JP4956041B2 - Coreless grinding machine - Google Patents

Description

The present invention relates to a regulating wheel and the blade and at the workpiece rotational support while coreless grinder for grinding a stepped workpiece by sandwiching the workpiece between the grinding wheel and the regulating wheel.

  The centerless grinding machine is an apparatus for grinding a workpiece by sandwiching the workpiece between a grinding wheel and an adjustment wheel while rotating and supporting the workpiece as a workpiece with an adjustment wheel and a blade. As shown in FIG. 5, when grinding a stepped workpiece (hereinafter referred to as a workpiece 100) having a large diameter portion 101 and a small diameter portion 102 having different diameters along the axial direction, adjustment with a grinding wheel 110 is performed. The vehicle 120 is formed with small diameter portions 111 and 121 having a diameter corresponding to the large diameter portion 101 of the workpiece 100 and large diameter portions 112 and 122 having a diameter corresponding to the small diameter portion 102 of the workpiece 100. ing. The adjusting wheel 120 is connected to a driving source (not shown) such as a motor by a belt or the like, and rotates by the driving force of the driving source. The workpiece 100 is rotated by transmitting the rotational force of the adjusting wheel 120 by the frictional force with the adjusting wheel 120. On the other hand, the grinding wheel 110 is connected to a driving source (not shown) such as another motor by a belt or the like, and is rotated by the driving force of the driving source.

  Since the small-diameter portion 121 and the large-diameter portion 122 of the adjustment wheel 120 are integrally formed, the rotational speed is the same, but the peripheral speed at the outer peripheral portion is smaller in the small-diameter portion 121. However, in the workpiece 100 to which the rotational force is transmitted from the adjusting wheel 120, the peripheral speed of the small diameter portion 102 that comes into contact with the large diameter portion 122 of the adjusting wheel 120 is larger than that of the large diameter portion 101. Accordingly, the outer peripheral portion of the workpiece 100 and the outer peripheral portion of the adjusting wheel 120 are in contact with each other but the peripheral speeds do not match, and therefore slip occurs between the workpiece 100 and the adjusting wheel 120. For this reason, vibration occurs in the workpiece 100 or uneven wear occurs on the surface of the adjustment wheel 120, so that the machining accuracy of the workpiece 100 is lowered. Further, due to the uneven wear, the adjustment wheel 120 needs to be frequently dressed.

In order to solve these problems, a coreless grinding machine as shown in Patent Document 1 has been developed. The centerless grinding machine of Patent Document 1 is provided with a large-diameter portion and a small-diameter portion of the adjustment wheel, which are separately supported by a fixed spindle via a bearing, and a large-diameter portion and a small-diameter portion. By being connected to separate motors and appropriately giving different rotations, the peripheral speeds of the workpieces of the respective diameter portions and the adjusting wheel are made equal.
Japanese Patent Laid-Open No. 4-93161

  However, in the above-described coreless grinding machine of Patent Document 1, although the peripheral speeds of the workpiece of the large diameter portion and the small diameter portion and the adjustment wheel can be equalized, a motor is connected to each of the large diameter portion and the small diameter portion of the adjustment wheel. As a result, the number of parts increases, the structure of the entire grinding machine becomes complicated, and the weight increases.

Therefore, the present invention is for solving the above-mentioned problems, and can prevent the workpiece and the adjustment wheel from slipping to increase the workpiece machining accuracy and reduce the weight while preventing the structure from becoming complicated. It is an object of the present invention to provide a coreless grinding machine capable of achieving the above.

The invention according to claim 1 for solving the above problem is to grind the stepped workpiece by sandwiching the workpiece between the grinding wheel and the adjusting wheel while rotating and supporting the workpiece by the adjusting wheel and the blade. In the centerless grinding machine, the adjustment wheel includes a fixed adjustment wheel that is fixed to the rotating main shaft, and a different diameter adjustment wheel that is arranged coaxially with the fixed adjustment wheel and has a diameter different from the diameter of the fixed adjustment wheel. The different diameter adjusting wheel is supported by the rotating main shaft via a fluid bearing so as to be relatively rotatable, and the fluid bearing is formed on an inner circumferential surface of the different diameter adjusting wheel formed in a cylindrical shape. A pressure chamber formed along a circumferential direction; and a flange formed on an outer peripheral surface of the rotation main shaft of the adjusting wheel and protruding into the pressure chamber of the different diameter adjusting wheel. A first fluid supply channel that opens on one side surface in the axial direction of the rotating spindle; and Rolling a second fluid supply passage that opens in the axial direction other side of the main shaft are formed, the fluid pressure supplied to the second fluid supply flow path and the fluid pressure supplied to the first fluid supply passage And a dressing state in which a fluid is supplied and pressurized only to one of the first fluid supply channel and the second fluid supply channel. fluid pressure selection control means for switching the a coreless grinder you characterized by comprising further.

According to the above configuration, the different-diameter adjusting wheel is supported relative to the rotating main shaft via the fluid bearing so as to be relatively rotatable, and thus is relatively rotatable with respect to the fixed adjusting wheel fixed to the rotating main shaft. Therefore, the different-diameter adjusting wheel can rotate in accordance with the outer periphery of the workpiece (hereinafter referred to as a workpiece), and absorbs the difference in the peripheral speed generated between the outer periphery of the large-diameter portion and the outer periphery of the small-diameter portion. it can. This prevents slipping between the outer peripheral surface of the workpiece and the outer peripheral surface of the adjustment wheel, does not give vibration to the workpiece, and the adjustment wheel does not wear unevenly. The number of times of processing can be reduced. Further, unlike the coreless grinding machine of Patent Document 1, it is not necessary to provide a motor for each adjustment wheel, so that the structure can be simplified and the weight of the coreless grinding machine can be achieved. it can. Further, if the fluid supply pressures of the first fluid supply channel and the second fluid supply channel are made equal, a fluid film is formed between the pressure chamber wall of the different-diameter adjusting wheel and the flange portion of the rotating main shaft, The adjusting wheel is supported so as to be rotatable relative to the rotation main shaft. Further, if the fluid is supplied and pressurized only to one of the first fluid supply channel and the second fluid supply channel, the different-diameter adjusting wheel is placed on one side to which the fluid is supplied. When pushed, the inner wall of the pressure chamber on the other side comes into contact with the flange. As a result, the different-diameter adjusting wheel can be rotated together with the rotating main shaft, so that the dressing process for scraping the surface of the adjusting wheel can be performed in both the fixed adjusting wheel and the different-diameter adjusting wheel. Furthermore, it becomes possible to easily switch between the grinding state and the dressing state of the different diameter adjusting wheel using the fluid pressure selection control means.

  ADVANTAGE OF THE INVENTION According to this invention, while being able to prevent the slip of a workpiece | work and an adjustment vehicle and to raise the process precision of a workpiece | work, the outstanding effect that weight reduction can be achieved, preventing the complication of a structure is exhibited. .

  BEST MODE FOR CARRYING OUT THE INVENTION Best modes for carrying out a centerless grinding machine and a centerless grinding machine adjusting wheel according to the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a cross-sectional view showing the best mode for carrying out the adjusting wheel of the centerless grinding machine according to the present invention, and FIG. 2 shows the best mode for carrying out the centerless grinding machine according to the present invention. FIG. 3 is a front view and a plan view showing the best mode for carrying out the coreless grinding machine according to the present invention, and FIG. 4 is an adjustment wheel for the coreless grinding machine according to the present invention. It is the elements on larger scale which showed the dress state of.

  First, the configuration of the centerless grinding machine and the adjustment wheel of the centerless grinding machine according to the present embodiment will be described.

  As shown in FIG. 3, the centerless grinding machine 1 according to the present invention includes a grinding wheel 40 and an adjustment wheel 10 while rotating and supporting a workpiece (hereinafter referred to as a work 30) with the adjustment wheel 10 and the blade 50. Thus, the workpiece 30 is sandwiched and the stepped workpiece 30 is ground without core.

  The grinding wheel 40 is rotatably supported by a grinding wheel frame 41 provided on the bed 2, and is configured to be rotated by a motor 43.

