JP4182172B2 - Grinding equipment - Google Patents

Description

  The present invention relates to a grinding apparatus for grinding a workpiece by a grinding wheel that rotates by supplying coolant.

  As a method for supplying coolant to a grinding point in a grinding apparatus that grinds a workpiece with a grinding wheel that supplies coolant and rotates at high speed, there are, for example, the following conventional techniques.

  First, the first prior art is a grinding point nozzle system shown in FIG. 6 in which coolant is supplied from a nozzle 100 near a grinding point that is a contact point between a grinding wheel G and a workpiece W.

  In the second conventional technique, the nozzle 200 has a nozzle 200 facing the outer peripheral surface of the grinding wheel G at a right angle upstream of the grinding point, and coolant is sprayed at a right angle on the outer peripheral surface of the grinding wheel G. This is a right angle nozzle system shown in FIG.

An example of disclosing the above-described prior art is Japanese Patent Laid-Open No. 2000-108032.
JP 2000-108032 A

  Now, the nozzle that normally supplies coolant interferes with the workpiece, the device that carries the workpiece into and out of the machine, and the sizing device that measures the outer diameter of the workpiece during and after grinding. In order to avoid this, it is disposed at a position away from the outer peripheral surface of the grinding wheel. Accordingly, in order to reliably supply coolant to the grinding point by the above-described grinding point nozzle method or right angle nozzle method disposed at a position away from the outer peripheral surface of the grinding wheel, a high pressure and large capacity coolant is supplied to the grinding wheel. It is necessary to eject the coolant from a position away from the outer peripheral surface of the steel, and to force the target coolant to reach the target site by overcoming the accompanying air layer that rotates around the outer peripheral surface of the grinding wheel.

  However, when using large-capacity coolant, the size of the high-pressure pump and coolant tank is increased, resulting in higher equipment costs, increased coolant consumption and power consumption, and increased maintenance costs. there were. Further, when a high-pressure and large-capacity coolant is jetted onto the grindstone, there is a problem that the load power of the grindstone shaft motor that rotates the grindstone is increased.

  Therefore, in recent years, research on a grinding apparatus that reliably supplies coolant to a grinding point even with a small amount of coolant has been advanced.

  Therefore, the applicant of the present application is based on the knowledge that the problem of the conventional technique can be solved by blocking the air layer accompanying the grinding wheel on the upstream side in the rotational direction of the grinding wheel at the grinding point. It came to invention of 2002-55046. In the prior invention, the fluid jet is blown across the grinding surface of the grinding wheel from one side to the other side at a position upstream of the grinding point in the rotational direction of the grinding wheel. Thereby, the air layer accompanying a grinding wheel is interrupted | blocked, coolant can be reliably made to land on the outer peripheral surface of a grinding wheel, and it can supply to a grinding point.

  In the prior invention, a small amount of coolant is supplied between the landing point where the coolant lands on the outer peripheral surface of the grinding wheel and the shut-off position where the associated air layer of the grinding wheel is blocked by the fluid jet. However, as shown in FIGS. 8A and 8B, depending on the arrangement of the nozzle 300 that discharges the fluid jet and the shape of the discharge port, the grindstone-associated air layer 310 that accompanies the outer peripheral surface of the grindstone G is caused by the fluid jet. In other words, the coolant 330 circulates upstream of the coolant landing point Gd and blows off the coolant 330 supplied from the coolant nozzle 320, so that the coolant 330 is not landed on the outer peripheral surface Gd of the grinding wheel G. This tendency becomes more prominent as the coolant flow rate decreases.

  The present invention was made in order to achieve the above-described problem, and optimizes the arrangement of the nozzle for discharging the fluid jet and the shape of the discharge port to reliably block the air layer associated with the grindstone around the outer peripheral surface of the grindstone, The coolant is surely landed on the outer peripheral surface of the grinding wheel and supplied to the grinding point.

  According to a first aspect of the present invention, there is provided a coolant nozzle for grinding a workpiece by a disc-shaped rotating grinding wheel having a grinding wheel layer on an outer peripheral surface while supplying coolant, and supplying the coolant to the outer peripheral surface of the grinding wheel. And a fluid nozzle that is located upstream of the coolant nozzle in the rotational direction of the grinding wheel and that ejects a fluid jet from one side of the grinding wheel toward the other side, the fluid nozzle comprising: The discharge port at the tip has a shape that extends long in the radial direction of the grinding wheel, and the length of the long side adds the shortest distance between the tip of the coolant nozzle and the outer peripheral surface of the grinding wheel and the thickness of the grinding wheel layer. It is formed so that it may become more than the length.

  According to a second aspect of the present invention, the fluid nozzle overlaps in the radial direction the tip of the coolant nozzle on the outer diameter side when viewed from the rotational axis direction of the grinding wheel and the innermost circumferential side of the grinding wheel layer on the inner diameter side. It is characterized by that.

  In the invention according to claim 3, the innermost diameter side portion of the fluid nozzle has a height of 20 mm or more and 50 mm or less from a landing point at which coolant supplied from the coolant nozzle lands on the outer peripheral surface of the grinding wheel. It is characterized in that it is located.

  The invention according to claim 4 is characterized in that the fluid nozzle and the coolant nozzle are integrally formed.

  According to the grinding apparatus according to claim 1, even if the coolant nozzle is disposed at a position away from the outer peripheral surface of the grinding wheel, the shape of the discharge port of the fluid nozzle is a shape that extends long in the radial direction of the grinding wheel, In addition, since the length of the long side is equal to or longer than the sum of the distance between the tip of the coolant nozzle and the outer peripheral surface of the grinding wheel and the thickness of the grinding wheel layer, the fluid jet ejected from the discharge port Thus, the air layer associated with the grinding wheel traveling around the outside of the grinding wheel is reliably blocked. As a result, the coolant can surely land on the outer peripheral surface of the grinding wheel and can be reliably supplied to the grinding point.

  According to the grinding device according to claim 2, it is prevented that the air layer accompanied by the grindstone blown off by the fluid jet wraps around the upstream side of the coolant landing point and blows off the coolant, and the coolant is prevented from flowing to the outer peripheral surface of the grinding wheel. Therefore, it is possible to surely land the water.

  According to the grinding device of the third aspect, it is possible to more reliably block the air layer associated with the grindstone, and to reliably allow the coolant to land on the outer peripheral surface of the grinding wheel.

  According to the grinding device of the fourth aspect, since the fluid nozzle and the coolant nozzle are integrally formed, the relative position of both nozzles is not changed, and stable coolant supply can be performed for a long time.

  Hereinafter, a grinding apparatus according to an embodiment of the present invention will be described with reference to FIGS. A grindstone table 11 is slidably mounted on the bed 10 and moved forward and backward in the X-axis direction by a servo motor 12 via a ball screw mechanism. A grinding wheel shaft 13 having a grinding wheel G attached to the tip thereof is rotatably supported on the grinding wheel base 11 and is rotated by a motor 13. The grinding wheel G is configured such that a plurality of grinding wheel chips 16 are bonded to the outer peripheral surface of a disk-shaped base 15 formed of a metal such as iron or aluminum. The grinding wheel tip 16 corresponds to the grinding wheel layer of the grinding wheel G.

  A table 17 is slidably mounted on the bed 10 and is moved by a servo motor 14 through a ball screw mechanism 18 in the Z-axis direction perpendicular to the X-axis.

  A headstock (not shown) and a tailstock 20 constituting the workpiece support device 19 are mounted on the table 17, and the workpiece W is sandwiched between both centers of the spindle stock and the tailstock 20 and rotated. Is done.

  A grinding wheel cover 30 that covers the grinding wheel G is fixed to the grinding wheel base 11, and a coolant nozzle 32 of a coolant supply device 31 is attached to the upper surface of the grinding wheel cover 30. The coolant 33 from the coolant nozzle 32 is discharged toward the landing point Gd of the grinding outer peripheral surface Ga of the grinding wheel G located on the upstream side of the grinding point P where the grinding wheel G grinds the workpiece W.

  On the side plate 30 b of the grinding wheel cover 30, the coolant 33 is slightly upstream from the landing point Gd where the coolant 33 lands on the grinding surface Ga of the grinding wheel G, and is located on the other side 35 from one side 34 to the other side 35 of the grinding wheel G. A fluid nozzle 41 of a fluid jet ejection device 40 for blowing away the grinding wheel-associated air layer 36 that ejects the fluid jet 42 toward the grinding wheel G and is disposed is provided. The shape of the discharge port 41a of the fluid nozzle 41 is a rectangle or an ellipse that extends long in the radial direction of the grinding wheel G, and the length C of the long side is the tip of the coolant nozzle 32 and the outer peripheral surface Ga of the grinding wheel G. Is set so as to satisfy C ≧ A + B, where A is the shortest distance between and the thickness of the grindstone tip 16 (grindstone layer) is B. The discharge port 41a of the fluid nozzle 41 is viewed from the grinding wheel axis direction, the tip of the coolant nozzle 32 on the outer diameter side, the innermost circumferential side of the grinding wheel tip 16 on the inner diameter side, and the upstream side of the coolant nozzle 32, respectively. It overlaps in the radial direction. The fluid used as the fluid jet 42 may be air, mist, coolant, or the like.

  A wind shield plate 37 is fixed to the ceiling plate 30 a of the grindstone cover 30. An opening groove 38 is formed in the wind shielding plate 37, and a groove end edge 38 a of the opening groove 38 is slightly smaller than the fluid jet 42 in order to block the grinding wheel associated air layer 36 that rotates around the grinding outer peripheral surface Ga of the grinding wheel G. At the position upstream of the grinding wheel rotation direction, it faces the outer circumferential surface Ga of the grinding wheel G with a small gap and extends in a direction crossing the outer circumferential surface Ga of the grinding wheel G. Both side edges 38b, 38c of the opening groove 38 are opposed to the both side surfaces 34, 35 of the grinding wheel G with a slight gap and extend from the grinding point P to a position below. In order to keep a slight gap between the groove edge 38a and the outer peripheral surface of the grindstone G constant, the wind shield plate 37 is automatically positioned as the grindstone diameter decreases due to grinding or dressing of the grinding wheel G. You may attach to the grindstone cover 30 via a position correction mechanism so that it may correct | amend.

  In the grinding apparatus configured as described above, the grinding wheel G has a peripheral speed of 120 meters / second, the coolant 33 has a flow rate of 15 liters / minute, and the shortest distance A to the outer peripheral surface Ga of the grinding wheel G is about 30 millimeters. The dynamic pressure at each grinding point P was measured by changing the height h from the landing point Gd of the innermost diameter side portion of the fluid nozzle 41. The dynamic pressure at the grinding point P is measured by a force sensor (not shown) provided on the spindle stock or tailstock when the coolant is supplied with the grinding wheel G and the workpiece W slightly separated from each other. Value. In addition, this time, air was used as a fluid jet.

  The measurement results are shown in FIG. As shown in the graph of FIG. 4, it was confirmed that the dynamic pressure at the grinding point P was high when the height h from the landing point Gd was 20 mm or more and 50 mm or less, particularly 40 mm or less. This means that the coolant is sufficiently supplied to the grinding point P within the above range. When the height h from the landing point Gd is 20 millimeters or less, the distance between the fluid jet and the coolant is too short, so the fluid jet blows off the coolant, and the coolant is not reliably supplied to the grinding point P. Therefore, it is considered that the dynamic pressure has decreased. If the height is 50 mm or more, a new accompanying air layer is generated between the grinding point and the location where the accompanying air layer is blocked by the fluid jet, and the coolant supplied from the coolant nozzle is blown away, resulting in grinding. It is considered that the dynamic pressure is lowered because the coolant is not reliably supplied to the point P.

  Conventionally, when the grindstone peripheral speed is 120 to 160 meters / second, the amount of coolant supplied per minute is 30 to 50 liters. By using the fluid nozzle 41 of the present invention, 15 to 25 liters is required. Can be halved to the extent. In consideration of the environment, so-called eco-grinding is being tried in which the amount of coolant supplied to the workpiece is set to about 300 cc / min and a small amount of lubricating oil such as vegetable oil is supplied to the outer peripheral surface of the grindstone. Even in the case of this eco-grinding, by using the fluid nozzle 41 according to the present invention, the coolant is supplied to the work piece and the lubricating oil is supplied to the grindstone outer peripheral surface without being obstructed by the accompanying air layer 37 rotated around the grindstone outer peripheral surface Ga. It is reliably supplied to Ga.

  In the present embodiment, the configuration in which the coolant nozzle 32 and the fluid nozzle 41 are separately provided has been described. However, for example, a fixing bracket 50 for fixing the fluid nozzle 41 to the coolant nozzle 32 as shown in FIG. The coolant nozzle 32 and the fluid nozzle 41 may be formed integrally. In this case, since the relative position of both nozzles does not change, it is possible to perform a stable coolant supply for a long period of time.

The side view made into the partial cross section of the grinding device concerning the embodiment of the present invention. The front view of the grinding device concerning the embodiment of the present invention. The partial view at the time of seeing the grinding device concerning the embodiment of the present invention from the side. The graph which shows the relationship of the dynamic pressure in the grinding point P with respect to the height from the landing point Gd of the innermost diameter side part of a fluid nozzle. It is a figure which shows the case where a coolant nozzle and a fluid nozzle are united, (a) is a side view, (b) shows a front view. The figure which shows the grinding point nozzle system. The figure which shows a right angle nozzle system. The figure which shows the conventional grinding device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 16 ... Grinding wheel chip | tip (grinding wheel layer), 31 ... Coolant supply apparatus, 32, 320 ... Coolant nozzle, 33, 330 ... Coolant, 36, 310 ... Whetstone accompanying air layer, 40 ... Fluid jet ejection apparatus, 41, 300 ... Fluid nozzle 41a ... discharge port, 42 ... fluid jet, 50 ... fixed bracket, A ... shortest distance between the tip of the coolant nozzle and the outer peripheral surface of the grinding wheel, B ... thickness of the grinding wheel tip (grinding wheel layer), C ... of the discharge port Long side length, h: Height from the landing point of the innermost side of the fluid nozzle, G: Grinding wheel, Ga: Outer peripheral surface of grinding wheel, Gd: Landing point, P: Grinding point, W ... Workpiece

Claims (4)

A grinding device that grinds a workpiece with a disc-shaped rotating grinding wheel having a grinding wheel layer on the outer peripheral surface while supplying coolant.
A coolant nozzle for supplying coolant to the outer peripheral surface of the grinding wheel;
A fluid nozzle that is located upstream of the coolant nozzle in the direction of rotation of the grinding wheel and ejects a fluid jet from one side of the grinding wheel toward the other side;
The fluid nozzle has a shape in which a discharge port at its tip extends long in the radial direction of the grinding wheel, and the length of its long side is the shortest distance between the tip of the coolant nozzle and the outer peripheral surface of the grinding wheel and the grinding wheel A grinding apparatus, wherein the grinding apparatus is formed so as to have a length equal to or longer than a total thickness of the layers.   The fluid nozzle overlaps the tip of the coolant nozzle on the outer diameter side and the innermost peripheral side of the grinding wheel layer on the inner diameter side in the radial direction when viewed from the rotational axis direction of the grinding wheel. The grinding apparatus according to claim 1.   The innermost diameter side portion of the fluid nozzle is located at a height of 20 mm or more and 50 mm or less from a landing point at which coolant supplied from the coolant nozzle is landed on the outer peripheral surface of the grinding wheel. The grinding apparatus according to claim 1 or 2. The grinding apparatus according to any one of claims 1 to 3, wherein the fluid nozzle and the coolant nozzle are integrally formed.

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