JPH03202225A - Tooth profile finishing device - Google Patents

Abstract

PURPOSE:To form gear teeth accurately and evenly by generating the vibration with back lash between teeth of a work and teeth of a grinding stone, and moving these work and grinding stone relatively and approachably till the detected vibration becomes less than the vibration under the non-back-lash condition. CONSTITUTION:Teeth of a grinding stone is engaged with teeth of a work, and the voltage command for increasing and decreasing the voltage with a constant period is given from a control device 27 to a grinding stone driving motor 21 through an amplifier 29 for a grinding stone motor, and the rotation of the grinding stone driving motor 21 is regulated, and while a casing driving means 24 is driven to progress the whole of a casing 23 of a grinding stone base unit 17 to a work W at the intermediate speed. A vibration sensor 25 converts the vibration of the casing 23 of the grinding stone base unit 17 to the electrical signal to fetch and input it to the control device 27. The control device 27 judges that a vibration level is less than a set value decided with the vibration level under the non-back-lash condition or not to continue the regulated rotation of the grinding stone driving motor 21 and drive of the casing driving means 24 till the vibration level becomes a value less than the set value.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an improvement in a tooth profile finishing device for finishing a tooth profile previously formed on a workpiece using a grindstone that rotates relative to the workpiece.

(Prior Art) There are many gear parts such as transmission gears or steering gears in the parts that make up an automobile.

Such gear parts for automobiles are required to be finished with high precision and to have high work efficiency in order to support mass production. Therefore, gear parts are pre-processed to form a tooth profile using a hob or pinion cutter, etc., then finished by shaving, and after heat treatment, the final final shaping of the tooth profile is performed by honing. .

FIG. 9 shows a conventional tooth profile finishing device for finishing and shaping the tooth profile of a workpiece by honing.

This tooth profile finishing device 1a includes a holding means 2 for holding the head end of the workpiece W, a holding means 3 for holding the tail end of the work W, and a grindstone unit 17 equipped with a grindstone 16. , a workpiece W on which a gear G has been formed in advance is rotatably held via the holding means 2.3, and a grindstone 16 shaped into a shape corresponding to the tooth profile 18 of the gear G is placed relative to the workpiece W. The tooth profile 18 is finished and shaped by honing by rotating the tooth profile 18.

The holding means 2 on the head side is provided on the bed 4 of the tooth profile finishing device 1a, and therein is a bearing '5.
A shaft 6 that is rotatably held via the shaft 6 is built-in. A center 7 is attached to one end of the shaft 6 to support the center of rotation of the work W at the head side end.

A work rotation motor 9 for rotating the work W is connected to the other end of the shirt (shirt)-6 via an electromagnetic clutch 8. A pulse generator 10 for detecting the rotational position of the shaft 6 is attached to the holding means 2, and a rotary plate 10a of the pulse generator 10 is meshed with a gear 6a formed on the outer peripheral surface of the shaft 6. ing.

The tail-side holding means 3 is also provided on the bed 4, and has a center 11 that supports the center of rotation at the tail-side end of the workpiece W.

Further, in order to move the center 11 forward and backward relative to the workpiece W, a rod 13 of a cylinder 12 driven by hydraulic pressure or the like is connected to the center 11.

When the electromagnetic clutch 8 is turned off, the workpiece W is supported by both centers 7 and 11 and rotates freely. Further, by turning on the electromagnetic clutch 8, it is possible to forcibly rotate the workpiece W with the workpiece rotation motor 9 or to brake the rotation of the workpiece W.

The whetstone head unit 17 includes a ring-shaped whetstone 16 rotatably mounted thereon, and a whetstone driving motor 21 for rotationally driving the whetstone 16. The grindstone 16 has teeth (hereinafter referred to as grindstone teeth 3) corresponding to the tooth profile 18 (hereinafter referred to as work teeth 18) of the gear G on its grinding surface.
0) is shaped and fixed to the inner circumferential surface of the pulley 20 via one grindstone holder. Further, a pulley 22 connected to the grindstone driving motor 21 is connected to the pulley 20 on the grindstone side via a belt. These grindstone 16, motor 21, and pulleys 20, 22 are mounted inside a casing 23. And grindstone tooth 30
The grinding wheel head unit 17 is provided with a casing drive means for moving the entire casing 23 forward and backward relative to the workpiece W in order to mesh with and release the workpiece teeth 18 .

Then, when the grindstone drive motor 21 is rotated at a predetermined spindle speed while bringing the gear G and the grindstone 16 into contact under a predetermined pressure, the work teeth 18 are moved by the grindstone teeth 30 as the grindstone 16 rotates. It will be ground and final shaping will be performed. At this time, the workpiece W supported by both centers 7 and 11 is rotating as the grindstone 16 rotates.

