JPS6246302B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a centerless grinding device capable of correcting the cylindricity of a workpiece in a centerless grinder.

Figure 1 is a schematic diagram illustrating a conventionally used centerless grinder, and Figure 2 is a diagram showing the lines in Figure 1.
It is a sectional view along AA. If the workpiece 2 is subjected to centerless grinding using this grinder, and its cylindricity is measured using a high-precision micrometer, etc., and it is found that the required specifications are not met, the following corrections will be made. Ta. That is, the fixing bolts 7a, 7b, 7c, 7 fixing the adjustment chassis 5 to the grinding machine main body 1
d, and by rotating the adjusting chassis turning bolt 6, the adjusting chassis 5 is rotated in either direction shown by the arrow in FIG. 2 by an amount corresponding to the desired cylindricity correction amount, and then the fixing bolt 7a is ~7d was tightened.
However, during this tightening, the adjusting chassis 5 always makes some slight movement in either direction and moves from the corrected position given by the pivot bolt 6. In order to know the amount of movement and thus the adjusted state of the adjustment chassis 5, it is necessary to grind the dummy and measure its cylindricity. If the amount of movement when tightening the fixing bolt is within the swivel range of the adjustment axle rotation device described later, it can be corrected, but if it is outside the range, you will have to start over by loosening the fixing bolt again. It was impossible. In any case, the process of grinding the dummy and measuring it with a high-quality micrometer or the like is required at least once, which takes time and reduces efficiency. In particular, when the required specification for cylindricity is 10 μm or less, the number of corrections required to satisfy the required specification increases, resulting in a significant drop in efficiency.

In addition, in Figures 1 and 2, 3 is a grinding wheel, 4 is an adjustment wheel, 8 is a blade fixing stand, 9 is a blade, 1
0 is an adjustment chassis feed handle, 41a and 41b are adjustment axle bearings, 42 is a hydraulic adjustment device, and 14 is a stopper. 3 and 4 are schematic diagrams of the adjusting axle turning device, and oil in an oil tank 420 is supplied to the hydraulic adjusting device 42 by an oil pump 421. The hydraulic pressure supplied to the throttle resistors 422c and 422d changes relatively depending on the direction and amount of rotation of the pulse motor 44, and the adjustment axle 43 moves along the line in FIG.
Turn like bb' or cc'. Note that the aperture resistance 42
The hydraulic pressure supplied to 2a and 422b is not affected by the direction and amount of rotation of the pulse motor 44, and functions to maintain the rigidity of the adjustment axle 43.

The object of the present invention is to eliminate the drawbacks of the prior art mentioned above,
To provide a centerless grinding device capable of efficiently and accurately correcting cylindricity.

That is, in order to achieve the above object, the present invention has the following features:
A grinding wheel that is rotationally driven; a blade stand that is equipped with a blade that supports a workpiece; and an adjustment wheel that is installed opposite to the grindstone and that is rotationally driven to press the workpiece against the grindstone. , a pair of hydraulic bearings that rotatably support both ends of the adjustment wheel and are configured to be able to be slightly displaced by hydraulic pressure supplied via a throttle resistance, and adjust the hydraulic pressure supplied to each hydraulic bearing. a hydraulic adjustment device, an adjustment vehicle on which the hydraulic bearing is installed and configured to be able to rotate in a horizontal plane with respect to the grinding wheel, and the adjustment vehicle is sent and the workpiece is ground by the adjustment wheel. In a centerless grinding machine equipped with a feeding means for pressing against a grindstone for centerless grinding, a post-process inspection device installed to measure the cylindricity of a workpiece subjected to centerless grinding in the centerless grinding machine. a rough turning means for roughly turning the adjusting chassis based on power from a turning drive source; a fixing means for fixing the adjusting chassis after rough turning adjustment of the adjusting chassis by the rough turning means; A precision position detector that accurately detects the rough turning amount of the chassis and a target turning amount H ₀ =αΔd= corresponding to the cylindricity correction amount based on the cylindricity of the workpiece measured by the above-mentioned post-process inspection device. α(D ₁ −
D ₂ ) (However, D ₁ is the diameter of the workpiece at the first post-process detection point, D ₂ is the diameter of the workpiece at the second post-process detection point. Also, α is the diameter of the workpiece at the first post-process detection point. α is the diameter of the workpiece at the first post-process detection point. This is a coefficient determined by the distance to the precision position detector and the measurement distance of the post-process inspection device of the workpiece.), and the amount of rotation of the adjustment platform detected by the precision position detector is The rough turning means is operated to coarsely adjust the adjusting chassis so that the calculated target turning amount H is ₀ , and the adjusting chassis is fixed by the fixing means, and then the position detected by the precise position detector is Error between the rough turning amount H ₁ of the adjustment chassis and the above target turning amount H ₀ (H _{0
H 2 =} β( _{H 0}
−H ₁ ) (where β is a coefficient determined by the distance between the hydraulic bearings and the distance from the center of rotation of the adjustment wheel to the post-process detection point of the workpiece.) This is a centerless grinding device characterized by the following features:

FIG. 5 is a schematic diagram of a centerless grinding machine equipped with the apparatus of the present invention, FIG. 6 is a sectional view taken along the line C--C in FIG. 5, and FIG. 7 is a block diagram of FIG.

A scanning head of a precision position detector 11 (preferably, for example, a linear encoder from Nippon Kogaku Co., Ltd. or a Minirod 300 from Johannes Heidenheim AG of West Germany) is attached to the centerless grinding machine 1.
A pulse scale read by this scanning head is fixed to the adjustment chassis 5. 12 counts and displays the pulses output from the scanning head.
This counter generates a BCD output and is connected to the arithmetic processor 13. The processor 13 is preferably a microcomputer or a minicomputer, and includes a data reading routine from the counter 12 as well as a cylindricity correction routine and a memory circuit to calculate the cylindricity of the workpiece 2' after the grinding cycle. Arithmetic processing for cylindricity correction is performed on the measured value from the post-process measuring device 15 that measures the cylindricity and the measured value from the counter 12. The measuring device 15 has measuring heads 152a, 152a, 152a, 151b equipped with probes 151a, 151b at the tips and a transformer inside.
52b, and amplifiers 153a and 153b that convert the amount of displacement output from the measurement head into an amount of electricity,
Converts the amount of electricity output from the amplifier to BCD
It consists of AD converters 154a and 154b. The correction pulse signal from the arithmetic processor 13 is sent to the respective pulse motor drive devices 45 and 47 that control the rotational speed and rotation direction of the pulse motors 44 and 46, and also to the hydraulic cylinder drive device 49 that controls the hydraulic cylinder 48. sent to. The pulse motor 44 is connected to a hydraulic pressure adjustment device 42 that adjusts the hydraulic pressure sent to the adjustment axle 43 and adjustment axle bearings 41a, 41b (both collectively referred to as the adjustment axle rotation device) as shown in FIGS. 3 and 4. connected. A pulse motor 46 is shown connected to and rotates the adjustment chassis pivot bolt 6. The pulse motor 46 and the adjustment chassis turning bolt 6 constitute a rough turning means for roughly turning the adjustment chassis based on the power from the turning drive source. It is clear that other types of rough turning means may also be used. Hydraulic cylinder 48 is shown to tighten and loosen fixing bolts or pins 7e-7h. These hydraulic cylinders 48 and fixing bolts or pins 7e to 7h are releasable so that the adjustment chassis can be roughly adjusted, and further constitute fixing means for fixing the adjustment chassis. It is clear that other types of fastening means are also possible.

As a result of measuring the machined workpiece 2' with the calibrated post-process inspection device 15, if the required cylindricity correction amount is greater than the rotation range of the adjustment axle rotation device, the adjustment chassis 5 is groundless. Board body 1
The fixing pins 7e to 7h that are fixed to are loosened using a hydraulic cylinder 48 controlled by the arithmetic processor 13 via a hydraulic cylinder drive device 49, and the adjustment chassis 5 is made rotatable, and the pulse motor 46 The adjusting chassis turning bolt 6 is rotated by a desired amount in a desired direction. The relationship between the amount of cylindricity correction obtained for the workpiece and the amount of rotation of the adjustment chassis changes depending on the span length of the adjustment axle, the grinding position of the workpiece, the adjustment axle rotation method, etc., so please measure it in advance. It is necessary to incorporate it into the arithmetic processor.

When the adjusting chassis 5 rotates, the pulse scale fixed to the adjusting chassis also moves, and a pulse signal is generated by the scanning head fixed to the centerless grinding machine body by an amount corresponding to the amount of movement. The pulse signal is displayed on the counter 12 and sent to the arithmetic processor 13 as a BCD output. When the amount of movement matches the target value, the rotation of the adjustment chassis 5 is stopped, and the hydraulic cylinder 48 tightens the fixing pins 7e to 7h to fix the adjustment chassis 5 to the centerless grinding machine main body 1. When the fixing pins 7e to 7h are tightened, the adjustment chassis 5 moves slightly and tends to be fixed at a position different from the target value. The position after this fine movement is displayed on the counter 12, so it is read by the arithmetic processor 13, and the amount of fine movement is calculated by comparing it with the previously stored target value. A pulse signal is supplied to the pulse motor drive 45 to drive the pulse motor 44 connected to the hydraulic adjustment device 42 of the adjusting axle swivel device. Pulse motor 44
The hydraulic pressure supplied to the throttle resistors 422c and 422d shown in FIG. 4 changes depending on the direction and amount of rotation of the adjusting axle 43, causing the adjustment axle 43 to turn slightly, and finally a turning position that matches the target value is obtained.

