JPH07249B2 - NC gear grinding method and gap eliminator for NC gear grinding machine - Google Patents

Description

The present invention relates to an improvement for improving tooth grinding efficiency in an NC gear grinding machine, and more particularly, to an object to be ground in which a gear to be ground is retracted from directly under a grinding wheel. Positioning and setting from the gear indexing position to the tooth grinding position where the grinding stone enters the tooth groove directly under the grinding wheel, and setting is performed in a short time to "reduce" the air cutting time of the grinding wheel as much as possible and improve the tooth grinding efficiency of the gear. And a NC gear grinding method and a gap eliminator for an NC gear grinding machine to achieve labor saving.

[Conventional technology]

The gear grinding machine rotates at high speed a grinding wheel having a predetermined diameter at a fixed position that is adjusted in advance corresponding to the tooth profile of the gear to be ground, and positions the teeth of the gear to be ground immediately below the grinding wheel. The tip of the grindstone contacts the gear to be ground at the engaging position in the tooth groove,
The tooth surface is ground to a desired tooth profile, for example, an involute tooth profile, by engaging and engaging a rolling motion according to a certain motion formula to the gear to be ground in that state.
The grindstone is of course adjusted to the fixed position as described above by setting the inclination (pressure angle setting) of the grindstone shaft according to the gear specifications, for example, the gear pressure angle.

In this case, in the gear grinding machine, when setting the grinding start position where the gear and the tip of the grinding wheel come into contact, in the conventional method, first, the high speed rotation of the grinding wheel is stopped and the grinding target gear and the gear mounting spindle on the grinding machine are stopped. In the state where the fastening between and is loosened, the spindle to be ground and the gear to be ground are moved to the position just below the stopped grinding wheel by the slow speed synchronous operation using the steel belt and the rolling disk, and the gear to be ground is mounted at the same time. While rotating minutely to adjust the rotation phase relative to the main shaft, it reaches the position where the tip of the grindstone enters the tooth groove, and at this time, it is still between the tooth surface of the gear to be ground and the tip of the grindstone. A gap eliminator that secures a minute gap, fastens the gear to be ground to the mounting spindle in this state, starts rotation of the grindstone, and pulls the steel belt to eliminate the minute gap. The ® down position confirmed by the occurrence of sparks, so that to start the actual teeth grinding step to establish the grinding start position. In this way, since the gear to be ground and the mounting spindle are fastened after the gap elimination position was initially established, the gear to be ground is moved away from the grinding position in response to the end of the grinding operation of one tooth. If the next tooth flank to be ground is split and the tooth flank to be ground is returned to the grinding start position and grinding is performed again with the grindstone, the gear grinding process will be performed sequentially for each tooth. Will be applied to. In the conventional process described above, in the process of initializing the grinding start position of the gear, pay close attention to the operator in the process of determining the gap elimination position where the grinding wheel contacts the tooth surface to be ground and starts grinding. Therefore, the amount of high-speed idling time of the grindstone inevitably depends on the skill of the operator. Therefore, the grinding wheel idle time,
The so-called air cut time tended to be long. That is,
In the conventional gear grinding machine, in order to start grinding each tooth, (1) index the tooth surface to be ground of the gear to be ground set on the grinding machine at the indexing position retracted from the grinding position, and (2) indexing Move the tooth surface directly below the grinding wheel that does not contact the grinding wheel, that is, to the standby position near the grinding start position, and (3) establish the initial gap elimination position, and then set the gear to be ground as the spindle for the grinding machine. (4) A series of steps for performing grinding while performing a generating motion using a belt and a rolling disk for the gear to be ground are performed to prevent the synchronism from slipping tightly. The initial work process of bringing the tooth surface into contact with the grindstone is a manned work process that depends on the skill of the operator, and it takes a relatively long time, so the labor saving of the gear grinding machine and the efficiency of the work are improved. And It has been a cause harm.

[Problems to be Solved by the Invention]

Therefore, NC gear grinders that have introduced a numerical control method as part of automation of gear grinders tend to employ various gap eliminators to reduce the air cut time as described above in order to save labor. Moreover, there is a tendency to demand the development of a more accurate gap eliminator.

Accordingly, the present invention is to provide a gap eliminator that is effective when applied to the NC gear grinding machine described above.

Another object of the present invention is to provide an NC gear grinding method and a gap for an NC gear grinding machine that significantly reduces the initial air cut time from setting the gear to be ground on the grinding machine to establishing the start of grinding. The purpose is to provide an eliminator.

[Means for Solving the Problems]

In order to achieve the above object, according to the present invention, there is provided a first drive means for rotating an attachment spindle of a gear to be ground about an axis and a first translation means for translating the attachment spindle in a direction perpendicular to the axis. In an NC gear grinding machine equipped with two driving means, an NC device for synchronously operating the first and second driving means, and a grinding wheel provided at a predetermined grinding position, the NC gear grinding machine is moved away from the grinding start position. Phase detecting means for detecting and calculating the tooth surface phase of the gear to be ground on the mounting spindle at the phase indexing position of the gear; and the first and second tooth surface phase data based on the tooth surface phase data detected by the phase detecting means. The gear to be ground is moved closer to the grinding start position from the phase indexing position of the gear by the driving means, and the gear to be ground is moved to the standby position where the tooth flank to be ground faces the grinding wheel via a minute gap. To be moved forward Structure comprising tooth surface indexing control means and detection means for detecting contact with the grinding wheel when the tooth surface to be ground moves in parallel from the standby position to the grinding start position by eliminating the minute gap An NC gear grinding machine gap eliminator is provided.

The phase detecting means for detecting the tooth flank phase of the gear to be ground includes a proximity sensor installed close to the tooth tip of the gear to be ground, a rotary encoder provided to detect the rotation of the mounting spindle of the gear to be ground, and these proximity sensors. And a calculation means for detecting and calculating the phase of the tooth flank to be ground based on the output information of the sensor and the rotary encoder, and the contact between the tooth flank to be ground of the gear to be ground and the rotary grindstone is the main bearing stand or grinding. It is effective to detect with an AE (Acoustic Emission) sensor attached to the grinding wheel bearing base.

[Action]

Has a gap eliminator configured as above
When the gear to be ground is set on the NC gear grinder, the gear sensor (proximity sensor) reads the tooth tip and tooth groove position information of the gear and the angular encoder angle information indication value at that time at the phase indexing position. . From these values and the gear specifications of the gear to be ground that have been input in advance, the tooth surface phase is calculated so that the tooth surface of the gear and the rotating grindstone do not come into contact with each other when parallel movement occurs simultaneously with the turning motion. The gear is rotated up to. At this time, the tooth surface is determined by indexing and determining the tooth surface to be ground by the grinding wheel, so that the tooth surface to be ground itself can be moved and displaced to the standby position directly below the grinding wheel. That is, the moving amount S _t of the spindle and the rotation angle θ of the spindle of the calculated and detected tooth surface from the detection position to the tooth surface grinding standby position satisfy the relationship of S _t = r · θ (r: rolling circle radius). Thus, the gear moves to the grinding standby position without interfering with the grindstone. From the grinding standby position to the grinding start position where it comes into contact with the grindstone, only the parallel movement of the spindle to which the gear to be ground is attached (without rotation) was reached, and the moment when the grindstone and the tooth surface contacted was set on the main bearing stand. The AE sensor detects this and the grinding operation starts. The grinding wheel that rotates at a high speed during this period does not need to stop its rotation.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to the embodiments shown in the accompanying drawings. FIG. 1A is a perspective view schematically showing the essential configuration of an NC gear grinding machine equipped with a gap eliminator mechanism according to the present invention, and FIG. 1B is an NC gear grinding machine equipped with the gap eliminator mechanism. It is a block diagram showing an operating mechanism.

In the NC gear grinding machine shown in FIGS. 1A and 1B, the gear to be ground 1 is mounted on the mounting spindle 2 of the gear grinding machine. The mounting main shaft 2 is rotatably supported by a slide 3 via a rotary bearing (not shown), and a forward / reverse direction is provided by a servomotor 4 forming a first driving means via a transmission mechanism including a worm gear 5a and a worm wheel 5b. It is driven to rotate in both directions.

A well-known rotary encoder 6 is connected to the mounting spindle 2 by an appropriate method to detect the spindle rotation angle.

The slide 3 is translated by a second drive means 7 (servo motor) via a feed screw 8 in a direction perpendicular to the axis of the mounting spindle 2 on a bed (not shown) of the grinder and at the same time. The displacement position is detected by a known linear displacement detecting means 9 such as a linear scale or a linear encoder, which is fixedly installed on the bed of the grinding machine.

The above-mentioned first and second driving means 4 and 7 generate a generating movement during the grinding action between the grinding tooth surface of the gear to be ground 1 and the rotary grindstone 11 and in the action of eliminating the minute gap according to the present invention. It is used as a driving source. Above slide 3
An AE (Acoustic Emission) sensor 10 is attached at an appropriate position above, and is connected to a CPU 13 via an amplifier 14 as described later, and a gear to be ground is applied to a rotating grindstone 11 of a grinding wheel that rotates at a high speed at a fixed position. When 1 makes an approaching motion and detects a voice signal generated at the time of contact between the two, the detection signal is applied to the CPU 13. That is, the grinding start position is detected.

On the other hand, the position of the gear to be ground shown by the imaginary line in FIG. 1A is the phase indexing position which is distant from the grinding start position, and when it is at this phase indexing position, the fixed position outside the slide 3 is fixed. As will be described later, the tooth flank sensor 12 arranged at the position detects the tooth flank phase of the gear to be ground. Further, as shown in FIG. 1B, a central processing unit (the above-mentioned CPU 13) forming a part of the NC device for controlling the NC gear grinding machine is provided, and based on the information signals from the tooth surface sensor 12 and the rotary encoder 6. A system for controlling the servomotors 4 and 7 through a servo amplifier by performing a predetermined arithmetic process is constructed.

2 and 3 illustrate the operating principle of the gap eliminator according to the invention.

In FIG. 2, a gear position B is a grinding standby position in which one tooth surface of the gear to be ground 1 mounted on the mounting spindle 2 is positioned immediately below the rotary grindstone 11, and at the same position, FIG. )
As shown in FIG. 3, the tooth surface was separated from the grinding start position (FIG. 3 (b)) where the grindstone 11 entered the tooth groove and contacted the grindstone 11 by a small amount G in the direction perpendicular to the main axis. It is the position in the state.

On the other hand, the gear position A in FIG. 2 is set on the gear grinding machine at a position retracted and separated from the gear position B by a sufficiently large distance S in the direction perpendicular to the main shaft, and is placed on the gear grinding machine to rotate at a fixed position at a high speed with the rotating grindstone 11 and the workpiece. This is a position (tooth surface phase indexing position) where there is no possibility that the grinding gear 1 interferes. Now, where the rolling circle radius of the gear r, the rotational angle of the main shaft theta, if the translation distance was _{S t S t = γ · θ} ...... (1) relationship from the gear phase indexing position A When the synchronous movement of the rotational movement and the parallel movement of the mounting spindle 2 is performed while maintaining the above, if the phase of the gear is adjusted at the A position before the movement starts, the tooth surface and the grindstone from the A position to the grinding standby position B point. Can move without causing interference. At the position A, the above-mentioned tooth surface sensor 12 is provided in order to detect one tooth surface phase of the gear 1 to be ground, actually the phase of the tooth surface to be ground. The tooth surface sensor 12 can be configured by a well-known proximity sensor of a non-contact detection type, and an optical sensor using an LED, an electromagnetic sensor using an eddy current, or the like can be used as well. The gear sensor 12 is mounted at a predetermined position outside the slide 3 on the gear grinding machine in the radial direction of the gear to be ground 1 so as to face the tooth tips, and according to the size of the gear to be ground. The position can be adjusted in the radial direction.

FIG. 4 shows the output of the gear sensor 12 when the gear 1 to be ground rotates around the main shaft at the gear position A for phase indexing.

Here, the signal waveform diagram (F) in FIG. 4 shows the output pulse of the tooth surface sensor 12 when the gear is normally rotated at the phase indexing position. The high level H is the tooth tip portion, and the low level L is the low level L. It corresponds to the root part. Further, the signal waveform diagram (B) in FIG. 4 shows the output pulse for the same tooth as in (F) when the gear is rotated in the reverse direction. Now, the output pulse when the gear rotates in the normal direction is H → L. The angle of 3 pulses Pf ₁ , Pf ₂ , Pf ₃ are read by the rotary encoder 6 connected to the main shaft, and the same as when the gear is rotated in the forward direction. H → L when reversing teeth
Pb ₁ , Pb ₂ and Pb ₃ for 3 pulses at an angle of Pb ₁ −
Since there is a tooth bottom between Pf ₃ , Pb ₂ −Pf ₃ and Pb ₃ −Pf ₁ , the phase of the gear at the position A can be obtained by averaging the above numerical values by the CPU 13, and In advance
Using the distance between the AB2 positions and the radius of the rolling circle input to the CPU13 to synchronize the rotary motion and the linear motion as described above, when moving from the A position to the B position, the B position is moved to the position of FIG. 3 (a). The phase at the A position for coming is calculated, and the rotation angle for adjusting the gear to that phase is obtained. At this time, when it is necessary to start grinding from a certain specific tooth surface (for example, the tooth surface of FIG. 2C), a tooth surface used by the tooth surface sensor 12 to detect the phase at the phase indexing position, If the phase difference with the specific tooth flank C is input to the CPU 13 in advance, when the gear 1 to be ground is moved to the grinding standby position, the specific tooth flank C will be in the grinding standby state at the position A. You can also adjust the phase. In the above example, when detecting the gear phase, the pulse for three teeth was read in each of the forward rotation and the reverse rotation, because the outer diameter part of the gear has little relation to the gear performance and the machining accuracy is low and the shaving cutter This is to prevent the gear phase detection accuracy from being lowered due to the influence of serration grooves and the like.

After adjusting the gear phase at the position A, the gear 1 to be ground performs the above-described synchronous movement and comes to the grinding standby position in FIG. 3 (a). From this grinding standby position, only the parallel movement of the mounting spindle 2 occurs, and when the rotating grindstone 11 and the tooth flank to be ground come into contact (the state of FIG. 3 (b)), the AE sensor 10 causes the grindstone to move.
The contact between 11 and the tooth surface to be ground is detected to set the grinding start point. The detection signal of the AE sensor 10 is input to the CPU 13.

After that, the CPU 13 controls the operation of the two servomotors 4 and 7 forming the first and second driving means on the tooth surface to be ground of the gear to be ground 1 with respect to the grindstone 11 to perform the tooth profile creating motion on the tooth surface. By doing so, grinding is achieved.

The above process is shown in a flowchart of FIG. The above description is from the mounting of the gear to be ground 1 on the gear grinding machine to the start of grinding any one of the tooth flanks. The gear to be ground 1 is returned to the phase indexing position by the operation, and the gear to be ground can be detached from the mounting spindle to perform tooth measurement or the like.

〔The invention's effect〕

Since the present invention is configured as described above, the grinding start is automatically performed only by mounting the gear to be ground on the spindle of the grinder at a fixed position and adjusting the radial direction of the gear sensor so that the tip portion can be detected. Since it is performed in a conventional manner, the work requiring skill as in the past is not required, and the air cutting time is shortened, so that the grinding work time of each gear is significantly shortened.

Further, if the gap eliminator according to the present invention is provided, in the automatic gear grinding process by the NC gear grinding machine,
Both the process of positioning the tooth flanks to be ground next to the standby position directly under the grinding wheel and the process of positioning to the grinding start position where the tooth flanks to be waited at the standby position via the minute gap are brought into contact with the grindstone are both high. It is possible to obtain an effect that can be performed with accuracy.

[Brief description of drawings]

FIG. 1A shows a gap eliminator according to the present invention.
A schematic view of a main part of an NC gear grinding machine, FIG. 1B is a control system diagram showing an operation system of the same gear grinding machine, and FIGS. 2 and 3 show an operation principle of a gap eliminator according to the present invention.
FIG. 2 is a schematic view showing the phase indexing position of the gear to be ground and the grinding standby position, FIG. 3 is an enlarged tooth surface view showing the grinding standby position and the grinding start position, and FIG. 4 is the principle of tooth surface phase detection. The output pulse shape diagram of the tooth surface sensor showing the. FIG. 5 is an operation flowchart of the gap eliminator for NC gear grinding machine according to the present invention. 1 ... Gear to be ground, 2 ... Mounting spindle, 3 ... Slide, 4 ...
… Servo motor, 5a …… Worm gear, 5b… Worm wheel, 6 …… Rotary encoder, 7 …… Servo motor, 8 …… Feeding shaft, J, 9 …… Linear encoder,
10 …… Acoustic emission sensor, 11 …… Grinding wheel, 12 …… Tooth surface sensor, 13 …… CPU.

Claims (5)

[Claims] 1. A first mounting shaft of a gear to be ground is provided around a shaft center.
To rotate the main shaft in parallel to the main shaft in a direction perpendicular to the axis by the second drive means to generate a generating motion on the tooth flank of the gear to be ground, In the NC gear grinding method that grinds the tooth surface with the grinding wheel provided at a fixed position, the tooth surface phase of the gear to be ground is detected and calculated at the phase indexing position of the gear, which is far from the grinding start position, and the calculation result The phase is adjusted to a predetermined value determined by the distance to the grinding start position and the rolling circle radius of the gear, and then the main shaft is paralleled by the first and second driving means in synchronization with the turning. The grinding wheel is moved to the grinding standby position where the grinding wheel and the gear to be ground face each other through the gap, and then the main shaft is moved in parallel by the second driving means to bring the grindstone and the tooth surface to be ground into contact with each other. NC gear grinding method which comprises causing automatically perform grinding start position detected by the working until the start of grinding that. 2. The NC according to claim 1, wherein in the tooth surface phase detection, a reading error due to a proximity sensor is eliminated by detecting and calculating a phase while rotating the gear forward and backward. Gear grinding method. 3. A first driving means for rotating a mounting main shaft of a gear to be ground around an axis, and a second driving means for translating the mounting main shaft in a direction perpendicular to the axis, the first,
In a gap eliminator provided in an NC gear grinding machine equipped with an NC device for synchronously operating the second drive means and a grinding wheel provided at a predetermined grinding position, a phase separation of the gears separated from the grinding start position is performed. Phase detection means for detecting and calculating the tooth surface phase of the gear to be ground on the mounting spindle at the extended position, and the first and second drive means for the tooth surface phase data detected by the phase detecting means. The gear to be ground is moved closer to and moved from the phase indexing position of the gear to the grinding start position, and the gear to be ground is moved forward to a standby position where the tooth surface to be ground faces the grinding wheel via a small gap. Grinding tooth surface indexing control means and detection for detecting contact of the grinding wheel when the grinding tooth surface moves in parallel from the standby position to the grinding start position by eliminating the minute gap. A gap eliminator for an NC gear grinding machine, which is characterized in that it has a structure including: 4. The tooth surface phase detection device comprises a proximity sensor provided at a fixed position in the radial direction of the gear to be ground, and a rotary encoder connected to the mounting spindle. A gap eliminator for an NC gear grinding machine according to item 3. 5. The gap for an NC gear grinding machine according to claim 3, wherein the contact detecting device between the tooth surface and the grindstone comprises an AE sensor mounted on the main bearing stand or the grinding wheel wheel bearing stand. Eliminator.