JPH08309499A - Method and equipment for manufacturing gear - Google Patents

Abstract

PURPOSE: To mass-produce die cast gears of excellent precision at a low cost by filling the molten metal in each cavity, separating a third die and a first die in the vertical direction to the enclosed surface, and retracting a second die in the direction parallel to the enclosed surface of either of the first die or the third die. CONSTITUTION: When a molten metal extruding mechanism is operated, the molten metal flows from a sprue 10 to a spreading part 9 through a columnar runner 11, and is poured into gear body parts 6, 6 of each cavity from gates 15, 15... successively through a plate runner 12 and branched runners 14, 14..., and expanded to tooth parts 7, 7.... When the molten metal in the die is solidified, a seaming mechanism is operated, and a movable die 1 is retracted from a fixed die 3, and the castings are detached from the fixed die 3 together with the movable die 1. A spreading pin 8 helps a cast part by the columnar runner 11 to be smoothly separated at the sprue 10. The obtained castings are a plurality of gears connected at the runner parts, and each gear can be easily detached.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a gear by die casting.

[0002]

2. Description of the Related Art Conventionally, in order to manufacture a gear by die casting, dies 31 and 32 as shown in FIGS. 4 and 5 have been used. That is, the die 31 has a plurality of gear-shaped cavities 34, 34 ...
.. indicates the tooth portion. On the other hand, the die 32 includes a columnar runner 37 extending from the sprue 36 toward the closing surface 33, a plate-like runner 38 spreading along the closing surface 33, and a branch from the plate-like runner 38 in a branch shape to form a tooth portion 35 of the cavity. , 35 ... Branch runners 39, 39, 3 toward the tip of some of
9 and.

The die 32 is attached to the molten metal injection mechanism, the die 31 is attached to the mold clamping mechanism, and the die 31 is pressed against the die 32 at the closing surface 33 by the operation of the mold clamping mechanism during casting. Molten metal flows from the sprue 36 to the runways 37, 38 and 3
Via the cavities 34, 34 ...
Injected inside.

[0004]

DISCLOSURE OF THE INVENTION The conventional die 3 described above
In 1 and 32, it is cast by the cavities 34, 34 ... Injecting the molten metal into the tips of the tooth portions 35, 35 ... Of the gears through the branch runners 39, 39. This is because a gate having a small cross-sectional area is formed between the product and the metal ingot solidified in the runner to facilitate the division of the gate and the simultaneous casting of a large number of gears.

As a result, in the cast gear, the dimensional accuracy of the tooth into which the molten metal is injected is lower than that of other teeth, and the gear meshing accuracy standard JGMA 116-02 (1983)
Only gears of a class or less can be manufactured, and resin-molded gears have been used as a drive mechanism for loading and unloading cassettes and discs such as video cassette decks and compact disc players.

However, in these devices, an accident occasionally occurs in which the driving gear is damaged when the user suddenly pushes in and out the portion by an external force, and an inexpensive and accurate gear made of metal, which replaces the resin gear, is replaced. Appearance was desired. The present invention is intended to mass-produce gears with high precision at low cost by die casting.

[0007]

The gear manufacturing die used in the present invention is classified into the following three dies. The first die has a plurality of gear-shaped cavities recessed in the closing surface. The second die is in close contact with a part of the closing surface of the first die, and its edge portion extends beyond the tooth portion of each cavity of the first die and reaches the gear body portion. The third die is
The second die is in close contact with the rest of the closing surface of the first die, and for each of the cavities, except for the gate located in the gear body portion,
Cooperate with the die to close the cavities. Then, the first runner rising from the gate along the edge of the second die and the second runner continuous with the first runner and arranged along the surface of the second die are left. Close to the die.

One of the first die and the third die is connected to the molten metal injection mechanism, and the other is supported by the mold clamping mechanism.
The die on the side of the molten metal injection mechanism is provided with a sprue for receiving the molten metal on a surface opposite to the closing surface, and a third spout running from the spout to the second spout is formed.

