JPH04189418A - Finish working device for gear - Google Patents

Abstract

PURPOSE:To improve work precision by providing a gear pitch detecting means for measuring the pitch total number of a gear to be worked and an operation controlling means which seeks a pitch error correction amount and outputs a signal of rotational phase difference between the gear to be worked and a grindstone to each drive motor control system. CONSTITUTION:A grindstone stand 9 is temporarily retreated after working is completed, and a gear pitch measuring unit 19 is advanced, so that a work W and a master gear 25 are brought into nutual meshing A main shaft motor 6 is driven by means of a positioning controller 18, and the work W is divided tooth by tooth and rotated, and the actual pitches of the work W are detected in order by means of a rotary encoder 26, and memorized in an operation control unit 28. By the operation control 28, for example, whether or not a difference between the maximum and minimum values out of the total number of actually measured values is within an allowable range, is discriminated, and if it is outside the allowable range, a pitch error correction amount is sought by operation, and simultaneously the specification of the positive and negative directions of each tooth surface to be ground is carried out, and a rotational phase difference creation signal for the purpose of giving a rotational phase difference (an offset amount (a)) between the work W and a grindstone 8, is outputted to the control system of the main shaft motor 6 and grindstone drive motor 13.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a gear finishing device, and more particularly to a finishing device having a gear pitch error correcting function.

BACKGROUND OF THE INVENTION In order to improve the surface roughness of the tooth surfaces of spur gears and helical gears and to improve the tooth profile accuracy, finishing of the gears is carried out by grinding. In such a finishing machine by grinding, for example, a gear to be machined is supported on both sides by a head stock and a tail stock, and the gear to be machined is meshed with an internal gear-shaped grindstone, while the gear to be machined is supported by a main shaft. The basic method is to rotate the grinding wheels synchronously with a motor and a grinding wheel drive motor, thereby utilizing sliding contact between the tooth surfaces of the gear to be processed and the grinding wheel.

Problems to be Solved by the Invention In the conventional finishing equipment as described above, in order to improve the surface roughness and tooth profile accuracy of the gear to be machined, the gear to be machined and the grindstone are processed as if they were a pair of gears. Therefore, it does not have a gear pitch measurement function or a pitch error correction function.

Therefore, the pitch accuracy of the gear to be machined depends on the machining performed before finishing, and even though finishing is performed for the purpose of improving surface roughness and tooth profile accuracy, it cannot be expected to improve the pitch accuracy of the gear.

Particularly in the case of gears to be machined where pitch accuracy is a problem, finishing machining must be separately performed for the purpose of correcting pitch errors, which increases the number of machining steps.

The present invention was made in view of the above problems.
An object of the present invention is to provide a finishing device capable of simultaneously correcting gear pitch errors and improving gear pitch accuracy in finishing processing aimed at improving the surface roughness and tooth profile accuracy of gears to be machined. It is.

Means for Solving the Problems The present invention is characterized in that a workpiece gear supported on both sides by a head stock and a tail stock and rotationally driven by a spindle motor, and a gear-shaped grindstone rotationally driven by a grindstone drive motor are interlocked. A gear pitch correction device that corrects the gear pitch after measuring the total number of pitches of the gear to be processed, in a gear finishing device that performs finishing on the gear to be machined by rotating both gears in synchronization. It is equipped with

Furthermore, this gear pitch correction device has a master gear that moves forward and backward to mesh with the workpiece gear supported on both sides by the headstock and tailstock, and a master gear that meshes the workpiece gear and the master gear. A gear pitch detection means measures the total number of pitches of the workpiece gear for each tooth rotation from the rotational displacement of the master gear when the workpiece gear is indexed and rotated one tooth at a time in a state where the workpiece gear is indexed and rotated one tooth at a time. The amount of pitch error correction necessary to average the pitch of all the teeth of the gear to be machined is calculated based on the actual measured value of the total number of pitches. It is composed of an arithmetic control means that applies a rotational phase difference generation signal for creating a phase difference to the control system of the spindle motor and the grindstone drive motor.

Function In this structure, the gear to be machined is supported on both sides by the headstock and tailstock and has been finished once, or the gear is supported on both sides by the headstock and tailstock and has not yet been finished. After meshing the gear to be machined that has not been used with the master gear, the gear to be machined is indexed and rotated one tooth at a time by a main shaft motor.

Then, the gear pitch detecting means detects the gear pitch each time the gear to be processed is indexed and rotated, and the actual measured values of the total number of pitches are sequentially stored.

After that, the arithmetic control means performs a predetermined calculation to correct the pitch error necessary to average the actual measured values of all the pitches (for example, adjust the difference between the maximum and minimum values of the actual pitch values to within an allowable range). Find the amount of pitch error correction required to correct the pitch error. At this time, the direction necessary for the correction, that is, whether the rotation direction of the gear to be machined is positive or negative is specified.

Then, a grindstone is meshed with the gear to be machined instead of the master gear, and the above-mentioned pitch error correction amount is given as a rotational phase difference generation signal to the control system of the spindle motor and the grindstone drive motor.

This rotational phase difference generation signal generates a predetermined amount of meshing phase shift in the positive or negative direction when the gear to be machined and the grinding wheel are in mesh with each other. The grindstone will be strongly pressed against one tooth surface. As a result, in areas where the measured pitch value is relatively small, either the positive or negative side of the tooth surface is shaved off to widen the pitch, and as a result, the gear pitch is corrected and the total pitch is increased. are averaged.

Embodiment FIGS. 1 to 4 are configuration explanatory diagrams showing an embodiment of the present invention.

As shown in FIGS. 1 and 2, a gear to be machined (this example shows an example of a helical gear) equipped with a shaft portion S,
W (hereinafter referred to as a workpiece) is supported at one end by the chuck 2 and head center 3 on the head stock 1 side, and at the other end by the tail center 5 on the tail stock 4 side, and is rotated by the main shaft motor 6. Driven. Reference numeral 7 denotes a table on which the head stock 1 and the tail stock 4 are mounted, and this table 7 is movable in the axial direction of the shaft portion S.

On the outer periphery of the workpiece W, an internal gear-shaped grindstone 8 that meshes with the workpiece W is disposed so as to be supported by a grindstone holder 11, and the grindstone boulder 11 is rotatably supported on the grindstone head 9 via a bearing 10. has been done. A chain sprocket 12 is fixed to the outer periphery of the whetstone holder 11, while a chain 15 is wound between the chain sprocket 12 on the whetstone bolt 11 side and the chain sprocket 14 on the whetstone drive motor 13 side. 8 is rotationally driven by a grindstone drive motor 13.

Therefore, after meshing the workpiece W and the grindstone 8,
By synchronously rotating the workpiece W by the spindle motor 6 and the grindstone 8 by the grindstone drive motor 13, the workpiece W and the grindstone 8 rotate as if they were a pair of gears, and there is no sliding contact between the tooth surfaces of the two. Therefore, the tooth surface on the workpiece W side is subjected to grinding finishing.

The main shaft motor 6 and the grindstone drive motor 13 each have a pulse generator 16 or 1 as a position detector.
7, and forms a position feedback loop with the positioning control device 18.

Further, a gear pitch measuring unit 19 is arranged adjacent to the table 7. This gear pitch measuring unit 19 has a slider 21 mounted on a base 20 as shown in FIG.
By the functions of the ball screw 23 and the ball screw 23, the work W is moved forward and backward in a direction perpendicular to the axis thereof. Note that the forward and backward movement of the slider 21 is controlled by the positioning control device 18. 24 is a pulse generator.

A master gear 25 having a reference tooth profile is rotatably mounted on the tip of the slider 21.
5 is directly connected to the input shaft of a rotary encoder 26 as gear pitch detection means.

Therefore, as will be described later, when measuring the gear pitch of the workpiece W, the slider 21 is advanced and the master gear 2 is
5 and the workpiece W are meshed, and the workpiece W is indexed and rotated one tooth at a time by the main shaft motor 6, so that the master gear 25 is also rotated synchronously, whereby the total number of pitches of the workpiece W is sequentially detected by the rotary encoder 26. Ru.

The output of the rotary encoder 2G is input to an arithmetic and control unit 28 that constitutes a gear pitch measuring device 27 together with a gear pitch measuring unit 19. The arithmetic control unit 28 temporarily stores the measured pitch values of all the pitches of the workpiece W obtained by the rotary encoder 26, calculates and calculates the amount of pitch error correction required to average the pitches, and calculates the amount of pitch error correction necessary to average the pitches. The pitch error correction amount is output to the control system of the spindle motor 6 and the grindstone drive motor 13 as grinding allowance data necessary for pitch error correction.

The finishing device configured in this way (in 4, the first
As shown in the figure, the workpiece W supported on both sides by the headstock 1 and the tailstock 4 and the grindstone 8 are engaged with each other, and then the main shaft motor 6 and the grindstone drive motor 13 are driven to connect the workpiece W and the grindstone 8. Rotate synchronously. As a result, the workpiece W and the grindstone 8 rotate as a pair of gears, and the tooth surfaces on the workpiece W side are ground by sliding contact between their tooth surfaces. Note that at this time, the slider 21 of the gear pitch measuring unit 19 has retreated to a position where it does not interfere with the grindstone head 9.

When the machining of the workpiece W is completed, the grindstone head 9 is temporarily retracted, and instead, the slider 21 of the gear pitch measuring unit 19 is advanced to engage the workpiece W and the seven star gear 25, as shown in FIG.

Then, the main shaft motor 6 is driven according to instructions from the positioning control device 18, and the workpiece W is indexed and rotated tooth by tooth (by reference pitch). When the workpiece W is indexed and rotated, the master gear 25 meshing with the workpiece W rotates synchronously, and the actual pitches of all the pitches of the workpiece W are sequentially detected by the rotary encoder 26, and the actual measured values are stored in the arithmetic control unit 28. be done.

When the measurement of the total number of pitches of the workpiece W is completed, the sliver 21 of the gear pitch measuring unit 19 is moved back, while the calculation control section 28 performs a predetermined calculation based on the actual measured value of the total number of pitches.

That is, the arithmetic control unit 28 determines whether or not the value of the difference between the maximum value and the minimum value of the actual measured values of the total number of pitches is within the permissible range, and determines whether the difference value is within the permissible range. For example, a machining completion command is given to the positioning control device 18.

On the other hand, if the value of the difference in "-" is not within the allowable range,
The amount of pitch error correction required to bring the difference value within the allowable range is calculated and determined. At the same time, when correcting the pitch error, it is determined whether the positive tooth flank or the negative tooth flank of each tooth flank should be milled. Then, the arithmetic control unit 28 applies the pitch error correction amount to the control system of the main spindle motor 6 and the grindstone drive motor 13 to create a rotational phase difference for creating a rotational phase difference between the workpiece W and the grindstone 8. Give as a signal.

The rotational phase difference referred to here is the difference between the meshing position during initial machining and the meshing position during subsequent machining when the teeth on the workpiece W side and the teeth on the grindstone 8 side are meshed, as shown in Fig. 4. This is the offset amount a between the two and corresponds to the grinding allowance when correcting the pitch error.

After that, when the workpiece W and the grindstone 8 are engaged again and machining is started, the workpiece W and the grindstone 8 are rotated by an offset amount a in the positive or negative direction compared to the initial machining, as described above. Because they rotate synchronously while being strongly pressed with a phase difference, either the positive or negative side of the tooth surface is offset in areas where the pitch was relatively small in the previous pitch measurement step. It is scraped off with a width of amount a.

As a result, the gear pitch error of the workpiece W is corrected, and the pitches of all pitches are averaged.

Effects of the Invention As described above, the present invention has a function of measuring the pitch of the gear to be machined and correcting the pitch error, thereby improving the surface roughness and tooth profile accuracy of the gear. Pitch errors can be corrected at the same time as the intended finishing process, which improves gear accuracy and reduces machining man-hours.

In addition, the pitch of the gear to be machined set on the processing equipment is measured on the equipment, and the amount of pitch error correction is directly fed back to the drive system of the processing equipment to correct the pitch error. The pitch accuracy itself is also significantly improved.

[Brief explanation of the drawing]

FIG. 1 is a configuration explanatory diagram showing an embodiment of the present invention, FIG. 2 is an explanatory diagram showing the meshing state of a gear to be processed and a master gear, and FIG. 3 is a cross-sectional explanatory diagram of a gear pitch measuring unit. FIG. 4 is an enlarged view of the main part showing the state of engagement between the workpiece and the grindstone. 1...Head stock, 3...Head center, 4.
Tail stock, 5... Tail center, 6... Main shaft motor, 8... Grinding wheel, 9... Grinding wheel head, 13... Grinding wheel drive motor, 19... Gear pitch measuring unit, 21
...Slider, 25. Master gear, 26=-rotary encoder (gear pitch detection means), 27.. Gear pitch measuring device, 28. Arithmetic control unit, W.. Gear to be processed.

Claims (1)

[Claims] (1) A workpiece gear supported on both sides by a head stock and a tail stock and rotationally driven by a main shaft motor;
In a gear finishing device that finishes the workpiece gear by meshing with a gear-shaped grindstone that is rotationally driven by a grindstone drive motor and rotating both in synchronization, the total number of pitches of the workpiece gear is adjusted. The device is equipped with a gear pitch correction device that corrects the pitch of the gear after measuring the pitch of the gear. The master gear meshes with the processed gear, and when the processed gear is indexed and rotated one tooth at a time with the processed gear meshed with the master gear, the entire pitch of the processed gear is calculated by one tooth rotation from the rotational displacement of the master gear. Based on the gear pitch detection means that measures each gear pitch and the actual measured value of the total number of pitches obtained by the gear pitch detection means, the pitch error correction amount necessary to average the pitch of the entire tooth of the gear to be machined is determined, and an arithmetic control means that applies this pitch error correction amount to the control system of the main shaft motor and the grindstone drive motor as a rotational phase difference generation signal for creating a rotational phase difference between the gear to be processed and the grindstone. A gear finishing device that is characterized by: