Forming method of disk-shaped member

A forming method of a disk-shaped member in which a plate formed into a disk shape and a protruded flange protruding from an outer periphery of the plate are integrally formed, includes: forming a preformed body from a plate member by a press forming, the preformed body having a protrusion in an outer periphery of the plate, the protrusion having a width larger than a width of the flange; and forming the flange by cutting and removing an outer peripheral surface side of the protrusion to punch the preformed body from the plate member in a state where a mold is in contact with an inner peripheral surface of the protrusion and a portion connected to a root of the protrusion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Japanese Patent Application No. 2018-099024 filed on May 23, 2018 with the Japan Patent Office, the entire disclosure of which is incorporated herein by reference.

BACKGROUND

The present disclosure relates to a forming method of a disk-shaped member.

Recliners at least comprise, for example, as described in Japanese Unexamined Patent Application Publication No. 2010-213839, a disk-shaped guide member fixed to a cushion frame, and a disk-shaped ratchet fixed to a back frame. The recliner rotatably connects the back frame to the cushion frame.

The ratchet has a protruded flange formed in an outer periphery of the ratchet, and the flange has serrations to be engaged with serrations formed on a pawl. The pawl is movable toward and from the flange. The pawl is housed in a space between the guide member and the ratchet.

The guide member has a guide wall guiding the pawl's movement in a radial direction of the guide member and restricting the pawl's movement in a circumferential direction. In an outer periphery of the guide member, a protruded flange protruding along an entire periphery of the guide member is formed.

The pawl is a plate member housed in a space formed between the ratchet and the guide member. The guide wall is in sliding-contact with an end face of the pawl, whereby the guide wall guides the pawl's movement in the radial direction while restricting the pawl's movement in the circumferential direction.

SUMMARY

The ratchet is positioned on an inner peripheral side of the flange of the guide member. Thus, to reduce external dimensions and weight of the recliner, it is preferable to reduce a width of the flange.

However, when a whole of the guide member including the flange is formed from a plate member by press forming, it is difficult to form a flange having a small width.

The present disclosure discloses an example production method of a flange having a small width in a disk-shaped member, such as a guide member.

According to an aspect of the present disclosure, a forming method of a disk-shaped member in which a protruded flange protruding from an outer periphery of a disk-shaped plate is integrally formed preferably comprises the following constituent features.

A forming method of a disk-shaped member according to an aspect of the present disclosure comprises: a first step to form a preformed body from a plate member by press forming, the preformed body comprising a plate and a protrusion formed in an outer periphery of the plate, the protrusion having a width larger than a width of a flange; and a second step to form the flange after the first step by cutting and removing an outer peripheral surface side of the protrusion to punch the preformed body from the plate member in a state where a mold is in contact with an inner peripheral surface of the protrusion and a portion connected to a root of the protrusion.

According to the above, in the first step, a protrusion having a width formable by press forming, that is, a portion to become a flange is formed. In the second step, the preformed body is punched from the plate member by cutting and removing the outer peripheral surface side of the protrusion. Thus, it is possible to produce a disk-shaped member with a flange having a small width.

It is preferable to form the flange by moving a certain punch used in the second step in a direction opposite to another punch used in the first step in a state where the certain punch is in contact with an inner peripheral surface of the protrusion and a portion connected to a root of the protrusion. This facilitates punching of the preformed body from the plate member.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The embodiments described below are example embodiments within the technical scope of the present disclosure. In other words, matters specifying the invention recited in the claims are not limited to specific configurations, structures, or the like shown in the embodiments below.

At least a member or portion described with a reference numeral is provided at least one in number unless there is a specifying term, such as “only one”. In other words, two or more members or portions may be provided unless there is a specifying term, such as “only one.”

The present embodiments describe examples of a recliner of the present disclosure applied to a seat (hereinafter, referred to as a vehicle seat) mounted on a vehicle, such as a passenger car. Arrows and other marks indicating directions shown in the figures are provided for the purpose of easy understanding of mutual relationships of the figures.

The present disclosure is not limited by the directions shown in the figures. The directions shown in the figures mean respective directions in a state where a vehicle seat of the present embodiment is assembled to a vehicle.

First Embodiment

1. Overview of Recliner

For example, as shown inFIG. 1, a recliner1at least comprises a guide member10, a ratchet20, an outer periphery ring30, and pawls41,42,43.

The guide member10is one example of a disk-shaped member fixed to, for example, a cushion frame (not shown). The cushion frame is a member forming a framework of a seat cushion. The seat cushion is a portion supporting an occupant's buttocks.

As shown inFIG. 2, the guide member10is a disk-shaped member comprising a substantially disk-shaped plate11and a flange12. The flange12is a protrusion protruding from an outer periphery of the plate11in a direction orthogonal to the plate11.

