JP2003236748A - Grinder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a grinder that corrects a grinding wheel position referring to work thickness measured during grinding and certainly provides work having a desired thickness. <P>SOLUTION: This grinder has the grinding wheel facing the surface of the plate-like work and grinds the surface of the work. The grinding device comprises a work thickness measuring means for measuring a thickness of the work during the grinding, a grinding wheel position detecting means for detecting a moving position in the cutting in direction of the grinding wheel grinding the work, a detecting means for detecting an amount of a grinding wheel abrasion based on the thickness information from the work thickness measuring means and positional information from the grinding wheel position detecting means, and a movement controlling means for controlling the movement of the grinding wheel while correcting the grinding wheel position using the amount of the grinding wheel abrasion detected by the detecting means. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grinding device for simultaneously grinding both surfaces of a work such as a silicon wafer. In particular, the work is highly accurately ground by measuring the work thickness during grinding (also called in-process) and checking the grindstone movement amount at that time so that the position of the worn grindstone can be accurately corrected. The present invention relates to a grinding device that is made possible.

[0002]

2. Description of the Related Art In a conventional general grinding apparatus, a target cutting depth is set in a controller for controlling the cutting depth of a grindstone to grind a workpiece. Here, the cutting amount of the grindstone is the amount of movement of the grindstone for grinding the workpiece in the traveling direction.

However, by grinding the work,
The grindstone itself also wears and the thickness decreases. Therefore, when the grinding amount is repeated while maintaining the cutting amount of the grindstone set at the initial stage, a state in which the grindstone idles before contacting the work (called an air cut) occurs. When this air-cut state occurs, problems occur such as wasting time until the grindstone comes into contact with the work and not being able to grind the work to a desired thickness.

Therefore, conventionally, the thickness of the unworked and processed work is measured to confirm the amount of deviation from the target work thickness, and the amount of wear of the grindstone is estimated from this amount of deviation. Then, the grindstone position is sequentially corrected based on the estimated value, and then the work is ground.

[0005]

However, the above-mentioned conventional correction method is not based on the work thickness in the in-process or the position of the grindstone. Since the measurement environment is different between the state of the work when the grinding machine is being driven and being ground and the state of the work when the machine is stopped, such as after processing and after processing as described above, the measured data may be subtle. There is a wide variation.

That is, in the conventional correction based on the work thickness measured in the state where the grinding device is stopped and the work is not performed and after the work is performed, there is a limit in accurately grinding the work to the target thickness. The same problem occurs in the case of a double-headed grinding machine in which a pair of grindstones are arranged so as to face both surfaces of a workpiece and both surfaces are ground simultaneously.

Therefore, a main object of the present invention is to provide a grinding apparatus which can surely obtain a work having a desired thickness by using the work thickness measured during the in-process to correct the position of the grindstone. is there.

[0008]

According to a first aspect of the present invention, there is provided a grinding apparatus for grinding a surface of a work piece, wherein a grindstone is arranged so as to face the surface of the work piece. A work thickness measuring means for measuring the thickness of the work being ground, a grindstone position detecting means for detecting a moving position in the cutting direction of the grindstone grinding the work, and a thickness from the work thickness measuring means Using the grindstone wear amount detection means for detecting the grindstone wear amount based on the information and the position information from the grindstone position detection means, and using the grindstone wear amount detected by the grindstone wear amount detection means, the position of the grindstone is corrected. However, it is achieved by a grinding device provided with a movement control means for controlling the movement of the grindstone.

Further, as described in claim 2, in the grinding apparatus according to claim 1, the position of the grindstone is corrected by the movement control means, and the initial position of the grindstone is set when the grinding of the unworked work is started. It may be executed at the time of.

According to the first and second aspects of the invention, the grindstone wear amount detecting means detects the grindstone wear amount based on the work thickness information and the grindstone position information, and the movement control means detects the grindstone wear amount. The movement control of the grindstone is executed while correcting the movement amount of the grindstone using the above. Since this correction is based on the data during grinding, a work having a desired thickness can be processed with high accuracy. Further, according to the present invention, it is possible to surely suppress the air cut state, and there is also an advantage that the processing time can be shortened.