If the diameter at one end of the workpiece 2', for example, the position of the measuring tip 151a, is _D1 , and the diameter at the other end, for example, the measuring tip 151b, is _D2 , then the cylindricity correction amount is Δd= _D1 - _D2 ...(1) The amount of rotation of the adjustment chassis required to achieve this correction is expressed as H ₀ = α (D ₁ − D ₂ ), where α is the adjustment chassis rotation coefficient. ...(2) This becomes the target value of the precision position detector 11. Since the value of the precision position detector in the state in which the adjustment chassis is fixed, that is, in the state in which the coarse adjustment has been completed, does not normally match the target value, fine adjustment is performed using the adjustment axle, that is, H ₂ = β (H ₀ −H ₁ ) ...(3) Here, H ₁ : Value of the precision position detector when the adjustment chassis is fixed H ₂ : Adjustment axle rotation amount β : Adjustment axle conversion coefficient The arithmetic processor 13 calculates D ₁ , D ₂ It stores data such as, performs arithmetic processing on each equation, and provides a desired output.

As described above, according to the present invention, depending on the cylindricity measurement value obtained by the post-process inspection device,
The adjustment chassis is rotated by an amount equivalent to the required cylindricity correction amount, and the position after the rotation is completed and the position when the adjustment chassis is fixed by the adjustment chassis fixing device are detected by the precision position detection device, and both Since the adjustment axle is rotated by an amount corresponding to the difference in position, correction of cylindricity of about 5 to 10 μm is performed very efficiently and accurately to about 0.2 μm.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a conventional centerless grinding machine, Fig. 2 is a sectional view taken along line A-A in Fig. 1, Figs. 3 and 4 are explanatory diagrams of a conventional adjustment axle turning device, and Fig. 3 B of
-B sectional view is shown in FIG. FIG. 5 is a schematic diagram showing a centerless grinding machine equipped with a correction device according to the present invention, FIG. 6 is a sectional view taken along the line CC in FIG. 5, and FIG. 7 is a block diagram of the correction device. 1: Centerless grinder body, 2, 2' workpiece,
4: Adjustment wheel, 5: Adjustment chassis, 6: Adjustment chassis rotation bolt, 7a to 7h: Adjustment chassis fixing pin (bolt), 11: Precision position detector, 12: Counter,
13: Arithmetic processor, 14: Stopper, 15: Post process inspection device, 41a, 41b: Adjustment axle bearing, 43: Adjustment axle, 44, 46: Pulse motor, 42: Hydraulic pressure adjustment device.

Claims (1)

[Claims] 1. A grinding wheel that is rotationally driven, a blade stand equipped with a blade that supports a workpiece, and an adjusting wheel that is installed opposite to the grinding wheel and that is rotationally driven to press the workpiece against the grinding wheel. and a pair of hydraulic bearings that rotatably support both ends of the adjustment wheel and are configured to be able to be slightly displaced by hydraulic pressure supplied via a throttle resistance, and hydraulic pressure supplied to each hydraulic bearing. A hydraulic adjustment device to be adjusted, an adjustment vehicle on which the hydraulic bearing is installed and configured to be able to rotate in a horizontal plane with respect to the grinding wheel, and the adjustment vehicle is sent and the workpiece is adjusted by the adjustment wheel. A post-process inspection installed to measure the cylindricity of a workpiece subjected to centerless grinding in the centerless grinder, in a centerless grinder equipped with a feeding means that presses against a grinding wheel and performs centerless grinding. a rough turning means for roughly turning the adjusting chassis based on power from a turning drive source; a fixing means for fixing the adjusting chassis after rough turning adjustment of the adjusting chassis by the rough turning means; The target rotation amount H ₀ corresponding to the cylindricity correction amount is calculated based on the cylindricity of the workpiece measured by the precision position detector that accurately detects the rough rotation amount of the adjustment vehicle and the post-process inspection device mentioned above. Then, the rough turning means is operated to coarsely adjust the adjusting chassis so that the turning amount of the adjusting chassis detected by the precision position detector becomes the calculated target turning amount H ₀ , and the fixing means The adjustment chassis is fixed, and then the rough turning amount H ₁ of the adjustment chassis detected by the precision position detector and the target turning amount H ₀ are determined.
and an arithmetic and control device that calculates the error (H ₀ − _{H 1} ) between the two and controls and adjusts the hydraulic adjustment device so as to eliminate the calculated error, thereby precisely adjusting the adjustment wheel relative to the hydraulic bearing. A centerless grinding device characterized by: