JP2601397B2 - Helical gear continuous production method and production equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous production method of helical gears and a production facility therefor.

[0002]

2. Description of the Related Art Conventionally, when manufacturing a helical gear, as a general manufacturing method, a gear material is manufactured by cutting a material from a round bar steel and then performing cutting or hot, warm, or cold forging. The gear material is subjected to gear cutting with a hobbing machine, and finishing is performed with a shaving hob machine. If further accuracy is required, polishing is performed after the heat treatment. In order to suppress the rotation noise, a crowning process is separately performed. However, there is a problem that the hobbing operation requires a very long processing time. As a method for solving the above problem, it is very effective if a helical gear can be manufactured by press working. JP-A-63-2531 and JP-A-6
Japanese Patent Application Laid-Open No. 3-2532 discloses a method for manufacturing a spur gear in a single step with high accuracy.

[0003]

However, in the case of a helical gear, the helical line, which is the line of intersection between the tooth surface and the pitch surface, is a spiral line. On the other hand, the direction in which the shearing force generated by the punch and the female die according to the conventional method acts is only the vertical direction. Therefore, the above method cannot be used as it is because it does not match the direction of the helical gear. The present invention has been made in order to solve the above problems, and by making a female die spiral, it is possible to produce a helical gear by press working, thereby reducing the processing time. It is an object of the present invention to provide a helical gear continuous production method and production equipment that can be significantly shortened.

[0004]

According to the present invention, as a specific means for solving the above-mentioned problems, as shown in FIG. 1, the upper and lower surfaces are previously formed into a required shape by an arbitrary processing method. A gear material 1 having an outer peripheral disk shape is prepared, and the gear material 1 has a predetermined torsion angle so that the gear material 1 can be subjected to a tooth profile cutting in a cold state.
In addition, an irregular involute curve in which the tooth width is smaller than the finished tooth profile by the tooth width on the tooth bottom side than the reference pitch circle radius, and the tooth width is larger by the extra thickness than the finished tooth shape on the tooth tip side than the reference pitch circle radius. A female die 2 having an inlet tapered portion 20 at the upper entrance, and a die hole having a straight portion 21, a reverse tapered portion 22, and a relief portion 23 following the inlet tapered portion 20. Female dice 2
Next, the gear blank 1 is sandwiched between the counter 13 and the punch 3 from above and below, and the gear blank 1 is lowered from the inlet tapered section 20 to the relief section 23.
The female material 2 is passed through the female die 2 by raising the relief material 23 from the relief portion 23 to the inlet taper portion 20 to perform tooth profile cutting on the outer periphery of the gear material 1. Finished female die 2 having a predetermined torsion angle for sizing and having a substantially finished tooth shape
Having a chamfer 24 at the upper entrance and an entry taper 20 with a very small taper,
Subsequently, the gear material 1 having a tooth-shaped outer periphery is countered on a finished female die 2 having a straight portion 21, a reverse taper portion 22 having a very small taper, and a helical die hole having a relief portion 23. 13 and the punch 3 sandwich the gear material 1 from the inlet tapered portion 20 to the relief portion 23.
Is moved down to generate the debris, and then raised from the relief portion 23 of the finished female die 2 to the entrance taper portion 20 to allow the finished female die 2 to pass therethrough so that the gear material whose outer periphery forms a tooth shape (1) A method for continuously producing a helical gear, characterized by performing a sizing process.

Further, according to the present invention, an outer disk-shaped gear material 1 whose upper and lower surfaces are processed into a required shape by an arbitrary processing method.
A helical gear production facility for press-forming cold helical gears by generating a shear force with a female die 2 and a punch 3 and punching out the helical gears. It has a torsion angle, the outer circumference is larger than the finished tooth profile by the extra thickness, and the tooth width is smaller than the finished pitch profile by the extra thickness on the tooth bottom side, and the tooth width on the tooth tip side from the reference pitch radius is smaller than the finished pitch profile. Is a female die 2 having an irregular involute curve transcribed by a margin larger than the finished tooth profile. The female die 2 has an entrance taper portion 20 at an upper entrance and a straight portion 2 following the entrance taper portion 20.
1. A die hole having a reverse taper portion 22 and a relief portion 23 is formed. The tooth shape of the punch 3 has the same twist angle as the female die 2, and the counter 13 has the female die 2
A helical spline 5 having the same twist angle as that of the counter guide plate 12 for guiding the counter 13
A helical groove 6 having the same helix angle as the helical spline 5 is provided on the inner peripheral wall of the counter guide plate 12 so that the helical spline 5 of the counter 13 slides on the helical groove 6 of the counter guide plate 12 when the gear material 1 moves up and down. When the counter 13, the gear material 1, and the punch 3 move in a spiral motion, the female die 2 is moved to the outer disk-shaped gear material 1.
A helical gear production facility characterized by forming a helical gear is provided.

[0006]

According to the helical gear continuous production method and the production equipment of the above construction, the helical spline 5 of the counter 13 slides in the helical groove 6 of the counter guide plate 12 when the gear blank 1 moves up and down. , The counter 13, the gear blank 1, and the punch 3 make a spiral motion to process the gear blank 1 into a bevel gear.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a helical gear production facility according to the present invention will be described with reference to the accompanying drawings. FIG. 1 is a configuration diagram showing the entire helical gear production facility. The female tooth mold on the inner periphery of the female die 2 having a cylindrical shape and being a lower mold is provided with the same helix angle as the helix angle required for a product in order to process the gear material 1 into a bevel gear. The cross-sectional shape of the female die 2 is as shown in FIG.
1, a reverse taper portion 22 and a relief portion 23 are provided.
In the first step of the continuous production method, the taper angles of the inlet tapered portion 20 and the reverse tapered portion 22 are 20 degrees to 150 degrees, and are appropriately selected according to the thickness of the gear material 1. Then, the female die 2 is set in the insertion hole 17 a inside the die holder 4, and is firmly fixed by the set screw 11. The counter 13 is inserted through the inside of the female die 2, and a rotating sphere R portion 19 c provided in a spherical shape is provided at a lower end portion, and the helical spline 5 is provided at an upper portion thereof. The insertion hole 1 of the counter guide plate 12 for guiding the counter 13
A helical groove 6 having the same screw angle as the helical spline 5 is provided on the inner peripheral wall of 7c.

The pressing member 27b has a cylindrical shape, is inserted into an insertion hole 17d of a spring holder 29 provided below the counter guide 12, and is provided in a spherical shape on the upper portion so as to abut the rotating ball R portion 19c of the counter 13. And a rotating sphere R portion 19d. The lower flat surface of the pressing body 27b is pushed up by the push-up pin 28 and the spring 15c inserted into the insertion hole 17d, and
9d is pressed against the rotating ball R portion 19c of the counter 13, so that the counter 13 is rotatable. The die holder 4, the counter guide plate 12, and the spring holder 29 are fixed to the base plate 9 by bolts 30b.

A male die on the outer periphery of the upper punch 3 is provided at the same helix angle as the female die 2 in order to process the gear material 1 into a bevel gear. Further, a rotating SR portion 19b is provided at the uppermost portion, and a flange 32a is provided below the rotating SR portion 19b. The punch 3 is inserted into the insertion hole 17d of the punch holder 8. The flange 32b of the punch holder 8 is
2a. The pressing body 27a is inserted into the insertion hole 17e of the pressing body holder 33, and the rotating sphere R part 19a provided in a spherical shape at the lower end is connected to the rotating sphere R part 19b provided in the spherical shape on the uppermost part of the punch 3. The abutment makes the punch 3 freely rotatable. Also,
The springs 15b are respectively fixed to spring grooves 16a provided at several places below the punch holder 8 by mounting brackets (not shown), and the lower ends of the springs 15b are
The stripper 14 is suspended by fixing it to the spring groove 16b of the stripper 14 with a mounting bracket (not shown). Then, the punch 3 is inserted into an insertion hole 17f provided at the center of the stripper 14.

The punch holder 8 and the pressing body holder 33 are fixed to the pressure receiving plate 31 by bolts 30a. The pressure receiving plate 31 fixes two to four guide shafts 26 vertically downward on the lower surface. Each guide shaft 26
Springs 15a are respectively incorporated outside the
The tip is inserted through the lubricating metal bearing 10 fitted in the insertion hole 17b of the die holder 4. In addition, the rotating ball R
The spherical portions of the portions 19a to 19d are selected to be approximately sphere R100 to sphere R1200 mm depending on the thickness and size of the work 1 at the time of processing.

As shown in FIG. 6, the gear blank 1 can be a work with both bosses having bosses 1a and 1b on the upper and lower surfaces, respectively. Also, as shown in FIG.
The gear material 1 can be a cap work having a cap 1c. The punch 3 and the counter 13 are provided with concave portions or convex portions that match the planar shape of the gear blank 1.

Next, the tooth shape of the female die 2 will be described. The female die 2 is provided asymmetrically with respect to the center of the tooth ridge as shown in FIG. This is because the rotational movement acts when the female die 2 bites into the gear blank 1, so that the pressure on the left and right sides of the tooth ridge is not the same but becomes higher on the rotational direction side and lower on the opposite side. Therefore, if the tooth profile of the female die 2 is symmetrical with respect to the center of the tooth ridge, the tooth ridge of the processed gear material 1 will not be symmetrical. Therefore, as shown in FIG. 10, the left and right involute curves are changed by about 0.005 to 1.5 mm according to the thickness of the module and the gear material 1.

Further, due to the expansion at the time of punching which is a feature of the press working, the area of the gear blank 1 to be removed on the tooth bottom side is smaller than the reference pitch circle radius, so that the expansion coefficient becomes negative and shrinks. Further, since the area to be removed is larger on the tooth tip side than the reference pitch circle radius, the expansion rate is high. Therefore, in order to produce a high-precision gear of Japanese Industrial Standards (JIS), the tooth helical gear of the female die 2 has the tooth ridge provided on the female die 2 as shown in FIG. An irregular involute in which the tooth width is smaller than the finished tooth profile (such as JIS standard) by the extra thickness on the tooth bottom side than the reference pitch circle radius, and larger by the extra thickness than the finished tooth shape on the tooth tip side than the reference pitch circle radius. Must be manufactured on a curved tooth. The surplus portion is selected according to the size of the module, the material and thickness of the gear material 1, and the like. Basically 0.003
About 0.2 mm.

Next, the first operation of the helical gear production equipment according to the above-described configuration, which is the first step, will be described with respect to the operation at the time of descending gear cutting. First, the pressure receiving plate 31 of the helical gear according to the present embodiment is set so that the center of the pressure receiving plate 31 and the center of the press cylinder 18 of the press device substantially coincide with each other, so that the force is uniformly applied to the pressure receiving plate 31. Next, the center of the gear blank 1 is set to the center of the upper surface of the counter 13. Then, when the press cylinder 18 of the press device is lowered,
The pressure receiving plate 31 is first brought into contact with the pressure receiving surface on the pressure receiving plate 31 to push down the pressure receiving plate 31. When the pressure receiving plate 31 is depressed, the springs 15a begin to bend and the respective guide shafts 26 descend while sliding on the lubricating metal bearing 10 to protrude to the lower side of the die holder 4, and the punch 3 attached to the pressure receiving plate 31 The surrounding upper component descends. Then, the pressure receiving plate 31 further descends, and the stripper 14 and the die holder 4 come into contact with each other, so that the spring 15b starts to bend.

FIG. 3 is an explanatory diagram continuously exaggerating the state in which the gear blank 1 is processed. Press cylinder 18
As a result, the pressure receiving plate 31 is further lowered, and FIG.
When the tip of the punch 3 comes into contact with the gear blank 1, the gear blank 1 is pressed down by the counter 13 and the punch 3. The force of the counter 13 pressing the gear blank 1 is constantly applied by the spring 15c, and becomes stronger as the press cylinder 18 descends. Also, punch 3
Descends and the counter 13 is pressed downward,
From the counter 13, the pressing body 27b and the push-up pin 2
8, the spring 15c starts to bend. As a result, when the counter 13 descends, the helical spline 5 provided on the counter 13 moves the counter guide plate 1
In order to slide in the helical groove 6, the counter 13 is subjected to a rotational movement, so that the counter 13 spirally moves with the punch 3 and the gear blank 1. Then, as shown in FIG. 3 (2), the helical gear is punched from the time when the gear blank 1 and the inlet tapered portion 20 of the female die 2 shown in FIG.

As the press cylinder 18 descends, each helical spline 5 slides in the helical groove 6, whereby the counter 13, the gear blank 1 and the punch 3 descend spirally along a predetermined twist angle. As a result, an oblique shearing force is applied to the gear material 1 by the female die 2 and the punch 3, and the gear material 1 passes through the straight portion 21, the reverse tapered portion 22, and the relief portion 23 of the female die 2. In the state of 3 (3), the shaving allowance of the gear blank 1 is completely punched out, and the punch 3 becomes a bottom dead center and starts to move upward. At this point, the gear blank 1 is punched from the disc-shaped gear blank 1 into a helical gear shape. As shown in FIG. 11, the gear material 1 at this time is tapered such that the diameter of the upper surface is larger than that of the lower surface due to the effect of passing through the inlet tapered portion 22. Since a strong rotational force is applied to the gear blank 1 during the above-described processing, the gear blank 1 may be rotated. For this reason, by increasing the spring constant of the spring 15c to increase the force with which the counter 13 presses the gear blank 1, or by providing a plurality of insertion holes in the gear blank 1 as shown in FIG. The gear blank 1 is provided by a method such as providing a non-rotating pin 34 of
Can be suppressed.

Next, the operation of the helical gear production equipment when it is raised will be described. The bottom dead center of the lowering of the punch 3 can be detected by sensing the position with a limit switch, a photo sensor or the like. The switching circuit is set so that when the bottom dead center of the punch 3 is detected, the press cylinder 18 of the press machine switches to ascending. And then
When the press cylinder 18 rises, the pressure receiving plate 31 rises due to the restoring force of the spring 15a. As the pressure receiving plate 31 rises, the spring 15c is gradually restored, and the force with which the counter 13 presses the gear blank 1 decreases.

When the pressure receiving plate 31 rises, the flange 32b of the punch holder 8 is
2a by lifting the spring 15b
When the stripper 14 pushes the die holder 4 downward due to the restoring force, the punch 3 moves up inside the female die 2 with a rotational movement. Thereby, the spring 1
The push-up pin 28 is raised by the restoring force of 5c. Accordingly, the pressing body 27b, the counter 13, and the gear blank 1 rise. At this time, the helical spline 5 on the outer peripheral wall of the counter 13 slides in the helical groove 6 to apply a rotational motion, and the helical spline 5 ascends in a reverse helical motion and moves upward.

The gear material 1 is linked to the movement of the counter 13.
Spirally moves upward, whereby the gear material 1 passes through the reverse taper portion 22 from the relief portion 23 of the female die 2. At this time, as shown in FIG. 11, there is a taper (provided about 0.05 to 0.08 when the thickness of the gear material 1 is 10 mm) due to the passage through the inlet taper portion 20 at the time of descending. Then, by passing through the inverse tapered portion 22, the gear blank 1 is processed the opposite taper to that of the inlet tapered portion 20 pass, and most diameter center [phi] D ₁ of the thickness as shown in FIG. 12 Is large, and the diameter φD ₂ of the upper surface portion and the lower surface portion is reduced to the same degree (0.01 to 0.0 in diameter).
3mm). Thus, the crowning can be simultaneously performed on the gear blank 1. Crowning is a process of forming a peak on the contact surface of a gear, and has the effect of suppressing noise during meshing. Although the amount of crowning in the first step is larger than a general amount, the second step adjusts the required accuracy.

Subsequently, the gear material 1 is extracted from the female die 2 through the straight portion 21 and the inlet tapered portion 20. When the spring 15a is completely restored and the pressure receiving plate 31 returns to the initial position, the pressure receiving plate 31
Is stopped, and the operation at the time of the rising of the first step is completed. According to the first step, the gear material 1 has the inlet tapered portion 20,
By the action of the straight portion 21, the reverse taper portion 22, and the relief portion 23, the hardness of the gear material 1 does not increase, and the removal of the gear material 1 at the time of removal can be minimized.

Next, the second step of the helical gear by the above-mentioned helical gear production equipment will be described. The female die of the female die 2 used in the second step has the above-mentioned twist angle, and is provided with an inlet tapered portion 20, a straight portion 21, an inverted tapered portion 22, and a relief portion 23 as shown in FIG. ing. The angle of the inlet tapered portion 20 is 20 ° to 1
The angle is about 50 °, and an appropriate angle is separately determined by an experiment. The straight portion 21 is provided straight with a reference dimension. The reverse taper portion 22 is provided with a taper having an angle of 20 ° to 150 ° in a direction opposite to that of the inlet taper portion 20. And
The inner diameter of the relief portion 23 is increased by 10 μm to 200 μm from the reference dimension of the straight portion 21, but in the second step, the taper angle is made smaller than in the first step, and
The one reference dimension also increases accuracy. In addition, since the clearance between the female die 2 and the punch 3 is made smaller, the purpose of preventing the blade portions of the mold from hitting each other is:
Fig. 3 (1) so that there is no burr and a beautiful finish
As shown in the figure, an appropriate amount of chamfering 2 is applied to the entire periphery of the opening corner of the entrance tapered portion 20 of the female die 2 and the entire periphery of the tip corner of the punch 3.
4 is provided.

The female die 2 is prepared in two types, one for gear removal as a first step and the other for sizing as a second step. Not much precision is required for gear removal in the first step, but the gear material 1 must not be hardened in order to prevent the female dies 2 from cracking or chipping in the second step and improve the mold holding. The size of the tooth profile and the inclination of the taper are set with emphasis on. For the second step, sizing processing, slight hardening of the gear material 1 is not a problem because it is the final processing, but emphasis is placed on the precision after processing,
It is necessary to provide it close to the required standards such as JIS and the required crowning. Further, the removal amount during the sizing processing as the second step is symmetrical with respect to the upper and lower sides of the reference pitch circle radius as shown in FIG.
It is selected from the most suitable place depending on the thickness of the gear in the range of about 0.5 to 0.1 mm.

The two types of female dies 2 are set on helical gear production facilities installed on two general-purpose presses located at predetermined intervals.
The transfer of the gear material 1 between the two press machines is performed by attaching an automatic feeder such as a roll feeder or a gripper feeder, or by manual feeding by an operator. Further, it is also possible to make an automatic press by incorporating two helical gear production facilities into a transfer press apparatus in which a feed device is incorporated.

According to the above-described embodiment, since the helical gear production equipment can be incorporated into a general press, no special equipment is required. Further, the size of the manufactured helical gear can be easily changed by replacing the female die 2 and the punch 3. Further, the torsion angle of the manufactured helical gear can be changed by changing the torsion angle of the helical spline 5 and the helical groove 6 by replacing the counter 13 and the counter guide plate 12. Also, integrated into the press device,
It is also possible to use a dedicated processing device for the helical gear. Also, the rotating sphere R portions 19a to 19c which constitute the rotating mechanism of each device.
19d, depending on the thickness and size of the gear material 1 and the size of the module, it is also possible to select and use a structure in which steel balls are inserted in U grooves or V grooves as shown in FIG. 5 or a structure using a thrust bearing. it can.

[0025]

The method for producing a helical gear according to the present invention has the above-described configuration and the female die has an irregular tooth profile, so that the finished tooth profile can be a product closest to the correct standard. By realizing the press working of the helical gear, there is an excellent effect that the processing time of the helical gear can be greatly reduced, thereby making it possible to manufacture the helical gear at low cost. Also, since the helical gear production equipment of the present invention rotates the counter, the gear material, and the punch by the helical spline and the helical groove, it is possible to process the helical gear into the gear material by the female die. be able to.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing the overall configuration of the present invention.

FIG. 2 is a sectional view showing a tapered portion of a female die.

FIG. 3 is an explanatory diagram continuously showing processing of a material to be processed.

FIG. 4 is a side view of a counter and a punch provided with a detent pin for a material to be processed.

FIG. 5 is an explanatory view showing grooves and steel balls as substitutes for the rotating ball R portion.

FIG. 6 is an explanatory view showing a case where both bossed gear materials are processed.

FIG. 7 is an explanatory view showing a case where a gear material with a cap is processed.

FIG. 8 is a plan view showing the tooth profile of the female die in the first step.

FIG. 9 is a plan view showing a tooth profile of a female die in a second step.

FIG. 10 is an explanatory diagram showing a state in which the tooth profile of the female die is provided asymmetrically in the left-right direction according to the torsion direction of the helical gear.

FIG. 11 is a sectional view showing a gear material tapered by an inlet tapered portion.

FIG. 12 is a cross-sectional view showing a gear material on which crowning has been performed.

[Explanation of symbols]

1 ... Gear material, 2 ... Female dies (finished female dies),
3 ... punch, 4 ... Die holder, 5 ... Helical spline, 6 ... Helical groove, 12 ... Counter guide plate, 13 ... Counter, 15a-15c ... Spring, 17a-17f ... Insertion hole, 20 .. .Inlet taper part, 21 ... straight part, 22 ... reverse taper part, 23 ... relief part

 ──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-2-63632 (JP, A) JP-A-59-56916 (JP, A) JP-A-61-129248 (JP, A) JP-A-62 28040 (JP, A) JP-A-63-2531 (JP, A) JP-A-5-138284 (JP, A) JP-A-57-134230 (JP, A) JP-A-63-2532 (JP, A)

Claims (2)

(57) [Claims] 1. An outer disk-shaped gear material in which upper and lower surfaces are processed into a required shape by an arbitrary processing method is prepared in advance, and a predetermined torsion angle is set so that the gear material is cold-formed with a tooth profile. The outer circumference is larger than the finished tooth profile by the extra thickness, and the tooth width is smaller than the finished tooth profile by the extra thickness on the tooth bottom side than the reference pitch circle radius, and the tooth width is finished on the tooth tip side than the reference pitch circle radius. A female die that transfers an irregular involute curve that is larger than the tooth profile by the extra thickness,
A female die having an inlet tapered portion at the upper inlet and a die hole having a straight portion, a reverse tapered portion, and a relief portion following the inlet tapered portion, the gear material is vertically moved by a counter and a punch. After pinching and lowering the gear material from the inlet tapered portion to the relief portion, subsequently raising the female die from the relief portion to the inlet tapered portion to allow the female die to pass therethrough and to form a tooth profile on the outer periphery of the gear material A finishing female die having a predetermined helix angle and a substantially finished tooth shape for cold sizing of a gear material having a tooth shape with an outer periphery, and a chamfered upper entrance. A helical die hole having a straight part, a reverse taper part with a very small taper and a relief part following the inlet taper part and a small taper inlet taper part. On the finished female die formed by drilling, the gear material whose outer periphery is tooth-shaped is sandwiched from above and below by a counter and a punch, the gear material is lowered from the inlet tapered portion to the relief portion, and after removing debris is generated, subsequently The sizing process is performed on a gear material having a tooth profile with the outer periphery formed by passing the finishing female die by raising the relief portion from the relief portion of the finishing female die to an inlet taper portion, a continuation of the helical gear. Production method. 2. A helical gear having a cold helical gear formed by punching an outer disk-shaped gear material obtained by processing the upper and lower surfaces into a required shape by an arbitrary processing method using a female die and a punch by generating a shearing force. A helical gear production facility for press forming, wherein the tooth profile of the female die has a predetermined torsion angle, the outer circumference is larger than the finished tooth profile by the extra thickness, and at the tooth bottom side from the reference pitch circle radius. A female die in which an irregular involute curve in which the tooth width is smaller than the finished tooth profile by the extra thickness, and the tooth width is larger than the finished tooth profile by the extra thickness on the tip side of the reference pitch circle radius, The inlet has a taper at the inlet and a straight part following the taper at the inlet,
A die hole having a reverse taper portion and a relief portion is formed, the tooth profile of the punch has the same helix angle as the female die, and the counter is provided with a helical spline having the same helix angle as the female die. A helical groove having the same helix angle as the helical spline is provided on the inner peripheral wall of the counter guide plate for guiding the counter, and the helical spline of the counter is moved by the helical groove of the counter guide plate when the gear material moves up and down. Wherein the counter die, the gear material, and the punch make a spiral motion, whereby the female die forms a helical gear on the outer disk-shaped gear material. Facility.