According to a third aspect of the present invention, in the grinding apparatus according to the first or second aspect, the work thickness measuring means includes a pair of contacts formed so as to sandwich the work being ground. The movement control means may control the movement of the grindstone so as to include a step of grinding a scratch remaining on the work surface after the contact is separated from the work surface.

According to the third aspect of the present invention, it is possible to obtain a product work without damage even when a contactor is used for measuring the work thickness.

According to a fourth aspect of the present invention, in the grinding apparatus according to any of the first to third aspects, the grindstone wear amount detecting means further has a function of integrating the detected grindstone wear amounts, It is preferable to set a warning for wheel replacement when the integrated value exceeds a preset allowable wear value.

According to the fourth aspect of the invention, the operator can surely know that it is time to replace the grindstone.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of a double-sided grinding machine according to an embodiment. This double-headed grinding device includes a first spindle device 1 and a second spindle device 2, a work holding device 3, and a work thickness measuring device 50 as work thickness measuring means.

The first spindle device 1 includes a cup-shaped grindstone 11 and a main shaft portion 12 for rotating the grindstone 11. The cup-shaped grindstone 11 has a front end formed into a flat surface. The cup-shaped grindstone 11 has its center axis taken as X in FIG.
Is fixed to the main shaft portion 12 in the direction. The spindle device 1 is set to be slidable in the rotation axis direction of the main shaft portion 12 (X direction in FIG. 1) by a linear guide 41 provided on the bed 4.

Further, the spindle device 1 has a slide mechanism 13. The slide mechanism 13 functions as an actuator that slides the spindle device 1 in the direction of the rotation axis of the main shaft portion 12. This slide mechanism 13
For example, a hydraulic cylinder mechanism can be adopted. The slide mechanism 13 illustrated in FIG. 1 includes a cylinder 131, a piston 132 fitted in the cylinder 131, and a piston rod 133 fixed to the piston 132. The cylinder 131 is provided in a housing chamber 14 formed in the housing of the spindle device 1 in the same manner as being hollowed out into a substantially cylindrical shape. Specifically, one end of the cylinder 131 (left in FIG. 1) is
It is fixed to the wall surface on the left side in FIG. A through hole is provided in the side wall. The piston rod 133 is fitted in this through hole, and one end of the piston rod 133 projects leftward in FIG.
The protruding end of this piston rod 133 is
It is fixed to the fixing portion 42 protruding from the.

In the spindle device 1 having the above structure, when the slide mechanism 13 is driven by receiving hydraulic pressure (not shown),
It moves in the X direction of FIG. Therefore, the main shaft portion 12 and the cup-shaped grindstone 11 of the spindle device 1 can move in the X direction of FIG. 1 in a rotated state.

Further, the other second spindle device 2 is
It has the same configuration as the first spindle device 1 described above,
A grindstone 21, a main shaft portion 22, and a slide mechanism 23 are provided. These spindle devices 1 and 2 each have their cup-shaped grindstones 11 and 21 coaxially opposed to each other, and each of them has a bed 4
It is arranged on the upper side and is movable in the left-right direction (X direction) in FIG. When each of these spindle devices 1 and 2 moves, the main shaft portions 12 and 22 also move. Therefore, the grindstones 11 and 21 are attached to the spindles 12 and 22, respectively.
In a state in which is fixed, both cup type grindstones 11, 2
Since the interval of 1 can be freely adjusted, it is possible to grind the work W arranged between the cup-shaped grindstones 11 and 21 from both sides.

Further, the spindle device 1 is provided with a linear sensor 16 as a grindstone position detecting means for detecting the positions of the spindle devices 1 and 2 which are moved by the slide mechanism 13. The position of both cup type grindstones 11 and 21 can be confirmed by this linear sensor 16. As this linear sensor 16, a linear encoder, a laser interferometer, or the like can be adopted.

The work holding device 3 is provided with a work holder 31 for holding the work W in a rotated state, a holder mechanism 32 for arranging the work holder 31 between the spindle devices 1 and 2, and the like. As this work holding device 3, a conventional general structure can be adopted.