The second die is supported by one of the first and third dies so as to be slidable in the direction parallel to the closing surface, and is connected to a driving means for moving the die in the sliding direction.
When the second die is supported by the mold clamping mechanism side of the first and third dies, the driving means is inclined to the die on the melt injection mechanism side with respect to the closing surface. By engaging the inclined pin that is erected in the direction with the second die, it is possible to move the second die by guiding the inclined pin when the die on the mold clamping mechanism side moves. The third die closes the rest of the closing surface of the first die and cooperates with the second die to close the cavities except for the gate located in its gear body portion for each cavity. . Then, the first runner rising from the gate along the edge of the second die and the second runner arranged continuously along the surface of the second die are left behind. Two
Close to the die.

When casting a gear, the molten metal is injected into each of the above-mentioned cavities from the molten metal injection mechanism in order through the above-mentioned gate, the third runner, the second runner, the first runner and the gate. . After the molten metal is solidified, the mold clamping mechanism is operated to
The die and the third die are separated from each other, and the second die is withdrawn to take out the gear cast in each cavity together with the solidified matter in the runner.

[0011]

In the above casting, when the mold clamping mechanism is operated to close the die and the molten metal injection mechanism is operated, the molten metal passes through the gate, the third, the second, and the first runners in order, and from each gate. It is injected into each cavity. Here, since each gate is provided in the gear body portion of each cavity, the molten metal spreads from here and reaches each tooth portion.

When the molten metal is solidified in each cavity, the separating movement between the first die and the third die and the retreat movement of the second die are performed by the operation of the mold clamping mechanism, so that the molten runner is solidified. The part and the plurality of gears connected to the part at the gate part are integrally released from the mold. Further, each gear is a gate portion and can be easily separated from the runner portion.

The gears obtained by the above-mentioned casting have the dimensional accuracy of all the teeth because the molten metal is poured from the gear body portion, not from the tooth portions, and cannot be realized by the conventional die cast products. Interlocking accuracy standard JGM
It is possible to manufacture high-precision gears that are in the third grade of A.

The second die is generally called a slide core, but it is difficult to machine the slide core, and using a plurality of slide cores at the same time is extremely disadvantageous in terms of die manufacturing cost. However, in the present invention, the object of the invention can be achieved by using a single slide core. Moreover, since a plurality of gears can be produced at the same time and the dimensional accuracy thereof is excellent, the economic value is great.

[0015]

1 and 2, a movable die 1 on the side of a mold clamping mechanism includes a slide core 2 (second die) which can move in a direction perpendicular to the paper surface of FIG. 1 (in the direction of an arrow shown in FIG. 2). The fixed die 3 on the molten metal injection mechanism side is in close contact with the closing surface 4. In the closing surface 4, the movable die 1 has a plurality of gear-shaped cavities 5, 5 ... Composed of gear body portions 6, 6 ... And tooth portions 7, 7, ... And a flow dividing portion 9 having a flow dividing pin 8. Further, the slide core 2 is slidably supported. The sliding movement of the slide core 2 with respect to the movable die 1 is performed by a hydraulic cylinder (not shown).

The fixed die 3 has a sprue 10 connected to the molten metal injection mechanism, a columnar runner 11 extending from the spout 10 to the flow dividing portion 9, and a plate-like runner extending from the flow dividing portion 9 along the slide core 2. 12 and a plurality of branch runners 1 extending from the plate runner 12 along the side edge portion 13 of the slide core 2 toward the closing surface 4.
4 and 14 are provided. This branch runway 14,
The tips of 14 ... Form gates 15, 15 ... With a small area in the closed surface 4.

The side edge portion 13 of the slide core 2 extends to the gear body portions 6, 6 ... of the respective cavities 5, 5, ... When the dies are closed as shown in the drawing, and the gate 15,
15 ... Are open to this portion respectively. Therefore, when the molten metal injection mechanism is operated, the molten metal enters the flow dividing portion 9 from the sprue 10 through the columnar runners 11, then passes through the plate-shaped runner 12 and the branch runners 14, 14, ...・
.. are respectively injected into the gear body portions 6, 6, ... Of each cavity and spread from there to the tooth portions 7, 7 ..

When the molten metal in the die is solidified, the mold clamping mechanism is operated to move the movable die 1 out of the fixed die 3,
The casting is separated from the fixed die 3 together with the movable die 1. At this time, the flow dividing pin 8 helps the portion cast by the columnar runner 11 to be smoothly separated at the sprue 10. Next, pull out the slide core 2 by the operation of the hydraulic cylinder,
The casting die is moved to the movable die 1 by a well-known mechanism such as a discharge pin.
Take out from.

In the obtained casting, a plurality of gears are connected by a runner portion. Each gear can be easily separated from the runner at the gate. Since each gear is cast by pouring molten metal from the gear body, the accuracy of the tooth is extremely high.

In the above-described embodiment, the cavity is provided only on the left side of the slide core 2 in FIG. 2, but it is possible to arrange the cavity above the slide core 2 or on a part of the right side. In addition, after the molten metal flows through the columnar runner 11 into the flow dividing portion 9 which is once provided in the movable die 1,
Although it has reached the plate-shaped runner 12, the columnar runner 11 is provided by providing the slide core 2 with an appropriately-shaped pulling portion.
It is also possible to directly flow into the plate-shaped runner 12 from.

Although the slide core 2 is slidably supported by the movable die 1 and is removed by a hydraulic cylinder or the like in the above embodiment, it is engaged with the inclined pin provided on the fixed die 3 side. By doing so, the movable die 1 may be configured to move while sliding on the movable die 1 while being guided by the inclined pin during the moving movement of the movable die 1. Further, the slide core 2 can be slidably supported by a fixed die, and in that case, it is necessary to pull out the slide core 2 by a hydraulic cylinder or the like prior to the moving movement of the movable die.

In the embodiment shown in FIG. 3, the cavities 5, 5 ... Consisting of the gear body portion 6 and the tooth portion 7 are provided in the fixed die 21 on the melt injection mechanism side, and the cavity 5 is closed at the closing surface 24 with the gate. Except for 15, 15, ..., It is closed by the movable die 22 and the slide core 2 on the mold clamping mechanism side. The slide core 2 is supported by the movable die 22 so as to be slidable in a direction perpendicular to the paper surface. Gate 15,
15 are provided on the gear body portions 6, 6 ... of the respective cavities, as in the embodiment shown in FIG.

The molten metal supplied from the molten metal injection mechanism to the sprue 10 of the fixed die 21 passes through the columnar runner 11 and the movable die 2
2 flows into a flow dividing portion 9 provided in a concave shape, spreads from here to a plate-shaped runner 12 provided along the lower surface of the slide core 2, and branch runners 14, 14 ...・ Injected into the cavities 15, 15 ... through the gates 15, 15 ... The positional relationship of each runner and each cavity as viewed from above conforms to FIG.

The gear formed in each cavity by solidification of the molten metal is released from the fixed die 21 together with the solidified material in the runners 11, 12, 14 by moving the movable die 22 away, and then the slide core 2 Can be taken out from the movable die 22 by removing it with a hydraulic cylinder or the like.

As described above, the slide core 2 is removed after the movable die 22 is removed, and the slide core 2 is removed in parallel with the movement of the movable die 22 using the inclined pin.
A hydraulic cylinder or the like may be used to remove the movable die 22 prior to the withdrawal movement. Further, the slide core 2 may be slidably supported on the fixed die 21 side, and the movable core may be removed by a hydraulic cylinder or the like prior to the withdrawal of the movable die.

The slide core 2 is supported on either side of the fixed die 21 or the movable die 22 when the movable die 22 is moved when the movable die 22 is removed before it is removed. The gear is the cavity 5,
Since it becomes difficult to release from the mold 5, the pins 25, 25, for forming the central shaft hole of the gear are provided from the movable die 22 side in each cavity. It is desirable to distract 5, 5, ...

[0027]

As described above, according to the present invention, since a plurality of gears can be cast at the same time, the productivity is high, and the cast gear has a feature that the tooth accuracy is extremely high. In addition, since a slide core generally requires a lot of labor for production, a die using the same is expensive, but according to the present invention, it is possible to achieve high accuracy and high productivity as described above by using only one slide core. It can be realized at the same time.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

FIG. 2 is a plan view excluding the fixed die 3 of the above embodiment.

FIG. 3 is a sectional view of another embodiment of the present invention.

FIG. 4 is a sectional view of a conventional gear casting die.

FIG. 5 is a plan view of the conventional gear casting die from which a fixed die is removed.

[Explanation of symbols]

 1 Movable Die 2 Slide Core (Second Die) 3 Fixed Die 4 Closing Surface 5 Cavity 6 Gear Body Part 7 Tooth Part 10 Tooth Gate 11 Columnar Runway (Third Runway) 12 Plate Runway (Second Hot Water) Road) 14 Branch runners (1st runway) 15 Gates

Claims (20)

[Claims] 1. A first die in which a plurality of gear-shaped cavities are provided side by side on a closed surface, and a concave portion, and a part of the closed surface is in close contact with the first die, and an edge portion of the first die is close to that of each cavity. A plate-shaped second die extending beyond the gear tooth portion to the gear main body portion, and a first die at the rest of the closing surface.
The cavities in close contact with the second die, except for the gates present in the gear body portions of the cavities at the edge portions of the second die. The first rising along the edge of the second die
And a third die which is in close contact with the second die leaving a second runner disposed along the surface of the second die in succession thereto. 2 and the first runner in that order, the molten metal is injected into the gear body of each cavity from each gate to fill each cavity, and after the solidification, the third die and the first die are closed. It is possible to remove the gear formed in each of the cavities by separating the second die in the direction perpendicular to the surface and withdrawing the second die in the direction parallel to the closing surface of either the first die or the third die. Characteristic gear manufacturing method. 2. The molten metal is supplied to a second runner from a gate provided on the opposite side of the closing surface of the third die through a third runner provided in the third die. Claim 1 characterized by
The gear manufacturing method described. 3. The molten metal is supplied to the second runner from a sprue provided on the side opposite to the closing surface of the first die through a third runner provided in the first die. Claim 1 characterized by
The gear manufacturing method described. 4. The second die is supported by the first die so as to be slidable in a direction parallel to the closed surface, and the second die is separated from the third die before the second die is moved. The gear manufacturing method according to claim 2, wherein the gear is moved by sliding motion with the first die. 5. The second die is supported by the first die so as to be slidable in a direction parallel to the closing surface thereof, and in parallel with the movement for separating the first die from the third die, The gear manufacturing method according to claim 2, wherein the second die is moved away by a sliding motion with respect to the first die. 6. The second die is supported by the first die so as to be slidable in a direction parallel to the closed surface thereof, and after the second die is moved by the sliding movement with the first die, 3. The method for manufacturing a gear according to claim 2, wherein the first die is separated from the third die. 7. The second die is supported by the third die so as to be slidable in the direction parallel to the closing surface thereof, and after the second die is moved away by the sliding movement with the third die. 3. The method for manufacturing a gear according to claim 2, wherein the first die is separated from the third die. 8. The second die is supported by the third die so as to be slidable in a direction parallel to the closing surface thereof, and the second die is separated from the first die before the second die is separated from the first die. The gear manufacturing method according to claim 3, wherein the gear is moved by sliding motion with the third die. 9. The second die is supported by the third die so as to be slidable in a direction parallel to the closing surface thereof, and the second die is moved in parallel with the movement of separating the third die from the first die. The gear manufacturing method according to claim 3, wherein the second die is moved away by a sliding motion with respect to the third die. 10. The second die is slidably supported by the third die in a direction parallel to the closing surface thereof, and after the second die is moved by sliding movement with the third die, , Third
The gear manufacturing method according to claim 3, wherein the die is separated from the first die. 11. The second die is supported by the first die so as to be slidable in a direction parallel to the closing surface, and after the second die is moved by sliding movement with the first die, , Third
The gear manufacturing method according to claim 3, wherein the die is separated from the first die. 12. A first die in which a plurality of gear-shaped cavities are provided side by side in a concave manner in the closing surface, and a part of the closing surface is in close contact with the first die, and an edge portion of the first die is in contact with the first die. A plate-shaped second die extending beyond the gear tooth portion to the gear main body portion, and in close contact with the first die at the rest of the closing surface, and at each of the cavities at the edge portion of the second die. And a first runner that rises along the edge of the second die from the gates by closing the cavities in cooperation with the second die except for the gates present in the gear body of A third die which is in close contact with the second die leaving a second runner disposed along the surface of the second die in succession to one of the first die and the third die. Molten metal injection machine configured to supply molten metal to a sprue provided on the side opposite to the closing surface Structure, a third runner connecting the sprue and the second runner, a position for supporting the other of the first or third die and closing it with the one die, and separated from the one die. A mold clamping mechanism configured to move between the two positions and a means for supporting the second die on one of the first die and the third die so as to be slidable in a direction parallel to the closing surface, A gear manufacturing apparatus comprising drive means for moving a second die forward and backward in the slidable direction. 13. A first die in which a plurality of gear-shaped cavities are provided side by side in a concave manner in the closing surface, and a part of the closing surface is in close contact with the first die, and an edge portion of the first die is close to that of each cavity. A plate-shaped second die extending beyond the gear tooth portion to the gear main body portion, and in close contact with the first die at the rest of the closing surface, and at each of the cavities at the edge portion of the second die. And a first runner that rises along the edge of the second die from the gates by closing the cavities in cooperation with the second die except for the gates present in the gear body of A third die which is in close contact with the second die leaving a second runner disposed along the surface of the second die in succession to one of the first die and the third die. Molten metal injection machine configured to supply molten metal to a sprue provided on the side opposite to the closing surface Structure, a third runner connecting the sprue and the second runner, a position for supporting the other of the first or third die and closing it with the one die, and separated from the one die. A mold clamping mechanism configured to move between the two dies, a means for slidably supporting the second die on the other die in a direction parallel to the closing surface, and the one die on the above. The second die with respect to the other die is guided by the inclination pin in association with the movement of the other die by the mold clamping mechanism, including an inclination pin that is erected in a direction inclined with respect to the closing surface. A gear manufacturing device comprising means for sliding movement. 14. The cavity according to claim 12, wherein at least a part of the cavity is arranged in parallel with the sliding direction of the second die and along the side edge of the cavity on the closing surface of the first die. Or the gear manufacturing device according to 13. 15. The method according to claim 12, wherein a part of the cavity is arranged at a closing surface of the first die at a part of an edge crossing the sliding direction of the second die. Gear manufacturing equipment. 16. A third runner provided inside one of the first die and the third die has an opening on the closing surface, and the third runner faces the opening and faces the opening on the other side of the first or third die. The shunting part where the shunting pin is planted on the closing surface is recessed.
14. The gear manufacturing apparatus according to claim 12, wherein the runner is connected to the second runner via the flow dividing portion. 17. The gear manufacturing apparatus according to claim 12, wherein the third runner is connected to the second runner at a position where it contacts the second die. 18. The gear manufacturing apparatus according to claim 12, wherein the first die is supported by the mold clamping mechanism, and the third die is coupled to the molten metal injection mechanism. 19. The gear manufacturing apparatus according to claim 12, wherein the first die is connected to the molten metal injection mechanism, and the third die is supported by the mold clamping mechanism. 20. The gear manufacturing apparatus according to claim 12, wherein a pin for forming a central shaft hole of the gear to be manufactured extends into the cavity from the closing surface of the third die. .