JPH0641105B2 - Whetstone dressing method and device in surface grinding process - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a surface grinding process using a surface grinding device,
The present invention relates to a dressing method capable of efficiently dressing a grindstone and a dressing device for realizing the method.

[Conventional technology]

As shown in FIG. 8, the surface grinder has a saddle i movable in the front-rear direction mounted on a machine base h, and a direction orthogonal to the moving direction of the saddle i on the saddle i (in the figure, A table j movable in the left-right direction is superposed, and a magnet chuck a is fixed on the upper surface of the table j, and a workpiece b (hereinafter referred to as a work b The work b is machined by magnetically adhering.

By the way, in the surface grinding step, there is a step of dressing a disc-shaped grindstone which is spilled, that is, a dressing step. Conventionally, this dressing is performed as follows.

FIGS. 7A to 7F are explanatory views showing this step. FIG. 7A shows a state in which a workpiece b magnetically adhered to a magnet chuck a is being ground by a disc-shaped grindstone c. Dressing of the grindstone c, that is, dressing, is performed during grinding. It is carried out at the stage when the spillage of c becomes remarkable and the grinding effect is reduced. The dresser shown as d in the figure is formed by projecting a dresser head g having a diamond tip attached to the upper end face f of a truncated cone-shaped pedestal e having a constant height. When the dressing needs to be done, the dresser d is magnetically attached to the magnet chuck a on the side of the work, and then the table j is horizontally moved to horizontally move the magnet chuck a and rotate the dresser head g. The surface of the grindstone is scraped by bringing the inner grindstone into contact. To position the dresser head g on the surface of the grindstone, first, move the table j to move the magnet chuck a horizontally, position the dresser d below the grindstone (Fig. 7 (b)), and then lower the grindstone c. Then, the surface of the grindstone is brought into contact with the dresser head g. The contact between the grindstone c and the dresser head g is
Check by the ignition phenomenon from the rotating whetstone.

Then, after grinding to a certain depth from the surface of the grindstone to complete the conspicuousness, the grindstone c is once moved upward, and then the magnet chuck a is horizontally moved to position the work b below the grindstone.
After lowering the grindstone c until it comes into contact with the work b, the grinding of the work b is restarted (Fig. 7 (c), (d),
(E)). By the way, in the above process, if the height position of the dresser head g and the height position of the upper surface of the work b are the same, the vertical movement of the grindstone c is unnecessary, but in reality, there are countless types of work b. The height position of the upper surface of the grindstone c is also not constant, and therefore the vertical movement of the grindstone c cannot be eliminated.

[Problems to be Solved by the Invention]

However, the vertical movement of the grindstone c in the above method is troublesome, and since the popular type surface grinder that does not use the numerical control system does not have means for measuring and displaying the vertical movement amount of the grindstone, the grindstone c is raised and lowered. The amount of movement at that time depends only on the experience and intuition of the worker, and the skill level is required for the work. Further, when returning the work b to the lower side of the grindstone, forgetting to move the grindstone c upward, or if the amount of upward movement is insufficient, the grindstone c collides with the work b and is damaged, or the work is repelled. It was also extremely dangerous.

The present invention has been made in view of the present situation, and it is possible to perform the positioning of the work and the dresser directly under the grindstone without depending on the experience and intuition of the operator,
It is an object of the present invention to provide a dressing method capable of completely preventing a grindstone from colliding with a work and further simplifying a surface grinding process, and a dressing apparatus for realizing the method.

[Means for solving the problem]

The present inventor has conceived that the vertical movement of the grindstone may be eliminated in order to solve the above-mentioned problem, and positioning of the work and the dresser immediately below the grindstone necessary when shifting between the grinding process and the dressing process. The basic idea is to perform only by the horizontal movement operation of the magnet chuck.

That is, as the dresser, the one whose height position of the tip of the dresser head is matched with the work surface height position is used, and the work and the dresser of the work and the dresser directly under the grindstone necessary when shifting between the grinding process and the dressing process are used. As shown in FIGS. 1 (a), (b) and (c), the positioning is basically performed only by the horizontal movement operation of the magnet chuck a, and the idea of eliminating the vertical movement of the grindstone c is proposed.

Then, in order to apply such a method to various works having different heights, it is necessary that the height position of the dresser head can be changed. We have developed a dresser in which the upper end surface of the pedestal on which the dresser head is projected can be raised or lowered manually or automatically.

As described above, it is necessary to make the height position of the dresser head match the height position of the work top surface. However, whether the height position of the dresser head after ascending and descending matches the work top surface height position. In order to know that, it is essential to measure the height position of the dresser head. However, the tip of the dresser head is extremely small, and direct measurement is difficult. Therefore, instead of directly measuring the height position of the tip of the dresser head, the present inventor externally fits a metal cap having a flat top surface to the dresser head, and measures the height position of the top surface of this metal cap. Therefore, the height position of the dresser head is indirectly detected. When the metal cap is externally fitted to the dresser head, the height position of the top surface of the dresser head becomes higher than at least the height position of the dresser head. Therefore, the height position of the tip of the dresser head and the height position of the work top surface are matched. If the work is to be performed with the top surface of the metal cap as a reference, it is necessary to arrange a member for raising the work surface on the top surface of the work.

The gist of the method of the present invention made based on such an idea is to configure a dresser in which a head serving as a grinding blade is projected from the upper end surface of the pedestal body and the upper end surface can be moved up and down, and the dresser is a work piece. It is placed on the side magnet chuck, and the upper end surface of which is fitted with a metal cap having an internal space capable of accommodating a protruding dresser head and having a flat top surface, and the top surface of the other work. Is a metal block having a height obtained by subtracting a distance corresponding to the protruding height from the upper end surface of the pedestal of the dresser head from the height of the metal cap alone, and the top surface of which is a flat surface. Place the work on which the metal block is placed and position it below the detection head of the distance sensor to measure the distance to the top surface of the metal block and store the data. The distance sensor is moved up and down so that the separation distance becomes a preset distance, and then the magnet chuck is moved horizontally to position the dresser with the metal cap fitted on the outside of the detection head to the top surface of the metal cap. The height of the dresser is determined by raising and lowering the dresser so that this distance matches the distance between the top surface of the metal block and the detection head, which is necessary when the grinding process and the dressing process are changed. The feature is that the work and the dresser are positioned right under the grindstone only by the horizontal movement operation of the magnet chuck.

A dressing device which is a second invention capable of implementing such a method includes a dresser in which a head serving as a grinding blade is projectingly formed on an upper end surface of a pedestal whose upper end surface can be raised and lowered.
A metal cap having an internal space into which the dresser head can be fitted and having a flat top surface, and the height of the metal cap alone corresponds to the protruding height of the tip of the dresser head from the upper end surface of the pedestal. A metal block having a height obtained by subtracting the distance to be placed on the work upper surface whose top surface is a flat surface, and is positioned above the height position of the dresser head and the work upper surface position, A distance sensor that can continuously measure the distance to the object or can set the sensing distance of the object in advance and sends a notification signal when the object reaches the set distance, and the distance sensor measures or the distance sensor It is intended to provide a dressing device including an arithmetic processing unit for processing a notification signal sent from the device and a notification means for notifying an operator of the operation result.

[Action]

The dressing method and the dressing device of the present invention are such that a metal cap is externally fitted to a dresser magnetically adhered to a magnet chuck, while a metal block is placed on the upper surface of a work and a metal sensor is used by using a distance sensor. The height positions of the cap top surface and the metal block top surface are made to coincide with each other, and as a result, the height position of the dresser head is made to coincide with the height position of the work top surface. And when the need for sharpening arises during the surface grinding work,
While the height position of the grindstone is fixed, only the magnet chuck is horizontally moved to position the dresser directly below the grindstone and bring the dresser head into contact with the surface of the grindstone. According to this method, the transfer between the grinding work and the dressing work can be performed only by the horizontal movement of the magnet chuck, so that the dressing work can be made more efficient, and the worker who was indispensable for the conventional dressing work. No need for intuition or experience.

