JPS62107805A - Method and apparatus for grinding - Google Patents

Abstract

PURPOSE:To prevent the chipping of a grinding wheel and to reduce the time for interrupting grinding by grinding a surface to be ground by pressing the disk-shaped or cylindrical grinding wheel to said surface without rotating the same and rotating the grinding wheel to the position where the fresh grinding surface faces the surface to be ground and grinding said surface in the case of wear. CONSTITUTION:A pneumatic cylinder 65 is driven to retract a grinding wheel holder 45 into a casing 34 when the grinding wheel 53 causes wear, clogging, etc. by grinding. Then a flange 40 of the casing 34 retracts a feed rod spring and pushes a feed pawl rod 59. As a result, the grinding wheel 53 is rotated inch by inch in the rotating direction of the grinding wheel by one pitch of a ratchet wheel 58 by a feed pawl 60 via the ratchet wheel 58, so that the fresh grinding wheel appears on the front. The continuation of the grinding by the fresh grinding surface is thus made possible simply by interrupting the grinding for a several seconds.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of on-vehicle application) The present invention relates to a method and apparatus for grinding the cylindrical surface of a rotating object to be ground, such as a work roll of an operating steel plate rolling mill, using a grindstone. be.

(Prior Art) In a steel plate rolling mill, it is known to perform roll grinding by pressing a grindstone against a rotating work roll, and many proposals have been made. For example, Utility Public Act 49-45037
No., JP-A-53-58951, JP-A No. 54-1989,
This is a roll grinding method or apparatus disclosed in publications such as No. 55-65081 and No. 513-53806.

The applicant also has Japanese Patent Application Laid-open Nos. 58-1401.0 and 5
No. 9-40443 and others have proposed a grinding method. In the prior invention by the present applicant, a plate-shaped grindstone is pressed against a rotating roll and reciprocated from side to side in the roll axis direction, and simultaneously reciprocated along the rotational direction of the roll to perform diagonal oscillation grinding. . As a result, stable grinding became possible.

Further, in all of the above-mentioned known techniques, a rectangular parallelepiped-shaped grindstone is used. The rectangular parallelepiped-shaped grindstone is used for grinding by extending it a predetermined length from the grindstone holder, and when the tip wears out, the grindstone is fed out toward the object to be ground to replenish it. That is, since the rectangular parallelepiped grindstone replenishes grinding wear by feeding out, a new grinding surface is prepared behind the current grinding surface. Therefore, if the current grinding surface becomes clogged or clogged and grinding becomes impossible, grinding must be stopped and sharpening performed, or the grindstone that cannot be ground must be removed and replaced.

(Problems to be Solved by the Invention) Based on the above-mentioned prior invention, the present inventors installed a full-scale grinding device in an operating steel plate rolling mill, and while performing online roll grinding, further improved the grinding behavior of the grindstone. We conducted observational research on the following topics.

As a result, it was found that there were still some inconveniences when the invention of the prior application was applied to an actual machine. In other words, in rare cases, the whetstone may chip. The reason why the whetstone is chipped is as follows.

When the rotating cylindrical object to be ground (for example, a rolling roll) 5 is subjected to the diagonal oscillation grinding using the rectangular parallelepiped grindstone 8, the tip surface of the grindstone is pressed against the object to be ground 5, as shown in FIG. This becomes the ground surface 9. The grinding surface is flat (almost straight when viewed from the side). Therefore, the grinding surface 9 is attached to the workpiece 5.
As shown in FIG. 13, the state in which the two parts are in pressure contact can be divided into three states: front end pressure contact A, center pressure contact opening, and rear end pressure contact C. The pressure contact state changes depending on the time as follows.

