JPS6028627B2 - Taper correction device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a taper correction device for correcting the taper into a correct cylindrical shape when a workpiece machined by a grinding machine does not have the correct cylindrical shape and tapers.

In order to keep the ground workpiece within the same tolerance, the workpiece axis D supported between the headstock side center and tailstock side center must be parallel to the axis ○ of the grinding wheel on the grindstone head. It is extremely important to always maintain this within a certain range.

However, changes in the amount of work due to thermal displacement of the grinding machine body, grinding wheel shaft, table, tailstock, headstock, etc., and further due to the shape of the workpiece,
Due to various factors such as changes in the cutting edge of the grinding wheel, the parallel relationship between the axis of the workpiece and the axis of the grinding wheel breaks down, causing a problem that the workpiece becomes tapered. Taper correction devices for secondary grinding machines include a method of moving the tailstock shaft in the cutting direction, a method of tilting the table that connects the headstock and tailstock with respect to the grinding wheel axis, and a method of grinding the grinding wheel axis. A method is known in which the mirror is tilted with respect to the workpiece axis during machining.

However, the first method has the disadvantage that when both ends of the workpiece are supported at the center, the relative position with other units on the table changes. For example, when grinding the pin part of a crankshaft, it is not possible to move the tailstock spindle that grips the end of the workpiece with a chuck in the direction of the cut, making taper correction grinding impossible. had. In the second method, the table is usually thin and has low rigidity, so when the mirror is tilted for taper correction, the table itself has to be manipulated and does not follow the instructions, making it difficult to perform correction grinding. Was. The third method has the drawback of causing chatter in the workpiece due to the movement of the grinding wheel which rotates at high speed. In addition, with this method, a heavy grinding wheel stand with a grinding wheel that rotates at high speed must be moved obliquely, making the entire taper correction device large and complicated.
Not only does it require space, but it also has the drawbacks of being expensive. In the present invention, the grinding wheel, which is the largest source of vibration, is supported by rotating at high speed, and the heavy grinding wheel head is fixed to the bed, and the saddle is movable perpendicular to the grinding wheel axis (in the x-axis direction). It is supported by a hydrostatic bearing against the bed.

A table with a headstock and a tailstock fastened to it is remounted on the top of this saddle to rotatably support the workpiece parallel to the grindstone axis. Stopper members for limiting the amount of saddle movement are provided at both left and right ends of the bed so as to be movable in the X-axis direction. Also, the rear center portion of the saddle is connected to a piston to move the saddle in all directions along the x axis. Then, while pressing the saddle against the two stopper members at the same time, the two stopper members are synchronously moved in the cutting direction in the X-axis direction at a cutting speed to perform the grinding process. When a taper occurs in the workpiece, the two stopper members are moved asynchronously to make their positions different from the grindstone axis, so that the saddle pressed by the stopper member is tilted relative to the grindstone axis; This enables grinding for taper correction. First, an embodiment in which the present invention is applied to a multi-wheel grinder will be described with reference to the drawings.

On the bed 1 of the grinding machine, a saddle 2, which has a substantially square shape in the plan view (FIG. 2), is remounted. The saddle 2 has a pair of parallel slide bodies 3, 3' on both sides, and
The main beam 4 and the sub beam 4' connect the two slide bodies at right angles to each other. Both slide bodies 3, 3' have their entire lower surfaces in a horizontal plane shape and are supported by the bed 1 using hydrostatic bearings.

The left and right outer surfaces of the saddle 2 are supported by the bed 1 under static pressure in the vicinity of the intersection line A between the vertical plane passing through each grinding point of the workpiece on the main beam 4, which will be described later, and the left and right outer surfaces of the saddle. There is. (FIG. 4) Furthermore, the sub-beam 4' is supported by the bed 1 in the left-right direction at the central position using shark pressure bearings. (Fig. 5) On the upper surface of the main beam 4, a headstock 6 is mounted on the left side of the table 5, and a tailstock 7 is mounted on the right side, facing each other so that their positions can be changed in the direction of the sea bream line. There is. A workpiece 8 is rotatably supported between the headstock 6 and tailstock 7. On the upper surface of the table 5, two known sizing devices 9, 9' are mounted axially apart, corresponding to the grinding points, for measuring the ground diameter of the workpiece. A grindstone head 10 is fixed to the bed 1 at a closed central portion of the saddle 2 at a position that does not interfere with the saddle, and rotatably supports a grindstone shaft (not shown) parallel to the main beam.