〔Example〕

Next, details of the present invention will be described based on illustrated embodiments.
FIGS. 2A and 2B show one embodiment of a dresser newly developed to enable the method of the present invention. This dresser is characterized in that the height of the dresser head of the conventional dresser is fixed and can be changed. For example, as shown in the figure, this dresser 1
Is the pedestal body 2a, the pedestal body 2a
The pedestal 2 is configured so that it can be moved up and down through a threaded relationship between a male screw 3 threaded on the outer peripheral surface of the upper part of the above and an annular dial 4 threaded on the inner peripheral surface of a female screw (not shown), A dresser head 7 having a diamond tip 6 attached to the top end of the pedestal 2 is provided so as to project therefrom. Dresser head 7
In order not to bite into the surface of the grindstone, is inclined so as to be in a free-running state with respect to the rotating direction of the grindstone.

In the example shown in the figure, a screwing relationship between a male screw and a female screw is used as the elevating mechanism of the dresser 1, and the elevating and lowering of the dresser head 7 is performed by rotating the annular dial 4 manually. It is also optional to use another one, and for example, a driving source such as a servo motor may be incorporated and the dresser head 7 may be moved up and down by the driving force of the motor. Further, since the height of the dresser head 7 in the illustrated example is detected by a method described later, it is not necessary to calibrate the annular dial 4, but the annular dial 4 is calibrated in order to visually grasp the outline of the lifting distance. May be.

The ▽ mark on the bottom of the pedestal body 2a of the dresser 1 is
It is a matching mark used for positioning when the dresser 1 is magnetically attached to the magnet chuck, and a Δ mark is printed on the magnet chuck in correspondence with the ▽ mark.

What is shown as FIG. 3 is a principal part explanatory view showing one embodiment of the method of the present invention using the dresser having the above-mentioned structure. 8 in the figure
Is a workpiece that is a workpiece, and 1 in the figure is the dresser described above. According to the method of the present invention, the height of the work top surface and the height of the tip of the dresser head are made to coincide with each other, and the work 8 directly below the grindstone is
The positioning work of the dresser 1 is basically performed only by the horizontal movement operation of the magnet chuck 9. Figure 3 shows the height D1 of the work top surface in this series of operations.
The step of making the tip height D2 of the dresser head coincide with that of the dresser head is shown.

The dresser 1 is magnetically attached to a side position of the work 8 magnetically attached to the magnet chuck 9, and a cylindrical metal cap 10 having a lid shape is externally fitted to the upper end surface 5 of the base 2 of the dresser 1. The magnetic attachment of the dresser 1 to the upper surface of the magnet chuck 9 is performed by matching the ∇ mark on the dresser 1 side with the Δ mark on the upper surface of the magnet chuck 9. The metal cap 10 has a flat top surface 11, has an internal space in which the dresser head 7 can be housed, and is made of non-ferrous metal such as stainless steel. A metal block having a height d3 (d3 = d1-d2) on the upper surface of the work 8 that is obtained by subtracting the protruding height d2 of the dresser head 7 based on the pedestal upper end surface 5 from the height d1 of the metal cap alone. 12 are placed. The metal block may be hollow or solid, and like the metal cap 10, may have a cylindrical shape with a lid. Like the metal cap 10, the metal block 12 is made of a non-ferrous metal such as stainless steel, and its top surface 13 is a flat surface.

The metal cap 10 is externally fitted to the dresser head 7 because there is no means for directly observing a minute tip of the dresser head. Therefore, the top surface 11 of the metal cap 10 fitted externally serves as a detection surface. The height position of the dresser head 7 is indirectly measured by measuring the separation distance up to 11, while the metal block 12 is placed on the upper surface of the work.
Is placed by aligning the height position of the top surface of the metal block 12 with the height position of the top surface 11 of the metal cap 10 externally fitted to the dresser 1. This is because it is intended to indirectly realize the fundamental idea of the present invention of making them coincide.

Top surface 11 of metal cap 10 and top surface of metal block 12
The reason why 13 is a flat surface is to enable observation with a sensor, and the area of the top surface is appropriately set according to the sensitivity of the sensor.

A reference numeral 14 in the drawing is a detection head of a distance sensor, and a notification means such as a lamp or a buzzer is connected to the distance sensor, and when the distance between the detection head 14 and an object reaches a predetermined distance, these The notification means is configured to operate. In this embodiment, a metal cap is used as the distance sensor.
A non-ferrous metal compatible high-frequency oscillation type proximity sensor that is sensitive to stainless steel, which is the material of 10 and the metal block 12, is used. By using the non-ferrous metal compatible type for the distance sensor, the work 8 and the dresser 1, and further, the influence of iron members such as the magnet chuck 9 is eliminated, and
The effect of iron powder scattered by grinding can be eliminated. As the distance sensor, optical type, ultrasonic type, etc. can be used, but the optical type tends to malfunction when oil or water is attached to the work surface, and the ultrasonic type makes the device larger. It is preferable to use a high-frequency oscillation type distance sensor for the reasons described above. If the top surface height positions of the metal cap 10 and the metal block 12 are sufficiently distant from the iron members such as the work 8 and the dresser 1, an iron-compatible magnetic sensor can be used. Further, the distance sensor used in this embodiment is a proximity sensor that sends a detection signal when the distance between the detection target and the sensor reaches a predetermined distance. It is also possible to use a distance sensor in the original sense that can continuously detect changes.

Such an apparatus group is provided on the magnet chuck 9, and the magnet chuck 9 itself is fixed on the table 24 as shown in FIG. The table 24 is slidably provided on a saddle 23 slidably mounted on the machine base 22 in a direction orthogonal to the sliding direction of the saddle 23, and the saddle 23 and the table 24 are independently provided. By horizontally moving, the work 8 and the dresser 1 magnetically attached to the magnet chuck 9 are guided to the lower part of the grindstone. The dresser 1 is removed from the magnet chuck 9 when not dressing, and is magnetically adhered to the magnet chuck 9 when dressing. However, if the magnetizing position changes each time, the positioning work of the dresser 1 to the lower part of the grindstone is performed each time. It is very complicated because it needs to be adjusted visually. In this embodiment, in order to solve this, as shown in FIG. 4, a locking mechanism 25 for defining the locking position between the saddle 23 and the table 24 is proposed. The locking mechanism 25 is composed of a stopper 25a fixed to the upper surface of the saddle 23 and a receiver 25b fixed to the side surface of the table 24, the details of which are shown in FIGS. The stopper 25a has a pin 28 having a tapered head 26 at the tip and a grip 27 at the base, and a pin 28 slidably extending in the thickness direction of the column 29 on a column 29 standingly fixed on the upper surface of the saddle 23. It is configured, and by rotating the grip,
The pin 28 moved back and forth can be fixed in position. On the other hand, the holder 25 that is attached to the side surface of the table 24
The b is formed with a recess 30 into which the head 26 of the pin 28 can be fitted. As the locking mechanism, any other structure may be adopted as long as it can define the positional relationship between the table 24 and the saddle 23.