The double-sided grinding machine is equipped with a work thickness measuring device 50 for measuring the thickness of the work. The work thickness measuring device 50 can measure the thickness of the work ground by the cup-shaped grindstones 11 and 21 during grinding. In FIG. 1, the structure of the work thickness measuring device 50 is omitted, but it will be described later in detail.

In the double-sided grinding machine of this embodiment, the work thickness during grinding is measured and the moving positions of the double cup type grindstones 11 and 21 are detected, and the grindstone wear amount is detected based on these. Both cup-shaped grindstones 11 and 2 using this grindstone wear amount
Since the position 1 is corrected, the work can be ground with high accuracy.

FIG. 2 is a block diagram showing a configuration relating to drive control of a grindstone position provided in the double-sided grinding machine.
As shown in FIG. 2, the double-sided grinding machine includes a controller 60. The controller 60 is realized by, for example, a CPU. The controller 60 may be realized by a computer or the like that executes drive control of the entire double-sided grinding machine.

The controller 60 includes the thickness measuring device 5
0 is connected. The controller 60 controls the drive of the thickness measuring device 50, and acquires the thickness data of the work measured by the thickness measuring device 50 during grinding.

The line sensor 16 is connected to the controller 60. As described above, the line sensor 16 detects the moving position of the spindle devices 1 and 2. That is, the controller 60 receives the output signal from the line sensor 16 and monitors the movement amount (position information) of the grindstones 11 and 21 to the work W side based on the output signal.

Further, as described above, the spindle devices 1 and 2 of the apparatus of this embodiment are driven in the X direction by the slide mechanisms 13 and 23 driven by hydraulic pressure. The controller 60 also controls the movement of the grindstones 11 and 21 formed on the spindle devices 1 and 2 by controlling the hydraulic pressure supplied to the slide mechanisms 13 and 23.

Furthermore, an input panel 61 is connected to the controller 60. With this input panel 61,
The operator can input a predetermined instruction and a desired set value. A ROM 62 is connected to the controller 60. In the ROM 62, various measurement programs for executing the work thickness measurement, the grindstones 11 and 2,
A drive control program of the slide mechanism 13 for moving the spindle devices 1 and 2 to which 1 is fixed are stored. The controller 60 uses the information from the ROM 62 to execute drive control of the double-headed grinding machine.

From the configuration shown in FIG. 2, the controller 60 can obtain the thickness information from the thickness measuring device 50 during the in-process, and the output of the line sensor 16 which detects the positions of the spindle devices 1 and 2. Therefore, it is possible to confirm the positional information on the grindstones 11 and 21.

Assuming that the grindstones 11 and 21 are not worn, the thickness measurement device 50 measures the thickness of the unmachined work in the initial setting of the work machining, and the initial positions of the spindle devices 1 and 2 are accurately measured. If set to, the work thickness data and the position data of the grindstones 11 and 21 correspond to each other. That is, the amount of cut into the work can be specified from the position data of the grindstones 11 and 21 indirectly confirmed from the detected positions of the spindle devices 1 and 2. Since the work W is ground corresponding to the depth of cut, the thickness data measured by the thickness measuring device 50 and the position data based on the output of the line sensor 16 match.

However, as described above, the abrasion of the grindstones 11 and 21 progresses as the work is ground. That is, the front end positions of the grindstones 11 and 21 are retracted by grinding. Therefore, the position data of the grindstones 11 and 21 based on the position detection of the spindle devices 1 and 2 deviates from the expected value.

Therefore, in this embodiment, the controller 60
However, when one work grinding is completed, the deviation caused by the abrasion of the grindstone is detected as the grindstone wear amount based on the thickness information and the position information. Further, the controller 60
Adjusts the positions of the grindstones 11 and 21 to proper positions by using this grindstone wear amount. That is, in this double-headed grinding machine,
Every time the controller 60 starts grinding of an unworked work, the above-mentioned grindstone wear amount is added to the position data based on the output of the line sensor 16 as a correction value, and the positions of the grindstones 11 and 21 are controlled to approach the work W side. To do.

