JP4788132B2 - Grinding wheel apparatus and grinding machine equipped with the same - Google Patents

Description

  The present invention relates to a grinding wheel device that grinds a cylindrical workpiece, for example, and a grinding machine equipped with the grinding wheel device.

  For example, a grinding machine as a machine tool includes a bed on which a work table and a grindstone table are mounted, a grindstone shaft having a grindstone shaft that can be rotationally driven by a rotational drive device, and a grindstone device that grinds the workpiece, and the entire drive Are controlled by a computer numerical control (CNC) device.

  Conventionally, in this type of grinding machine, the grinding wheel shaft is cantilevered so as to be rotatable with respect to the grinding wheel base because it is easy to attach / remove (replace) the grinding wheel and perform maintenance / inspection. The thing is employ | adopted (for example, refer patent document 1).

  In such a grinding machine, it is required to increase the rigidity of the grinding wheel shaft and realize stable grinding.

By the way, in the grinding machine, with the recent reduction in size (reduction in diameter) of the grinding wheel, the grinding wheel (abrasive layer) has a sufficient amount of processing (processing time) and a centering on the work table. In order to avoid interference with a table or the like, the outer diameter of the bearing that supports the grindstone shaft is reduced as much as possible.
Japanese Patent Laid-Open No. 7-40237 (FIG. 2)

  However, in the grinding machine shown in Patent Document 1, when the outer diameter of the shaft diameter is reduced, the shaft diameter of the grindstone shaft is reduced, and its rigidity and load capacity are reduced. Therefore, the grindstone shaft is excessively bent during rough grinding, There is a problem that stable rough grinding cannot be performed. This is more noticeable during rough (rough) grinding than during fine (finish) grinding.

  The present invention has been made in view of such circumstances, and can provide a grinding wheel device that can prevent excessive bending of the grinding wheel shaft during rough grinding, and can perform stable rough grinding. Provided with a grinding machine.

(1) A grinding wheel device according to the present invention (first invention) is cantilevered so as to be rotatable with respect to a grinding wheel table, and can be driven to rotate by a rotation driving device, and a free end of the grinding wheel shaft. A grinding wheel device equipped with a grinding wheel for grinding a workpiece, the grinding wheel device further comprising movement restriction means for restricting movement of the grinding wheel shaft to the workpiece opposite processing region side, the movement restriction means, It is a rotating body having a shape that can contact the outer peripheral surface of the grindstone shaft and having a support shaft parallel to the grindstone shaft on the grindstone base, and the support shaft is along a virtual line parallel to the grindstone axis It is arranged relative to the grindstone table so as to be able to advance and retreat .
According to the grinding wheel device of the first aspect of the present invention, when the grinding wheel shaft is bent toward the workpiece counter-working region side by grinding resistance during rough grinding of the workpiece, an acting force that corrects a part thereof by receiving this bending force is obtained. The movement restricting means is applied to the grindstone shaft, and the movement of the grindstone shaft toward the workpiece counter machining area is restricted. Thereby, the excessive bending generation | occurrence | production in a grindstone axis | shaft at the time of rough grinding can be prevented, and the stable rough grinding process can be performed with high efficiency. On the other hand, since the grinding resistance is small at the time of precise grinding, the grinding wheel shaft does not bend so as to come into contact with the movement restricting means, and only the grinding wheel shaft is stably rotated, so that highly accurate grinding can be performed.
Because of this configuration, when the rotating body rotates due to the contact of the grindstone shaft during rough grinding, the grinding resistance received by the grindstone shaft can be reduced without greatly increasing the rotational driving force of the grindstone shaft.
Since it is comprised in this way, in order to make a movement control means approach with respect to a grindstone axis | shaft, a support shaft will be advanced to the grindstone axis | shaft side along a virtual line. On the other hand, in order to separate the movement restricting means from the grindstone shaft side, the support shaft is retracted from the grindstone shaft side along the virtual line. Thereby, when exchanging the grinding wheel, if the movement restricting means is moved in the direction away from the grindstone shaft, a sufficient space for exchanging the grinding wheel can be secured between the movement restricting means and the grindstone shaft. .

( 2 ) In the grinding wheel device according to the above (1 ), the movement restricting means is based on a virtual extension line connecting an axis of the grinding wheel and a workpiece grinding point in the same plane on an outer circumference circle of the grinding wheel shaft. It is preferably composed of a pair of rollers arranged in parallel with each other at equal intervals.
Since it is configured in this manner, the load resistance from the grindstone shaft is evenly distributed to the pair of rollers during rough grinding, and a rotating operation of the grindstone shaft with a good balance can be obtained.

( 3 ) In the grinding wheel device according to ( 1 ) or ( 2 ), it is preferable that the support shaft is rotatably supported by the grinding wheel platform via a bearing.
Since it is constituted in this way, the grinding resistance which a whetstone axis receives can be reduced, without greatly increasing the rotational driving force of a whetstone axis by rotating a support axis to a whetstone stand via a bearing.

( 4 ) The grinding machine of the present invention (second invention) is mounted on the grindstone shaft that is cantilevered and supported rotatably with respect to the grindstone table, and can be rotationally driven by a rotation driving device, and the free end of the grindstone shaft. And a grinding wheel having a grinding wheel device that grinds a workpiece, wherein the grinding wheel device is the grinding wheel device according to any one of (1) to ( 3 ) above. Features.
According to the grinding machine of the second aspect of the present invention, when the grinding wheel shaft is bent toward the workpiece counter-working region side by the grinding resistance during the rough grinding of the workpiece, the roller is applied with an acting force that receives this bending force and corrects a part thereof. Is applied to the grindstone shaft, and the movement of the grindstone shaft toward the workpiece counter-working region is restricted. As a result, a grinding machine capable of performing stable rough grinding with high efficiency can be obtained. On the other hand, at the time of fine grinding, since the grinding resistance is small, the grinding wheel shaft does not bend such that the grinding wheel shaft comes into contact with the roller, and only the grinding wheel shaft is stably rotated, so that highly accurate grinding can be performed.

(Embodiment)
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a plan view showing a grinding machine (cylindrical grinding machine) provided with a grinding wheel device according to an embodiment of the present invention. FIG. 2 is a sectional view showing the grinding wheel device according to the embodiment of the present invention. FIG. 3 is a cross-sectional view showing a state where the movement of the grinding wheel shaft is restricted by the movement restricting member in the grinding wheel device according to the embodiment of the present invention. FIG. 4 is a cross-sectional view for explaining the advance / retreat operation of the movement restricting means in the grinding wheel device according to the embodiment of the present invention, and FIG. 4 (a) is a cross section showing the movement restricting means in the non-grinding position. FIG. 4 and FIG. 4B are cross-sectional views showing the movement restricting means at the grinding position.

(Configuration of each part)
In FIG. 1, a cylindrical grinding machine 1 includes a bed 2 as a base, a grinding wheel device 3 for grinding a workpiece W, and a grinding wheel shaft 31 in the grinding wheel device 3 toward a workpiece rework area A side. An NC for driving and controlling the movement regulating unit 4 for regulating movement, the workpiece support / rotation drive device 5 for supporting and rotating the workpiece W, the workpiece support / rotation drive device 5 and the grinding wheel device 3 and the like. (Numerical control) It is roughly constituted by a device (not shown).

  On the bed 2, as shown in FIG. 1, a grindstone base 21 that can be advanced and retracted in the ± X-axis direction by a first moving device (not shown) and a ± Z-axis direction by a second moving device (not shown). A work table 22 that can be advanced and retracted is mounted.

  As shown in FIG. 1, the grinding wheel device 3 includes a grinding wheel shaft 31 and a grinding wheel 32, and is disposed on the grinding wheel base 21. And it is comprised so that it may drive with a rotational drive motor (not shown).

  As shown in FIG. 2, the grindstone shaft 31 is supported by a cantilever rotatably supported on a grindstone table 21 via a bearing 33, and has a stepped shaft having a plurality of shaft portions 31 </ b> A to 31 </ b> C having different outer diameters. Is formed. And it is comprised so that it may be rotationally driven by the rotational drive apparatus (rotary drive motor of the grinding wheel apparatus 3).

  The shaft portion 31A has an outer diameter larger than the outer diameter of the other shaft portions 31B and 31C, and is rotatably supported by a bearing 33 such as a fluid bearing. A pulley 506 is fixed to the end of the shaft portion 31A on the side opposite to the grinding wheel. Thereby, the rotational driving force from the rotational driving device (the rotational driving motor of the grinding wheel device 3) is transmitted to the pulley 506 via the transmission belt 507, and the grinding wheel shaft 31 is rotationally driven by the rotation of the pulley 506. A wheel stopper 34 that restricts the movement of the grinding wheel 32 toward the pulley is provided on the peripheral edge of the end surface on the side opposite to the pulley of the shaft portion 31A. Further, a plurality (two in FIG. 2) of bolt mounting holes 35, 35,... Arranged in parallel at equal intervals in the circumferential direction are provided on the end surface portion on the non-pulley side (end surface portion on the wheel stopper side) of the shaft portion 31A. ing.

  The shaft portion 31B has an outer diameter that is an intermediate dimension between the outer diameter of the shaft portion 31A and the outer diameter of the shaft portion 31C, and is connected to the central portion of the end surface on the side opposite to the pulley of the shaft portion 31A.

  The shaft portion 31C has an outer diameter smaller than the outer diameters of the other shaft portions 31A and 31B, and is connected to the central portion of the end surface on the side opposite to the pulley of the shaft portion 31B.

  As shown in FIG. 2, the grinding wheel 32 has a wheel 32 </ b> A and an abrasive grain layer 32 </ b> B, and is attached to a free end portion (shaft portion 31 </ b> A) of the grinding wheel shaft 31 by a bolt 36. And it is comprised so that it may be rotationally driven with the grindstone axis | shaft 31. FIG.

  The wheel 32 </ b> A is entirely formed of an annular plate, and is held by the shaft portion 31 </ b> B of the grindstone shaft 31 with the wheel one side end face being pressed against the wheel stopper 34. The wheel 32A is provided with a plurality of bolt insertion holes 32a, 32a,... Corresponding to the plurality of bolt mounting holes 35, 35,.

  The abrasive grain layer 32B is disposed on the outer peripheral surface of the wheel 32A, and is configured to grind the workpiece W by the rotation of the grinding wheel 32 (grinding wheel shaft 31).

  As shown in FIG. 3, the movement restricting portion 4 is composed of a rotating means having a pair of rollers 40 and 41 as movement restricting members. It is supported so that it can rotate. For this reason, when the grindstone shaft 31 (shaft portion 31C) rotating in the arrow M direction during rough grinding is moved from the position indicated by the two-dot chain line in FIG. 3 to the position indicated by the solid line in FIG. The rollers 40 and 41 are rotated in the directions of arrows m and n by the rotational contact resistance, respectively. Thereby, when the rollers 40 and 41 are rotated by the contact of the grindstone shaft 31, the grinding resistance from the rollers 40 and 41 received by the grindstone shaft 31 can be reduced.

  As shown in FIG. 3, the rollers 40 and 41 have outer peripheral surfaces 40a and 41a that can contact the outer peripheral surface 31c of the grindstone shaft 31 (shaft portion 31C), and are supported by the support shafts 43A and 43B. On the outer circumference of the grindstone shaft 31, they are arranged at positions parallel to each other at equal intervals from a virtual extension line a that connects the axis O of the grinding wheel 32 and the workpiece grinding point P in the same plane (virtual plane). As a result, the grindstone shaft 31 that moves on the virtual extension line a during rough grinding abuts the load resistance evenly distributed on the rollers 40 and 41, so that the rotating operation of the grindstone shaft 31 with good balance can be obtained. it can.

  The support shafts 43 </ b> A and 43 </ b> B are disposed with respect to the grindstone table 21 so as to be able to advance and retreat together with the bearing 42 along a virtual line b parallel to the grindstone shaft 31. For this reason, in order to make the rollers 40 and 41 (only the roller 41 shown) in the retracted position shown in FIG. 4A approach the grinding wheel shaft 31, the roller 40 is attached after the grinding wheel 32 is attached to the grinding wheel shaft 31. , 41 together with the bearing 42 are moved along the virtual line a to the advancing position shown in FIG.

  On the other hand, in order to separate the rollers 40 and 41 in the advancing position shown in FIG. 4B from the grindstone shaft 31, the rollers 40 and 41 together with the bearing 42 are retracted positions shown in FIG. Will be moved to. Thus, when the grinding wheel 32 is replaced, if the rollers 40 and 41 are moved together with the bearing 42 in a direction away from the grinding wheel shaft 31, sufficient space for replacing the grinding wheel 32 as shown in FIG. S can be secured between the rollers 40 and 41 and the grindstone shaft 31.

  As shown in FIG. 1, the work support / rotation drive device 5 includes a spindle stock 5 </ b> A and a tailstock 5 </ b> B and is mounted on a work table 22. And it is comprised so that the workpiece | work W may be supported and rotationally driven.

  The headstock 5A includes a main shaft 51 protruding toward the tailstock and a rotation motor (not shown) that rotationally drives the main shaft 51, and is configured to support and rotate the workpiece W together with the tailstock 5B. ing.

  The tailstock 5B has a center 52 that protrudes toward the main shaft, and is configured to support the workpiece W so as to be rotatable from the opposite side to the main shaft 5A.

  The NC device (not shown) includes a computer numerical control (CNC) device having a built-in hard disk for storing a machining program executed when the workpiece W is ground. The first moving device of the grindstone table 21 and the work table 22 The second moving device (both not shown), the grinding wheel device 3, the work support / rotation drive device 5 and the like are configured to be driven and controlled.

(Grinding of workpiece W in the present embodiment)
With the above configuration, in the grinding machine 1 of the present embodiment, in order to grind the workpiece W by the grinding wheel device 3 in the state shown in FIG. It moves after moving to the advancing position shown to (b) along the virtual line a with the bearing 42, and arrange | positioning the rollers 40 and 41 around the grindstone axis | shaft 31. In this case, when the grindstone shaft 31 is bent toward the workpiece counter-working region A side by the grinding resistance during the rough grinding of the workpiece, the rollers 40 and 41 receive the bending force to correct a part thereof. 31 (shaft portion 31 </ b> C) and the movement of the grindstone shaft 31 toward the workpiece counter machining area A is restricted.

(Effect of this embodiment)
According to the above-described embodiment, the grinding wheel shaft 31 always has an allowable rigidity and load capacity, so that excessive bending of the grinding wheel shaft 31 during rough grinding can be prevented, and stable and highly efficient. Coarse grinding can be performed.

  Further, at the time of fine grinding, the grinding wheel shaft 31 is not bent so as to contact the rollers 40 and 41, and only the grinding wheel shaft 31 is stably rotated, so that the grinding process with high accuracy can be performed.

  Further, in the grinding machine 1 of the present embodiment, in order to replace the grinding wheel 32 of the grinding wheel device 3 in the state shown in FIG. 4B, the rollers 40 and 41 are moved to the retracted position shown in FIG. It is performed after moving along the virtual line b together with the bearing 42. In this case, when the rollers 40 and 41 are disposed at the retracted position together with the bearings 42, a sufficient space S for exchanging the grinding wheel 32 can be secured between the rollers 40 and 41 and the grinding wheel shaft 31.

  In addition, although the grinding machine 1 (grinding wheel device 3) of the present invention has been described based on the above-described embodiment, the present invention is not limited to the above-described embodiment, and in a range not departing from the gist thereof. The present invention can be implemented in various modes, and for example, the following modifications are possible.

(1) Although the grinding wheel device 3 of the above embodiment has been described with respect to the case where the movement restricting portion 4 is composed of the rollers 40 and 41, the present invention is not limited to this. It may be composed of a bearing such as an oilless metal having a bearing surface having a curvature substantially the same as the curvature.

(2) Although the grinding wheel device 3 of the above embodiment has been described as a fluid bearing (slide bearing) as the bearing 42 for rotatably supporting the support shafts 43A and 43B on the grinding wheel base 21, the present invention is However, it may be a rolling bearing (radial bearing), and other bearings may be used as long as the grinding operation by the grinding wheel 32 is not hindered by the contact of the rollers 40 and 41 during rough grinding.

The top view which shows the grinding machine provided with the grinding wheel apparatus which concerns on embodiment of this invention. Sectional drawing which shows the grinding wheel apparatus which concerns on embodiment of this invention. Sectional drawing which shows the state by which the movement of the grinding wheel axis | shaft was controlled by the movement control means in the grinding wheel apparatus which concerns on embodiment of this invention. Sectional drawing shown in order to demonstrate the advancing / retreating operation | movement of the movement control means in the grinding wheel apparatus which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Cylindrical grinder, 2 ... Bed, 3 ... Grinding wheel apparatus, 4 ... Movement control part, 5 ... Work support / rotation drive device, 5A ... Spindle head, 5B ... Tailstock, 21 ... Grinding wheel base, 22 ... Workpiece Table, 31 ... Grinding wheel shaft, 31A, 31B, 31C ... Shaft, 31c ... Outer peripheral surface, 32 ... Grinding wheel, 32A ... Wheel, 32B ... Abrasive layer, 32a ... Bolt insertion hole, 33 bearing, 34 ... Wheel stopper, 35 ... bolt mounting hole, 40, 41 ... roller, 40a, 41a ... outer peripheral surface, 42 ... bearing, 43A, 43B ... support shaft, 51 ... main shaft, 52 ... center, 506 ... pulley, 507 ... transmission belt, A ... work Counter machining area, a ... virtual extension line, b ... virtual line, M ... rotation direction of grinding wheel axis, m ... rotation direction of roller 40, n ... rotation direction of roller 41, P ... workpiece grinding point, O ... axis, S ... Space, W ... Work

Claims (4)

A grindstone shaft that is cantilevered and rotatably supported by a grindstone base, and can be rotationally driven by a rotational drive device;
A grinding wheel device equipped with a grinding wheel that is attached to a free end of the grinding wheel shaft and grinds a workpiece,
A movement restricting means for restricting the movement of the grindstone shaft toward the workpiece re-working region side;
The movement restricting means is a rotating body having a shape capable of contacting an outer peripheral surface of the grindstone shaft, and having a support shaft parallel to the grindstone shaft on the grindstone base,
The grinding wheel device according to claim 1, wherein the support shaft is disposed with respect to the grinding wheel base so as to advance and retreat along a virtual line parallel to the grinding wheel shaft . The movement restricting means, according to claim 1 consisting of a pair of rollers arranged in parallel to each other at equal intervals from a virtual extension line connecting the axis and the workpiece grinding point of said grinding wheel in the same plane on the outer periphery yen of the wheel spindle grinding wheel device according to. The grinding wheel device according to claim 1 or 2 , wherein the support shaft is rotatably supported by the grinding wheel platform via a bearing. A grindstone shaft that is cantilevered and rotatably supported by a grindstone base, and can be rotationally driven by a rotational drive device;
A grinding machine provided with a grinding wheel device attached to a free end of the grinding wheel shaft and having a grinding wheel for grinding a workpiece,
The grinding wheel device according to any one of claims 1 to 3 , wherein the grinding wheel device is the grinding wheel device.