  The adjustment wheel 10 is arranged on the side of the grinding wheel 40 so that the rotation main shaft 11 of the adjustment wheel 10 is parallel to the rotation shaft 44 of the grinding wheel 40. The adjusting wheel 10 is rotatably supported by an adjusting wheel frame 12 provided on the bed 2. The adjustment wheel frame 12 is supported on the slide table 3 disposed on the bed 2 so as to be able to move forward and backward so as to be able to approach and move away from the grinding wheel 40. An actuator 13 for moving the adjustment vehicle frame 12 forward and backward on the slide table 3 is provided on the side of the adjustment vehicle frame 12.

  Above the adjustment wheel 10, a dressing device 4 that cuts the outer peripheral surface of the adjustment wheel 10 is provided. The dressing device 4 scrapes the outer peripheral surface by moving the blade (not shown) along the axial direction of the adjusting wheel 10 while contacting the surface of the rotating adjusting wheel 10.

  As shown in FIGS. 1 and 2, the adjustment wheel 10 includes a rotating main shaft 11 that is rotatably supported at both ends by bearings 14 and 14 (shown only in FIG. 1) such as ball bearings, and the rotating main shaft 11. The fixed adjustment wheel 15 is fixed to the fixed adjustment wheel 15 and the different diameter adjustment wheel 16 is arranged coaxially with the fixed adjustment wheel 15 and has a different diameter. The fixed adjustment wheel 15 and the different diameter adjustment wheel 16 each have a rubber surface layer portion 19 formed on the surface thereof. The fixed adjustment wheel 15 is configured by an adjustment wheel whose axial length is longer than the axial length of the other adjustment wheel (different diameter adjustment wheel 16). In the present embodiment, the fixed adjustment wheel 15 has a larger diameter than the different diameter adjustment wheel 16, the fixed adjustment wheel 15 constitutes the large diameter portion 17, and the different diameter adjustment wheel 16 includes the small diameter portion 18. It is composed. A motor (not shown) for rotating the adjustment wheel 10 is connected to the rotation main shaft 11 via a rotational force transmission means (not shown) such as a belt.

  As shown in FIG. 1, the different-diameter adjusting wheel 16 is formed in a cylindrical shape and is supported on the rotary main shaft 11 via a fluid bearing 20 so as to be relatively rotatable. The fluid bearing 20 forms a fluid film with high viscosity oil or the like between the rotation main shaft 11 and the different diameter adjustment wheel 16 to allow relative rotation between the rotation main shaft 11 and the different diameter adjustment wheel 16. In addition, the fluid used for the fluid bearing 20 is not limited to oil, and may be other liquid such as water or coolant, or gas such as high-pressure air. The fluid bearing 20 includes a pressure chamber 21 formed in a groove shape along the circumferential direction on the inner circumferential surface of the different diameter adjusting wheel 16, and a flange portion formed along the circumferential direction on the outer circumferential surface of the rotary main shaft 11. 22. The pressure chamber 21 is formed in a groove shape having a rectangular cross section, and has side wall surfaces 21 a and 21 b positioned on both sides in the axial direction of the rotary main shaft 11 and a bottom surface 21 c positioned on the radially outer side. The flange portion 22 is formed so as to protrude into the pressure chamber 21 of the different-diameter adjusting wheel 16 so as to leave a gap between the side wall surfaces 21 a and 21 b and the bottom surface 21 c of the pressure chamber 21.

  The flange portion 22 includes a first fluid supply passage 24 that opens to one axial side surface (right side surface in FIG. 1) 23 of the rotary main shaft 11 and an axial other side surface (left side surface in FIG. 1) 25 of the rotary main shaft 11. A second fluid supply channel 26 is formed. Further, the flange portion 22 is formed with a third fluid supply channel 28 that opens to the outer peripheral surface 27 thereof. The first fluid supply channel 24, the second fluid supply channel 26, and the third fluid supply channel 28 extend to one end of the rotary main shaft 11, and are respectively supplied to pumps 29a, 29b, and 29c for supplying fluid. It is connected.

