JPH02212056A - Centerless grinder - Google Patents

Abstract

PURPOSE:To improve the surface toughness of a work without re-arrangement by providing a feeding device moving a work rest toward the space between an adjusting wheel and a grinding grindstone and relatively operating the adjusting wheel and/or cutting device of the grinding grindstone by a control device. CONSTITUTION:A blade 3 is ascended by a motor 29, a work W is brought into contact with the outer periphery of the adjusting wheel 2 and the apex face of the blade 3, the center is descended from the center line X connecting a grindstone center O1 to an adjusting wheel center O2 and a grindstone 1 is advanced by a motor 9 to execute rough grinding. The work W is pushed in by the force to be lifted with the blade 3 apex face as the reference by tangent force of the adjusting wheel 2 and the bent of the work W, the bent is ground, the whole body is ground in roundness and when the diameter of the work W becomes smaller, the center thereof is descended but kept constant by the ascent of the blade 3. In case of becoming a spark out, the grindstone 1 is retreated rapidly, changed over to the cutting speed of a finish grinding, the blade 3 is ascended, the center of the work W becomes at the upper part than the center line X, the finish grinding is performed, becoming a spark out and subjected to grinding at the position of the work W optimum respectively for rough and finish grinding.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a centerless grinding machine, and particularly to a centerless grinding machine for infeed grinding of a long workpiece.

``Conventional technology'' For example, when manufacturing a long and slender polished shaft by grinding,
Even if the material is bent in advance, it is difficult to remove the bend completely, and some bends remain. If you perform centerless grinding with normal infeed, the material will jump during grinding. Therefore, as shown in FIG. 6(a), the center OW of the workpiece W is r
J1=The workpiece W is supported by the blade 3 of the work rest by a lower than X, and the adjusting wheel 2 and/or grinding wheel 1 is lowered by
Rough grinding is performed by cutting in the direction toward the workpiece W. For example, if the diameter of the workpiece W is 25 m, the distance a which lowers the center OW of the workpiece W from the center line X is approximately 6 tm. After rough grinding, the adjusting wheel 2 and/or the grinding wheel 1 are moved back and the blade 3 of the work rest is moved so that the center OW of the work W is above the center line X by an amount b, as shown in FIG. 6(b). The workpiece W is then finished ground by cutting with the adjusting wheel 2 and/or the grinding wheel 1.

Alternatively, after the rough grinding described above, finish grinding is performed by leaving the blade 3 as is and reducing only the cutting speed.

``Problem to be solved by the invention'' The conventional device for advancing and retracting the work rest from the grinding wheel 1 and the adjustment wheel 2 is a screw feeding device, which was manually moved up and down after rough grinding and before moving on to finish grinding. . Therefore, it is necessary to stop the grinding machine, open the outer cover of the grinding machine, and operate the screw feeding device of the work rest, which is a hassle. To avoid this, we use a centerless grinder for rough grinding.
There was an inconvenience that two centerless grinders would be required if separated for finish grinding. In addition, it is possible to carry out only rough grinding of multiple workpieces W at once using a centerless grinding machine with a -base, and also perform finish grinding at once after the setup has been completed, but it is necessary to change the setup.
High-variety, medium-volume production is not appropriate.

Therefore, in the latter case, when grinding is carried out at a small cutting speed while the height of the grinding blade 3 is lowered, the workpiece W is adjusted with the grinding wheel 1 due to the cutting force applied by the adjustment wheel 2 to give rotation to the workpiece W1. A wedge-shaped grinding wheel 1 is lifted between two wheels.
Since it is pushed into the surface between the adjusting wheel 2 and the grinding wheel 2, a large cutting depth is applied by the grinding wheel 1, and even if the cutting speed is reduced, it is difficult to improve the dimensional accuracy and surface roughness of the workpiece W.

The purpose of the present invention is to solve the above-mentioned problems with the conventional centerless grinding machine using in-feed feeding, and to provide a centerless grinding machine that can improve the surface roughness of the workpiece without changing the setup. 0 "Means for Solving the Problems" The present invention provides a centerless grinding machine equipped with an adjustment wheel, a grinding wheel, and a work rest, which includes a feeding device that advances and retreats the work rest toward between the adjustment wheel and the grinding wheel, This is a centerless grinding machine characterized by being provided with a control device for operating a work rest feeding device, an adjusting wheel, and/or a cutting device of a grinding wheel in a related manner.

"Embodiments" Examples of the present invention will be described below with reference to the drawings. FIG. 1 is a front view. The grinding wheel 1 and the adjusting wheel 2 are arranged so that their outer circumferences face each other.

The grinding wheel 1 is attached to a grinding wheel main shaft 4, and the grinding wheel main shaft 4 is rotatably supported on a grinding wheel head 5 by a bearing (not shown).
Driven by an electric motor (not shown) in the direction of arrow A shown in the drawing,
It is now possible to The grindstone head 5 is guided in the horizontal direction by a guide 7 of the machine stand 6. The grindstone head 5 is connected to a cutting device. This cutting device consists of a screw feed device 8 and a feed motor 9. That is, the screw feed device 8 includes a grindstone feed nut 11 fixed to the grindstone head 5, and a feed screw 13 screwed into the feed nut 11 and supported by a bearing 12 so as not to move in the axial direction. The bearing 12 is the machine base 6
Fixed. The feed motor 9 is a pulse motor or D
It is a C motor, and its output shaft is the feed screw 1! is connected to.

The adjustment wheel 2 is fixed to an adjustment axle 14, and the adjustment axle 14 is rotatably supported by an adjustment chassis 15 through a bearing (not shown), and is driven in the direction of the arrow shown by an electric motor (not shown). The adjustment chassis 15 is guided in the horizontal direction by guides 16 of the machine chassis 6. 1sX connecting the center 01 of the grindstone main shaft 4 and the center 02 of the adjustment axle 14 coincides with the moving direction of the grindstone main shaft 4 and the adjustment axle 14. The adjustment chassis 15 is connected to the cutting device. This cutting device consists of a screw feed device 17 and a feed motor 18. That is, the screw feed device 17 has a feed nut 19 fixed to the adjustment chassis 15, and a bearing 2 which is screwed into the feed nut 19 and fixed in the axial direction. It consists of a feed screw 22 that is visually supported. The bearing 21 is fixed to the machine base 6. The feed motor 18 is a pulse motor or a DC motor, and its output shaft is connected to a feed screw 22.

The work rest 10 equipped with the upper end number ζ blade 3 is attached to the machine base 6
#This is provided. In the work rest 10, a housing 23 is fixed to the machine base 6, a sleeve 25 is slidably fitted into a cylindrical hole with a key groove 24 in the housing, and a key 26 fixed to the sleeve 25 is slidably fitted into the key groove 24. I'm doing it,
A screw feeding device is connected to the sleeve 25ζ.

The screw feeding device has an internal thread 2 cut in the center of the sleeve 25.
The output shaft of a feed motor 29 is connected to the feed screw 27, which is fixed to a bearing cover 28, in which the feed screw 27 screwed into the housing 23 is supported by a bearing cover 284. The piston rod of the hydraulic cylinder 31 fixed to the housing 23 is connected to the housing 26
The sleeve 25 is penetrated in the radial direction so that the sleeve 25 can be fixed by pressing the sleeve 25. Immediately after the sleeve 25 is stopped, it is fixed by the hydraulic cylinder 31, and the fixation is released immediately before the movement starts. The feed motor 29 is a pulse motor or a DC motor, and its output shaft is connected to the feed screw 27.

FIG. 2 is a partial plan view of FIG. 1. The adjustment axle 14 is slightly tilted with respect to the grinding wheel main shaft 4 in a vertical plane perpendicular to the plane of the paper including the adjustment axle 14 in FIG. 2, so that the workpiece W moves in the direction of the stopper δ2 during operation. Therefore, the axial position of the workpiece W is kept constant.

Grinding wheel 1, cutting device of adjustment wheel 2 and work rest 1
The feed motor 9 for the grinding wheel head, the feed motor 18 for the adjustment table, and the feed motor 29 for the work rest are operated by servo amplifiers 5g, 34. ! 5 to a control device &6 which performs the grinding cycle by CNC control or program control.

The centerless grinding machine described above is an adjustable type machine with a grinding wheel 1 and an adjustment wheel 2, but the grinding wheel 1 is fixed type,
It may be a machine with two fixed adjustment wheels. In this example, (1) the adjustment chassis 15 is fixed and only the grindstone feed motor 9 and the work rest feed motor 29 are controlled, and the work rest 1G is controlled continuously or by a combination of continuous and intermittent movements. A method of controlling the grindstone head 5.

(2) A method of controlling by adding the feed of the adjustment table feed motor 18 to the above (1) (depending on the size of the workpiece W and the grinding process).

Grinding is done in

Before explaining the overall operation, let me explain how the grinding wheel 1, adjusting wheel 2, and blade δ move. When the grindstone feed motor 9 is energized by the command 56 via the servo amplifier 33, the feed screw 16 rotates, the feed nut 11 is fed, and the grindstone head 5 is guided by the guide 7 to advance and retreat. The center 01 of the whetstone 1 moves on the center line X and advances and retreats.