The work of matching the height positions of the metal cap top surface 11 and the metal block top surface 13 is performed as follows. First, the magnet chuck 9 is moved horizontally to move the metal block 12
Move the work 8 on which the
12 is placed below the detection head 14. When the detection head 14 is lowered in this state to reduce the distance d4 between the detection head 14 and the top surface of the metal block, the distance is preset to the proximity sensor, for example, a lamp or a buzzer when the distance becomes 10 mm. Since the notification means of (3) is activated, after confirming this, the descent of the detection head 14 is stopped. Next, by moving the table 24, the magnet chuck 9 is horizontally moved and the metal cap 10 is fitted on the dresser 1.
By moving the metal cap 10 below the detection head 14 and then turning the annular dial 4 until the distance between the metal cap top surface 11 and the detection head 14 reaches a preset distance. Move up. Metal cap top surface 11
Whether or not the distance between the detection head 14 and the detection head 14 has reached a predetermined distance is informed to the operator by a notification means such as a lamp or a buzzer as described above. Therefore, when the above notification is made, the rotation of the annular dial 4 is prevented. By simply stopping, the height positions of the metal cap top surface 11 and the metal block top surface 13 can be made to coincide, and as a result, the work top surface height position and the dresser head tip position can be made to coincide. it can. The height of the dresser head does not need to be readjusted while the work to be ground is of the same standard,
When the standard of the target work changes, it is adjusted again.

Further, since the height position of the dresser head 7 is made to coincide with the height position of the upper surface of the work 8, the work 8 to be used
The height position of the dresser head 7 slightly fluctuates up and down depending on whether it is before grinding or after grinding. The height position of the dresser head will be set higher when the pre-grinding work is used as the reference for height setting, and it will be set lower when the post-grinding work is used as the reference work. Will be done.
Therefore, it is necessary to consider whether or not to use the reference work before grinding or after grinding. It is also possible to use a test piece having the same shape as the work, without using the actual work as the reference work.

FIG. 6 shows an embodiment in which the height setting device for the dresser head described above is incorporated in a surface grinder.

In the figure, reference numeral 15 is a disk-shaped grindstone, 16 is a casing that covers the grindstone 15, and 17 is a grinding fluid supply path. Reference numeral 18 denotes a mounting table that moves up and down in conjunction with the lifting and lowering operation of the grindstone 15, and a detection head 14 of a proximity sensor is attached to the tip of an arm 19 extending downward from the mounting table 18, while on the mounting table. Is an arithmetic processing unit for processing a signal sent from the detection head 14.
20 are installed. In addition, a grindstone is provided on the side of the arithmetic processing unit 20.
A digital meter 21 that digitally displays the amount of descent of 15 is installed. The digital meter 21 is a standard equipment of the numerical control type surface grinder, and the grindstone 15 is the work 8
It is provided to digitally display the amount of work or grindstone cut by digitally displaying the vertical change position from the height position by pressing the reset switch when touching the ing.

The method of using the surface grinder having such a structure is as follows. First, the reference work 8 and the dresser 1 are magnetically adhered to the magnet chuck 9, and the metal block 12 is placed on the work, while the metal cap 10 is attached to the dresser 1.
After the external fitting, the magnet chuck 9 is horizontally moved to move the work 8 and the dresser 1 to position the metal block 12 immediately below the detection head 14 and lower the grindstone 15 and the detection head 14. If the detection head 14 is continuously lowered, when the distance between the detection head 14 and the top surface of the metal block reaches a pre-registered distance, for example, 10 mm, notification means such as a lamp or a buzzer will operate, so this notification Make sure to stop the descent of the 15 wheels. Next, the magnet chuck 9 is moved horizontally to place a metal cap just below the detection head.
Position 10 and turn the annular dial 4 to raise the metal cap 10 so that the distance from the detection head 14 is 10 mm.
To be set. When the distance from the detection head 14 becomes 10 mm, the notification means operates, so that the adjustment of the annular dial 4 is easy. When the setting of the dresser head height is completed in this manner, the actual work to be ground is magnetically attached to the magnet chuck, and the grindstone is lowered to start the grinding of the work. And when it becomes necessary to sharpen the grindstone during grinding,
Move the magnet chuck 9 horizontally to move the dresser 1
Is positioned immediately below the grindstone, and the dresser head 7 is brought into contact with the surface of the grindstone to sharpen the grindstone 15.
It is necessary to remove the dresser 1 whose height is adjusted from the magnet chuck 9 when grinding the work 8 and to magnetically attach it to the magnet chuck 9 again when dressing is required to accurately position the dresser 1 under the grindstone. However, in this embodiment, this work is performed by magnetically attaching the dresser 1 onto the table 24 so that the ▽ mark on the dresser 1 and the △ mark on the magnet chuck 9 may coincide, and moving the table 24 to move the pin of the stopper 25a. This can be done simply by fitting the head 26 into the receiving tool 25b. And
By doing so, the dresser head can be easily and accurately positioned immediately below the grindstone at any time, and therefore fine adjustment for positioning the dresser head directly below the grindstone is unnecessary.

In addition, when the separation distance d5 between the detection head 14 and the lowermost part of the grindstone is set to be a distance obtained by adding the sensitive distance d4 of the detection head 14 to the height d3 of the single metal block as shown in the figure, the dresser After finishing the work of setting the height position of the head 7,
The dresser head 7 can be brought into contact with the grindstone 14 simply by horizontally moving the magnet chuck 9 as it is, and basically the vertical movement of the grindstone is unnecessary. Especially, if the height position of the dresser head 7 is set and the digital meter 21 is reset to zero display, the vertical movement of the grindstone 15 thereafter is displayed digitally. The quantity can be easily grasped.

〔The invention's effect〕

The dressing method and the apparatus for the grindstone in the surface grinding step of the present invention as described above constitutes a dresser capable of adjusting the height position of the dresser head, and the dresser is fitted with a metal cap on the other work. Mounts a metal block, and matches the distance between the detection head of the distance sensor and the top surface of the metal cap to the distance between the detection head and the top surface of the metal block. When the need arises for dressing during the grinding process, the magnet chuck is moved horizontally to bring the dresser head into contact with the grindstone for dressing, and after dressing is finished. Since the grindstone is returned to the work surface simply by moving the magnet chuck horizontally, Dressing operation down movement of the stone becomes unnecessary is greatly simplified, proficiency relative dressing operation as in the prior art is it is eliminated request.
Further, basically, the vertical movement of the grindstone is not required, so that there is no occurrence of an accident that a dresser or a work collides with the grindstone that has been forgotten to raise and the grindstone is damaged as in the conventional case.

In addition, the proximity sensor is used as the distance sensor, and the detection head of the proximity sensor is lifted up and down integrally with the grindstone.The mounting position of the detection head is the height of the metal block from the bottom of the grindstone and the sensitive distance of the proximity sensor. When it is set to the position displaced upward by the distance obtained by adding, the height of the dresser head is set, and when shifting to the work grinding, there is no need to readjust the height of the grindstone and the magnet chuck The grinding operation can be restarted immediately by simply moving it horizontally. Moreover, in the case of a surface grinding machine equipped with a digital meter, if the height position of the dresser head is reset and reset to zero, the vertical displacement of the grindstone thereafter will be displayed digitally. The amount of grindstone cut can be easily determined.

Also, when stainless steel is used as the material of the metal cap and metal block, and a non-ferrous metal compatible high-frequency oscillation type is used as the proximity sensor, the surface condition of the workpiece and the presence of grinding debris affect the measurement results. It is possible to perform highly accurate measurement without giving.

