JPH07276138A - Lapping engineering of hypoid gear - Google Patents

Abstract

PURPOSE:To provide lapping engineering of a hypoid gear capable of shortening cycle time by maintaining surface roughness. CONSTITUTION:The number of swing of a pinion gear 2 is detected by providing a swing number detection means 21. A brake torque setting means 19a for rough machining and a brake torque setting means 19b for finish machining are provided in front of a brake gear 20, and one of them is selected by a torque changeover means 22 in accordance with the detected number of swing. Electric power to generate large brake torque is supplied to the brake gear 20 at the time of rough machining, and lapping with large machining allowance is carried out by the small number of swing. Electric power to generate small brake torque is supplied at the time of finish machining, and favourable surface roughness is secured. It is possible to shorten cycle time by reducing the total number of swing by way of combining two step machining.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for lapping a hypoid gear that removes the burning strain after carburizing and smoothes the meshing with a pinion gear, and more particularly to a method for shortening the lapping cycle time.

[0002]

2. Description of the Related Art Hypoid gears used for vehicle parts or the like are usually subjected to lapping in order to remove the burning strain after carburization and smooth the mesh.

The conventional lapping process is shown in FIGS.
No. 0 is used for the hypoid gear wrapper, and the processing method thereof will be briefly described below. FIG. 7 (A) is an external perspective view showing the outline of a hypoid gear wrapper, in which a hypoid gear 1 to be subjected to lapping and a pinion gear 2 used in combination with the hypoid gear 1 are attached to predetermined positions of the wrapper. It is in mesh.
In this device, the pinion gear 2 is on the input shaft side, and as shown in FIG. 7 (B), the pinion gear 2 swings horizontally (white arrow 3 in the figure) around the meshing center, while rotating normally and reversely (in the figure). The input rotation of the white arrow 4) is performed. On the other hand, a constant brake torque (arrow 6 in the figure) is applied to the pinion gear 2 from the brake mechanism 5 according to the input rotation direction, and in this state, lapping is performed while compounding the meshing portion.

FIG. 8 is a diagram showing the outline of the swing mechanism of the wrapper. When the swing cam 7 is driven by a servomotor, the cam follower 8 is moved, and further the springs 9 and 10 act to guide the rollers 11 and 12. The swinging part 16 shown by the broken line is configured to swing along the pedestal 15 shown by the solid line by tracing 13 and 14. The center of this swing is set at the meshing center 17 between the hypoid gear 1 and the pinion gear 2.

FIG. 9 is a block diagram showing the control of the brake torque applied to the hypoid gear 1, where 18 is the power source of the brake mechanism 5, 19 is the brake setting means, and 20 is the brake device. As the brake torque setting means 19, for example, control of current or voltage by a variable resistor or the like is effective.
A powder brake that uses magnetic iron powder for torque transmission is suitable.

By the way, in the lapping process by the above-mentioned wrapper, the brake torque and the number of swings (the number of passes) are appropriately set according to the meshing accuracy required for the hypoid gear 1 and the pinion gear 2. As shown in FIG. 6 (A), the magnitude of the brake torque affects the tooth allowance, and the greater the brake torque, the more efficient. The magnitude of the brake torque also affects the surface roughness of the tooth surface, and the larger the brake torque is, the rougher the tooth surface is when the number of swings is the same.

FIG. 10 shows an example of setting the brake torque and the number of swings in the conventional lapping process. In this case, the brake torque is 3.75 for both forward and reverse rotations.
Kgf · m and the number of swings are set to 13 times for both forward rotation and reverse rotation, for a total of 26 times. This machining (Fig. 6 (B))
877), the cycle time required to complete
Seconds. The reason why the side of the pinion gear 2 is swung is to machine the entire tooth surface evenly, and the direction of normal rotation and reverse rotation of the side of the pinion gear 2 is to machine both sides of the tooth surface. Then, the hypoid gear 1 and the pinion gear 2 that have finished this lapping process will be used in a pair thereafter.

[0008]

According to the conventional lapping method described above, only one type of brake torque can be set. Therefore, if the brake torque is increased to shorten the cycle time, the surface roughness must be sacrificed to some extent. On the contrary, if the brake torque is reduced to obtain a good surface roughness, the cycle time becomes long and the productivity is lowered. In particular, when the size of the hypoid gear is increased, a large increase in cycle time is unavoidable. Therefore, the present invention shortens the cycle time without degrading the quality such as surface roughness, thereby improving productivity. The purpose is to provide a wrapping method for hypoid gears.

[0009]

The present invention has been made to solve the above-mentioned problems, and a hypoid gear is meshed with a pinion gear mounted on the input shaft side, and a compound is applied to the meshing portion, and the pinion gear is attached. In the hypoid gear wrapping method in which the hypoid gear is lapped in the normal rotation and the reverse rotation while swinging around the meshing center, and the predetermined brake torque is applied, the braking torque applied to the hypoid gear is set in plural stages, and the pinion gear is set. Is detected, and the braking torque is switched stepwise to a smaller one during processing in accordance with the increase in the number of swings, which is a lapping method for a hypoid gear.

Further, the present invention is characterized in that the braking torque of the hypoid gear is reduced steplessly as the number of swings increases. In this case, the surface roughness of the hypoid gear increases as the number of swings increases. It is preferable to control the brake torque so that the degree increases linearly.

[0011]

According to the above-mentioned means, the brake torque is reduced stepwise or steplessly during machining according to the detected number of passes. The cost is increased, and it becomes possible to perform processing such that good surface roughness can be obtained with a small brake torque in the latter stage of processing. Therefore, in the initial rough machining with a large torque, a large machining allowance can be secured to shorten the cycle time, and in the latter stage finishing machining with a small torque, a desired surface roughness can be secured, improving quality and productivity. Can achieve both.

Further, if the brake torque is controlled so that the surface roughness of the hypoid gear is linearly improved with the increase of the number of swings, the machining allowance and the surface roughness are properly balanced, and the shortest number of swings is required. Enables wrapping processing.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a hypoid gear lapping method according to the present invention will be described with reference to the drawings.

The block diagram of FIG. 1 shows an embodiment of a brake mechanism 5 which enables the first construction method of the present invention.
As a brake torque setting means for setting the brake torque of the brake device 20, two stages of brake torque setting means 19a, 1 having different sizes for rough machining and finish machining are used.
9b, a swing number detecting means 21 for detecting the number of swings 3 of the pinion gear 2 (that is, the number of passes), and a brake torque setting means 19a, 19b of two stages in response to a signal from the swing number detecting means 21. A torque switching means 22 for selecting and switching one of them is provided in addition to the conventional example of FIG.

In the case of the lapping device provided with the above-mentioned brake mechanism 5, for example, as shown in FIG. 2, the brake torque setting means 19a for rough machining is set to 7.5 Kgf · m and the brake torque for finish machining is set. Setting means 19b
Is set to 2.5 Kgf · m, the number of swings during rough machining is 6 and the number of swings during finishing is 14; a total of 20 swings, and a total of 26 swings with a brake torque of 3.75 Kgf · m. It is possible to complete the lapping process equivalent to that of the conventional method, and the cycle time is 87
It is reduced from 7 seconds to 668 seconds. That is, in rough machining with a large brake torque, as shown in FIG. 3A, although the machining allowance due to lapping is large, the tooth surface becomes rough due to the large force applied to the tooth surface. Further, in finishing with a small brake torque, as shown in FIG. 3 (B), although the machining allowance due to lapping is small, the surface roughness of the tooth surface is good because the force applied to the tooth surface is small. Note that FIG. 6A shows a concrete example of such a characteristic, which is 2 Kgf · m, 4 K
The relationship between the tooth allowance and the number of swings, and the relationship between the surface roughness and the number of swings are shown for each of the brake torques of gf · m and 8 kgf · m.

6 (B) and 6 (C) show the lapping processing characteristics of the above-described method of the present invention and the conventional method in comparison, with a machining allowance of 0.02 mm and a surface roughness of 7 μm. The number of swings required to obtain the degree is reduced from 13 times to 10 times during normal rotation (or reverse rotation).

FIG. 4 is a block diagram showing a more specific configuration example for realizing the detection of the number of swings and the switching of the brake torque. The limit switch 24 picks up the movement of the swing cam 7 driven by the servo motor 23, The signal is input to the sequencer 25. The sequencer 25 receiving this signal selects the high load counter 26 installed in the line of the brake torque setting means (for example, variable resistor) 19a for rough machining according to the machining process, and the counter 26 counts a predetermined number of swings. Until then, electric power for generating a high brake torque is supplied from the power source 18 to the brake device 20 through this line. And
After the high load counter 26 counts a predetermined number of swings, the sequencer 25 switches to the low load counter 27, so that the electric power for generating the brake torque passes through the line of the low brake torque setting means 19b for finishing and the brake device. 20. Although FIG. 4 shows two counters, a high load counter 26 and a low load counter 27, actually two counters (four in total) are required for the forward rotation and the reverse rotation, respectively. Also,
In the figure, 28 is a servo amplifier, 29 is an encoder, and 30 is a rotation drive motor for the pinion gear 2. In addition, in the above embodiment, the brake torque is set in two stages, but it goes without saying that it can be set in three or more stages.

Next, the block diagram of FIG. 5 shows an embodiment of the brake mechanism 5 which enables the second construction method of the present invention, and replaces the brake torque setting means 19a, 19b and the torque switching means 22. A brake torque control unit 31 is provided. As shown in FIG. 6D, the brake torque control unit 31 controls the power supply 18 so that the brake torque decreases steplessly as the number of swings increases, that is, in a continuous straight line or curve without steps. The electric power supplied to the braking device 20 is controlled. In particular, it is ideal to set the brake torque so that the surface roughness increases linearly with the increase in the number of swings, and good surface roughness can be obtained with the shortest number of swings (thus, the cycle time is also minimum). . If such a construction method is adopted, as shown in FIG.
It is expected that machining similar to the conventional method shown in (B) will be completed in about 8 swings, and a drastic reduction in cycle time can be expected.

[0019]

According to the lapping method for a hypoid gear of the present invention described above, the cycle time can be greatly shortened without deteriorating the quality of the surface roughness, and the effect of cost reduction due to the improvement of productivity is exerted.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration example of a brake mechanism according to a first lapping method of the present invention.

FIG. 2 is a diagram showing an example of setting the brake torque and the number of swings according to the first lapping method of the present invention.

FIG. 3 is an enlarged view of tooth flanks showing different machining characteristics depending on the magnitude of brake torque.

FIG. 4 is a block diagram showing a more specific version of FIG.

FIG. 5 is a block diagram showing a configuration example of a brake mechanism according to a second lapping method of the present invention.

FIG. 6 is a diagram showing a relationship and characteristics of a brake torque, a machining allowance, a surface roughness, and a number of swings in lapping.

FIG. 7 is an external perspective view showing the outline of a hypoid gear wrapper.

FIG. 8 is a plan view showing the outline of the swing mechanism of the wrapper.

FIG. 9 is a block diagram showing a configuration example of a brake mechanism according to a conventional construction method.

FIG. 10 is a diagram showing an example of setting a brake torque and a number of swings according to a conventional method.

[Explanation of symbols]

 1 Hypoid Gear 2 Pinion Gear 5 Brake Mechanism 17 Engagement Center 18 Power Supply 19 Brake Torque Setting Means 19a Brake Torque Setting Means (for Roughing) 19b Brake Torque Setting Means (for Finishing) 20 Brake Device 21 Swing Count Detection Means 22 Torque Switching Means 24 Limit switch 25 Sequencer 26 High load counter 27 Low load counter 31 Brake torque controller

Claims (3)

[Claims] 1. A pinion gear mounted on the input shaft side is meshed with a hypoid gear, a compound is applied to the meshing part, and the pinion gear is rotated forward and backward while swinging about the meshing center to apply a predetermined brake torque. In the hypoid gear lapping method for lapping the hypoid gear, the brake torque applied to the hypoid gear is set in multiple stages, the number of swings of the pinion gear is detected, and the brake torque is processed according to the increase in the number of swings. A hypoid gear wrapping method characterized by gradually switching to smaller ones. 2. The lapping method according to claim 1, wherein the braking torque of the hypoid gear is reduced steplessly as the number of swings increases. 3. The lapping method according to claim 2, wherein the braking torque is controlled so that the surface roughness of the hypoid gear is linearly improved as the number of swings is increased.