A plurality of grinding wheels 11 are attached to the grinding wheel shaft at intervals in the direction of grinding, depending on the location to be ground on the workpiece.
A cylinder 12 is located in the center of the saddle 2 below the grindstone head 10.
is fixed to bed 1 in the x direction. A hole 13 is bored in the center of the sub-beam 4' so that the center line coincides with the cylinder, and inside the hole 13 there is a spring receiver 14 and a space between the spring receiver 14 and the wall surface of the sub-beam 4. A compression spring 15 interposed therein is embedded. and the spring receiver 1
4 is normally urged toward the cylinder 12 by a compression spring 15 and is pressed against the cylinder side wall surface of the sub beam 4'.
A piston rod 16 of the cylinder 12 passes through the wall surface of the hole 13, and its tip and the spring receiver 14 are fastened together. Pressure fluid is sent to the cylinder 12 and the piston rod 16
When the saddle 2 moves upward in FIG. 2, that is, moves forward, the saddle 2 is moved forward in the cutting direction via the compression spring 15.
When the piston rod 16 is retracted, the spring receiver 14 pushes the wall surface and the saddle 2 is retracted. Further, a pin 17 is provided in the spring receiver 14 so as to protrude through the wall surface in the forward direction of the saddle 2, and a limit switch 1 is fixed to the sub-beam 4 against the compression 1 imitation 15 when the saddle 2 stops moving forward.
8. A pair of nuts 1 are installed on the outer sides of both slide bodies 3 and 3' of the saddle 2 so as to be prevented from rotating with respect to the bed 1 and to be movable in all directions along the x axis.
9, 19' are attached by ball guides 20, 20'.