The flange12is integrally formed with the plate11from a metal plate by plastic forming, such as press forming. The ratchet20is arranged on an inner peripheral side of the flange12. Thus, the inner peripheral surface of the flange12and an outer peripheral surface of flange22may be in sliding-contact with each other.

The ratchet20is a member fixed to, for example, a back frame (not shown). The back frame is a member forming a framework of a seatback. The seatback is a portion supporting an occupant's back.

The ratchet20is, as shown inFIG. 1, a disk-shaped member comprising a disk-shaped plate21and the flange22. The plate21is a portion arranged to face the plate11of the guide member10across a space (seeFIG. 2).

As shown inFIG. 1, the flange22is a protrusion protruding from an entire outer periphery of the plate21toward the plate11. The flange22is integrally formed with the plate21from a metal plate by plastic forming, such as press forming.

The guide member10and the ratchet20are coupled by the outer periphery ring30. The outer periphery ring30restricts a separation of the guide member10from the ratchet20while allowing the guide member10to be rotatable relative to the ratchet20.

In the inner peripheral surface of the flange22, as shown inFIG. 1, serrations24are formed so as to be engaged with serrations41A,42A,43A. The serrations41A to43A are respectively provided on the pawls41to43. Each of the pawls41to43is moved in a radial direction of the guide member10, thus, the pawls41to43are moved toward and from the serrations24.

Each of the pawls41to43is housed in a space between the guide member10and the ratchet20(seeFIG. 2). A hinge cam44is a member to move the pawls41to43. When the hinge cam44rotates in response to an external operation force, each of the serrations41A to43A of each of the pawls41to43is separated from the serrations24.

When the operation force disappears, the pawls41to43are moved to positions where the serrations41A to43A fit in the serration24by an elastic force of a spiral spring45(seeFIG. 1), then, the pawls41to43are maintained at the positions by the elastic force.

As shown inFIG. 3, the guide member10has a plurality of protrusions13,14,15on an inner peripheral side of the flange12. The protrusions13to15are substantially fan-shaped portions protruding toward the plate21(the ratchet20).

The protrusion13has guide walls13A,13B formed on its sides. The protrusion14has guide walls14A,14B formed on its sides. The protrusion15has guide walls15A,15B formed on its sides.

Each of the guide walls13A to15B is formed by a wall surface extending in a direction parallel to the radial direction. Between two guide walls facing each other among the guide walls13A to15B, each one of the pawls41to43is arranged.

Specifically, a first pawl41is positioned between the guide wall13A and the guide wall14B. A third pawl43is positioned between the guide wall14A and the guide wall15B. A second pawl42is positioned between the guide wall15A and the guide wall13B.

For example, due to the sliding-contact with the pawl41, the guide wall13A and the guide wall14B serve as a guide for a movement of the first pawl41, and at the same time, serve as a restriction for a movement of the first pawl41in a circumferential direction.

As shown inFIG. 1, the plate11is provided with at least one protrusion16(three protrusions in the present embodiment). These protrusions16are portions fitted into recesses (not shown) formed in the cushion frame.

2. Production Method of Guide Member

The guide member10according to the present embodiment is made of a metal plate by press forming. Specifically, the guide member10is produced by performing at least three steps (a first preforming step, a second preforming step, and a punching step).

A pressing device for producing the guide member10is a transfer type pressing device that implements each step for a metal strip member P (seeFIG. 4) while delivering the strip member P, for example, in a direction of an arrow shown inFIG. 4.

As shown inFIG. 4andFIG. 5, a first preforming step is a step to form the protrusions13to15,16and the like on the metal strip member P by press forming. Holes Ph shown inFIG. 4are through holes into which pilot pins (not shown) are inserted. The pilot pin is a protrusion for positioning the strip member P with respect to a mold for press forming, such as a die.

As shown inFIG. 6andFIG. 7, a second preforming step is a step to form a strip member P in which a protrusion17is provided on an outer periphery of the plate11(hereinafter, referred to as a preformed body) by performing press forming on the metal strip member P.

The protrusion17is a flange protruding from an outer periphery of the plate11in a direction orthogonal to the plate11. The protrusion17has a width W1(seeFIG. 6) larger than a width W2of the flange12(seeFIG. 3). An inner peripheral surface17A of the protrusion17(seeFIG. 8) corresponds to an inner peripheral surface12A of the flange12(seeFIG. 3).

Specifically, as shown inFIG. 7andFIG. 8, in the second preforming step, a portion in which the plate11, the protrusions13to15,16and the like are formed, that is, a portion of the strip member P except for the protrusion17is sandwiched and held by molds Pm1, Pm2, Pm3and Pm4, and in such a state, the protrusion17is pressed and formed by a punch Pm5and a die Pm6.