When the work rest motor 29 is energized via the servo amplifier δ4 by a command from the control device &6, the feed screw 2,
7 rotates, and the sleeve 25 becomes the housing 2! A blade 6, which moves up and down in I and is removably attached to the sleeve 25, advances and retreats between the opposing surfaces of the outer periphery of the grinding wheel 1 and the adjusting wheel 2.

When the adjustment chassis feed motor 18 is energized via the servo amplifier 35 in response to a command from the control device 36, the feed screw 22 rotates, the feed nut 19 is sent, and the adjustment chassis 15 is guided by the guide 16 to move forward and backward. However, the center 02 of the adjusting wheel 2 moves on the center line X and moves back and forth.

The control device 36 is controlled by CNC control or program control.
Feed motor 9 for grinding wheelhead, feed motor 1゛8 for adjustment wheel base,
The work rest circumferential speed motor 29 is operated in conjunction with each other, and the respective feed motors move the grinding wheel 1, adjusting wheel 2, and blade 6 forward and backward in conjunction with each other. 2. Since the blade 6 moves, the following explanation is based on the grinding wheel 1.
, the movement of the adjustment wheel 2, the blade 3, and the workpiece W will be explained, and the explanation related to the control device 66 will be omitted.

First, a case will be described in which the above-mentioned adjustment chassis 15 is fixed and the grindstone 1 and blade 6 are operated in conjunction with each other. Such operations are performed when the diameter of the workpiece W is not large and the machining allowance and curvature of the workpiece W are large.

FIG. 3 is a time chart in which the horizontal axis shows time and the vertical axis shows the positions of the grindstone 1 and blade 6.

At time tOl, the blade 6 is raised and stopped at the blade position at time t1 in FIG. At this blade position, as shown in FIG. 4(a), the workpiece W has a blade δ.
The slope of the top surface of W is in contact with the outer periphery of the adjusting wheel 2, and the workpiece W
The center OW is located a distance a below the center line X connecting the grindstone center 01 and the adjustment wheel center 02. For example, when the diameter of the workpiece W is 20118, a = 6 tar. At time t1, the grinding wheel 1, which is away from the workpiece W as shown in FIG. 4(a), is energized to advance rapidly and reaches the grinding wheel position shown in FIG. 6 at time t2J, and the cutting feed number for rough grinding is changed. . This grindstone position A is a position where the grindstone 1 and the workpiece W are close to each other. Shortly after time t2, the grinding wheel 1 turns to the workpiece W.
is cut into. From this point on, the blade 3 begins to rise from the blade position L (=K) force 1 in FIG. 3 in conjunction with the grinding action. As shown in FIG. 4(a), the grindstone 1 rotates in the direction of arrow A, the adjustment wheel 2 rotates in the direction of arrow C, and the workpiece W rotates in the direction of arrow C. From time t2 to tδ is rough grinding, and by this grinding, the workpiece W is lifted by the force of the adjustment wheel 2 to lift the workpiece W with the tangential force that rotates the workpiece W, and due to irregularities such as bending of the workpiece W. The workpiece W tends to be pushed into the opposing surfaces of the grinding wheel 1 and the adjustment wheel 2 by the force that lifts the top surface of the blade as a reference, and the convex part of the workpiece W is first ground from the center due to bending or irregularity. Then, the whole thing is ground into a perfect circle. As the diameter of the workpiece W decreases due to grinding, the center OW of the workpiece W will move downward, and the distance a between the workpiece center OW and the center lsX connecting the grinding wheel center 01 and the adjusting wheel center 02 will increase. Due to the rise of 3,
is kept constant. Then, at time t6, the grindstone 1 and the blade 6 stop moving (the grindstone 1 is at the grindstone position B in FIG. 6, and the blade 3 is at the blade position M in FIG. 3). When sparking out from c- and ending after the time tag,
The grindstone 1 rapidly retreats from the grindstone position C (=B) in FIG. 6 at time tS, and rapidly advances at the grindstone position shown in FIG. 6 at time t6. At the grindstone position E in Fig. δ, the cutting speed is switched to the finish grinding speed. On the other hand, time t4. The blade 6 rapidly rises from the blade position N in FIG. 6 and reaches the blade position Q in FIG. 3 at time t6. The state at time t6 is the fourth
In the figure, the center OW of the workpiece W is located above the center aX connecting the grinding wheel center 01 and the adjusting wheel center 02 by a distance b. It is a value.

At time t6, the blade δ stops, and soon the grinding wheel 1
is cut into the workpiece W. This cutting speed is for finish grinding and is slower than that for rough grinding.

At time t7, the grindstone 1 stops moving forward at the grindstone position F in the diagram @δ. The blade 3 remains stopped (blade position R (=Q) in FIG. 6). Spark-out is performed from time t7 to t8, and at time t8, the grindstone 1 and blade 6 rapidly retreat from the grindstone position G (=F) and the blade position 8 (=R) in FIG. (time t9)
). Through the above steps, rough grinding and finish grinding are performed continuously.
Each of the workpieces W is ground at a position suitable for rough grinding, so that the machining time of the workpiece W is short and good accuracy is obtained.

Depending on the diameter, bending, and grinding allowance of the workpiece W (when the bending and grinding allowance are small), the position of the blade 6 from time t1 to time t4 in the above may be changed to the blade position Kf in FIG.
) At a constant position between h and M, the blade 6 is rapidly moved from time t4 to time t6, and at time 164ζ, the blade 6 is
Blade position Q in the figure.

The state shown in FIG. 4(b) can be achieved.

Next, when the diameter of the workpiece W is large and the grinding allowance is large (if the straightness and surface roughness of the material are not good), the adjusting wheel 2 is moved back and forth. If the workpiece is ground using the above method, as shown in Fig. 5 (a) As shown in °, even if the workpiece center OW is lower than the center line X connecting the grindstone center 01 and the adjustment wheel center 02 by a distance a when grinding starts
By raising the blade 6, the distance a between the workpiece center OW and the center line X is maintained.

However, the initial contact point P1 between the workpiece W and the blade B becomes P2 as shown in Figure 5). Contact points P1 and P2 are separated by a distance C in the horizontal direction. When this distance C increases, the supporting conditions of the workpiece W change, the slippage in the action of rotating the workpiece W of the adjustment wheel 2 changes, and the workpiece W leaves the desired rotational speed tolerance range. A case may occur where the blade 3 is ground by the grinding wheel 1. Therefore, the position of the adjusting wheel 2 is changed as shown by line H-I-J in FIG. That is, shortly after time t2, the grinding wheel 1 touches the workpiece W.
When the wheel begins to act on the wheel, the adjustment wheel 2, which was at the adjustment wheel position H in FIG.
, and keep the horizontal position of the contact point between the blade 3 and the workpiece W at almost the same position, and for a time t.
The adjusting wheel 2 is stopped at the adjusting wheel position I shown in FIG. 3, where the spark-out occurs in step 3, and the blade 6 is stopped at the blade position M shown in FIG. 3. In other respects, this method is the same as the first grinding method described above.

〔Effect of the invention〕

As described above, the present invention has a configuration in which the blade moves forward and backward toward the opposing surface of the grinding wheel and the adjustment wheel, and the movement of the grinding wheel and/or adjustment wheel and the movement of the blade can be performed in conjunction with each other. (1) Rough grinding , finish grinding can be continued, and the contact position of the blade and workpiece, the contact position of the adjustment wheel and workpiece, and the position of action of the grinding wheel surface on the workpiece can be adjusted sequentially depending on the grinding condition, so the optimal Centerless grinding is possible (2) The workpiece can be placed at an optimal position depending on the bending of the workpiece, grinding allowance, diameter of the workpiece, etc., resulting in faster grinding time and excellent grinding accuracy.

[Brief explanation of the drawing]

FIG. 1 is a front view of the embodiment of the present invention, FIG. 2 is a partial plan view of FIG. 1, FIG. 3 is a time chart showing an example of the operation of the embodiment of FIG. 1, and FIG. 4(a) , Fig. 4(b), Fig. 5(a)
), FIG. 5(b) is a front view for explaining the action, and FIG.
FIG. 6(a) and FIG. 6(b) are explanatory diagrams of a conventional example. 1. Grinding wheel 2. Adjustment wheel 6. Blade 4.
・Whetstone spindle 5・・Whetstone stand 6・Machine stand 7・・Guide 8
...Screw feeding device?・・Feed motor 10・・Work rest 11・Wheelhead feed nut 12・・Bearing 16
・・Feed screw 14・・Adjustment axle 15・・Adjustment chassis
16...Guide 17...Screw feeding device 18...Motor
19...Feed nut 21Φ bearing 22...Feed screw
26..Housing 24..Keyway 25..Sleeve 25a.Female thread 26..Key 27..Feed screw 28..Bearing cover 29..Feed motor 31..Hydraulic cylinder 62..Stopper MB, 54, 55.・Servo amplifier s6...control device. Patent applicant Nippei Toyama Co., Ltd.

Claims (1)

[Claims] 1. In a centerless grinding machine equipped with an adjusting wheel, a grinding wheel, and a work rest, a feeding device for moving the work rest forward and backward between the adjusting wheel and the grinding wheel is provided, and the feeding device of the work rest, the adjusting wheel, and/or the grinding wheel A centerless grinding machine characterized by being provided with a control device for operating a cutting device in conjunction with the cutting device.