Contact pieces 21, 21' are provided on both outer surfaces of both slide bodies 3, 3' near the main beam 4 mounting layer in the x-width direction so that they come into contact with the end faces of the nuts 19, 19' when the saddle 2 moves forward. are arranged opposite to each other so that their positions can be adjusted. and the contact piece 21,
The position of the front end surface of 21' is adjusted so that the workpiece is aligned with a straight line connecting the respective grinding points at which the workpiece is ground by the grinding wheel 11. A protruding piece 22 is fixed to one 19 of the pair of nuts, and operates a rapid forward end confirmation limit switch 23 attached to the saddle 2 at the forward end of the saddle 2. A frame-shaped actuating body 24 is attached to the other nut 19' of the pair so as to be rotatable about the axis of the nut 19', which actuates a deceleration valve 46 (described later) for converting the saddle movement speed. A piece 25 having a sloped surface on the side of the bale piece 21' is fixed to the body 24.
Furthermore, a saddle 2 is provided on the outer surface of the mounting portion of the twill piece 21'.
A pin 26 is protruded at a position where it presses the inclined surface of the piece 25 when the piece 25 moves forward toward the bag, and when the pin 26 presses the inclined surface of the piece 25, the actuating body 24 to which the piece 25 is attached is activated. It can be rotated around the axis of the nut 19'. As a mechanism for driving the pair of nuts, a gear box 27 is attached to the rear of the bed 1, and an electric motor 2 with a position detector is attached to the gear box 27.
Rotation is given from 8. The output shaft 29 of the gear box 27 is rotatably attached to the bed 1 parallel to the grindstone shaft, and a gear 30 is fixed to the end thereof. gear 3
A gear wheel 32 having a gear 31 meshing with the grinding wheel 31 is rotatably mounted on the bed 1 parallel to the grindstone shaft. A double helical gear 33 is attached to the gear shaft 32 at the center of the sub-beam 4' so as to be slidable in the crosswise direction. a helical gear 34 that meshes with each gear portion of the milk gear 33;
Intermediate shafts 35, 35' having a diameter of 34' are rotatably mounted on the bed 1 parallel to the grinding wheel axis with their marking lines coincident. The intermediate shafts 35, 35' serve as input shafts of two gear boxes 36, 36' provided at the left and right ends of the rear portion of the bed 1, respectively. Output shafts 37, 37 of gear boxes 36, 36', respectively
It is rotatably attached to the bed 1 parallel to the slide bodies 3, 3' of the saddle 2, and has a threaded portion at its front end, and is screwed into the nuts 19, 19', respectively. Axis 37.
When 37' is rotated, the nuts 19, 19' are moved in the cross direction, and a position detector attached to the electric motor 28 detects the front end positions of the nuts 19, 19'. Then, due to the rotation of the electric motor 28, the two nuts 19,
19' are configured to be moved in the same direction and by the same amount at the same time. The double-hung gear 33 is threadedly engaged with a screw shaft 38. As the shifter 39 moves, it is moved in the axial direction. If the double gear 33 moves in the direction of the bag line,
A pair of helical gears 34, 34 meshing with the milk gears
' rotate in mutually opposite directions, and a pair of nut members 20,
The positions of the grindstones 20' from the grindstone edge line can be made different from each other. The screw shaft 38 is a second shaft equipped with a position detector.
It is rotated by an electric motor 40 via a gear train. Therefore, the position of the double-helical gear 33 is detected by a position detector attached to the second electric motor 401. The shifter 39 also has a rod 4 having two pieces 41, 41'.
The pieces 41, 41' actuate limit switches 43, 43' fixed to the bed 1 to detect the limit of left and right movement of the double helical gear 33. FIG. 3 is a pressure fluid circuit diagram for moving the saddle. Pressure fluid sent from the pump P first passes through an electromagnetic switching valve 44 for moving the saddle forward and backward. A speed adjustment valve 45 and a deceleration valve 46 are disposed in a flow path leading from the cutout valve 44 to the front chamber a of the cylinder 12. When the saddle 2 moves forward, the deceleration valve 46 is activated by the pin 26.
4 is rotated, the tip is pushed and worked by the actuating body 24, and only the throttle passage is moved. The switching valve 4
4 to the rear chamber b of the cylinder 12, there are a speed adjustment valve 45', a saddle rapid feed/cut feed switching valve 47, a saddle jig feed/automatic feed switching valve 48, and two speed adjustment valves 49, 50. A consultation has been arranged.

When the switching valve 47 is switched to the inching feed side port, the pressure fluid is sent to the speed regulating valve 49, and when the switching valve 48 is switched to the inching feed side port, the pressure fluid is sent to the speed regulating valve. 50 and then to the rear chamber b of the cylinder 12. Next, the effect will be explained.

It is assumed that the saddle 2 is at the rearward end position.

It is assumed that the saddle rapid feed/cut feed switching valve 47 is switched to the saddle rapid feed side A, and the saddle inching feed/automatic feed switching valve 48 is switched to the automatic feed side A'. It is assumed that the speed regulating valves 45, 45' are adjusted so that the saddle feeding speed becomes a predetermined speed. It is assumed that the double helical gear 33 is in the central position and therefore the two nuts 19, 19' are equidistant from the grindstone axis. Now, when the electromagnetic switching valve 44 for the saddle forward and backward movement is switched to the saddle forward side, the pressure fluid is transferred to the speed adjustment valve 45', the electromagnetic switching valve 47 for the saddle rapid feed/cutting feed, and the electromagnetic switching valve 48 for the saddle jig feed/automatic feed. and is sent to the rear chamber b of the cylinder 12. Therefore, the piston moves forward at a rapid traverse speed, and the saddle 2 starts to move forward rapidly as it is pushed from the spring receiver 14 at the tip of the piston rod via the compression spring 15. At this time, the fluid in the cylinder front chamber a is returned to the tank through the deceleration valve 46, the speed adjustment valve 45, and the electromagnetic switching valve 44 for advancing and retracting the saddle. When the saddle 2 reaches near the fast-travel forward end, the pin 26 presses the piece 25 to cause the actuating body 24 to spread, and the actuating body 24 pushes the valve end of the deceleration valve 46, so that the deceleration valve 46 only passes through the throttle passage. It becomes like this. Therefore, the amount of fluid in the cylinder front chamber a that returns to the tank is limited, and the forward speed of the saddle 2 is reduced. When the saddle 2 reaches the table feed forward end, the contact pieces 21, 21' contact the front end surfaces of the nuts 19, 19', respectively, and the forward movement is stopped. At the same time, the limit switch 23 hits the protruding piece 22 and the forward end of the rapid feed is confirmed. Since the pressure fluid is further sent into the cylinder rear chamber b, the piston rod 16 moves forward against the compression spring 15, and the end surface of the spring receiver 14 is brought into contact with the sub beam 4.
′ comes into contact with the inner surface of the hole. At this time, the protruding pin 17 of the spring receiver 14 operates the limit switch 18. By operating the two girder mitt switches 18 and 23, the electromagnetic switching valve 47 for saddle rapid feed/cut feed is switched to the cut feed side port.

The pressure fluid then passes through the speed regulating valve 49 and is sent into the rear chamber b of the cylinder 2 with its flow rate being restricted. Next, the electric motor 28 is rotated by a predetermined amount in a predetermined direction based on a command from a control device (not shown), and the two nuts 19, 19' are simultaneously moved in the cutting direction by the same amount. At this time, the positions of the tips of the two nuts 19, 19' are detected by a position detector attached to the electric motor 28. As the nut moves, the saddle 2 moves at a cutting speed due to the limited flow rate fed into the rear chamber b' of the cylinder 2. At the start of cutting, the supply of pressure oil to the hydrostatic bearing (FIG. 5) that laterally supports the central portion of the sub-beam 4' is stopped. Then, the supply of v is restarted by the early return signal of the saddle 2. During this cutting movement, the two IJ mitt switches 18 and 23 are always activated. Even if an abnormal situation occurs where the nuts 19, 19' move rapidly, the saddle 2 will move at a slow feeding speed, so the limit switch 23
is separated from the protruding piece 22 and becomes in a poor state, an abnormality is detected and the machine is stopped. Therefore, there is no chance of the machine colliding and breaking down. In addition, if an abnormality occurs in the static pressure bearing for moving the saddle during rapid saddle movement and the saddle stops moving forward, the limit switch 23
Since the limit switch 18 is activated before the machine is activated, an abnormality is detected and the machine is stopped. As a result of the grinding process, if a taper has occurred in the workpiece as measured by the sizing process 9, 9', the second electric motor 40' is rotated by a control device (not shown) according to the amount of taper and the direction of the taper. Instructions are given.

The rotation of the second electric motor 40 moves the shifter via the gear and the screw, and the crown gear 33 is moved by a predetermined amount in the axial direction. Detected. And Yamaba gear 33
The two helical gears 34, 34' meshing with each other are rotated in opposite directions, and the two nuts 19, 19' are moved in opposite directions. Therefore, the saddle 2 pressed against the end face of the nut by the pressing force of the cylinder 12 is inclined by the amount of relative movement of the nuts 19, 19'. At this time, the supply of pressure oil to the hydrostatic bearing (FIG. 5) that laterally supports the central portion of the sub-beam 4' has already been stopped, and the saddle 2 can be easily tilted. After tilting the saddle 2, grinding is performed in the same manner as described above, and the taper amount of the workpiece is removed by correction grinding. If the helical gears and helical gears used for the napper correction are all set at the same helix angle, the saddle 2 will be able to maintain its center point on the straight line connecting the tips of the two contact pieces 21 and 21'. It's annoying as a point.