According to the apparatus of this embodiment, the controller 6
The control of 0 makes it possible to grind a work having a target thickness with high accuracy while suppressing the occurrence of an air cut state. In the present apparatus, the controller 60 includes a grindstone wear amount detecting means for detecting the grindstone wear amount and the grindstones 11 and 21.
It functions as a movement control means for controlling the movement of the.

Further, the controller 60 uses the grindstones 11 and 2
The usage limit of 1 is also monitored. The controller 60 integrates the wear amount of the grindstone generated by one grinding, and when the integrated value exceeds a preset allowable wear value, a warning signal is supplied to the warning device 65 to notify the operator of the grindstone 11. , 21
Is trying to recognize that it is time to replace. The warning device 65 is not particularly limited as long as it prompts the operator to replace the grindstone. A general warning device such as a warning light and a warning sound may be adopted.

Further, with reference to FIG. 3 to FIG. 5, the peripheral structure of the work thickness measuring device 50 of the double-sided grinding machine will be described. FIG. 3 is a view showing a part of the double-sided grinding machine of FIG. 1 as seen from the direction of arrows I-I. With reference to FIG. 3, the relationship between the work holding device 3 and the work W and the work thickness measuring device 50 are shown.
You can check the arrangement.

Work holder 31 having a drive source (not shown)
Is rotated in the direction of arrow R while supporting the work W. This work holder 31 is a holder mechanism 3
It is installed on 2. The holder mechanism 32 is movable in the X direction and the Y direction, so that the work W can be loaded into the work holder 31 and the work W can be positioned in the X direction.

Although only the front side is shown in FIG. 3, the above-mentioned cup-shaped grindstones 11 and 21 are arranged at positions deviated from the center of the work on both sides of the work W, and a pair of the pair of grinding wheels is provided. The static pressure pad 35 is arranged so as to face the surface of the remaining work W. A fluid such as water is ejected from the surface of the static pressure pad 35 facing the work W toward the work W, and the work W can be rotated and positioned in the X direction. The static pressure pad 35
Are arranged so that the peripheral portion of the work W is slightly left. The work thickness measuring device 50 is fixed to the frame of the holder mechanism 32 so as to measure the thickness of the peripheral portion.

FIG. 4 is an enlarged view of the peripheral portion including the work thickness measuring device 50 indicated by the arrow α in FIG. The work thickness measuring device 50 includes a pair of holding arms 51 that hold the work W from both sides.
The thickness of the workpiece W being ground can be measured according to the opening degree of 1. In the present embodiment, a voltage generation circuit that generates a voltage according to the opening degree of each of the two holding arms 51 is provided in the main body of the work thickness measuring device 50 that is the base of the holding arm 51. This voltage generates a predetermined voltage according to the opening degree of each holding arm 51. Therefore, the opening state of each of the two holding arms 51 can be confirmed.

Further, FIG. 5 is a diagram showing the relationship between the work W and the holding arm 51 of the work thickness measuring device 50 in more detail. 5 (A) is a view shown by the arrow II in FIG. 4, and FIG. 5 (B) is a view showing an enlarged region β of FIG. 5 (A).

As shown in FIG. 5B, each holding arm 5
A contact 52 is attached to each of the one ends. The contact 52 is fixed to the front end of the sandwiching arm 51 with a screw so that the position of the tip contacting the work can be adjusted.

Further, in the following, an example of steps for processing a work by using the double-sided grinding machine having the above-mentioned structure will be described.

When the work W is ground by using this apparatus, the thickness of the work (hereinafter referred to as unprocessed work) to be processed as a preparatory step is the work thickness measuring device 5.
It is measured at 0. Therefore, the work thickness measuring device 50
The origin of is adjusted.

FIG. 6 is a diagram schematically showing a procedure for measuring the thickness of an unprocessed work by the work thickness measuring device 50. FIG. 6A is a diagram showing a state of the origin adjustment using the reference work BW whose thickness is previously recognized, and FIG. 6B shows a state of measuring the thickness of the unprocessed work W after the origin adjustment. It is the figure shown.

In FIG. 6A, the reference work BW is set as the coordinate origin of this device. The positioning of the reference work BW is performed by driving the work holding device 3 described above. With respect to the reference work BW, the pair of holding arms 51 of the work thickness measuring device 50 are closed, and the contacts 52 are adjusted so as to contact the reference work BW substantially symmetrically. For example, when the thickness of the reference work BW is 802 μm, the thickness detected by each holding arm 51 is 401 μm, which is half that thickness, and the output voltage (thickness detection voltage) at that time is adjusted to 0 mV. To do. This completes the origin adjustment.

Next, as shown in FIG. 6 (B), the holding arm 51 is opened (referred to as a retract) to mount the unprocessed work W, and then the holding arm 51 is closed to remove the unprocessed work W. Measure the thickness.

As described above, the grinding of the unmachined work W is started after the preparatory process before machining is completed. FIG. 7 is a diagram showing how the unworked work W undergoes double-sided grinding and changes in thickness until it is processed into a work having a final target thickness.

The process of grinding the unworked work W will be described with reference to FIG. 7 and FIGS. 1 and 2 shown above.
In each process shown below, the input panel 6 is used in principle.
Based on the instruction from the operator via 1, the above-described controller 60 performs overall drive control.

The input panel 61 is provided with a later-described distortion correction amount for the unworked work W, a target work thickness of the product work (hereinafter,
The controller 60 executes the control after the predetermined information such as the final target thickness) and the allowable limit thickness are set.

First, the controller 60 uses the grindstones 11 and 21.
Is controlled to move to the initial position PR. This initial position PR is
It is set by adding the work distortion correction amount DC to the thickness T of the unprocessed work W measured before processing. The unprocessed work W is not smooth and has some distortion, and its thickness varies. Therefore, it may be assumed that the portion whose thickness is measured before processing is a particularly thin portion. In this state, when the grindstones 11 and 21 are rotated to start the processing of the unworked work W, the thick portion of the unworked work W becomes the grindstones 11 and 2.
There is a problem such that the workpiece 1 is strongly contacted and the workpiece is damaged.

Here, in this apparatus, the grindstones 11 and 21 are made to approach the unprocessed work W from the position of (thickness T of the unprocessed work W) + (work distortion correction amount DC) as described above. This work distortion correction amount DC is, for example, several μm.
It is a degree.

Thereafter, under the control of the controller 60, grinding is performed while cutting the grindstones 11 and 21 to the unworked workpiece W side. For example, in the case of the present embodiment, the first target thickness FI, the second target thickness SD and the final target thickness E
D is set via the input panel 61, and the controller 6
0 controls the movement of the grindstones 11 and 21 so that the unworked work W has these target thicknesses in order.

The first target thickness FI is set to such a thickness that the work can be strained and both surfaces can be flattened. In the grinding process for making the unprocessed work W the first target thickness FI, the controller 60 moves the grindstones 11 and 21 toward both surfaces of the work at a relatively high cutting speed.

In the step of setting the first target thickness FI, grinding may be performed in a plurality of steps, for example, in four steps so that the cutting speed becomes slow. That is, the grindstones 11 and 21 are moved earlier at the beginning of grinding, and the moving speed of the grindstones 11 and 21 in the X direction is slowed down when the first target thickness FI is approached. By doing so, it is possible to obtain an intermediately machined work having the first target thickness FI while shortening the process time without damaging the unprocessed work W or the like.

The second target thickness SD is the final target thickness ED
And the contact margin 52 of the thickness measuring device 50 includes a scratch allowance IN which includes a scratch left on the work surface. This double-headed grinding machine measures the work thickness during grinding by bringing a pair of contacts 52 into contact with the surface of the work under grinding. As a result, the contact 52 may come into contact with the surface of the work, resulting in scratches.