In other words, the die Pm6is a fixed mold with a recess to form the protrusion17. The punch Pm5is a movable mold to form the protrusion17by pressing the strip member P toward the die Pm6and plastically flowing a part of the strip member P.

The molds Pm1to Pm4may be molds used in the first preforming step. In a case where the molds used in the first preforming step are used in the second preforming step, the strip member P may not be moved at the time of shifting from the first preforming step to the second preforming step.

In other words, in the first preforming step, the punch Pm5and the molds Pm1and Pm3are integrally moved toward the die Pm6, and the molds Pm2and Pm4to press the strip member P. When the step is shifted from the first preforming step to the second preforming step, the die Pm6is moved, and then the punch Pm5is moved so as to follow the die Pm6to press the strip member P toward the die Pm6.

As shown inFIG. 9andFIG. 10, a punching step is a step to punch the preformed body from the strip member P by cutting and removing an outer peripheral surface side of the protrusion17, thereby forming the guide member10having the flange12.

Specifically, in the punching step, as shown inFIG. 11, the preformed body is punched from the strip member P in a state where a punch Pm7is in contact with the inner peripheral surface17A of the protrusion17and a portion17B connected to a root of the protrusion17.

This punching process is press forming performed by the punch Pm7and the die Pm8in a state where the strip member P including the preformed body is sandwiched and held by molds Pm9and Pm10.

The punch Pm7is a movable mold to cut and remove the outer peripheral surface side of the protrusion17by pressing the preformed body (strip member P) toward the die Pm8while the punch Pm7is in contact with the inner peripheral surface17A of the protrusion17and the portion17B connected to the root of the protrusion17. The die Pm8is a fixed mold to receive a pressing force of the punch Pm7acting on the protrusion17.

When the punch Pm7presses the protrusion17, the punch Pm7is moved in a direction opposite to the punch Pm5used in the second preforming step. More specifically, after the die Pm8is moved, the punch Pm7is moved so as to follow the die Pm8to press the strip member P toward the die Pm8.

3. Features of Forming Method of Present Embodiment

A forming method of the present embodiment at least comprises the second preforming step and the punching step. In the second preforming step, the preformed body, in which the protrusion17having a width larger than the width of the flange12is formed in the outer periphery of the plate11, is pressed and formed from the strip member P.

In the punching step, after the second preforming step, the outer peripheral surface side of the protrusion17is cut and removed in a state where the mold Pm7is in contact with the inner peripheral surface17A of the protrusion17and the portion17B connected to the root of protrusion17.

Accordingly, in the second preforming step, the protrusion17having a width formable by press forming, that is, a portion to become the flange12, is formed. In the punching step, the preformed body is punched from the plate member by cutting and removing the outer peripheral surface side of the protrusion.17. Thus, it is possible to produce the guide member10with the flange12having a small width.

Specifically, the punch Pm7used in the punching step is moved in a direction opposite to the punch Pm5used in the second preforming step while the punch Pm7is in contact with the inner peripheral surface17A of the protrusion17and the portion17B connected to the root of the protrusion17. This facilitates punching of the preformed body from the strip member P.

In the aforementioned embodiment, a recliner has been described in which the guide member10is fixed to a cushion frame and the ratchet20is fixed to a back frame. However, the present disclosure is not limited to this.

That is, the present disclosure may be a recliner in which, for example, the guide member10is fixed to the back frame and the ratchet20is fixed to the cushion frame.

In the aforementioned embodiment, an example production method of the guide member10has been described. However, the present disclosure is not limited to this. That is, the present disclosure is applicable, for example, for a flange22of the ratchet20or a flange of other disk-shaped members.

In the aforementioned embodiment, the punch Pm7used in the punching step is moved in the direction opposite to the punch Pm5used in the second preforming step. However, the present disclosure is not limited to this.

In the aforementioned embodiment, the molds Pm1to Pm4are the molds used in the first preforming step. However, the present disclosure is not limited to this. That is, it may be possible for the present disclosure to employ a configuration in which, for example, the second preforming is carried out by using molds for an exclusive use in the second preforming step.

In the aforementioned embodiment, the forming method of the present disclosure has been applied to a production of the recliner to be used in the vehicle seat. However, an application of the present disclosure is not limited to this, and the present disclosure may be applied to seats for vehicles, such as railway vehicles, ships and boats, and aircrafts, as well as stationary seats for theaters, homes, and the like.

Furthermore, the present disclosure may be embodied in various forms within the purpose of the invention described in the claims, and the present disclosure is not limited to the aforementioned embodiments. Accordingly, it may be possible to employ a configuration obtained by combining at least two embodiments among the aforementioned embodiments, or a configuration obtained by removing a constituent feature of the invention described in the embodiments.