JPH0428501B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a grinding method capable of performing oscillation cutting, traverse grinding, or traverse oscillation grinding on a grindstone in an internal grinding machine.

Prior Art In conventional internal grinding machines, the drive devices for oscillation and traverse are separate units, and oscillation is usually performed by rotating a cam via a drive ball screw, and traverse is performed by rotating a ball screw in the correct direction. This was done by reversing it. Although this method is a reliable method and poses no particular problem when used exclusively, it is expensive because the devices are separate, and adjustment of the oscillation amount is difficult because it requires replacing the cam. In addition, there is an inconvenience that a fixed position stopping mechanism is required for table positioning and grinding. In the case of JP-A No. 59-48489, 1
Although rapid axial forwarding, slow forwarding, and high-speed reciprocating motion of the grinding wheel in the axial direction are possible using multiple servo motors and screw actuation means, there is no idea of combining high-speed reciprocating motion with other motions, and efficient grinding cannot be achieved.

In addition, in the method disclosed in JP-A-59-90255, it is possible to combine traverse feed with oscillation feed of the grinding wheel shaft, but oscillation moves the grindstone using a grindstone rotation motor, and traverse moves the table using a hydraulic cylinder. Since two driving sources are used to move and combine the movements, it is impossible to perform both with one driving source, and the oscillation width cannot be changed.

Purpose Therefore, this invention was made in view of the above,
The purpose of the present invention is to provide a grinding method that has a simplified structure by reducing the number of parts, allows the amount of oscillation to be easily adjusted by input, and allows synthetic movement of traverse and oscillation to be performed, thereby improving operability and grinding efficiency. It is.

Solution: It has a processing program such as an NC tape in which the distinction between traverse grinding, oscillation grinding, and traverse oscillation cutting, the traverse grinding start position, the grinding width, the oscillation cutting start position, etc. is written, and the It is equipped with a Z-axis function generator that issues a Z-axis command and an oscillation function generator that issues an oscillation command. When the command is a Z-axis traverse grinding command, the Z-axis function is generated based on data such as an NC tape. The machine outputs commands for the traverse grinding start position and traverse grinding width in the Z-axis direction of the grindstone, and the Z-axis servo motor drives the feed screw to perform traverse grinding. When the command is a Z-axis oscillation grinding command, Based on data such as NC tape, the Z-axis function generator outputs a command for the oscillation cutting start position in the Z-axis direction of the grinding wheel, and the oscillation cutting width and oscillation cutting width input from the oscillation condition input device and stored in the data memory are output. An oscillation function generator outputs a sinusoidal command based on data on the number of oscillations per unit time, and the servo motor drives the feed screw using the two outputs to perform oscillation cutting, and when the command is Z. When an axis traverse oscillation cutting command is issued, the traverse oscillation cutting start position and traverse grinding width command in the Z-axis direction of the grinding wheel are output from the Z-axis function generator based on the data on the NC tape, etc. Based on the data of the oscillation cutting width and the number of oscillations per unit time input from the condition input device and stored in the data memory, a sine wave-like command is output from the oscillation function generator, and the two outputs are synthesized in the synthesis circuit. The servo motor drives the feed screw to perform traverse oscillation cutting, and one Z-axis servo motor drives and controls one feed screw to perform traverse grinding, oscillation cutting, or traverse oscillation cutting. This is a grinding method that can perform either of the following.

Embodiments Hereinafter, embodiments of the present invention will be described based on the drawings.

A headstock 1 is mounted on the bed of a well-known internal grinding machine so as to be movable and controllable in the X-axis direction, and a main shaft having a chuck 2 fitted on the tip of the headstock 1 is rotatably supported. Further, a table 3 movable in the Z-axis direction is placed on the bed, and a grindstone 4 is fitted onto this table 3, and a grindstone 4 rotatably supports an inner grinding shaft 5 having an axis in the Z-axis direction. A stand 6 is mounted so as to be slidable in the Z-axis direction, and the grindstone head 6 is screwed into a ball screw 8 horizontally supported on the table 3 through a female thread 7 provided on the lower side. ball screw 8
is connected to a servo motor 10 provided on the table 3 via a shaft joint 9, and this servo motor 10
The ball screw 8 is operated in response to a command from an NC tape, etc., on which the NC device's distinction between traverse grinding, oscillation grinding, traverse oscillation grinding, traverse grinding start position, grinding width, oscillation grinding start position, etc. is written. By repeating forward rotation and then reverse rotation several times with the grinding width tight, or by repeating forward and reverse rotation frequently,
Have the patient perform traverse, otsillation, or a combination thereof. The NC device is equipped with a decoder 12 that decodes the data recorded on the machining program tape 11, and the drive device includes a Z-axis function generator 13 that commands the Z-axis position by a Z-axis traverse grinding command, and a Z-axis a comparator amplifier 14 that compares the command position and position feedback amount, amplifies the difference, and outputs a command speed; and a servo amplifier that inputs this output command speed and speed feedback amount to drive the Z-axis servo motor 10. A position sensor 17 is provided which is coupled to the servo motor 15 and the servo motor 10 and provides position and velocity feedback.

In addition to the above, the present invention provides an operation panel 20 for inputting the oscillation grinding width and the number of oscillations per minute into the NC device, a data memory 21 for storing data from the panel, and a decoder 12.
an oscillation function generator 2 which outputs an oscillation command based on the data in the data memory 21 upon receiving an oscillation grinding command from the
2. A synthesis circuit 23 is added which outputs a Z-axis synthesis command based on the output of the oscillation function generator 22 and the output of the Z-axis function generator 13.

In the present invention configured in this way, when the grinding position and the grinding width are determined by the workpiece W,
A machining program and position data necessary for this purpose are given to the tape 11. In addition, the conditions necessary for oscillation, such as the oscillation grinding width and the number of oscillations, are manually input into the operation panel 20, and the data is stored in the data memory 2.
1 is stored. A workpiece W is attached to the chuck 2. Based on the machining command, the decoder 12 reads commands and data from the tape (or input from the MD 1), and when a Z-axis movement command is given, the Z-axis is moved to the oscillation/grinding start position based on the accompanying data given to the tape. For example, the command position of
200mm is output by the Z-axis function generator 13. Further, when an oscillation grinding command is given from the decoder 12, a Z-axis oscillation command is given such that sinusoidal oscillation is performed based on data stored in the data memory 21, such as the oscillation grinding width, for example, 50 mm, and the number of oscillations, for example, 10 times per minute. is output from the oscillation function generator 22. A command obtained by combining these two outputs, ie, the Z-axis command position and the oscillation command, is input to the comparator amplifier 14. This input is compared with the position feedback amount from the position detector 17, the difference is found, and the command speed corresponding to the error amount is inputted to the servo amplifier 15, and the Z-axis servo motor is 10 to rotate the ball screw 8 to advance the grindstone 4 by 200 mm toward the chuck 2 in the Z-axis direction, and perform 10 oscillations per minute with an oscillation grinding width of 50 mm. During this time, the necessary cutting feed is given to the headstock 1. It is something that can be done.
Oscillation After traverse oscillation or traverse oscillation can be arbitrarily selected depending on the timing at which the oscillation grinding command is given.

Effects As detailed above, this invention combines a circuit for inputting and storing the oscillation grinding width and the number of oscillations in an NC internal grinding machine, an oscillation function generator, a sinusoidal oscillation command, and a traverse Z-axis command. With the addition of a composite circuit, either traverse grinding, oscillation grinding, or traverse oscillation grinding can be performed using one servo motor and one feed screw for driving the Z-axis of the grindstone head. The driving device is simplified and costs are reduced, maintenance is easy, and the amount and position of oscillation and the number of oscillations can be arbitrarily and easily adjusted.The number of oscillations can be increased during rough grinding and decreased during finish grinding. This improves grinding efficiency. Further, it has the characteristics that a fixed position stopping mechanism is not required during table positioning and grinding, and speed-up is possible.

[Brief explanation of drawings]

FIG. 1 is a drive diagram of the grindstone head, and FIG. 2 is a diagram showing a block diagram of the control of the whetstone head. 6... Grindstone head, 8... Ball screw, 10... Servo motor, 20... Operation panel, 21... Data memory, 22... Oscillation function generator, 23... Synthesis circuit.

Claims (1)

[Claims] 1. The distinction between traverse grinding, oscillation grinding, or traverse oscillation grinding, the traverse grinding start position, grinding width, oscillation grinding start position, etc. are written.
It has a processing program for NC tape, etc., and is equipped with a Z-axis function generator that issues a Z-axis command based on the above distinction, and an oscillation function generator that issues an oscillation command, and when the command is a Z-axis traverse grinding command. outputs commands for the traverse grinding start position and traverse grinding width in the Z-axis direction of the grinding wheel from the Z-axis function generator based on data from the NC tape, etc., and drives the feed screw with the Z-axis servo motor to perform traverse grinding. When the command is a Z-axis oscillation grinding command, the Z-axis function generator outputs a command for the oscillation grinding start position of the grinding wheel in the Z-axis direction based on the data on the NC tape, etc., and also inputs oscillation conditions. Based on the data of the oscillation grinding width and the number of oscillations per unit time input from the device and stored in the data memory, the oscillation function generator outputs a sinusoidal command, and the two outputs cause the servo motor to control the feed. Oscillation grinding is performed by driving the screw, and when the command is a Z-axis traverse oscillation grinding command, the Z-axis function generator performs traverse oscillation grinding of the grinding wheel in the Z-axis direction based on the data on the NC tape, etc. It outputs commands for the start position and traverse grinding width, and also generates a sinusoidal command from the oscillation function generator based on the data of the oscillation grinding width and the number of oscillations per unit time that are input from the oscillation condition input device and stored in the data memory. The two outputs are combined in a synthesis circuit, and the servo motor drives the feed screw to perform traverse oscillation grinding, and one Z-axis servo motor drives and controls one feed screw. A grinding method characterized in that any one of traverse grinding, oscillation grinding, or traverse oscillation cutting can be performed.