Therefore, (second target thickness SD) = (final target thickness ED) + (scratch allowance IN), and this scratch allowance IN is grinded later so as to obtain a product work whose surface is not damaged. is doing. Therefore, the thickness measuring device 50
When the target thickness SD is measured, the controller 60
Retracts the contact 52 from the work surface. Then, the controller 60 further moves the grindstones 11 and 21 by the amount of the scratch allowance IN, and finally performs control such that the work thickness becomes the final target thickness ED. The thickness of the scratch allowance IN is submicron, and the control programmer for grinding the scratch allowance IN may be preset in the ROM 62.

As described above, the controller 60 functions as a grindstone wear amount detecting means. This point will be described. As described with reference to FIG. 2, the controller 60
Is the grindstones 11 and 21 based on the detection signal of the line sensor 16.
Position information and the thickness information of the workpiece being machined are monitored from the thickness measuring device 50. And the controller 60
Is the second thickness data measured from the thickness measuring device 50.
When the target thickness SD is reached, the position data is confirmed from the output of the line sensor 16. Then, when there is a deviation between the thickness data and the position data, this is detected as the grindstone wear amount. This grindstone wear amount becomes a correction value when the initial position PR of the grindstones 11 and 21 is set when the unprocessed work is loaded next and the processing is started. That is,
The controller 60 calculates the amount of wear of the grindstone, grindstones 11 and 21.
The machining control is started after the initial position PR of is corrected to the unmachined work W side. Since the grindstone wear amount is specified based on the data confirmed during the in-process, the work can be ground with high accuracy by correcting the positions of the grindstones 11 and 21 based on the data.

Then, the controller 60 integrates the grindstone wear amount each time the workpiece machining is started, and when the integrated value exceeds the allowable wear amount preset through the input panel 61, the grindstone replacement signal is given. Is supplied to the warning device 65.

In this double-headed grinding machine, an allowable limit thickness AT which is slightly smaller than the final target thickness ED is set. It is also conceivable that the thickness may be greater than the final target thickness ED due to a processing error or the like, and cutting may occur. Therefore, the allowable limit thickness A
T is set as a limit thickness that is allowable as a product work.

That is, after the machining of the unprocessed work W is started in the double-headed grinding machine, the controller 60 controls the movement of the grindstones 11 and 21, and the first target thickness FI is measured by the thickness measuring apparatus 50 as described above. Then, the second target thickness SD is measured, and after retracting the contactor 52, the contact 52 is further cut by a predetermined amount to obtain a work having the final target thickness ED. Then, the controller 60 repeats the processing while correcting the position of the grindstone by the amount of wear of the grindstone, so that the occurrence of the air cut is suppressed, and the grindstone can be immediately brought into contact with the surface of the unprocessed work and the grinding can be started after the device is driven. .

The double-headed grinding machine is set so as to be able to cope with an abnormality that occurs during workpiece grinding. The following control at the time of abnormality is also executed by the controller 60.

If any abnormality occurs, the first target thickness FI
If the thickness measured by the thickness measuring device 50 falls below the permissible limit thickness AT during grinding of the unmachined workpiece toward, the drive of this device is stopped as an abnormality. At the same time, the operator is warned. The warning device 65 can also be used for this warning.

Further, according to the position data based on the output from the line sensor 16, even though the grindstones 11 and 21 are moved to the position corresponding to the first target thickness FI or the second target thickness SD, the thickness measurement is performed. Even when the thickness data from the device 50 does not reach the first target thickness FI or the second target thickness SD, the controller 60 estimates that there is some abnormality. In this case also, the drive of this device is stopped and a warning is issued.

In the embodiment described above, the grindstone wear amount detected by the controller 60 which realizes the grindstone wear amount detecting means is determined by the grindstones 11 and 21 at the start of machining of the next unworked workpiece.
It is used for correction when setting the initial position PR of.
However, the position of the grindstones 11 and 21 may be immediately corrected when the controller 60 detects the grindstone wear amount.

Further, in the above embodiment, the double-head type grinding device for grinding both surfaces of the work has been shown, but it goes without saying that the present invention can be applied to a grinding device for grinding only one surface of the work. In this case, the configuration can be simplified as compared with the above-described embodiment, and the controller 60 may detect the wear amount of one grindstone and control the movement.

Further, in the above-mentioned embodiment, an example of the contactor in which the work thickness measuring means directly sandwiches the work is shown. However, the present grinding apparatus may employ a non-contact work thickness measuring means in addition to the structure in which the work is contacted to measure the thickness. A laser displacement meter or the like can be adopted as the non-contact type thickness measuring means. However, when the surface of the work is ground using a liquid such as water, it is preferable to measure the thickness of the work while air blowing the liquid.

Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the specific embodiments, and various modifications are possible within the scope of the gist of the present invention described in the claims. Can be modified and changed.

[0067]

As is clear from the above description, according to the inventions of claims 1 and 2, since the position correction of the grindstone is based on the data during grinding, a desired thickness is obtained. Work can be processed with high accuracy. Further, according to the present invention, it is possible to surely prevent the air cut state, so that there is an advantage that the processing time can be shortened.

According to the third aspect of the present invention, it is possible to obtain a product work without scratches even when a contactor is used to measure the work thickness.

Further, according to the invention described in claim 4, the operator can surely know that it is time to replace the grindstone.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of a double-sided grinding machine according to an embodiment.

FIG. 2 is a block diagram showing a configuration relating to drive control of a grindstone position provided in the double-sided grinding machine of the embodiment.

FIG. 3 is a view showing a part of the double-sided grinding device of FIG. 1 as seen from the direction of arrows I-I.

FIG. 4 is an enlarged view of a peripheral portion including a work thickness measuring device indicated by an arrow α in FIG.

FIG. 5 is a diagram showing in detail a relationship between a work and a holding arm of the work thickness measuring device.

FIG. 6 is a diagram schematically showing a procedure for measuring the thickness of an unmachined work with the work thickness measuring device.

FIG. 7 is a diagram showing how the thickness of a non-machined work is double-headed and ground to be machined into a work of a final target thickness.

[Explanation of symbols]

1, 2 Spindle device 3 Work holding device 11, 21 Cup type grinding wheel (grinding wheel) 13, 23 Slide mechanism 16 Linear sensor (grinding wheel position detecting means) 50 Work thickness measuring device (work thickness measuring means) 51 Clamping arm 52 Contact element 60 Controller (grinding stone wear amount detection means, movement control means) 61 Input panel 62 ROM 65 Warning device

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Ryuji Furukawa             8230 Tamashima Otoshima, Kurashiki City, Okayama Prefecture             Inside Intec Co., Ltd. F term (reference) 3C034 AA08 AA13 BB92 CA02 CA08                       CA12 CA26 CB13 CB18 DD12                 3C043 BC06 CC04 CC11

Claims (4)

[Claims] 1. A grinding device for arranging a grindstone so as to face a surface of a plate-like work and grinding the surface of the work, the work thickness measuring means for measuring the thickness of the work being ground. And a grindstone position detecting means for detecting a movement position in the cutting direction of the grindstone that is grinding the work, and a grindstone based on position information from the work piece thickness measuring means and the grindstone position detecting means. A grindstone wear amount detection means for detecting the wear amount, and a movement control means for performing movement control of the grindstone while correcting the position of the grindstone by using the grindstone wear amount detected by the grindstone wear amount detection means A grinding device characterized by the above. 2. The grinding apparatus according to claim 1, wherein the movement control unit corrects the position of the grindstone when the initial position of the grindstone is set when starting the grinding of the unprocessed work. A grinding device characterized by the above. 3. The grinding apparatus according to claim 1, wherein the work thickness measuring unit includes a pair of contacts formed so as to sandwich the work being ground, and the movement control unit moves the grindstone. The grinding apparatus, wherein the control includes a step of grinding a scratch remaining on the surface of the work after the contact is separated from the surface of the work. 4. The grinding apparatus according to any one of claims 1 to 3, wherein the grindstone wear amount detection means further has a function of integrating the detected grindstone wear amounts, and the integrated value is set to a permissible wear amount set in advance. A grinding device characterized in that it is set to issue a warning of wheel replacement when the value is exceeded.