mounted on the workpiece W. Reference numeral 4 denotes a grinding wheel, which is rotatably mounted on the processing head 4a, and is appropriately dressed by the dresser 3 as described below.

5 is a temperature detecting device, as shown in FIG.
At the two distal ends of one finger 6, a bullet-shaped contact 7 to which thermocouple wires 9 made of different materials are connected is integrated via an insulating material 8. Of course, the material of each contact 7 is the same as the material of the connected thermocouple wire 9. Each thermocouple wire 9 is connected to one end of a compensating wire 11 at an eye spot 10, and the other ends of both compensating wires 11 are connected to a detection unit 12 such as a voltmeter. Finger 6
Are arranged so that the contact 7 contacts the inner peripheral surface of the workpiece W.

The principle of the temperature detecting device 5 is as follows. That is, the workpiece W is ground on the inner peripheral surface by the grinding wheel 4 while rotating, and the surface temperature is substantially uniform except for the grinding wheel contact area during the grinding. For this reason, the law of the intermediate metal is established between the workpiece W and the thermocouple wire 9.
This is because one end of the thermocouple wire 9 is maintained at a constant temperature in the eye spot 10, and the contact 7 connected to the other end contacts the inner peripheral surface of the workpiece W having a uniform temperature as described above. If the contact position is far away, the workpiece W
Irrespective of the material, a thermoelectromotive force is generated in the thermocouple wire 9. Therefore, the thermoelectromotive force can be detected by the detector 12 via the compensating wire 11 connected in the eye spot 10, and the temperature corresponding to this voltage value can be obtained as the workpiece temperature.

In the temperature detecting device 5, the contact 7
Are provided at two places of one finger 6 to connect each contactor 7 to the detection unit 12, but as shown in FIG.
Terminals 9a made of the same material as each thermocouple wire 9 may be arranged on both sides of the contact 7 at the location, and the thermocouple wires 9 corresponding to each terminal 9a may be connected.

Reference numeral 13 denotes a control unit, which includes a comparison / calculation unit 14
It comprises a cutting table control unit 15 and a monitoring ON / OFF setting unit 16. An output signal from the detection unit 11 is input to the comparison / calculation unit 14. The first allowable temperature range and the second allowable temperature upper limit set in the allowable temperature setting unit 14a are input to the comparison / calculation unit 14 in advance.

Usually, the workpiece temperature is, for example, in rough grinding.
As shown by the solid line in FIG. 4, the value changes as the grinding progresses. However, when the grinding wheel falls off from the grinding wheel 4 and is in a so-called dropping state, the value changes as shown by the dotted line on the lower side. When the surface of the grindstone 4 is clogged with chips or the tip of the abrasive grain cutting edge is worn and closed, it changes as indicated by the upper dotted line.

For this reason, the first allowable temperature is set in a range of a temperature T _1L higher than the lower dotted line and a temperature T _1H which the upper dotted line exceeds during the period from the start to the end of reading the workpiece temperature. I have. Thus, during the grinding, it is possible to work piece temperature is the temperature T grinding wheel 4 is lower than _1L generates the shedding, it is determined that the temperature T _IH higher if generating a collapse clogging or eyes than. On the other hand, the second
Allowable temperature upper limit is set to temperature T ₂ in the first allowable temperature range. The temperature T ₂ is an upper limit temperature having a margin that does not cause a problem in the surface properties of the grinding wheel 4.

The comparing / calculating section 14 compares and calculates whether the value inputted from the detecting section 12 is within the allowable temperature range, and outputs a control signal to the cutting table control section 15. ing. The comparison / calculation unit 14 is supplied with ON / OFF signals from the monitoring setting unit 16. The monitoring setting unit 16 starts reading of the measured temperature in the comparison / calculation unit 14 after a lapse of a predetermined time from the start of grinding, and stops reading after a lapse of a predetermined time after starting the temperature measurement. The reading start time and the measurement time are set in advance. The comparison / calculation unit 14 drives the cutting motor 2 based on these input signals to move the cutting table 1.

In the grinding apparatus having the above-described configuration, the workpiece W is ground as follows. First, the workpiece W is attached to the cutting table 1 and driven to rotate, and the grinding wheel 4 is moved to the workpiece W.
To the inner circumference of. Then, while driving the cutting wheel 2 while rotating the grinding wheel 4, the cutting table 1 is moved toward the grinding wheel 4 to grind the inner peripheral surface of the workpiece W. In this case, the contact 7 of the finger 6 is
The surface temperature of the workpiece W during grinding is constantly measured by contacting the inner peripheral surface of the workpiece W.

When the rough grinding is started, the controller 13 controls the dressing, cutting dimensions, cutting speed and the like of the grinding wheel 4 in accordance with the flowcharts shown in FIGS. The flowchart in FIG. 5 shows a control method when the grinding wheel 4 is dressed during rough grinding. First, by starting rough grinding, the timer is once reset in step S1 and counting is started in step S2.

Then, in step S3, it is determined whether or not monitoring is started, that is, whether or not a predetermined time has elapsed from the start of rough grinding. If not, step S2
To continue counting, and if it has elapsed, go to step S
In step S4, the workpiece surface temperature _Tread input from the detection unit 12 is _read in step S4.

Subsequently, in step S5, it is determined whether the temperature read in step S4 is within the first allowable temperature range T _{1L to} T _1H . First allowable temperature range T _{1L to} T
If it is within _1H , the process proceeds to step S6 to determine whether rough grinding is being performed, that is, whether a predetermined time has elapsed from the start of rough grinding. If not, step S4
Then, the rough grinding is continued, and if it has elapsed, the process is terminated.

If the workpiece surface temperature T _read read in step S5 is out of the first allowable temperature range T _{1L to} T _1H during the rough grinding, the process proceeds to step S7 and the grinding wheel 4 is moved to step S7. , And the process returns to step S1 to repeat the above operation. As described above, in the above-described grinding apparatus, if the grinding is performed while directly measuring the temperature on the grinding surface of the workpiece W, the dressing can be performed before the grinding wheel 4 is damaged, and the length thereof can be increased. The service life can be extended.

FIG. 6 is a flowchart showing a method of controlling the cut size during finish grinding. The finish grinding is started at the same time as the end of the rough grinding by lowering the cutting speed as compared with the rough grinding (in this case, grinding wheel 4
No replacement is required).

First, at step S11, step S4 is performed.
The work surface temperature T _read input from the detection unit 12 is _read in the same manner as in the case of the first embodiment. Then, in step S12, the thermal expansion dimension of the workpiece W is calculated based on the _read workpiece surface temperature T _read , and in step S13, the step S12 is performed.
The finish grinding is performed by calculating a correction value of the cut dimension based on the thermal expansion dimension obtained in the step (1).

Subsequently, it is determined in step S14 whether or not finish grinding is being performed, that is, whether or not a predetermined time has elapsed since the start of counting in step S2. If it has not elapsed, the process returns to step S11 to repeat the above-mentioned operation, and if it has elapsed, finish grinding is finished. Thus, by taking into account the thermal expansion of the workpiece W during grinding, the finished dimensions can be made highly accurate.

The flowchart of FIG. 7 shows a method of controlling the cutting speed during rough grinding. In the control of the cutting speed, the cutting speed is set to a high speed in step S21 to start the rough grinding, the timer is reset in step S22, and the counting is started in step S23.

Then, in a step S24, it is determined whether or not a predetermined time has elapsed from the start of the rough grinding. If it has not elapsed, the process returns to step S23 to continue the rough grinding. If it has elapsed, the process proceeds to step S25, and similarly to step S4, the workpiece surface temperature T _{read according} to the input signal from the detection unit.
Read.

Subsequently, it is determined whether or not the workpiece surface temperature T _read read in step S26 is smaller than a second allowable temperature upper limit T ₂ . If smaller, to continue the grinding at a high cutting speed V _RH determined in the step S21 proceeds to step S27, the process proceeds to step S28 larger performing grinding on slow cutting speed V _RL.

Thereafter, it is determined in step S29 whether or not rough grinding is being performed, that is, whether or not a predetermined time has elapsed since the start of rough grinding.
Returning to step 5, the above operation is repeated, and if it has elapsed, the rough grinding is terminated. As described above, if the cutting speed during the grinding is changed according to the workpiece surface temperature, the grinding can be always performed in an appropriate state, and the surface accuracy and the life of the grinding wheel 4 can be improved.

In the above embodiment, only the temperature of the workpiece is measured by connecting the thermocouple wire 9 to the finger 6. However, as shown in FIG.
The temperature detecting device 5 may be incorporated in the device. The automatic sizing device 17 measures the inner diameter of the workpiece W. A pair of shaft portions 19 protrude from the front end surface of the measuring head 18 in a freely rotatable manner. Each extends at right angles. The shaft portion 19 is urged in a direction in which the distance between the tips of the fingers 6 is increased, so that a contact (not shown) for measuring the inner diameter, which is provided at the tip of the fingers 6, always abuts the inner peripheral surface of the workpiece W. It has become.
Further, a thermocouple wire 9 similar to that of the above embodiment is connected to one finger 6. Thus, the grinding can be performed while measuring the inner diameter and the temperature of the workpiece W, so that the inner peripheral surface of the workpiece W can be ground and finished with higher precision than the processing using the conventional measuring head. Further, regarding the setting of the second allowable temperature upper limit, the cutting speed may be more finely adjusted according to the workpiece temperature. Also, feedback control of the cutting speed based on the workpiece temperature may be performed.

[0035]

As is clear from the above description, according to the grinding apparatus of the first invention, it is only necessary to bring the thermocouple into contact with the workpiece, so that the surface temperature can be easily reduced even during grinding. The measurement can be performed, and it is not necessary to disassemble the work piece or drill a hole as in the related art.

According to the grinding device of the second aspect, the necessity of dressing the grinding wheel is detected based on the temperature of the workpiece, so that the grinding can be performed while the grinding wheel remains defective. Proceeding is prevented and the grinding wheel can be prevented from breaking.

According to the grinding apparatus of the third aspect, since the cutting speed is controlled based on the temperature of the workpiece, the grinding can be performed without difficulty, and the grinding wheel is always used in an appropriate state. It becomes possible. As a result, the surface accuracy of the grinding surface is improved, and the life of the grinding wheel can be extended.

According to the grinding device of the fourth aspect, the expansion dimension of the workpiece is obtained in accordance with the temperature of the workpiece, and the cut dimension is set based on the expansion dimension. It is possible to finish with higher precision.

According to the grinding apparatus of the fifth aspect, the grinding is performed based on the temperature of the workpiece while directly measuring the dimensions of the workpiece, so that the workpiece is finished to a desired product dimension with high precision. be able to.

[Brief description of the drawings]

FIG. 1 is a schematic view of a grinding device according to the present invention.

FIG. 2 is a circuit diagram of the temperature detection device of FIG.

FIG. 3 is a front view of a tip of a measuring finger showing another embodiment.

FIG. 4 is a graph showing a change in temperature of a workpiece due to grinding.

FIG. 5 is a flowchart showing a dress control method of a grinding wheel.

FIG. 6 is a flowchart showing a method for controlling a cutting dimension of a grinding wheel.

FIG. 7 is a flowchart showing a method for controlling a cutting speed of a grinding wheel.

FIG. 8 is a perspective view of a measuring head showing another embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Cutting table, 2 ... Cutting motor, 4 ... Grinding stone, 5 ... Temperature detection device (temperature detection means), 9 ... Thermocouple wire, 12 ... Detection part, 13 ... Control device (judgment means, cutting speed) Control means, cut size control means), 14 ... comparison / calculation section, 15 ... cut table control section.

──────────────────────────────────────────────────続 き Continuing from the front page (72) Taniyoshi Hirano 5-38-3 Ujinahigashi, Minami-ku, Hiroshima-shi, Hiroshima Prefecture Toyo Atec Co., Ltd. (72) Inventor Teru Higashi 5 Ujinahigashi, Minami-ku, Hiroshima-shi, Hiroshima JP-A-60-108268 (JP, A) JP-A-59-187461 (JP, A) JP-A 4-159077 (JP, A) 48-52088 (JP, A) JP 47-34304 (JP, B1) (58) Fields investigated (Int. Cl. ⁶ , DB name) B24B 49/14 B24B 49/18

Claims (5)

(57) [Claims] 1. An end of each thermocouple wire constituting a thermocouple is separated from and brought into contact with a workpiece surface being ground,
A grinding apparatus, comprising: temperature detection means for measuring a temperature of a workpiece, wherein the temperature detection means detects the temperature of the workpiece to perform grinding. 2. A temperature range which does not cause processing quality defects due to blinding, clogging or omission of a grinding wheel within a predetermined time during grinding is set as a first allowable temperature range, and the work is measured by the temperature detecting means. 2. The grinding apparatus according to claim 1, further comprising a determination unit configured to determine whether an object temperature is within the first allowable temperature range and determine whether dressing of the grinding wheel is necessary. 3. A temperature at which a grinding wheel does not cause blinding, clogging or dropping within a predetermined time during grinding is set to a second temperature.
It is set as an allowable temperature upper limit, it is determined whether the workpiece temperature measured by the temperature detecting means is the second allowable temperature upper limit, and the cutting speed is set to a predetermined high speed until the workpiece temperature reaches the second allowable temperature upper limit. 3. The grinding apparatus according to claim 1, further comprising a cutting speed adjusting means for adjusting the cutting speed to a predetermined low value after the temperature exceeds the second allowable temperature upper limit. 4. A cutting dimension adjusting means for calculating an expansion dimension of a workpiece based on a workpiece temperature measured by the temperature detecting means and adjusting a cutting dimension based on the expanded dimension. 4. The grinding device according to claim 1, wherein: 5. A contact is provided on each of a pair of fingers for measuring a processing diameter of a workpiece, and one end of a thermocouple wire constituting the thermocouple is attached to one of the contacts so as to clamp the contact. 5. The grinding device according to claim 1, wherein