[Brief description of drawings]

1 (a), (b) and (c) are explanatory views showing the basic idea of the present invention, and FIG. 2 (a) is a front view showing an embodiment of the dresser used in the present invention, FIG. 2 (B) is a front view showing a state in which the lift of the dresser is raised, FIG. 3 is an explanatory view showing a height position adjusting method of the dresser head in the present invention, and FIG. 4 is a table and a saddle. FIG. 5 (a) is a perspective view showing a main part of the locking mechanism, FIG. 5 (b) is the same plan view, and FIG. 6 is surface grinding to which the method of the present invention is applied. Explanatory views showing the main part of the machine, FIGS. 7 and 8 are conventional examples. Is. 1: Dresser, 2: Pedestal, 3: Male screw, 4: Ring dial, 5: Upper end surface, 6: Diamond tip, 7: Dresser head, 8: Work piece, 9: Magnet chuck, 10: Metal cap, 11: Top surface, 12: metal block, 13: top surface, 14: detection head, 15: grindstone, 16: casing, 17: grinding liquid supply path, 18: mounting table, 19: arm, 20: arithmetic processing unit, 21 : Digital meter, 22: Machine stand, 23: Saddle, 24: Table, 24: Locking mechanism, 26: Head, 27: Grip, 28: Pin, 29: Support, 30: Recess.

Claims (4)

[Claims] A disk-shaped grindstone is brought into descending contact with a work placed on a magnet chuck to grind the upper surface of the work, and when the grindstone spills, the grindstone is detached from the work. In the dressing work of the grindstone in the surface grinding process in which the dressing head is brought into contact with the head of the dresser mounted on the side magnetic chuck to perform the setting, and after the setting, the grindstone is returned to the work grinding position and the grinding is restarted. A dresser having a head serving as a grinding blade protruding from the upper end surface of the main body and having an upper end surface capable of moving up and down is configured, and the dresser is placed on a magnet chuck on the side of the work, and protrudes on the upper end surface. A metal cap having an inner space capable of accommodating the dresser head and having a flat top surface is fitted on the outer surface of the workpiece. A metal block having a height obtained by subtracting a distance corresponding to the protruding height from the upper end surface of the pedestal of the dresser head from the height of the single metal cap and having a flat top surface is placed. At the same time, the work on which the metal block is placed is positioned below the detection head of the distance sensor, the distance to the top surface of the metal block is measured, and the data is stored, or the separation distance becomes a preset distance. The distance sensor is moved up and down, and then the magnet chuck is moved horizontally to position the dresser with the metal cap fitted on the outside of the detection head and measure the distance to the top surface of the metal cap. The height of the dresser is determined by raising and lowering the dresser to match the distance between the top surface of the block and the detection head. Method of dressing the grinding wheel the position of the workpiece and the dresser to extent mutual grinding wheel immediately below required when migrating in the plane grinding process which was only be done by horizontal movement of the magnetic chuck. 2. A dresser in which a head serving as a grinding blade is projectingly formed on an upper end surface of a pedestal whose upper end surface can be raised and lowered, and an internal space into which the dresser head can be fitted, and a top surface is a flat surface. And a height obtained by subtracting a distance corresponding to the protruding height from the pedestal upper end surface of the dresser head tip from the height of the metal cap alone, and the top surface is a flat surface. It is positioned above the height position of the metal block placed on the work top surface and the dresser head and the work top surface position, and the distance to the object can be measured continuously or the sensing distance of the object is preset. A distance sensor that sends a notification signal when the object can be set and reaches a set distance, and the distance data detected by the distance sensor or the notification signal sent from the distance sensor is processed. A dressing device for a grindstone in a surface grinding process, which includes: a calculation processing unit that performs processing; and a notification unit that notifies a calculation result to an operator. 3. A proximity sensor is used as a distance sensor, and a detection head of the proximity sensor is configured to move up and down integrally with a grindstone, and a mounting position of the detection head is a height of a single metal block based on the lowermost part of the grindstone. The method of dressing a grindstone in the surface grinding step according to claim 1, wherein the position is displaced upward by a distance obtained by adding the sensitive distance of the proximity sensor. 4. The metal cap and the metal block are made of stainless steel, and the distance sensor is of a high-frequency oscillation type and is compatible with non-ferrous metals. A dressing method for a grindstone in a surface grinding process.