By the way, in order to finish the workpiece tooth 18 with high precision by honing, it is important to grind the workpiece tooth 18 and the grindstone tooth 30 while bringing them into contact with each other without backlash.

Therefore, before grinding is performed by rotating the grindstone drive motor 21 at a predetermined spindle speed, it is necessary to set the work teeth 18 and the grindstone teeth 30 in a positional relationship that does not cause backlash.

Therefore, in the tooth profile finishing device 1a described above,
I try to eliminate backlash as shown below.

That is, first, the workpiece W is supported by both holding means 2.3, the workpiece teeth 18 and the grindstone teeth 30 are lightly engaged, and the position of the shaft 6 at this time (the position before rotation) is detected by the pulse generator 10. . Next, the grindstone driving motor 21 is rotated by a predetermined angle, and then rotated again in the opposite direction to the original position, and the position of the shaft 6 at this time (position after rotation) is also detected by the pulse generator 10. If there is a positional difference between the position before rotation and the position after rotation, it is determined that backlash exists between the workpiece tooth 18 and the grinding wheel tooth 30, and based on the positional difference. The grinding wheel tooth 30 is advanced toward the workpiece tooth 18 by the distance calculated. As a result, the workpiece tooth 18
and the grinding wheel tooth 30 come into contact with each other without backlash.

(Problems to be Solved by the Invention) As described above, in the conventional tooth profile finishing device 1a,
The backlash between both teeth is eliminated based on the positional difference of the shaft 6 detected by the pulse generator 10.
Since the pulse generator 10 and the gear 6a of the shaft 6 are configured to mesh with each other, there is a possibility that backlash may exist in the pulse generator 10 itself. Furthermore, there is a possibility that the center 7 provided on the shaft 6 and the workpiece W may rotate idly.

Therefore, since the backlash on the side of the pulse generator 10 is affected, there is a drawback that the state where no backlash exists between the work tooth 18 and the grindstone tooth 30 cannot be accurately detected.

In this way, since it is not possible to detect with high precision whether there is backlash between the workpiece tooth 18 and the grindstone tooth 30, ideal honing cannot be performed, and the amount of cut of the workpiece 1f718 cannot be accurately detected. There was a problem that the accuracy of the product itself became unstable due to the inconsistency.

The present invention has been made in order to solve the problems associated with the above-mentioned conventional technology, and it is possible to detect with high precision the position where there is no backlash between the teeth of the gear and the teeth of the grindstone. It is an object of the present invention to provide a tooth profile finishing device capable of shaping teeth uniformly and with high precision.

(Means for Solving the Problems) In order to achieve the above object, the present invention rotatably holds a workpiece in which a tooth profile has been formed in advance, and a grindstone shaped into a shape corresponding to the tooth profile is attached to the workpiece. In the tooth profile finishing device, which is provided so as to be movable toward and away from a tooth, and performs honing processing by relatively rotating the workpiece and the grindstone to finish shaping the tooth profile of the workpiece. Vibration generating means for generating vibration due to backlash between the teeth of the workpiece and the teeth of the grinding wheel; Vibration detecting means for detecting the generated vibration; Based on the signal from the vibration detecting means, the vibration is tl' J. A tooth profile finishing device comprising a control means for moving the teeth of the workpiece and the teeth of the grindstone relatively close to each other until the vibration becomes less than the vibration in a state without backlash.

Further, the vibration generating means rotates at least one of a workpiece rotation motor that rotates the workpiece and a grindstone drive motor that rotates the grindstone while repeating acceleration and deceleration at a constant cycle. It is good to configure.

(Function) In the tooth profile finishing device configured as described above, the vibration generating means generates vibrations due to backlash between the teeth of the workpiece and the teeth of the grindstone, and the generated vibrations are detected by the vibration detecting means. The control means moves the teeth of the workpiece and the teeth of the grindstone relatively close to each other until the detected vibration becomes less than the vibration in a state without backlash. As a result, there is no backlash between the teeth of the workpiece and the teeth of the grinding wheel, and under this condition, the tooth profile of the workpiece is honed by the teeth of the grinding wheel. become.

Further, according to the vibration generating means configured as described above, when at least one motor is rotated while repeating acceleration and deceleration at a constant cycle, the teeth of the grindstone collide with the teeth of the grindstone, causing the backlash. Vibrations caused by the rush will occur.