  The first fluid supply channel 24, the second fluid supply channel 26, and the third fluid supply channel 28 are arranged so as not to interfere with each other, and are radially arranged at a predetermined angular pitch (for example, 120 ° pitch). It is formed by branching. Openings 24a (only one is shown) are formed at the distal ends of the first fluid supply channels 24 that are radially branched. A ring-shaped groove portion 31 is formed on one side surface (right side surface in FIG. 1) 23 of the flange portion 22 where the opening portion 24a is formed so as to connect the opening portions 24a. Openings 26a (only one is shown) are formed at the distal ends of the second fluid supply channels 26 that are radially branched. On the other axial side surface (right side surface in FIG. 1) 25 of the flange portion 22 where the opening portion 26a is formed, a ring-shaped groove portion 32 is formed so as to connect the opening portions 26a. Openings 28a (only one place is shown) are formed at the distal ends of the third fluid supply channels 28 branched radially. A ring-shaped groove 33 is formed on the outer peripheral surface 27 of the flange 22 where the opening 28a is formed so as to connect the openings 28a.

  Pumps 29a, 29b, and 29c are connected to the first fluid supply channel 24, the second fluid supply channel 26, and the third fluid supply channel 28, respectively. Each pump 29a, 29b, 29c is electrically connected to a fluid pressure selection control means 37 that controls its operation.

  The fluid pressure selection control means 37 is configured by a computer, and makes the fluid pressure supplied to the first fluid supply channel 24 and the fluid pressure supplied to the second fluid supply channel 26 equal to each other. Fluid is supplied only to the ground state to be held and one of the first fluid supply channel 24 and the second fluid supply channel 26 (the first fluid supply channel 24 in the present embodiment). A program for selectively switching between a dressing state in which one side of the pressure chamber 21 is pressurized is provided. Switching between the grinding state and the dressing state is performed by an operator using a switch or the like not shown. In the dress state, the fluid pressure in one of the first fluid supply channel 24 and the second fluid supply channel 26 is maintained at a pressure higher than the fluid pressure in the other fluid supply channel. You may comprise.

  In the grinding state, the pumps 29a, 29b, and 29c are operated so that the fluid pressures of the fluids supplied to the first fluid supply channel 24, the second fluid supply channel 26, and the third fluid supply channel 28 are equal. . As a result, a fluid film is formed between the flange portion 22 and the inner peripheral surfaces (side wall surfaces 21a, 21b and bottom surface 21c) of the pressure chamber 21 around the flange portion 22, and the rotation main shaft 11 and the different diameter adjusting wheel 16 are Is in a non-contact state (see FIG. 1), the different diameter adjusting wheel 16 is supported on the rotary main shaft 11 so as to be relatively rotatable.

  On the other hand, in the dress state, the fluid is supplied only to the first fluid supply channel 24 out of the first fluid supply channel 24 and the second fluid supply channel 26, and the fluid is supplied to the second fluid supply channel 26. The pumps 29a and 29b are operated so that is stopped. At this time, the fluid pressure in the third fluid supply channel 28 is kept the same as that in the ground state. As a result, as shown in FIG. 4, the different diameter adjustment wheel 16 moves in the fluid blowing direction of the first fluid supply passage 24 (right side in FIG. 4), and the pressure chamber 21 side of the different diameter adjustment wheel 16. The wall surface 21 b contacts the other axial side surface 25 of the flange portion 22. At this time, since the fluid is supplied at a predetermined fluid pressure between the one axial side surface 23 of the flange portion 22 and the side wall surface 21a of the pressure chamber 21 of the different diameter adjusting wheel 16, the different diameter adjusting wheel 16 is It will be pressed by the collar part 22 with a predetermined pressure. As a result, the different-diameter adjusting wheel 16 can rotate integrally with the rotary main shaft 11. The fluid pressure in the first fluid supply flow path 24 is determined when the frictional force generated when the different diameter adjustment wheel 16 is pressed against the flange portion 22 scrapes the surface of the different diameter adjustment wheel 16 with the blade of the dressing device 4. It is set to be larger than the frictional resistance. On the other hand, since the fluid is supplied from the third fluid supply channel 28 at a constant fluid pressure, the radial position of the different diameter adjustment wheel 16 is kept constant. The fluid pressure in each of the fluid supply channels 24, 26, and 28 is not limited to the configuration that is adjusted by the operating pressure of the pumps 29a, 29b, and 29c. The pump pressure is kept constant and the on-off valve is opened. Of course, it may be adjusted in degrees. In this case, if the valve is operated by a valve opening / closing switch, the fluid pressure selection control means 37 having a complicated configuration can be omitted. Further, the moving direction of the different-diameter adjusting wheel 16 is not limited to the fluid blowing direction of the first fluid supply passage 24, and is opposite to the present embodiment as long as it is along the axial direction of the rotary main shaft 11. The fluid blowing direction of the second fluid supply channel 26 may be used.

  In the present embodiment, the first fluid supply channel 24, the second fluid supply channel 26, and the third fluid supply channel 28 are formed so as not to interfere with each other, and pumps 29a and 29b are respectively provided. 29c are connected, but the present invention is not limited to this. For example, the first fluid supply channel and the third fluid supply channel may be branched from the same channel, and the second fluid supply channel may be formed in a separate circuit. In this case, the operating pressure of the pump is kept constant, and in the grinding state, the fluid pressures of the first fluid supply channel, the second fluid supply channel, and the third fluid supply channel are kept constant. By closing the flow path of the second fluid supply flow path using an on-off valve, the different diameter adjusting wheel is moved. In addition, the first fluid supply channel and the second fluid supply channel may be branched from the same channel, and the third fluid supply channel may be formed in a separate circuit. In this case, the fluid pressure in the first fluid supply channel and the second fluid supply channel is adjusted by changing the flow rate flowing to each fluid supply channel using a three-way valve or the like provided in the branch portion. The second fluid supply channel and the third fluid supply channel may be branched from the same channel, and the first fluid supply channel may be formed in a separate circuit.

  Next, the operation of the centerless grinding machine 1 and the adjustment wheel 10 of the centerless grinding machine 1 will be described.

  When grinding the workpiece 30, the fluid pressure selection control means 37 selects the grinding state, and as shown in FIG. 1, first, the first fluid supply channel 24, the second fluid supply channel 26, and the first The pumps 29a, 29b, and 29c are operated so that the fluid pressures in the three fluid supply passages 28 become equal, and the different-diameter adjusting wheel 16 is brought into a non-contact state with the rotary main shaft 11 so as to be relatively rotatable. .

  Then, the fixed adjustment wheel 15 is rotated by arranging the large diameter portion 38 of the work 30 in contact with the different diameter adjustment wheel 16 and the small diameter portion 39 of the work 30 in contact with the fixed adjustment wheel 15. Then, the work 30 rotates as the fixed adjustment wheel 15 rotates. As the workpiece 30 rotates, the different diameter adjustment wheel 16 also rotates. At this time, since the small-diameter portion 39 and the large-diameter portion 38 rotate integrally with the work 30, a difference in peripheral speed occurs between the outer periphery of the small-diameter portion 39 and the outer periphery of the large-diameter portion 38. Since the diameter adjusting wheel 16 is mounted so as to be rotatable relative to the rotary main shaft 11, it can be rotated in accordance with the peripheral speed of the large-diameter portion 38 of the workpiece 30. Therefore, the slip of the outer peripheral surface of the workpiece 30 and the outer peripheral surface of the adjustment wheel 10 can be prevented, the workpiece 30 is not vibrated, and the adjustment wheel 10 is not worn unevenly. Therefore, since the workpiece 30 can be supported while being accurately rotated, the machining accuracy of the workpiece 30 can be increased. In addition, since the number of dressing processes can be reduced, maintenance labor can be reduced.

  Further, unlike the conventional centerless grinding machine (see Patent Document 1), it is not necessary to provide a plurality of motors for each adjustment wheel, so that the structure of the centerless grinding machine 1 can be simplified. Weight reduction, size reduction, and cost reduction can be achieved.

  On the other hand, when the dressing process of the adjustment wheel 10 is performed, the dressing state is selected by the fluid pressure selection control means 37 to increase the fluid pressure in the first fluid supply channel 24 as shown in FIG. The pumps 29a and 29b are operated so that the supply of fluid to the two-fluid supply channel 26 is stopped. At this time, the fluid pressure in the third fluid supply channel 28 is kept the same as that in the ground state. As a result, the different diameter adjustment wheel 16 moves in the fluid blowing direction of the first fluid supply passage 24 (right side in FIG. 4), and the side wall surface 21 b of the pressure chamber 21 of the different diameter adjustment wheel 16 is It is pressed against the other side surface 25 in the axial direction.

