JPH07255983A - Manufacture of dewatering shaft - Google Patents

Abstract

PURPOSE:To provide an excellent manufacturing method of a dewatering shaft wherein the material cost and processing cost have been suppressed and the processing process also can largely be simplified. CONSTITUTION:A rod-shaped body of metal is compressed in a mold to cause a plastic deformation to form therein a shallow hole 43 facing downward from the upper end surface and a deep hole 44 facing upward from the lower end surface thereof, thereby providing a preformed body 50, and thereafter the body is compressed using a special mold 51 to cause plastic deformation thereof, whereby a flange 31 is formed and an almost lower half of the body is subjected to drawing to have a body with a smaller diameter, thereby providing a molded article having an almost completed shape. And a hole is formed through a portion between the hole 43 and the hole 44 to form a dewatering shaft.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a dehydration shaft used in a rotary drive mechanism of a one-tub electric washing machine.

[0002]

2. Description of the Related Art Conventionally, in a single-tub type electric washing machine that continuously performs washing and dehydration in a single tub, a rotary drive mechanism is used.
For example, a structure as shown in FIG. 8 is generally used. That is, the one-way spring clutch 14 is attached to the lower end of the main shaft 12 that rotates the dehydration tank 10 and the pulsator 11, and when the one-way spring clutch 14 is rotationally driven through the pulley 20 in the direction in which the main shaft 12 is closed, An outer cylinder 13 fitted on the shaft 12 is adapted to integrally rotate with the main shaft 12 at a high speed. This high-speed rotation is transmitted to the gear case 15 incorporating the sun gear 5, the planetary gear group 17, and the outer ring gear 22 meshing with the sun gear 5, and is transmitted to the dehydration tub 10 via the dehydration shaft 16 extending upward from the gear case 15. As a result, the dehydration operation is performed. Reference numeral 18 denotes a holding guide that integrally holds the respective rotation shafts of the planetary gear group 17 from above and below. The outer cylinder 13 has a first
The bearing 26 is rotatably supported by the lower bearing cover 25 fixed to the main body of the washing machine. The dehydration shaft 16 is rotatably supported by the upper bearing cover 27, which is also fixed to the washing machine body, via the second bearing 21. On the other hand, when the one-way spring clutch 14 is rotationally driven through the pulley 20 in the direction of loosening, the outer cylinder 13 does not rotate, but only the main shaft 12 rotates. This rotation is transmitted to the sun gear 5 and the planetary gear group 17 in the gear case 15, and the reduced rotation is transmitted to the pulsator shaft 19. As a result, the pulsator 11 attached to the upper end of the pulsator shaft 19 rotates at low speed, and the washing / rinsing operation is performed. In addition, 2 is a one-way bearing for preventing the outer cylinder 13 from rotating together with the main shaft 12, and 3 is a bearing thereof.

The dehydration shaft 16 used in the above rotary drive mechanism is usually manufactured as follows. That is, first, as shown in FIG. 9 (a), a stainless steel round bar is cut into a predetermined length and then subjected to a cold forging press to form a shallow hole downward from the center of the upper end surface as shown in FIG. 9 (b). While forming 30, the large-diameter collar portion 31 is formed at a position slightly lower than the upper end. Further, the outer peripheral surface of the lower portion from the substantially central portion in the axial direction is reduced in diameter to form the small diameter portion 32. Further, a center hole 33 is formed at the center of the lower end surface. Next, as shown in FIG. 3C, a hole is drilled at the position of the center hole 33 to form a through hole 34. Next, as shown in FIG. 10 (a), a screw hole 35 for attaching the dehydration tank 10 (see FIG. 8) is formed in the collar portion 31, and the inner wall upper and lower portions of the through hole 34 are cut. To form a step portion into which a bearing for mounting the pulsator shaft 19 (see FIG. 8) is fitted. Then, as shown in FIG. 10B, by polishing the peripheral surface, the desired dehydration shaft 16 can be obtained.

[0004]

However, the above-described manufacturing method has a problem that the material cost and the processing cost are high because the cutting allowance is large. Further, since the distance for drilling with a drill (indicated by L in FIG. 9C) is long, there is a problem that the machining time is long in combination with the fact that there are many other cutting allowances. Therefore, in manufacturing a dehydration shaft, it is strongly desired to realize simplification of these steps and cost reduction.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an excellent method for producing a dehydration shaft, which can suppress the material cost and the processing cost to a large extent and greatly simplify the processing process. And

[0006]

In order to achieve the above object, in the method for manufacturing a dehydration shaft of the present invention, a large-diameter brim portion is formed on the upper end side of a substantially cylindrical body, and the main body is lowered from the substantially central portion thereof. A method for manufacturing a dehydration shaft in which the outer peripheral surface of the portion is reduced in diameter and the lower half of the main body is formed in a small diameter portion, in which a metal rod-shaped body of a predetermined length is compressed and plastically deformed in a mold. The step of forming a shallow hole downward from the center of the upper end surface of the rod-shaped body and forming a deep hole upward from the center of the lower end surface to obtain a preform, and fitting the upper end of the preform to the center of the lower surface. And a male upper mold in which a recess is formed, and in the center of the upper surface, the same diameter as the outer diameter of the above preformed body is formed up to about half the depth, and the depth portion below that is reduced to a small diameter portion. It has a hole formed, and the inside diameter is the same as the deep hole inside diameter of the preform. A mold is prepared in which a shaft is combined with a female lower mold that is coaxially inserted into the hole, and the preform is formed in an annular gap formed by the hole and the shaft of the female lower mold. With the lower part of the male mold fitted and the upper half thereof protruding upward, the male upper mold is lowered from above, and the concave part of the male upper mold is fitted to the upper end of the preform. The lower part of the preform is press-fitted into the small diameter part of the female lower mold hole to squeeze to a small diameter, and a part of the preform is formed in the gap formed between the male upper mold lower surface and the female lower mold upper surface. And a step of forming a collar portion by plastically deforming in the radial direction, and a step of making a hole between the shallow hole and the deep hole of the demolded molded product with a collar.

[0007]

That is, according to the present invention, when a dehydration shaft is manufactured, a metal rod-like body is compressed and plastically deformed in a mold to form a shallow hole downward from the upper end surface and a deep hole upward from the lower end surface. After obtaining a preformed body with a molded body, it is further compressed by a special mold and plastically deformed to form a brim and at the same time, the lower half of the outer peripheral surface is squeezed to a small diameter to obtain a molded product with a nearly completed shape. To get Then, the formed dehydrated shaft shape is obtained by penetrating between the shallow hole and the deep hole of the flanged molded product. According to this manufacturing method, the entire forming is accurately performed by the plastic deformation, so that the cutting allowance for the final cutting is minimized, and the material cost and the processing cost can be significantly reduced. Moreover, since plastic deformation causes shallow holes and deep holes to be formed above and below the rod-shaped body, it is only necessary to drill a short distance between these shallow holes and deep holes at the end, which is necessary for conventional drilling. The time spent can be greatly reduced. And as a whole, there is an advantage that the process can be greatly simplified.

Next, the present invention will be described in detail based on embodiments.

[0009]

EXAMPLE First, the dehydration shaft 16 of interest has a shape as shown in FIG. That is,
A large-diameter collar portion 31 (diameter D = 48 mm, thickness T = 5 m) at a position where the distance S from the upper end of the substantially cylindrical body 40 is 5 mm.
m) is formed, and the outer peripheral surface of the lower portion (length U = 39 mm from the lower end) of the main body 40 is reduced in diameter to form the small diameter portion 32. The outer diameter N of the upper end portion of the main body 40 is 24 mm, the outer diameter P of the portion below the collar portion 31 is 27 mm, and the outer diameter Q of the small diameter portion 32 is 25 mm. Further, the total length R is 72 mm, and the hole diameter M of the through hole 34 is 16 mm.
Is.

In order to make the dehydration shaft 16, first, as shown in FIG. 1, a stainless wire 42 having a diameter of 26.8 mm wound into a coil was prepared. In the figure, 43 is a winding core. The coiled stainless wire 42 was unwound and supplied to a known continuous multi-stage forging machine. The continuous multistage forging machine is provided with the supplied wire rod 42.
Is first cut into a predetermined length, and then the cut wire 42
, Which can be continuously obtained by continuously repeating the steps of mounting a different mold tool and performing a plurality of compression molding steps to give plastic deformation. Is.

Using the continuous multi-stage press, the wire 42 is
First, as shown in FIG. 2 (a), it was cut into a length of 68 mm. Then, by subjecting this cut product 42a to the first compression step, as shown in FIG.
It was plastically deformed into a clean chamfered shape. Next, the opposite side of the cut product 42a was subjected to a second compression step to plastically deform it into a chamfered clean shape as shown in FIG. Then, by subjecting the cut product 42a to the third compression step, as shown in FIG. 3 (a), shallow holes 43, 43 'are formed in the center of both end faces of the cut product 42a, and one end edge is formed. The part was slightly squeezed to a small diameter. Further, the cut product 42a
Is subjected to a fourth compression step, so that the shallow hole 43 'on one side of the cut product 42a is deepened to some extent, as shown in FIG. Then, by applying the fifth compression step, the deepened hole 44 was formed by deepening the deepened hole to a certain extent, as shown in FIG. By repeating this series of steps, it was possible to continuously obtain the preform having the special shape from the continuous multi-stage forging machine.

Next, the preform 50 was mounted on a mold 51 as shown in FIG. 4 and pressed in the mold 51 to give plastic deformation. That is, the male upper mold 52 of the mold 51
Is formed by combining an outer cylinder 53, an inner cylinder 54 and a shaft body 55, and a recess 56 that can be fitted into the upper end of the preform 50 is formed at the center of the lower surface 52a.
On the other hand, the female lower die 60 of the die 51 has the same diameter as the outer diameter of the preform 50 up to about half the depth at the center of the upper surface 60a, and the depth of the half depth below that is reduced. Has a hole portion 61 formed in the small diameter portion 61a, and a shaft portion 62 having the same diameter as the deep hole inner diameter of the preformed body 50 is provided in the hole portion 61.
Is coaxially inserted. In addition, the "same diameter" is not limited to the literal "same diameter", but also includes a diameter of a dimension provided with a tolerance such that they can be fitted to each other, and the following "same diameter" is also included. It is used for the same purpose. The upper end of the push-up cylinder 63 is inserted into the lower end of the hole 61 from below. The lifting cylinder 63
Is configured to move up and down along the shaft portion 62 in accordance with the operation of the elevating pin 66 that moves up and down in the base 65 provided under the knife lower die 60. Then, the base 65
A low friction member 67 is fitted in a portion where the elevating pin 66 moves up and down.

Therefore, as shown in FIG. 4, the lower portion of the preformed body 50 is fitted into the annular gap formed by the hole portion 61 and the shaft portion 62 of the female lower die 60, and the upper half of the preformed body 50 is upward. After it is attached so that it protrudes, as shown in Fig. 5,
By lowering the male upper die 52 from above, the preformed body 50 is inserted into the hole 6 of the female lower die 60 with the concave portion 56 of the male upper die 52 fitted in the upper end portion of the preformed body 50.
1 by pushing it deeply into the lower half of the preform 50,
While press-fitting into the reduced small-diameter portion 61a to squeeze it to a small diameter, in the gap formed between the lower surface 52a of the male upper die 52 and the upper surface 60a of the female lower die 60, the shallow depth of the preform 50 is reduced. Set the bottom of the hole 43 and the bottom of the deep hole 44 to the shaft 5
While pressing with 5 and the shaft portion 62, this portion is plastically deformed in the radial direction. Then, the male upper mold 52 was further lowered to narrow the gap, whereby the collar portion 31 having a predetermined thickness was integrally formed as shown in FIG. Therefore, as shown in FIG. 7, the male upper mold 52 is raised, and the push-up cylinder 63 is raised from below the female lower mold 60 via the raising and lowering pins 66, whereby the obtained collared preform 50 is obtained. I demolded.

Next, after the penetrating portion (indicated by W in FIG. 7) between the shallow hole 43 and the deep hole 44 of the collared preform 50 thus obtained is penetrated by drilling, As shown in FIG. 10A and FIG. 10B, the desired dehydration shaft 16 could be obtained by performing cutting and polishing finishing.

According to the above-mentioned manufacturing method, the shallow hole 43 and the deep hole 44 are formed on the upper and lower sides of the preformed body 50 at the stage of molding the preformed body 50.
Next, the shallow hole 43 and the deep hole 44 are compressed with a part of the male upper die 52 and a part of the female lower die 60 being fitted to each other to compress the lower surface 52a of the male upper die 52 and the upper surface of the female lower die 60. The collar portion 31 is formed between the preform 50 and 60a.
The lower half of the above is narrowed to a small diameter to form the small diameter portion 32. Therefore, since the shape close to the final shape is accurately performed by the plastic deformation, the cutting allowance for the final cutting work is minimized, and the material cost and the processing cost can be significantly reduced. Since the shallow holes 43 and the deep holes 44 are formed in advance, the through holes 34 can be obtained only by finally making a short distance between the shallow holes 43 and the deep holes 44 for drilling. Therefore, the time required for conventional drilling can be significantly reduced. And as a whole, there is an advantage that the process can be greatly simplified. In particular, since the continuous multistage forging machine is used at the stage of obtaining the preform 50, the preform 50
It only takes a few seconds to mold one piece, and the processing time can be greatly shortened.

In the above embodiment, the stainless wire 42 was used to obtain the preformed body 50. However, as such a stainless wire 42, SUS403 and SUS410 are preferable from the viewpoint of rigidity, toughness and the like. is there. Further, not only stainless steel but also various high-strength metals, alloys and the like can be used.

In the above embodiment, the stainless wire 4 is used.
2 is wound in a coil shape and is applied to a continuous multi-stage forging machine to continuously obtain the preformed body 50. However, it is not always necessary to use the continuous multi-stage forging machine,
Alternatively, the stainless wire 42 or the stainless rod may be cut into a predetermined size in advance, and the preformed body 50 may be obtained by sequentially applying this to a forging machine having different mold shapes. According to this method, the number of steps is increased and the cost is slightly increased as compared with the case of using the above continuous multi-stage press, but it is advantageous in terms of steps and costs as compared with the conventional method.

Further, in the above embodiment, the deformation of the cut product 42a obtained by cutting the wire 42 is performed by the five steps of FIGS. 2B, 2C and 3A to 3C. It is not always necessary to limit to these 5 steps. For example, chamfering on one side and formation of the shallow hole 43 and drawing of the end portion may be performed simultaneously, and chamfering on the other side and formation of the shallow hole 43 ′ may be performed simultaneously. Further, it is not always necessary to chamfer at this stage, and it is possible to chamfer both ends of the continuous multi-stage press after taking it out. Of course, it does not matter if chamfering is performed during the final cutting process. However, it is easier as a process to complete the chamfer formation in the continuous multi-stage press as in the above-described embodiment.

[0019]

As described above, according to the manufacturing method of the dehydration shaft of the present invention, the metal rod-shaped body is compressed in the mold to be plastically deformed, so that the shallow hole downward from the upper end surface and the upward downward hole from the lower end surface are formed. After obtaining a preformed body with deep holes, it is further compressed by a special mold and plastically deformed to form a brim and at the same time squeeze the lower half of the outer peripheral surface to a small diameter to obtain a nearly completed shape. Get a close molded article. Then, the formed dehydrated shaft shape is obtained by penetrating between the shallow hole and the deep hole of the flanged molded product. According to this manufacturing method, the entire forming is accurately performed by the plastic deformation, so that the cutting allowance for the final cutting is minimized, and the material cost and the processing cost can be significantly reduced. Moreover, since plastic deformation causes shallow holes and deep holes to be formed above and below the rod-shaped body, it is only necessary to drill a short distance between these shallow holes and deep holes at the end, which is necessary for conventional drilling. The time spent can be greatly reduced. And as a whole, there is an advantage that the process can be greatly simplified.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a stainless wire used in an embodiment of the present invention.

2A, 2B, and 2C are process explanatory diagrams of the above-described embodiment.

3A, 3B, and 3C are process explanatory diagrams of the above-described embodiment.

FIG. 4 is an operation explanatory diagram of a mold used in the above-described embodiment.

FIG. 5 is an operation explanatory view of a mold used in the above-mentioned embodiment.

FIG. 6 is an operation explanatory view of the mold used in the above-described embodiment.

FIG. 7 is an operation explanatory diagram of a mold used in the above-described embodiment.

FIG. 8 is a general explanatory diagram of a rotary drive mechanism of an electric washing machine.

9 (a), (b) and (c) are explanatory views of a conventional method for manufacturing a dehydration shaft.

10 (a) and 10 (b) are explanatory views of a conventional method for manufacturing a dehydration shaft.

[Explanation of symbols]

 31 Collar part 32 Small diameter part 43 Shallow hole 44 Deep hole 50 Preform 51 Mold 52 Male upper mold 52a Lower surface 56 Recess 60 Female lower mold 60a Upper surface 61 Hole 61a Small diameter 62 Shaft

Claims (1)

[Claims] 1. A large-diameter collar portion is formed on an upper end side of a substantially cylindrical main body, and an outer peripheral surface of a portion below the substantially central portion of the main body is reduced in diameter so that a substantially lower half of the main body is formed in a small-diameter portion. A method for manufacturing a dehydration shaft, which comprises forming a shallow hole downward from the center of the upper end surface of the rod and upwardly from the center of the lower end surface by compressing and plastically deforming a metal rod of a specified length in a mold. A step of forming a deep hole in the preform to obtain a preformed body, a male upper mold having a recess formed in the center of the lower surface that can be fitted with the upper end of the preform, and a depth of approximately half in the center of the upper surface. Has a hole formed in a small diameter part by reducing the diameter of the outer diameter of the preform and having a depth of approximately half below the preform, and the deep hole of the preform in the hole. A mold made by combining a female lower mold in which a shaft part having the same diameter as the inner diameter is coaxially inserted in the hole part. Prepared, the lower part of the preform is fitted into the annular gap formed by the hole and shaft of the female lower mold, and the upper half of the preform is mounted so as to project upward, and the male upper mold is mounted from above. And lowering the lower part of the preform in a state where the recess of the male upper die is fitted to the upper end of the preform, and press-fitting it into the small diameter part of the female lower mold hole to squeeze it to a small diameter. A step of plastically deforming a part of the preform in the gap formed between the lower surface of the male upper die and the upper surface of the female lower die to form a collar portion, and the molded article with the collar removed from the die And a drilling step of penetrating between the shallow hole and the deep hole.