(Example) Hereinafter, an example of the tooth profile finishing apparatus according to the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of essential parts showing an embodiment of a tooth profile finishing device according to the present invention, and FIG. 2 is a plan view showing a grindstone head unit of the same embodiment, and the members shown in FIG. The same reference numerals are given to the same members, and some explanations thereof will be omitted.

The illustrated tooth profile finishing apparatus 1 includes a holding means 2 for holding the head end of the workpiece W, a holding means 3 for holding the tail end of the workpiece W, and a grindstone head unit 17 equipped with a grindstone 16. The workpiece W on which the gear G has been formed in advance is rotatably held via the holding means 2.3, and the workpiece teeth 18
The honing process is performed by relatively rotating the work W and the grindstone 16 on which the grindstone teeth 30 having a shape corresponding to the shape of the grindstone 30 have been shaped, thereby finishing and shaping the workpiece teeth 18 with high precision.

The head-side holding means 2 is provided on the bed 4 of the tooth profile finishing apparatus 1, and has a built-in shaft 6 rotatably held therein via a bearing 5. A center 7 is attached to one end of the shaft 6 to support the center of rotation ψ at the head side end of the workpiece W. A work rotation motor 9 is connected to the other end of the shaft 6 via an electromagnetic clutch 8. A servo motor is used as the work rotation motor 9. Note that the pulse generator 10 conventionally used for detecting the rotational position of the shaft 6 is not attached to the holding means 2 of this embodiment.

The holding means 3 on the tail side is also provided on the bed 4, and is on the right side of a center 11 that supports the center of rotation Φ at the tail side end of the workpiece W.

Further, in order to move the center 11 forward and backward relative to the workpiece W, a rod 13 of a cylinder 12 driven by hydraulic pressure or the like is connected to the center 11.

In addition, a work rest 14.
15 are respectively attached to the holding means 2.3.

Furthermore, in order to determine the workpiece teeth 18 of the workpiece W supported by both centers 7.11, a proximity sensor 26 for detecting the position of the teeth is attached to the workpiece rest 14.

As shown in FIG. 1.2, the grindstone head unit 17 is
A ring-shaped whetstone 16 rotatably mounted, and a whetstone drive motor 21 for rotationally driving this whetstone 16.
It has The grindstone 16 is fixed to the inner peripheral surface of the pulley 20 via a grindstone holder 19. A servo motor is used as the grindstone drive motor 21. A pulley 22 connected to this grindstone driving motor 21 is connected to the pulley 20 on the grindstone side via a belt. These grindstone 16, motor 21, and pulley 20
．． 22 is mounted inside the casing 23. Then, as shown by the arrow in FIG.
The grindstone head unit 17 is provided with a casing driving means 24 for moving the entire casing 23 forward and backward relative to the workpiece W in order to engage and disengage the workpiece W.

Furthermore, the tooth profile finishing device 1 of this embodiment has a workpiece tooth 18.
a vibration generating means 31 that generates vibration due to backlash between the grinding wheel teeth 30; a vibration detecting means 25 that detects the generated vibration; and a vibration detecting means 25 that detects the generated vibration. The control means 27 moves the grinding wheel tooth 30 toward the workpiece tooth 18 until the vibration becomes lower than that in a state where there is no vibration.

The vibration generating means 31 is constructed by rotating at least one of the work rotation motor 9 and the grindstone drive motor 21 while repeating acceleration and deceleration at a constant cycle. Well, the fifth
The vibration generating means 3 is generated by giving a voltage command in which the voltage increases or decreases at a constant cycle to the grinding wheel drive motor 21 as shown in the figure.
1 is configured.

The vibration detection means 25 is mounted on the casing 23 of the grindstone head unit 17, as shown in FIG. The vibration detection means 25 is a vibration sensor that converts mechanical vibration into an electrical signal and extracts it, and uses a piezoelectric type vibration sensor that applies a piezoelectric effect, a force balance type servo type vibration sensor, or the like.

FIG. 3 is a block diagram showing the control system of the same embodiment.

The control device 27 as a control means has a built-in microcomputer and includes a work motor amplifier 28 that controls power to the work rotation motor 9, and a grindstone drive motor 21.
A grindstone motor amplifier 29 that controls power to the grindstone motor, an electromagnetic clutch 8, a cylinder 12, and a casing drive means 24.
are connected via the input/output section. Each amplifier28.
The two include a work rotation motor 9 and a grindstone drive motor 2.
1 are connected to each other. The position detection sensors 9a and 21a connected to each motor 9.21 feed back signals of detected rotational positions to the ho 1j control device 27 via the human output section. In addition, the control device 27 is manually operated by electric signals sent from the proximity sensor 26, vibration sensor 25, etc., and based on these electric signals, etc., the cylinder 12 is moved forward and backward, and the electromagnetic clutch is controlled. 8 on/off, each motor 9.21 rotation,
It controls the stop and the forward and backward movement of the casing drive means 24.

The tooth profile finishing device 1 of the present invention configured as described above has the following features:
The operation is performed as follows based on the operation flowchart shown in FIG.

When the program starts, the control device 27 carries the workpiece W on which the gear G has been formed in advance into the tooth profile finishing device 1 with the cylinder 12 of the holding means 3 retracted, and then drives the cylinder 12 forward. Both centers 7.11
supports the workpiece W (step 1). At this time,
The entire casing 23 of the grindstone unit 17 is moved backward from the workpiece W by the casing drive means 24.

When the workpiece W is set, the control device 27 indexes the workpiece teeth 18 and the grindstone teeth 30 (step 2). That is, in order to index the workpiece teeth 18, the control device 27 turns on the electromagnetic clutch 8 and drives the workpiece rotation motor 9 to forcibly rotate the workpiece W.
At the same time as the proximity sensor 26 detects the work tooth 18, the work rotation motor 9 is stopped. Next, the control device 27 receives the stop position signal fed back from the position detection sensor 9a of the work rotation motor 9 and the grindstone drive motor 2.
The necessary rotational movement amount of the grindstone 16 is calculated based on the stop position signal fed back from the position detection sensor 21a of the grindstone 1, and the grindstone drive motor 21 is rotationally driven by an angle corresponding to this movement amount. The teeth 30 are indexed. As a result, the work teeth 18 and the grindstone teeth 30 are in a state where they can mesh with each other.

Next, the casing driving means 24 is driven to move the entire casing 23 of the grinding wheel head unit 17 forward relative to the workpiece W, and when the grinding wheel teeth 30 move forward to a position where they lightly engage the workpiece teeth 18, the electromagnetic clutch 8 is turned off. (Step 3.4).

When the grinding wheel tooth 30 meshes with the workpiece tooth 18, the control device 27
gives a voltage command to the grindstone drive motor 21 via the grindstone motor amplifier 29, in which the voltage increases or decreases at a constant cycle as shown in FIG. Then, the grindstone drive motor 21 becomes
It vibrates little by little and rotates while repeating acceleration and deceleration (step 5). Further, while accelerating and decelerating the grindstone driving motor 21 in this manner, the casing drive means 24 is driven, and the casing 2 of the grindstone head unit 17 is rotated.
3 is moved forward at a medium speed relative to the workpiece W (step 6).

The vibration sensor 25 is connected to the casing 2 of the grindstone unit 17.
3 is converted into an electric signal and extracted, and this output voltage is input to the control device 27 (step 7). Then, the control device 27 determines whether the vibration level is based on the electric signal sent from the vibration sensor 25 or is less than the set value EO determined from the vibration level in a state without backlash. The acceleration/deceleration rotation of the grindstone drive motor 21 and the drive of the casing drive means 24 set in step 5.6 are continued until the value becomes equal to or less than the set value EO (step 7.8).

That is, when the backlash between the work tooth 18 and the grinding wheel tooth 30 is large, the south sides of both collide with each other, so
This is transmitted to the casing 23, and a vibration level as shown in FIG. 6 is generated.

From this state, as the casing 23 gradually moves forward with respect to the workpiece W, that is, the grinding wheel tooth 3o changes to the workpiece tooth 18.
As the backlash approaches , the backlash becomes smaller and the vibration level gradually becomes smaller. By repeating this, the vibration level of the casing 23 becomes lower than the set value EO, as shown in FIG. And control device 2
Step 7 determines that the grinding wheel tooth 30 has moved toward the workpiece tooth 18 to a position where there is no backlash between the grindstone tooth 30 and the workpiece tooth 18, and proceeds to step 9.

When the backlash between the workpiece tooth 18 and the grindstone tooth 30 disappears, the control device 27 changes the voltage command given to the grindstone drive motor 21 via the two grindstone motor amplifiers to the eighth
Switch to the stable voltage command shown in the figure (step 9)
At the same time, the drive command for the casing drive means 24 is switched to a grinding feed command (step 10). As a result, the grindstone drive motor 21 rotates at a constant spindle speed while the work teeth 18 and the grindstone teeth 30 are in contact with each other under a predetermined pressure. Then, the work teeth 18 are ground by the grindstone teeth 30 as the grindstone 16 rotates, and the final finishing shaping is performed.

The control device 27 determines whether or not the workpiece tooth 18 has been cut by a predetermined amount, and performs steps 9 to 9 until the predetermined depth of cut is reached.
11 is repeated.