  Then, simultaneously with the rotation of the adjustment wheel 10, the dressing device 4 is moved in the axial direction of the adjustment wheel 10 while pressing the blade of the dressing device 4 against the rubber surface layer portion 19 on the surface of the adjustment wheel 10. As a result, the rubber surface layer portion 19 on the surface of the adjustment wheel 10 is uniformly cut. At this time, the different-diameter adjusting wheel 16 is pressed against the flange portion 22 with a predetermined pressure, and thus rotates integrally with the rotary main shaft 11. Therefore, the different-diameter adjustment wheel 16 can perform dressing similarly to the fixed adjustment wheel 15.

  In short, according to the above configuration, the peripheral speed of the outer periphery of the large-diameter portion 38 of the workpiece 30 and the outer periphery of the different-diameter adjusting wheel 16 can be increased by making the rotary main shaft 11 and the different-diameter adjusting wheel 16 freely rotatable during grinding. Since they are equal, uneven wear of the rubber surface layer portion 19 of the different diameter adjusting wheel 16 can be prevented. Further, at the time of dressing, the rotating main shaft 11 and the different diameter adjusting wheel 16 can be integrally rotated by pressing the different diameter adjusting wheel 16 against the flange portion 22, so that dressing can be performed. Further, since the operator can easily select the grinding state and the dressing state only by pressing the switch by the fluid pressure selection control means 37, no work load is applied.

  Although the best mode for carrying out the present invention has been described above, the present invention is not limited to the above-described embodiment, and can be appropriately changed in design without departing from the spirit of the present invention. For example, in the above-described embodiment, the adjustment wheel 10 is composed of one fixed adjustment wheel 15 and one different diameter adjustment wheel 16, but more different diameter adjustment wheels may be formed. In this case, an adjusting wheel having a diameter equivalent to that of the fixed adjusting wheel can be fixed to the rotary main shaft 11.

FIG. 1 is a cross-sectional view showing the best mode for carrying out an adjustment wheel for a centerless grinding machine according to the present invention. BRIEF DESCRIPTION OF THE DRAWINGS (a) which showed the best form for implementing the centerless grinding machine which concerns on this invention is a partial front view, (b) is a partial top view. BRIEF DESCRIPTION OF THE DRAWINGS (a) which showed the best form for implementing the centerless grinding machine which concerns on this invention is a front view, (b) is a top view. It is the elements on larger scale which showed the dressing state of the adjustment wheel of the coreless grinding machine concerning the present invention. (A) which showed the conventional coreless grinding machine, and (b) are partial sectional views.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Centerless grinding machine 10 Adjustment wheel 11 Rotation main shaft 15 Fixed adjustment wheel 16 Different diameter adjustment wheel 20 Fluid bearing 21 Pressure chamber 22 Gutter part 23 One axial side surface 24 First fluid supply flow path 25 Other axial side surface 26 Second fluid Supply flow path 30 Work 37 Fluid pressure selection control means 40 Grinding wheel 50 Blade

Claims (1)

In a centerless grinding machine for grinding a stepped workpiece by sandwiching the workpiece between a grinding wheel and the adjustment wheel while rotating and supporting the workpiece with an adjustment wheel and a blade,
The adjustment wheel has a fixed adjustment wheel fixed to the rotation main shaft, and a different diameter adjustment wheel arranged coaxially with the fixed adjustment wheel and having a diameter different from the diameter of the fixed adjustment wheel,
The different diameter adjustment wheel is supported relative to the rotation main shaft via a fluid bearing so as to be relatively rotatable,
The fluid bearing is formed on the inner peripheral surface of the different-diameter adjusting wheel formed in a cylindrical shape along the circumferential direction, and on the outer peripheral surface of the rotating main shaft of the adjusting wheel. And a flange that protrudes into the pressure chamber of the car,
A first fluid supply channel that opens on one side surface in the axial direction of the rotation main shaft and a second fluid supply channel that opens on the other side surface in the axial direction of the rotation main shaft are formed in the flange portion,
A ground state in which the fluid pressure supplied to the first fluid supply channel and the fluid pressure supplied to the second fluid supply channel are maintained at the same pressure, and the first fluid supply channel and the second fluid A centerless grinding machine, further comprising fluid pressure selection control means for selectively switching a dressing state in which a fluid is supplied and pressurized only to one of the fluid supply channels.

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