JP3669075B2 - Coolant supply device for grinding machine - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a coolant supply device for supplying coolant to a contact point between a grinding wheel and a crankpin in a grinding machine for grinding a crankpin of a crankshaft.
[0002]
[Prior art]
In general, in a grinding machine, coolant is supplied to the contact point (grinding point) between the workpiece and the grinding wheel to generate heat and remove chips from grinding, thereby preventing grinding burn of the workpiece. I was doing.
When performing cylindrical grinding, the aforementioned contact point is a fixed position of the grinding wheel, and the coolant nozzle for supplying the coolant is also fixed because it is only necessary to supply the coolant to this fixed position.
[0003]
[Problems to be solved by the invention]
However, as disclosed in Japanese Patent Application Laid-Open No. 53-115986, the journal of the crankshaft is held on the main shaft, and when the journal is rotated on this main shaft, it follows the turning trajectory of the crankpin that turns around the main shaft axis. When the grinding wheel is fed and controlled in a direction crossing the spindle axis, the contact point between the grinding wheel and the crank pin, that is, the grinding point moves along the outer periphery of the grinding wheel.
[0004]
For this reason, if the coolant is simply supplied to the fixed position as in the prior art, the coolant is not sufficiently supplied to the grinding point, and there is a risk of causing grinding burn or the like.
[0005]
[Means for Solving the Problems]
The present invention has been made to solve the above-mentioned problems, and the purpose thereof is to ensure that coolant can be supplied to the grinding point reliably even if the grinding point moves. The invention according to claim 1 is a coolant nozzle that discharges coolant, coolant nozzle moving means for moving the coolant nozzle along the outer periphery of the grinding wheel, and the coolant nozzle moving means is the grinding wheel base on which the grinding wheel is supported. The coolant nozzle moving means is controlled in synchronization with the profile creation movement of the grinding wheel by the profile data so that the coolant discharged from the coolant nozzle is supplied to the contact point between the grinding wheel and the crank pin. A swing control means is provided.
[0006]
According to a second aspect of the present invention, there is provided a coolant comprising a swing arm having one end holding a coolant nozzle and the other end rotatably mounted on the rotation axis of the grinding wheel, and a driving means for swinging the swing arm. The nozzle moving means is configured.
[0007]
DESCRIPTION OF THE PREFERRED EMBODIMENT
Hereinafter, the present invention will be described based on specific embodiments. FIG. 1 is a block diagram showing a numerically controlled grinding machine. Reference numeral 10 denotes a bed of a numerically controlled grinding machine, on which a table 11 is disposed so as to be slidable in the Z-axis direction parallel to the spindle axis. On the table 11, a headstock 12 on which a spindle 13 is pivoted is disposed, and the spindle 13 is rotated by a servo motor 14. A tailstock 15 is placed on the right end of the table 11, and a crankshaft W composed of a Janard J and a crankpin P is sandwiched between the center 16 of the tailstock 15 and the center 17 of the main shaft 13. The workpiece W is fitted to a positioning pin 18 projecting from the main shaft 13, and the rotational phase of the workpiece W matches the rotational phase of the main shaft 13.
[0008]
Behind the bed 10, a grinding wheel base 20 that can advance and retreat along a tool feed axis (X axis) is guided, and a grinding wheel G that is rotationally driven by a motor 21 is supported on the grinding wheel base 20. The grinding wheel base 20 is connected to a servo motor 23 via a feed screw (not shown), and is moved forward and backward by forward and reverse rotation of the servo motor 23.
A grinding wheel cover 24 is attached to the outer periphery of the grinding wheel G, and a servo motor 26 for moving a coolant nozzle 25 described later is attached on the grinding wheel cover 24.
[0009]
The coolant nozzle 25 is coupled to one end of the swing arm 27, and coolant is supplied from the pump 29 to the coolant nozzle 25.
The other end of the swing arm 27 is rotatably mounted on the rotation axis O of the grinding wheel G of the grinding wheel cover 24. By swinging the swing arm 27, the coolant nozzle 25 attached to one end moves along the outer diameter of the grinding wheel G.
[0010]
It is possible to cope with a change in the diameter of the grinding wheel G by appropriately adjusting the length from the rotation center of the swing arm 27 to the mounting position of the coolant nozzle 25.
One end of a first arm 28a is swingably coupled to the rotation shaft of the servo motor 26, and a second arm 28b is swingably coupled to the other end of the first arm 28a.
[0011]
The other end of the second arm 28b is fixedly coupled to the swing arm 27 so as to be swingable through an elongated hole 27a formed substantially at the center of the swing arm 27.
The elongate hole 27a allows the coupling position of the second arm 28b on the swing arm 27 to move. By moving the coupling position of the second arm 28b on the swing arm 27, the elongated nozzle 27 The swing amount can be adjusted as appropriate.
[0012]
The first and second arms 28a and 28b constitute a crank mechanism 28. When the servo motor 26 rotates, the swing arm 27 rotates around the rotation axis O of the grinding wheel G, and the swing arm. The coolant nozzle 25 attached to one end of the wheel 27 moves along the outer periphery of the grinding wheel G while maintaining a constant distance from the outer periphery of the grinding wheel G. As shown in FIG. 3, the drive units 40 and 41 are circuits that receive command values from the numerical controller 30 and drive the servo motors 23 and 14, respectively. As shown in FIG. 3, the drive unit 40 includes a deviation counter 401 for inputting a command value from the numerical control device 30 and a feedback signal from the rotary encoder 52, a DA converter 402 for DA-converting the output, and a speed at the output. It comprises an amplifier 403 that subtracts and amplifies the output of the generator 53 and applies a drive voltage to the servo motor. The drive unit 41 has the same configuration and will not be described.
[0013]
The drive unit 42 is a circuit that inputs a command value from the numerical control device 30 and drives the servo motor 26. The drive unit 42 amplifies the DA converter 421 that DA converts the command value from the numerical control device 30. It comprises an amplifier 422 that applies a drive voltage to the servo motor 26.
The numerical control device 30 is a device that mainly controls the rotation of the servomotors 23, 14, and 26 to control the grinding of the workpiece W. The numerical controller 30 is connected to a keyboard 43 for inputting control data and the like, a CRT display device 44 for displaying various information, and a control panel 45 for outputting various control signals.
[0014]
As shown in FIG. 3, the numerical controller 30 is mainly configured by a main CPU 31 for controlling the grinding machine, a ROM 33 storing a control program, a RAM 32 storing input data and the like, and an input / output interface 34. ing. On the RAM 32, there are provided an NC data area 321 for storing NC data and a profile data area 322 for storing profile data determined from the turning trajectory of the crankpin. In addition, a feed mode setting area 324 for setting various modes and a workpiece mode setting area 326 are provided.
[0015]
In the profile data area 322, as shown in FIG. 4, the position of the grinding wheel 13 for each unit angle of the spindle 13 and the rotational angle position of the servo motor 25 for determining the tip position of the coolant nozzle 25 are set as one block. One round of data is stored as profile data.
The numerical control device 30 is a drive system for other servo motors 23 and 14, and is provided with a drive CPU 36 and a RAM 35. The RAM 35 is a storage device that inputs positioning data of the grinding wheel G from the main CPU 31. The drive CPU 36 is a device that numerically controls the spindle 13 and the grindstone 20, performs calculations such as slow-up, slow-down, and target point interpolation, and outputs interpolation point positioning data at a constant cycle.
[0016]
Next, the operation will be described.
The RAM 32 stores NC data including machining cycle data, and the machining cycle data is shown in FIG. When the button 452 on the control panel 45 is pressed, the machining cycle data is activated. The NC data is decoded by the CPU 31 according to the procedure shown in the flowchart of FIG.
[0017]
In step 100, the NC data is read out by one block, and in the next step 102, it is determined whether or not it is a data end. In the case of a data end, this program is terminated. If it is not the data end, the process proceeds to step 104 and the subsequent steps, and the code of the instruction word is determined. If it is determined in step 104 that the instruction word is a G code, the CPU proceeds to step 106 in order to determine a more detailed instruction code.
[0018]
In steps 106 to 112, the mode is set according to the instruction code. If it is determined in step 106 that the G01 code is used, a flag is set in the feed mode setting area 323 in step 108, and the feed mode is set to the grinding feed mode. If the G51 code is determined in step 110, a flag is set in the workpiece mode setting area 324 in step 112, and the workpiece mode is set to the pin grinding mode.
[0019]
When the above mode setting is completed, the routine proceeds to step 114, where it is determined whether or not there is an M code. If it is determined in step 114 that the block read out has M code, the process proceeds to step 116 to determine whether or not the M code is an M08 code. If it is the M08 code, the routine proceeds to step 118, where the pump 29 is driven and the coolant is discharged from the coolant nozzle 25.
[0020]
If it is determined in step 116 that there is no M08 code, the process proceeds to step 120 and it is determined whether or not the M09 code.
If it is M09 code here, it will transfer to step 122, the pump 29 will be stopped, supply of coolant from the coolant nozzle 25 will be stopped, and it will transfer to step 124. If it is not the M09 code, the process proceeds to step 124.
[0021]
If it is determined in step 124 that the read block has an X code, the process proceeds to step 136, and it is determined whether or not the mode setting is a pin grinding mode and a grinding feed mode (hereinafter referred to as “pin / grinding mode”). In the pin / grinding mode, a distribution process for creating a pin is performed in step 128. On the other hand, when the mode is not the pin / grinding mode, distribution processing that is not synchronized with normal rotation of the main spindle is performed at step 130.
[0022]
<Processing>
When the button 452 on the control panel 45 is pressed, the machining cycle data shown in FIG. 5 is decoded block by block according to the flowchart of FIG. First, the grinding wheel G is rotated by a block (not shown) so that the grinding wheel base 20 is fast-forwarded to a predetermined position, and the table 11 is moved to a position where the crank pin P for grinding is opposed to the grinding wheel G. Be indexed.
[0023]
Next, the workpiece mode is set to the pin grinding mode by the G51 code of the block N010, and the profile data to be used is designated by the number P1234. The coolant supply is started by the N020 MO8 code of the next block.
The grinding feed mode is set by the G01 code of block N030, and the pin grinding process is performed by X-0.1 due to the presence of the X code. The F code indicates the grinding amount per rotation of the main shaft, and the R code indicates the grinding speed per rotation of the main shaft. The S code represents the rotational speed of the main shaft.
[0024]
In the NC data of FIG. 5, since the designated numerical values of the F code and the R code are equal, it is instructed to continuously cut at a constant speed with respect to the rotation of the spindle.
Profile creation is performed according to the flowchart of FIG. First, in step 200, a cutting amount for each unit rotation angle 0.5 ° of the spindle is calculated from the given F code. Next, at step 202, the head address of the address where the profile data for the origin of the command angle of the spindle is stored is set as the initial value of the read address I. Next, in step 204, an output completion signal is input from the drive CPU 36, and it is determined whether or not the output in the previous cycle is completed. If it is determined that the output is completed, the process proceeds to step 206 and the profile data D (I) Is read out, and it is determined in step 208 whether or not the cutting per spindle rotation is completed. This determination is performed using numerical data designated by the F code. In this case, the determination is made based on whether or not cutting of 0.1 mm has been performed. When the cutting per rotation of the main shaft is not completed, in step 210, the cutting amount per unit angle is added to the read profile data D (I) to generate movement amount data. In step 212, Positioning data that is a combination of the movement amount data and the speed data is output to the drive unit 40, and the grindstone table 20 is moved. At the same time, the corresponding rotation angle of the main shaft 13 and rotation angle of the servo motor 26 are output to the drive units 40 and 41, respectively.
[0025]
When the cutting per spindle rotation is completed, the execution profile data D (I) read in step 213 is used as the grinding wheel platform movement amount data as it is.
Next, in step 214, it is determined whether or not the read address I is equal to or higher than the end address Imax of the execution profile data. When I ≧ Imax, the read address I is set to the initial value in order to return to the top of the table in step 216. Otherwise, the read address I is updated by 1 in step 218, and the process proceeds to step 220 to complete the process. It is determined whether or not the cutting has been completed.
[0026]
This determination is made from numerical data designated by the X code. When all the cuts are not completed, the process proceeds to step 204 and proceeds to the next control cycle. On the other hand, when all the cuts have been completed, the pin grinding process commanded in block NO30 is terminated, and the supply of the clant is stopped by the M09 code commanded in block NO40. Fast forward to the predetermined position.
[0027]
By moving the grindstone base 20 in synchronization with the rotation of the main shaft 13 as described above, it is possible to grind the crankpin that rotates around the main shaft axis as shown in FIGS.
Further, the coolant nozzle moves in synchronization with the movement of the grinding wheel G, always supplies the coolant to the contact point between the crank pin and the grinding wheel G, and cools the grinding wheel G and the crank pin P and removes chips. Thus, grinding burn and processing failure of the crank pin P can be prevented.
[0028]
In the above-described embodiment, the rotary motion of the servo motor is converted into a linear motion using the crank mechanism 28 constituted by the first and second arms 28a and 28b to move the swing arm 27. However, the present invention is not limited to this, and the swing arm 27 may be moved by using a linear power source such as a cylinder device such as a hydraulic cylinder or a linear motor.
[0029]
【The invention's effect】
As described above, according to the first aspect of the present invention, the coolant nozzle is moved based on the profile data for causing the grinding wheel to generate a profile along the turning trajectory of the crank pin, and the coolant is moved to the contact point between the grinding wheel and the crank pin. Since it is supplied, it is possible to always supply the coolant to the contact point between the grinding wheel and the crankpin, and to prevent the occurrence of grinding burn.
[0030]
In the invention of claim 2, since the coolant nozzle is attached to the tip of the swing arm that turns on the rotation axis of the grinding wheel, the coolant nozzle can draw a locus along the outer periphery of the grinding wheel. Thus, the distance between the coolant nozzle and the outer periphery of the grinding wheel can be made constant, and more stable coolant can be supplied.
[Brief description of the drawings]
FIG. 1 is a block diagram of a numerically controlled grinder according to an embodiment of the present invention. FIG. 2 is a block diagram of a numerically controlled grinder according to an embodiment of the present invention. Fig. 4 shows a part of profile data. Fig. 5 shows a part of machining cycle data. Fig. 6 is a flowchart showing a processing procedure of the CPU. Fig. 7 is a processing procedure of the CPU. FIG. 8 is an operation explanatory diagram showing the movement of the grinding wheel base and the movement of the coolant nozzle.
10 Bed 11 Table 13 Main spindle 14 Servo motor 15 Tailstock 20 Grinding wheel base 25 Coolant nozzle 26 Servo motor 30 Numerical control device G Grinding wheel W Workpiece

Claims (2)

Based on the profile data for profile generating movement of the grinding wheel supported on the grinding wheel table along the turning trajectory of the crank pin that holds the journal of the crankshaft on the spindle and turns around the axis of the spindle, the spindle and the grinding wheel In a grinding machine that numerically controls a feed shaft and grinds the crank pin, a coolant nozzle that discharges coolant, a coolant nozzle moving means that moves the coolant nozzle along the outer periphery of the grinding wheel, and the coolant nozzle moving means include: Synchronized with the grinding wheel profile creation movement according to the profile data so that the grinding wheel wheel is supported by the grinding wheel table and the coolant discharged from the coolant nozzle is supplied to the contact point between the grinding wheel and the crank pin. And swing control means for controlling the coolant nozzle moving means. Grinding of the coolant supply device, characterized in that the. The coolant nozzle moving means is composed of a swinging arm having one end holding the coolant nozzle and the other end rotatably mounted on the rotation axis of the grinding wheel, and a driving means for swinging the swinging arm. The coolant supply device for a grinding machine according to claim 1.

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