JPS6279961A - Grindstone correcting device for grinder - Google Patents

Abstract

PURPOSE:To properly correct a grindstone without being given with the influence due to the thermal deformation of the machine by installing a rest work quantity calculating means, dressing execution judging means, and a controller. CONSTITUTION:A motor 2 for revolution-driving a grindstone 1 is arranged on a table 3, and a work mounting base 5 is loaded onto a cutting-in base 6, and moved in reciprocation in the cutting-in direction and the escape direction of the grindstone 1 by the operation of a cutting-in feed motor 7. Further, a dresser 8 is loaded at waiting position onto one side of the cutting-in base 6 in ordinary case. and a further a controller 9, rest working quantity calculating device 10, dressing execution judging device 11, timer 12, etc. are arranged. When the product of the rest working quantity and the working time per work is less than the thermal deformation time on starting a machine, the grinding surface of the grindstone 1 is dressing-corrected by the dresser 8. Therefore, proper correction for the grindstone can be realized in a stable time at all times.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a grinding wheel correction device for a grinding machine.

(Prior Art) Conventionally, in a grinding machine that rotates and drives a grindstone 20 shown in FIG. 2 to grind the inner surface of a workpiece 22 held in a spindle head 21, for example, clogging and uneven wear of the grindstone 20 are eliminated. For this purpose, the dressing device 23 performs the dressing work,
In other words, the grindstone correction work is performed.

This grindstone correction work is performed between the rough grinding process and the finish grinding process for the workpiece 22 when the workpiece 22 is relatively large and the grinding allowance is large. is large, it is performed one or more times during the rough grinding process.

Further, when the workpieces 22 are small and the grinding allowance is small, skip dressing is performed in which the grindstone is corrected after the plurality of workpieces 22 are ground.

These grindstone correction work is done while rotating the grindstone 2o.
This is accomplished by reciprocating the dressing device 23 by a stroke amount indicated by the imaginary lines x and x, and by feeding the dressing device 23 by a predetermined depth of cut from the standby position indicated by the solid line to the dressing position indicated by the imaginary line Y.

On the other hand, the grinding machine has a main shaft motor 24 and a grindstone drive motor 25.
, and heat generation of drive parts such as the cutting feed motor 26,
Temperature rises due to rise in lubricating oil temperature.

In other words, the grinding machine goes through a temperature rising period from the starting point shown at a in Fig. 3 to the equilibrium point shown at b, then through a stable period until it reaches the stopping point shown at C, and then from the stopping point C to the recovery point shown at d. The temperature fluctuates due to the characteristic of returning to normal temperature after passing through a period of cooling down to .

Therefore, in the region of the temperature increase period from a to b above, thermal deformation occurs in the grinding machine due to thermal expansion, and the distance from the grinding surface of the grinding wheel 20 to the dressing device 23 in FIG. 2 changes depending on the amount of thermal deformation. fluctuate.

That is, the above distance is the smallest at the starting point a in FIG. 3, and is the temperature between the starting point a and the equilibrium point I.

It increases as the temperature rises and reaches its maximum at the equilibrium point.

Therefore, when the above-mentioned grindstone correction work is performed by skip dressing, the dressing device 2 shown by the solid line in FIG.
A difference corresponding to the amount of thermal deformation occurs at the standby position of No. 3.

However, since the dressing device 23 is fed by a fixed cutting feed needle, the dressing position changes as the standby position l of the dressing device 23 changes.

In other words, the dressing position of the dressing device 23 fed by cutting in the temperature rising period region is closer to the axis of the grindstone 20 than the dressing position of the dressing device 23 fed by cutting in the region of the stable period in FIG. As a result, there is a problem that the amount of dressing increases and proper correction work cannot be performed.

(Objective of the Invention) This invention was made to solve the above-mentioned conventional problems, and it avoids the grinding wheel correction work when the grinding machine is in the temperature rising period region, and constantly corrects the grinding wheel in the stable period region. It is an object of the present invention to provide a grinding wheel correction device for a grinding machine that allows work to be performed and corrects the grindstone properly.

(Structure of the Invention) In order to achieve the above object, a grinding wheel correction device for a grinding machine according to the present invention is a grinding wheel correction device for a grinding machine that performs processing on a plurality of pieces by one grinding wheel correction. It has a workpiece machining remaining amount calculation device that calculates the number of workpieces that can be processed until the next grindstone correction based on the number of workpieces processed immediately after correction.

Then, when the machine is stopped, the product of the number of remaining machining parts of the above calculation device and the machining time per work piece is calculated, and this product time is compared with the thermal deformation time when the machine is started, and the inset interval is small. a dressing execution determination device that sometimes outputs a dressing signal;
The present invention is configured to include a control device that corrects the grindstone based on the above-mentioned dress signal.

Therefore, the grindstone correction work is performed only during the thermal deformation time of the machine starting surface, that is, during the stable period that avoids the temperature rising period.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention.
In the figure, l is a grindstone which is rotationally driven by a drive motor 2. The drive motor 2 is arranged 42 on the table 3,
By a reciprocating mechanism such as a cylinder (not shown),
The grindstone 1 is reciprocated in the axial direction, that is, in the front-back direction.

Reference numeral 4 denotes a workpiece, which is rotatably set on a workpiece mount 5 disposed in front of the grindstone I by a rotation mechanism and a clamp mechanism (not shown), and corresponds to the grindstone I.

The workpiece mounting table 5 is placed on the cutting table 6, and is reciprocated in the cutting direction and the withdrawal direction of the grindstone 1 by the operation of the cutting feed motor 7.

In this embodiment, the grindstone 1 and the workpiece 4 are cylindrical, and the workpiece 4 is cylindrical.
The inner surface of the workpiece 4 is ground by the outer peripheral grinding surface. Reference numeral 8 denotes a dressing device, which is placed on one side of the cutting table 6 and is normally in a standby position shown by a solid line.

Reference numeral 9 denotes a control device, and the control device 9 outputs the numerical signal No. of the workpiece that can be machined from immediately after the correction of the grinding wheel l until immediately before the next correction, and the count signal MS of the actual number of machining times to the workpiece machining remaining amount calculating device. After the machining remaining amount of the workpiece 4 is calculated by the workpiece machining remaining amount calculation device 10, it is inputted to the dressing execution determining device 11 as a machining remaining amount value signal N.

When the machine, that is, the grinding machine is stopped, the dressing execution determination device 11 calculates the number of remaining machining amounts N inputted from the workpiece remaining machining amount calculating device 10 and the machining amount per workpiece 4 manually inputted from the timer device 12. While finding the product with the time signal T-,
This cumulative time NXT- is compared with the thermal deformation time T (corresponding to T in Fig. 3) at the time of starting the grinder, and when the cumulative time NXT- is smaller than the thermal deformation time T, a dressing signal is output to the control device 9. do.

In the above configuration, the inner surface of the workpiece 4 set on the workpiece mount 5 shown in FIG. Grinding is performed sequentially.

In this case, the grinding machine deforms due to thermal expansion for a period corresponding to the thermal deformation time T from the starting point a to the equilibrium point s in FIG.
The distance from the grinding surface of the grindstone l shown in FIG. 1 to the dressing device 8 gradually becomes shorter.

This amount of thermal deformation reaches its maximum at the equilibrium point in Figure 3, and -(Z
There is no fluctuation in the stable period from the equilibrium point to the stopping point C.

On the other hand, if the grinding machine in Figure 1 starts (a in Figure 3)
point), the preset number of workpieces 4, that is, the number of workpieces 4 that can be machined before the next correction of the grinding wheel I, is sent from the control device 9 as a numerical signal No. to the workpiece machining remaining amount calculation device 10. is input.

Further, in accordance with the progress of machining the workpiece 4, a count signal NS of the actual number of machining times is inputted to the workpiece machining remaining amount calculation device 10.

Workpiece 4 calculated by workpiece machining remaining amount calculation device IO
The remaining machining amount is input to the dressing execution determination device 11 as a remaining machining amount value signal N.

When the remaining amount of machining of the workpiece 4 reaches O, the grinding wheel l is rotated and moved back and forth according to the stroke amount indicated by the imaginary lines x and x, and the dressing device 8 is moved from the standby position indicated by the solid line to the imaginary line Y A correction work is performed to dress the grinding surface of the grinding wheel 1 by feeding the cut by a predetermined depth of cut to the dressing position shown by .After this correction work is completed, the ILF grinding machine is started, and the same operation as above is performed to dress the grinding surface of the grinding wheel 1. Work 4 is processed.

Assume that the grinding machine has now stopped after -day's operation. At this point, in the dressing execution determination device 11, the machining remaining amount value signal N input from the workpiece machining remaining amount calculation device 10,
The product of the machining time signal ↑ for each workpiece 4 inputted from the timer device 12 is calculated.

Then, the cumulative time NXT and the thermal deformation time T from the time when the grinder is started the next day until the thermal deformation is completed.
(Fig. 3), the integral time N x TM is the thermal deformation time T
If it is smaller than , that is, if the timing of the dressing is within the thermal deformation time T shown in FIG. 3, the dressing execution determination device 11 shown in FIG. , the grinding wheel I is dressed by the dressing device 8 in the same manner as described above.

As a result, dressing in the temperature rising period region from the starting point a to the equilibrium point s in FIG. 3 is avoided, and the grinding wheel 1 is appropriately corrected.

On the other hand, the cumulative time NXT when the grinding machine in Fig. 1 is stopped,
If T is larger than the thermal deformation time T, the timing of dressing will be carried out after the start of the next day's work, after the equilibrium point in Fig. 3 where the thermal deformation of the grinding machine is completed, so that the dressing will not be executed. No dress signal is output from the l'4 constant device 11 to the control device 9.

(Effects of the Invention) As explained below, according to the present invention, the number of remaining pressurized workpieces and the machining time per workpiece are calculated, and this cumulative time and thermal deformation at the time of machine startup are calculated. Because it is designed to dress when the cumulative time is small by comparing it with the time,
Since the dressing position of the dressing device is not affected by thermal deformations of the machine during the heating period, proper corrections are made to the grinding wheel.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention, FIG. 2 is a schematic plan view of a conventional system, and FIG. 3 is a temperature characteristic diagram during operation. 1... Grindstone, 8... Dressing device, 9... Control device. 10... Workpiece machining remaining amount calculating device, 11... Dressing execution determining device. 'l'1'1'A, L 11th; 71 U 1: Grinding wheel 8 Nidressing device 92 Control device 10: Workpiece machining remaining amount calculating device 11 Nidressing execution determination device

Claims (1)

[Claims] (1) A grinding wheel correction device for a grinding machine that performs processing on multiple pieces by one grindstone correction, and the remaining workpieces that can be processed until the next grindstone correction based on the number of processes immediately after the grindstone correction. A workpiece machining remaining amount calculation device that calculates the amount,
When the machine is stopped, the product of the remaining amount of machining and the machining time per workpiece is calculated by the arithmetic unit, and this product time is compared with the thermal deformation time when the machine is started, and when the product time is small, a dress signal is output. A grinding wheel correction device for a grinding machine, comprising: a dressing execution determination device that outputs an output; and a control device that corrects the grinding wheel based on the dressing signal.