When the depth of cut reaches a predetermined amount and the final finishing shaping of the workpiece tooth 18 is completed, the control device 27 controls the grindstone drive motor 21
At the same time, the feeding of the grindstone head unit 17 is also stopped (step 12.13).

Then, the control device 27 moves the entire casing '23 of the grindstone unit 17 backward from the workpiece W by the casing driving means 24, and further moves the cylinder 12 backward to take out the workpiece W, thereby ending the execution of the program. (Step 14.15).

As described above, in this embodiment, when the grindstone tooth 3° is engaged with the workpiece tooth 18 without backlash, the vibration sensor 25 detects the mechanical vibration of the casing 23 caused by the backlash. , the grinding wheel tooth 30 is moved to the workpiece tooth 18 until the detected vibration level becomes less than the set value EO.
I am trying to move closer to the target.

Therefore, since the conventional pulse generator 10 is not required, the influence of backlash between the rotating plate 10a of the pulse generator 10 and the gear 6a of the shaft 6 is eliminated, and the backlash between the work teeth 18 and the grinding wheel teeth 30 is eliminated. Rush can be detected with high accuracy. As a result, the positions of the grinding wheel tooth 30 and workpiece tooth 18 can be quickly set to the grinding start position, thereby shortening the air cutting time, and since the depth of cut of the workpiece tooth 18 is constant, stable crystal manufacturing accuracy can be obtained. becomes possible. Furthermore, since the pulse generator 10 becomes unnecessary, the holding means 2 on the head side
The configuration can be simplified. Furthermore, since the presence of backlash is determined based on mechanical vibration, the detection accuracy is stable over a long period of time.

In the above embodiment, the vibration sensor 25 is attached to the casing 23, but the attachment position of the vibration sensor 25 is not limited to the casing 23, and it can be attached to the center 7, 11, etc. Mechanical vibrations caused by backlash may also be detected.

Furthermore, although a case is shown in which the vibration generating means 31 is constituted by the grindstone driving motor 21, the vibration generating means 31 may be constituted by applying the voltage command shown in FIG. 5 to the work rotation motor 9.

Furthermore, in the embodiment described above, the case where the grinding wheel 16 was provided so as to be movable toward and away from the workpiece W was shown;
It goes without saying that the same effect can be obtained by configuring the grinding wheel so that it can move towards and away from the grindstone 16.

(Effects of the Invention) As explained above, according to the tooth profile finishing device of the present invention, the position where there is no backlash between the teeth of the gear and the grindstone can be detected with high precision. The depth of cut is constant, and the gear teeth can be cut with high precision.
This has a great practical effect in that it can be shaped uniformly.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of essential parts showing an embodiment of a tooth profile finishing device according to the present invention, FIG. 2 is a plan view showing a grindstone head unit of the same embodiment, and FIG. FIG. 4 is a block diagram showing the control system, FIG. 4 is an operation flowchart of the same embodiment, FIGS. 5 and 8 are state diagrams showing the voltage applied to the grindstone drive motor, and FIGS. 6 and 7 are: FIG. 9, which is a state diagram showing the level of vibration, is a sectional view of a main part of a conventional tooth profile finishing device. 1.1a... Tooth profile finishing device, 9... Work rotation motor, 16... Grindstone, 17
...Wheelhead unit, 18...Work tooth,
21... Grindstone drive motor, 23... Casing, 24... Caning drive means, 25... Vibration sensor (vibration detection means), 27... Control device (control means), 30... Grinding wheel tooth, 31... Vibration generating means, W... Workpiece, G... Gear.

Claims (1)

[Claims] [1] A workpiece on which a tooth profile has been formed in advance is rotatably held, and a grindstone shaped into a shape corresponding to the tooth profile can be moved toward and away from the teeth of the workpiece. In the tooth profile finishing device, the tooth profile finishing device is configured to perform honing by relatively rotating the workpiece and the grindstone to finish and shape the tooth profile of the workpiece, and the gap between the teeth of the workpiece and the teeth of the grindstone. vibration generating means for generating vibration due to backlash; vibration detecting means for detecting the generated vibration; and based on a signal from the vibration detecting means, until the vibration becomes lower than the vibration in the state without backlash. A tooth profile finishing device comprising a control means for relatively moving the teeth of the workpiece and the teeth of the grindstone toward each other. [2] The vibration generating means rotates at least one of a work rotation motor that rotates the work and a grindstone drive motor that rotates the grindstone while repeating acceleration and deceleration at a constant cycle. The tooth profile finishing apparatus according to claim 1, which is constructed by: