GB2080403A - Method of making a hinge flap - Google Patents

Abstract

A hinge flap, suitable for use as part of a hinge for mounting a motor vehicle door, is made by upsetting a portion of a metal plate (1) to provide at least one integral boss (7), and piercing the boss, e.g. by drilling, to provide a bore for receiving a hinge pin. This may be achieved using a press with two main dies (3) which exert pressure to render the metal plate plastic, and an upper punch (6) which is driven down rapidly between the main dies to upset the metal into die cavities. A lower block (5) resists the pressure of the upper punch and helps feed metal. The method is simpler, quicker and cheaper than conventional manufacturing processes using specially forged or rolled stock. <IMAGE>

Description

SPECIFICATION Method of making a hinge flap This invention relates to a method of making a hinge flap and is particularly concerned with forming a hinge flap for a hinge for mounting vehicle doors.

Hinge flaps forming a part of a hinge mounting a vehicle door on a vehicle such as a motor car are typically either formed from rolled steel section having the desired profile so that the necessity for subsequent shaping is minimised, or by hot forging. The costs of hinge flaps formed by either method are high, and require either expensive steel stock to be held or costly hot-forging equipment to be installed and maintained.

According to the present invention, a hinge flap is formed by upsetting of a portion of a metal plate to provide at least one integral boss, and piercing the boss, e.g. by drilling, to provide a bore for receiving a hinge pin.

The metal plate may be stamped or otherwise cut from flat steel strip.

Preferably, the upsetting is carried out between two main die blocks exerting pressure on the two opposite faces of the plate to render the metal plastic, with a top punch then being quickly driven down on to one end of the metal plate between the main dies while the opposite end of the plate is pressed by a bottom pressure block movable between the dies. The plate may be heated before the upsetting operation by means of an induction heater on the press in which the dies are mounted.

The main dies preferably form between them a generally cylindrical die recess so that together the dies form a cylindrical boss across the plate.

The flap may be bent to provide two sections with an obtuse angle between them, according to the location in which it is to be used, and a strengthening rib or boss may also be formed by pressing part of the flap inwardly of the bend, across the bend. Weld pips may be raised on one surface of the flap to enable the flap to be secured to a vehicle or vehicle door, when forming part of a hinge, by projection welding, for example.

The flap provided by the method of the invention can be formed in relatively quick and.

simple operations from flat steel strip or sheet, for example.

Reference is made to the drawing, in which: Figure 1 is a plan view of a sheet metal plate before forming into a hinge flap: Figure 2 is a diagrammatic representation of the cold forging apparatus; and Figure 3 is a perspective of the completed hinge flap.

The steel plate 1 is pressed or otherwise cut from steel strip, and has a spaced pair of arms 2 extending from one end thereof. The plate is located between two die blocks 3 (Figure 2) having opposed semi-cylindrical recesses 4, and pressure is exerted. When the metal has become plastic, so that it begins to flow, a lower pressure block 5 is pressed against one end of the plate 1 and a top punch 6 is driven down on to the ends of the arms 2 causing the metal of the arms to flow into the recesses 4 in the die blocks 3, forming cylindrical bosses 7 in the arms.

After removal from the blocks 3, the plate is further formed by drilling through the bosses 7 to form aligned bores 8 which can receive a hinge pin (not shown) therethrough. The plate is bent up at an obtuse angle and pushed inwardly at the centre of the bend to form a strengthening rib or bow 9. Weld pips, for projection welding the flap to a door or vehicle body, are pressed up on the outer side of the flap. Alternatively, holes are drilled to receive fixing bolts or studs.

The hinge flap illustrated in Figure 3 has the two bosses 7 arranged to receive between them the single boss of the other hinge flap which, together with the hinge flap shown, forms a completed hinge. The hinge flap with the single boss may be formed by the method of the invention, or it may be of conventional form and construction.

1. A method of making a hinge flap, which comprises upsetting a portion of a metal plate to provide at least one integral boss, and piercing the boss to provide a bore for receiving a hinge pin.

2. A method according to Claim 1, wherein the boss is pierced by drilling.

3. A method according to Claim 1 or 2, wherein the metal plate is stamped or cut from a flat steel strip.

4. A method according to Claim 1, 2 or 3, wherein the upsetting is carried out by exerting pressure between two main die blocks on the two opposite faces of the plate to render the metal plastic, and then rapidly driving a punch to one end face of the metal plate while a pressure block is urged against the opposite end face between the dies.

5. A method according to Claim 4, wherein the metal plate is heated before the upsetting operation.

6. A method according to Claim 5, wherein the heating is carried out by means of an induction heater on the press in which the dies are mounted.

7. A method according to Claim 5 or 6, wherein the main dies form between them a generally cylindrical die recess so that the dies together form a cylindrical boss across the plate.

8. A method of making a hinge flap, substantially as described with reference to the drawings.

9. A method of making a hinge, which comprises making a first hinge flap in accordance with the method claimed in any preceding claim, and coupling the first hinge flap with a second hinge flap by means of a hinge pin passing into the bore provided in the first hinge flap.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (9)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Method of making a hinge flap This invention relates to a method of making a hinge flap and is particularly concerned with forming a hinge flap for a hinge for mounting vehicle doors. Hinge flaps forming a part of a hinge mounting a vehicle door on a vehicle such as a motor car are typically either formed from rolled steel section having the desired profile so that the necessity for subsequent shaping is minimised, or by hot forging. The costs of hinge flaps formed by either method are high, and require either expensive steel stock to be held or costly hot-forging equipment to be installed and maintained. According to the present invention, a hinge flap is formed by upsetting of a portion of a metal plate to provide at least one integral boss, and piercing the boss, e.g. by drilling, to provide a bore for receiving a hinge pin. The metal plate may be stamped or otherwise cut from flat steel strip. Preferably, the upsetting is carried out between two main die blocks exerting pressure on the two opposite faces of the plate to render the metal plastic, with a top punch then being quickly driven down on to one end of the metal plate between the main dies while the opposite end of the plate is pressed by a bottom pressure block movable between the dies. The plate may be heated before the upsetting operation by means of an induction heater on the press in which the dies are mounted. The main dies preferably form between them a generally cylindrical die recess so that together the dies form a cylindrical boss across the plate. The flap may be bent to provide two sections with an obtuse angle between them, according to the location in which it is to be used, and a strengthening rib or boss may also be formed by pressing part of the flap inwardly of the bend, across the bend. Weld pips may be raised on one surface of the flap to enable the flap to be secured to a vehicle or vehicle door, when forming part of a hinge, by projection welding, for example. The flap provided by the method of the invention can be formed in relatively quick and. simple operations from flat steel strip or sheet, for example. Reference is made to the drawing, in which: Figure 1 is a plan view of a sheet metal plate before forming into a hinge flap: Figure 2 is a diagrammatic representation of the cold forging apparatus; and Figure 3 is a perspective of the completed hinge flap. The steel plate 1 is pressed or otherwise cut from steel strip, and has a spaced pair of arms 2 extending from one end thereof. The plate is located between two die blocks 3 (Figure 2) having opposed semi-cylindrical recesses 4, and pressure is exerted. When the metal has become plastic, so that it begins to flow, a lower pressure block 5 is pressed against one end of the plate 1 and a top punch 6 is driven down on to the ends of the arms 2 causing the metal of the arms to flow into the recesses 4 in the die blocks 3, forming cylindrical bosses 7 in the arms. After removal from the blocks 3, the plate is further formed by drilling through the bosses 7 to form aligned bores 8 which can receive a hinge pin (not shown) therethrough. The plate is bent up at an obtuse angle and pushed inwardly at the centre of the bend to form a strengthening rib or bow 9. Weld pips, for projection welding the flap to a door or vehicle body, are pressed up on the outer side of the flap. Alternatively, holes are drilled to receive fixing bolts or studs. The hinge flap illustrated in Figure 3 has the two bosses 7 arranged to receive between them the single boss of the other hinge flap which, together with the hinge flap shown, forms a completed hinge. The hinge flap with the single boss may be formed by the method of the invention, or it may be of conventional form and construction. CLAIMS

1. A method of making a hinge flap, which comprises upsetting a portion of a metal plate to provide at least one integral boss, and piercing the boss to provide a bore for receiving a hinge pin.

2. A method according to Claim 1, wherein the boss is pierced by drilling.

3. A method according to Claim 1 or 2, wherein the metal plate is stamped or cut from a flat steel strip.

4. A method according to Claim 1, 2 or 3, wherein the upsetting is carried out by exerting pressure between two main die blocks on the two opposite faces of the plate to render the metal plastic, and then rapidly driving a punch to one end face of the metal plate while a pressure block is urged against the opposite end face between the dies.

5. A method according to Claim 4, wherein the metal plate is heated before the upsetting operation.

6. A method according to Claim 5, wherein the heating is carried out by means of an induction heater on the press in which the dies are mounted.

7. A method according to Claim 5 or 6, wherein the main dies form between them a generally cylindrical die recess so that the dies together form a cylindrical boss across the plate.

8. A method of making a hinge flap, substantially as described with reference to the drawings.

9. A method of making a hinge, which comprises making a first hinge flap in accordance with the method claimed in any preceding claim, and coupling the first hinge flap with a second hinge flap by means of a hinge pin passing into the bore provided in the first hinge flap.