At the initial stage of grinding, pressure contact is made at the front end or rear end, or at the center. When the grinding wheel 8 wears out to some extent and the grinding surface 9 appears on the entire surface of the grinding wheel's tip, the front end, center and rear end are pressed in sequence during diagonal buckling, and in the reverse order when returning. do. Further, the front end of the grinding wheel wears out due to grinding and becomes sharp in the shape of a bite, and when it is brought into pressure contact with the object to be ground again for subsequent grinding, the tip of the tool is brought into pressure contact.

On the other hand, grinding resistance is generated at the contact portion between the grindstone and the workpiece due to the cutting of the abrasive grain cutting edge into the workpiece.

The grinding resistance force can be easily calculated by setting the grinding wheel pressure force to P: F=p-PC
tt is a resistance coefficient), a pressure force P acts on the grindstone at right angles to the tip surface of the grindstone and a resistance force F parallel to the tip surface acts on the grindstone at the contact portion between the grindstone and the object to be ground.

When oblique oscillating grinding is performed, these two forces generate stress states in the grinding surface 9 as shown in FIG. 14 and C, respectively, in the press-contact state.

Let a be the width of pressure contact between the workpiece and the grindstone.

(1) In front end pressure welding A, the entire surface of the grinding surface 9 is in a state of tensile stress with the maximum value at the front end, and when this tensile stress exceeds the tensile strength (destructive stress) σ of the grinding wheel 8, the front end breaks at that position. There is a possibility that this will occur. This is because the grinding resistance force F applied to the front end of the grinding surface acts as a tensile force on the entire surface of the grinding surface.

(2) At the central pressure contact port, the grinding resistance force F that acts on the center of the grinding surface acts partially as a compressive force on the grinding surface in front of the acting part and as a tensile force on the grinding surface behind the acting part. The stress within the grinding surface also becomes a compressive stress state in front of the action part and a tensile stress state in the rear part, and the absolute value of these maximums (+fi is smaller than the maximum value of A (approximately 1/2), and the grinding wheel 8 The tensile stress on the grinding surface is kept below the tensile strength σ, and the possibility of damage to the grinding surface of the grinding wheel is extremely reduced.

(3) In rear end pressure welding, grinding resistance force F is applied to the rear end of the grinding surface, but this acts as a compressive force on the entire surface of the grinding surface, turning the in-plane stress into a compressive stress state and causing defects from the grinding surface. The chances are very low.

However, when oblique oscillation grinding is performed and a rectangular parallelepiped-shaped grindstone is used, there is a high possibility that the three types described above will occur repeatedly and the front end will break when the front end is pressed.

Furthermore, if the grindstone is chipped as described above, grinding must be interrupted and the grindstone must be replaced. It is better that the interruption time at that time be as short as possible.

Therefore, the present invention provides a grinding method that uses a grindstone shaped to maintain a stress state on the grinding surface that is difficult to break, and that generates a new grindstone surface in a short time when the currently used surface wears out, as well as a replacement device. The purpose is to

(Another means to solve the problem) The grinding method of the present invention uses a disc-shaped or cylindrical grindstone (hereinafter referred to as
A cylindrical grindstone is held so as not to rotate, is pressed against the cylindrical surface of a rotating workpiece, and is ground while being oscillated diagonally. When the grindstone has been ground a certain amount, the grindstone is rotated, that is, rotated in increments, until the new grinding surface faces the surface to be ground.

The rotation angle is determined, for example, as follows.

FIG. 1 shows the most basic case, in which the surface to be ground is completely new each time it is ground. In other words, the wear length around the grinding wheel per one grinding b (■, ■, ■...■) The outer radius of the grinding wheel r The number of grindings n The inching rotation angle θ, nb=nrθ=2πr n=2πr / b θ= 2π/n=b/r (rad).

Now, if b = 10 mm and r = 50 mm, the inching angle θ = 0.2 (rad) = 11.4° and the number of grinding times n = 31 times.

The above example is an example in which the surface used for the grinding wheel is completely renewed for each grinding, but depending on the situation, the grinding wheel may be rotated by an arbitrary rotation angle of 1/2, for example, by 1/2, depending on the situation. good.

After the grindstone has been rotated by the required angle as described above, the grindstone is held so as not to rotate again, and the surface to be ground is ground with the new grinding surface of the grindstone.

Further, the grinding device of the present invention includes a cylindrical grindstone, a grindstone holder, and a grindstone holder advancement/retraction device. The grindstone held in the grindstone holder is pressed against the cylindrical surface of the rotating object to be ground by the grindstone holder advancing/retracting device to grind the object to be ground.

An intermittent rotation device is connected to the grindstone shaft. As the intermittent rotation device, for example, a ratchet mechanism, a Geneva mechanism, an intermittent gear device, a one-way clutch, a link mechanism, a cam device, a sutenping motor, etc. are used.

(Function) During grinding, the grinding wheel is fixed so it does not rotate as a result of the object to be ground.Also, since the grinding wheel is cylindrical, the pressure contact with the object to be ground is always at or near the center pressure contact state. It is in good condition and there is very little chance of damage.

A certain part of the circumference of the cylindrical grindstone is used for grinding, and a new grinding surface is prepared adjacent to the current grinding surface on the circumference. If grinding becomes impossible due to a problem with the current grinding surface, the grindstone is rotated by a predetermined angle so that the part used for grinding previously is changed to the part used for new grinding during non-grinding. By repeating inching rotation,
The entire circumference of the whetstone is used for grinding.

(Example) Embodiments of the present invention will be described in detail below with reference to the drawings.

Figure 2 shows heating furnace 1. Rough rolling mill2. An example in which the present invention is applied to a hot rolling mill including four rows of finishing mills and a winding machine 6 is shown. The present invention provides work rolls 3. of a rough rolling mill 2 in a hot rolling mill. It is ideal for grinding rolls with large roll wear, such as the work roll 5 of the finishing mill 4.
pinch roll 7 and a tandem mill at a cold rolling mill (not shown).

It can be applied to rolls where roll wear is a problem, such as each roll of a reversing mill.

Although a simple four-fold rolling mill is taken as an example of the finishing rolling mill 4, it is also applicable to roll grinding of mills of different types, such as a six-fold rolling mill and a cross mill (not shown).

Arrow A indicates the flow direction of the rolled strip S, and arrow B indicates the roll rotation direction.The present invention is directed to the strip flow direction A.
Also, if the roll rotation direction B is reversed, there will be no problem.
It is possible to implement.

FIG. 3 is a side view of the entire roll grinding device 11, and FIG. 4 is a perspective view of the upper roll grinding device 11. Since the lower roll grinding device 11 has the same configuration and operation as the upper roll grinding device 11, except for its posture, the same members are given the same reference numerals and their explanations will be omitted. As shown in these drawings, the rolling mill stand 13 is provided with a pair of guides 15 that are inclined forward, that is, toward the rolls 5 .

A pedestal 17 is attached to the sedan 1'' 13 via the kite 15 so as to be movable forward and backward.

Further, a hydraulic cylinder 21 is swingably attached to the stand 13 via a pin 22. A crank 2G is connected to the rod 23 of the hydraulic cylinder 21 via a pin 25.
One end of the crank 26 is connected, and the middle of the crank 26 is fixed to a shaft 27 rotatably attached to the stand 13. Link rod 2 through pin 2 to the other end of crank 26
The other end of the link rod 29 is connected to the rear end of the pedestal 17 by a pin 30. That is,
The cylinder row, F23, crank 26, and link rod 28 constitute a link mechanism. Then, the pedestal 17 moves forward and backward by the operation of the hydraulic cylinder 21.

Near the front end of the pedestal 17 is a pedestal 17 extending in the roll axis direction.
A pair of rails 32 are provided that are inclined toward one side end.

A block-shaped casing 3 is mounted on the rail 32 so as to be able to move freely.
4 is placed. As shown in FIG. 5, the casing 34 is provided with seven holes 37 that open toward the front, and a sleeve 38 is fitted into each hole 37.

Further, a hydraulic cylinder 41 is arranged near the rear end of the pedestal 17, and a rod 42 of the hydraulic cylinder 41 is connected to the casing 34 via a joint 43. The casing 34 is moved to the rail 32 by the operation of the hydraulic cylinder 41.
J: reciprocates toward the side edge of the pedestal 17 in the pricking direction.

6 to 10 show details of the grindstone holder 45, FIGS. 6 to 8 show the state in which the grindstone 53 is not in contact with the roll 5, and FIGS. 9 and 10 show the state in which the grindstone 53 is not in contact with the roll 5. roll 5
The state of contact is shown in each case.

As shown in these drawings, the grindstone halter 45 consists of a cylindrical sliding part and a bearing 51 connected to the front part thereof.

The sliding portion 4B is located in the hole of the sleeve 38, that is, the guide hole 39.
They fit together so that they can move forward and backward. Since the inner circumferential surface of the guide hole 39 and the outer circumferential surface of the sliding part 46 are precisely finished, the sliding resistance is small, and the grindstone holder 45 can move forward and backward smoothly.

A grindstone shaft 54 of the grindstone 53 is supported horizontally on the partition wall 4 via a bearing 51. The grindstone 53 is a pawl type device 57 which will be described later.
It is rotated intermittently. Note that a bellows 55 is provided between the sliding part 46 and the casing 34 to prevent dust and water vapor from entering between the sliding part 46 and the sleeve 38. Further, a cover 56 surrounds the whetstone so that only the surface of the whetstone 53 required for grinding is exposed.

A pawl wheel is fixed to one end of the grinding wheel shaft 54.

On the other hand, the feeding rod 59 is inserted into the partition wall 4 inside the sliding part 46.
It passes through 8. A feed pawl 60 and a feed pawl spring 61 are provided at the tip of the feed pawl rod 59, and a spring seat 6 is provided at the rear end.
2 is provided. The feed pawl 60 is pressed against the ratchet wheel 58 by a feed spring 61 so as to constantly mesh with the ratchet wheel 58. Further, a presser pawl 83 is pin-coupled to the bearing 51, and is pressed by a feed spring 64 so as to constantly engage with the pawl weight 58.

The pneumatic cylinder 65 is connected to the sliding part 4 of each grindstone holter 45.
The cylinder tubes 66 are fixed to the rear wall 35 of the casing 34. The piston rod 72 is connected to a bracket 49 attached to the partition wall 48 by a pin 73.

A passage 75 is sunk into the rear wall 35 of the casing 34 and leads to the head side chamber 68 of the pneumatic cylinder 65.
In addition, compressed air is supplied to the rod side chamber 69 via the piping 76. These passages 75 and piping 76 are independent from each other, and compressed air is supplied from respective flexible tubes 78 shown in FIG. A stop valve and a pressure regulating valve (both not shown) are connected to each flexible tube 78.

When compressed air is supplied to the head side chamber 68 of the pneumatic cylinder 65, the piston rod 72 moves forward and draws out the entire grindstone holter 45 from the casing 34 until it comes into contact with the roll. Further, when compressed air is supplied to the rod side chamber 69, the entire grindstone holder 45 moves backward.

A plunger chamber 82 is provided in the bottom portion 36 of the casing 34 and extends toward the front. The tip of the plunger 83 inserted into the plunger chamber 82 is in contact with a collar 50 provided at the rear end of the grindstone holder 45 . These plunger chamber 82 and plunger 83 constitute a balance mechanism 81. That is, since compressed air is supplied to the plunger chamber 82 from the passage 84, the grindstone holder 45 is pushed rearward by the plunger 83. ” Since the lower roll grinding device 11 is inclined toward the front as shown in FIG. 3, the grindstone holder 45 tends to jump out of the casing 34 due to its own weight,
It is supported by the plunger 83 so that the weight of the whetstone holder 45 and the thrust of the plunger 83 are balanced. As shown in Figure i3, the lower roll grinding device 11
Since the posture is horizontal, there is no need to provide the balance mechanism 81.

A wiper 86 is attached to the front end of the pedestal 17. The wiper 86 is in close contact with the roll 5 between the grindstone 53 and the strip S, and wipes off grinding debris adhering to the roll surface. This prevents strip scratches from occurring due to grinding debris.

Next, a method of grinding a roll using one or more roll grinding devices 11 will be described.

When grinding the roll, the hydraulic cylinder 21 is driven to move the pedestal 17 forward to the grinding position.

At this point, the grindstone holder 45 is in a state of being drawn into the casing 34, as shown in FIGS. 6 and 7. Further, in the troll grinding bag 2211, the grindstone holder 45 is supported by the plunger 83 so as not to pop out from the casing 34.

When the profile of the roll 5 needs to be corrected during rolling, compressed air is supplied to the head side chamber 8 of the pneumatic cylinder 65 of the grindstone holder 45, which corresponds to the portion in the longitudinal direction of the roll lrl that requires correction and grinding. The grindstone holder 45 is let out from the casing 34. The whetstone 53 is integrated with the whetstone holder 45 and attached to the rod 72 of the pneumatic cylinder 85.
is pressed by the roller and comes into contact with the roll surface. At this time, the 9th
As shown in the figure and FIG.
and the presser pawl 63 engage with each other to restrain the rotational direction C of the grindstone 53. Since the compressed air is adjusted to a required pressure, the grindstone 53 contacts the roll surface with the required hydraulic pressure.

Simultaneously with the operation L, the hydraulic cylinder 21 is driven to reciprocate the casing 34 in a diagonal horizontal direction. Since the grindstone 53 is pressed against the roll surface, it reciprocates diagonally in the lateral direction and also reciprocates along the roll surface. Therefore, the grindstone 53 reciprocates in a spiral manner on the roll surface.

The profile of the roll 5 may be measured directly with a roll profile meter, but it can also be determined from the shape of the rolled S)-/Rip S. It can also be estimated by calculation from rolling conditions such as rolling load, strip length, material of the rolled material, material of the rolls, and temperature. Then, only the required grindstone 53 is pressed against the roll 5 according to the corrected profile of the roll for grinding.

When the grindstone 53 is worn out or clogged due to grinding, the grindstone 53 is intermittently rotated by the ratchet wheel device 57 in the following manner. First, the pneumatic cylinder 65 is driven to draw the whetstone holder 45 into the casing 34 .

As a result, the flange 40 of the casing 34 compresses the feed rod spring 67 and pushes the feed claw rod 59.

As a result, the grinding wheel 53 passes through the ratchet wheel 58 to the feed pawl 6.
0, the ratchet wheel 58 rotates by one pinch in the direction of rotation of the grinding wheel, and a new grinding surface appears at the front.

Furthermore, by changing the pitch of the ratchet wheel 58, a required inching rotation angle can be set.

As described above, according to the present invention, grinding can be continued using a new grinding surface by simply interrupting the grinding for a few seconds.

FIGS. 11 and 12 show other embodiments y and E of the present invention, and are a partially sectional side view and a partially sectional plan view, respectively. In these drawings, the same reference numerals are given to the same members as in the above embodiment, and the explanation thereof will be omitted.

A pneumatic cylinder 91 is installed in the partition wall 48 of the grindstone holder 45.
is attached, and a feed pawl 93 is provided at the tip of the shilling rod 92. The grindstone 53 rotates by an inch due to the operation of the pneumatic cylinder 91.

In such a configuration, when the grinding wheel 53 is worn out after grinding a predetermined amount or becomes unable to grind due to chipping or the like, air is supplied from the air supply port 95 to move the spear grinding wheel holder 45 backward and grinding is temporarily stopped. Next, the pneumatic cylinder 91 is operated, the cylinder-rond 92 is operated in the direction of the arrow, the ratchet wheel 58 is turned, the grinding surface of the grindstone 53 is changed, and roll grinding is performed again.

As described above, according to the present invention, grinding can be continued using a new grinding surface by simply interrupting the grinding for a few seconds.

Although an example has been shown in which a plurality of sets of cylindrical grindstones are set in the casing according to the size of the work roll, only one set may be used depending on the size of the object to be ground. Moreover, the object to be ground is not limited to a work roll. Furthermore, as shown in FIG. 1, it is also possible to design the grinding wheel surface to be used after using the grinding wheel from ■ to ■ as shown in ■, (F, ■).

(Effects of the Invention) As explained above, according to the present invention, 1. Since a disc-shaped or cylindrical grindstone is used, the grindstone is less likely to break.

2. Since the grinding surface of the grindstone can be quickly replaced using a grindstone intermittent rotation device, grinding interruption time can be shortened. for example,
Grinding can be continued with a new grinding surface by simply interrupting grinding for a few seconds.

There are effects such as It is also convenient for online grinding of rolling rolls and the like without removing them from the stand, and can also contribute to online roll grinding for schedule-free (patternless) rolling of steel plates.

[Brief explanation of drawings]

Fig. 1 is a diagram illustrating the repetition of the grinding surface of the grinding wheel in this invention, Fig. 2 is a schematic diagram of equipment showing an example of rolling equipment to which the roll grinding device of this invention is applied, and Fig. 3 is a roll grinding device. The overall side view, Figure 4 is a perspective view of the upper roll grinding device, Figure 5 is a sectional view taken along line V-V in Figure 3, and Figures 6 to 10 show details of the grindstone halter. Figures 6 to 8 are a plan sectional view, a side sectional view, and a front view showing the state in which the grindstone is not in contact with the roll, and Figures 9 and 10 are respectively in the state in which the grindstone is in contact with the roll. A top sectional view and a side sectional view, FIGS. 11 and 12 show other embodiments of the present invention, and a side sectional view and a plan sectional view, respectively, and FIG. 13 show a state in which the grindstone is in contact with the roll. is a drawing explaining the contact state of the grinding wheel, and the first
FIG. 4 is an explanatory diagram of stress generated in the grindstone. 2.4...Rolling mill, 3,5...Work roll, 8.
... Plate grindstone, 11... Roll grinding device, 13...
stand. 15... Kite, 17... Frame, 21... Hydraulic cylinder, 32... Rail, 34... Casing,
39...Sleeve, 41...Hydraulic shilling-145
... Grinding wheel holter 146 ... Sliding part, 51 ... Bearing 53 ... Cylindrical grindstone, 57 ... Pawl type device, 6
5...Pneumatic Schilling-, 81...q~Lance mechanism. Special 1st Applicant Attorney Tomoyuki Ya Fuki (and 1 other person) Figure 7

Claims (2)

[Claims] (1) In a method of grinding the cylindrical surface of a rotating workpiece with a grindstone, a disc-shaped or cylindrical grindstone is held so as not to rotate and is pressed against the surface to be ground for grinding, resulting in a certain amount of wear on the grindstone. Then, the grinding wheel is rotated to a position where the new grinding surface faces the surface to be ground, and the grinding wheel is held so as not to rotate again to grind the surface to be ground, and these operations are repeated to perform grinding. Grinding method. (2) In a device that grinds a rotating workpiece by pressing a whetstone held in a whetstone holder against the cylindrical surface of a rotating workpiece using a whetstone holder advance/retreat device, the whetstone is disc-shaped or cylindrical. A grinding device characterized in that an intermittent rotation device is connected to a grindstone shaft.