However, by making the helical gears for moving the nut 19 and the helical gears for moving the nut 19' different in helix angle, it is possible to arbitrarily determine the position of the fixed point on the straight line. can. Therefore, it is also possible to select the fixed point at the end of the workpiece or outwardly therefrom so that no non-grinding parts occur on the workpiece when the saddle mirror is tilted. It is also possible to form the double helical gear into two helical gears inclined in the same direction. In addition to automatic operation of the entire machine as described above, when inching only the saddle 2 alone, it is dangerous if the saddle 2 moves at high speed, so the electromagnetic switching valve 48 for saddle inching and automatic feeding is Switched to dynamic feed side port.

The pressure fluid then passes through the speed regulating valve 50 and is sent into the rear chamber b of the cylinder 12 with its flow rate being restricted, and the saddle 2 moves forward at the slow speed adjusted by the speed regulating valve 50. In addition, although the above description has been made regarding the case where the sizing device is installed on the grinding machine, it is also possible to perform the same taper correction as described above even if the sizing device is installed outside the machine.

As detailed above, in the present invention, the saddle on which the headstock and zero stock are placed is tilted during taper correction, so that the workpiece can be supported between the headstock and the tailstock. Regardless of the method used, it is possible to tilt the workpiece relative to the grindstone axis without the problem of changing the relative position of the workpiece to other units on the table, as in the case of taper correction using a tailstock.

Furthermore, since the saddle is supported by a hydrostatic bearing against the bed, the saddle can be easily tilted at any position on the bed. Furthermore, since the saddle is tilted so that the double-helical gear slides in the axial direction, taper correction can be performed regardless of whether it is during grinding or not, making control easier and the structure simpler. Furthermore, by changing the helix angle of the double helical gear, the fixed point of the saddle inclination can be selected at any position on the straight line connecting the grinding positions.
Further, since the cutting control is controlled by two systems including an electric motor and a hydraulic cylinder, even if the driven nut runs out of control due to an abnormality in the electric motor control system, the hydraulic system can prevent an accident. It has many characteristics such as

[Brief explanation of drawings]

Fig. 1 is an overall front view of a multi-wheel grinder embodying the present invention, Fig. 2 is a diagram of the saddle drive mechanism, Fig. 3 is a pressure fluid circuit diagram for driving the saddle, and Fig. 4 is a diagram of the saddle sliding part. A sectional view of the hydrostatic bearing section, and FIG. 5 is a view taken along the line V-V in FIG. 2. 1...Bed, 2...Saddle, 6...
... Headstock, 7 ... Tailstock, 8 ...
・Workpiece, 12... Grinding wheel, 13... Cylinder, 20, 20'... Nut, 27... Yamaha gear, 42, 42'... Support Piece. Figure 1 Figure 4 Crab 5 Strategy 2 Figure 3

Claims (1)

[Claims] 1. A grinding wheel head that supports a grinding wheel and is fixed on a bed, and a headstock and a tailstock that surround the grinding wheel head in a horizontal plane, and that support a workpiece on the upper surface facing the grinding wheel. A saddle is movably supported by static pressure on the bed so that the workpiece can be moved toward or away from the grinding wheel, and the workpiece is moved toward or away from the grinding wheel. a first drive device for moving the saddle; a pair of nut members provided on both sides of the bed so as to be movable in the same direction as the saddle; and a pair of nut members for regulating the approach position of the workpiece toward the grindstone; a pair of abutting members provided at both ends of the saddle so as to abut against the end surfaces of the members; a second drive device for moving each of the nut members; and a drive mechanism of the second drive device provided midway in the axial direction. a pair of helical gears that are movable in the axial direction; a third drive device that moves the helical gears in the axial direction; and two gears respectively connected to the pair of nut members, and by moving the pair of helical gears in the axial direction, the two gears meshing with the helical gears are moved opposite to each other. The grinding machine is characterized in that the two nut members are rotated to make the positions of the two nut members different from the grinding wheel axis, and the saddle is tilted with respect to the grinding wheel axis to enable taper correction grinding of the workpiece. Taper correction device.